| natural products phytotoxicity a bioassay suitable for small quantities of slightly water-soluble compounds. | a large variety of secondary metabolites that can inhibit germination and/or seedling growth are produced by plants in low quantities. the objective of this study was to develop a bioassay capable of reliably assessing reductions in germination percentage and seedling length of small-seeded plant species caused by exposure to minute quantities of these compounds. the germination and growth of alfalfa (medicago saliva), annual ryegrass (lolium multiflorum), and velvetleaf (abutilon theophrasti) w ... | 1990 | 24263494 |
| ambient has become strained. identification of acacia dealbata link volatiles interfering with germination and early growth of native species. | acacia dealbata link is a widespread invader in mediterranean type ecosystems, and traits promoting its invasiveness are currently under investigation. due to the dense atmosphere below its canopy, we hypothesized that volatile organic compounds (vocs) released from flowers, leaves, litter, or a mixture of treatments exert inhibitory effects on the natives trifolium subterraneum, lolium multiflorum, medicago sativa, and also on its own seeds. we reported that vocs from flowers significantly redu ... | 2014 | 25260655 |
| effects of dietary cottonseed oil and tannin supplements on protein and fatty acid composition of bovine milk. | this experiment was conducted to determine the effects of diets supplemented with cottonseed oil, acacia mearnsii-condensed tannin extract, and a combination of both on composition of bovine milk. treatment diets included addition of cottonseed oil (800 g/d; cso), condensed tannin from acacia mearnsii (400 g/d; tan) or a combination of cottonseed oil (800 g/d) and condensed tannin (400 g/d; cpt) with a diet consisting of 6·0 kg dry matter (dm) of concentrates and alfalfa hay ad libitum, which al ... | 2014 | 24594257 |
| characterization of resistance to multiple aphid species (hemiptera: aphididae) in medicago truncatula. | aphids are phloem-feeding insects that damage many important crops throughout the world yet, compared to plant-pathogen interactions, little is known about the mechanisms by which plants become resistant to aphids. medicago truncatula (barrel medic) is widely considered as the pre-eminent model legume for genetic and biological research and in australia is an important pasture species. six cultivars of m. truncatula with varying levels of resistance to two pests of pasture and forage legumes, th ... | 2007 | 17298680 |
| independent action and contrasting phenotypes of resistance genes against spotted alfalfa aphid and bluegreen aphid in medicago truncatula. | host resistance to aphids is poorly understood. medicago truncatula, a model legume and cultivated pasture species, was used to elucidate defense against two aphid species, therioaphis trifolii f. maculata (spotted alfalfa aphid, saa) and acyrthosiphon kondoi (bluegreen aphid, bga). aphid performance and plant damage were compared between near-isogenic cultivars, mogul and borung, that differ in resistance to both aphids. analyses of aphid resistance in mogul x borung f2 plants and their progeny ... | 2007 | 17244058 |
| aphid resistance in medicago truncatula involves antixenosis and phloem-specific, inducible antibiosis, and maps to a single locus flanked by nbs-lrr resistance gene analogs. | aphids and related insects feed from a single cell type in plants: the phloem sieve element. genetic resistance to acyrthosiphon kondoi shinji (bluegreen aphid or blue alfalfa aphid) has been identified in medicago truncatula gaert. (barrel medic) and backcrossed into susceptible cultivars. the status of m. truncatula as a model legume allows an in-depth study of defense against this aphid at physiological, biochemical, and molecular levels. in this study, two closely related resistant and susce ... | 2005 | 15778464 |
| influence of alfalfa cultivar on suitability of acyrthosiphon kondoi (homoptera: aphididae) for survival and development of hippodamia convergens and coccinella septempunctata (coleoptera: coccinellidae). | hippodamia convergens guérin-méneville and coccinella septempunctata l. (coleoptera: coccinellidae) larvae were supplied daily with 1, 2, 4, or 16 mg of acyrthosiphon kondoi shinji (homoptera: aphididae) reared on one of two susceptible ('ok08' or 'cuf-101') or one resistant ('54h55') alfalfa cultivar (imedicago sativa l.) . hippodamia convergens survived to the adult stage when supplied with > or = 1 mg of a. kondoi per day from both susceptible and aphid-resistant cultivars, whereas c. septemp ... | 2002 | 12075999 |
| turning in mid-air allows aphids that flee the plant to avoid reaching the risky ground. | when forced to drop from the plant, flightless arboreal insects can avoid reaching the risky ground by maneuvering their body through the air. when wingless pea aphids (acyrthosiphon pisum) are threatened by natural enemies, they often drop off their host plant while assuming a stereotypic posture that rotates them in mid-air, aligning them with their feet pointing downwards. this position may increase their chances to re-cling onto lower plant parts and avoid facing the dangers on the ground, t ... | 2017 | 28261994 |
| optimization of agroinfiltration in pisum sativum provides a new tool for studying the salivary protein functions in the pea aphid complex. | aphids are piercing-sucking insect pests and feed on phloem sap. during feeding, aphids inject a battery of salivary proteins into host plant. some of these proteins function like effectors of microbial pathogens and influence the outcome of plant-aphid interactions. the pea aphid (acyrthosiphon pisum) is the model aphid and encompasses multiple biotypes each specialized to one or a few legume species, providing an opportunity to investigate the underlying mechanisms of the compatibility between ... | 2016 | 27555856 |
| above-belowground herbivore interactions in mixed plant communities are influenced by altered precipitation patterns. | root- and shoot-feeding herbivores have the capacity to influence one another by modifying the chemistry of the shared host plant. this can alter rates of nutrient mineralization and uptake by neighboring plants and influence plant-plant competition, particularly in mixtures combining grasses and legumes. root herbivory-induced exudation of nitrogen (n) from legume roots, for example, may increase n acquisition by co-occurring grasses, with knock-on effects on grassland community composition. li ... | 2016 | 27047522 |
| performances of survival, feeding behavior, and gene expression in aphids reveal their different fitness to host alteration. | insect populations feeding on different plant species are under selection pressure to adapt to these differences. a study integrating elements of the ecology, behavior, and gene expression of aphids on different host plants has not yet been well-explored. the present study explores the relationship between host fitness and survival, feeding behavior, and salivary gland gene expression of a pea (pisum sativum) host race of acyrthosiphon pisum feeding on a common host vicia faba and on three genet ... | 2016 | 26758247 |
| enemy-free space promotes maintenance of host races in an aphid species. | the enormous biodiversity of herbivorous insects may arise from ecological speciation via continuous host-plant switches. whether such switches are successful depends on the trade-off between different selection pressures that act on herbivores. decreased herbivore performance due to suboptimal nutrition might be compensated for by a reduced natural enemy pressure. as a consequence, an "enemy-free space" on a certain plant might facilitate host-plant switches and maintain biotypes. to test this ... | 2016 | 26520659 |
| amino acid-mediated impacts of elevated carbon dioxide and simulated root herbivory on aphids are neutralized by increased air temperatures. | changes in host plant quality, including foliar amino acid concentrations, resulting from global climate change and attack from multiple herbivores, have the potential to modify the pest status of insect herbivores. this study investigated how mechanically simulated root herbivory of lucerne (medicago sativa) before and after aphid infestation affected the pea aphid (acyrthosiphon pisum) under elevated temperature (et) and carbon dioxide concentrations (eco2). et increased plant height and bioma ... | 2015 | 25403916 |
| pea aphid biotype performance on diverse medicago host genotypes indicates highly specific virulence and resistance functions. | aphid-plant interactions depend on genotypes of both organisms, which determine the two-way molecular exchange that leads to compatible or incompatible outcomes. the underlying genes are mostly unknown, making it difficult to predict likelihood of aphid success or host resistance, and hampering crop genetic improvement. here we screened eight pea aphid clonal genotypes collected from diverse legume hosts, on a species-wide panel of medicago truncatula (mt) genotypes. aphid virulence was measured ... | 2014 | 25375216 |
| species interactions and a chain of indirect effects driven by reduced precipitation. | climate change can affect species directly and indirectly by altering interactions between species within communities. these indirect effects can ramify through a community and affect many species, including some that may not have been directly affected by the perturbation. identifying these chains of indirect effects is difficult, and most studies only follow indirect effects across two or three species. here, we use a factorial field experiment to demonstrate that precipitation affects spotted ... | 2014 | 24669741 |
| effects of elevated temperature and co2 on aboveground-belowground systems: a case study with plants, their mutualistic bacteria and root/shoot herbivores. | interactions between above- and belowground herbivores have been prominent in the field of aboveground-belowground ecology from the outset, although little is known about how climate change affects these organisms when they share the same plant. additionally, the interactive effects of multiple factors associated with climate change such as elevated temperature (et) and elevated atmospheric carbon dioxide (eco2) are untested. we investigated how et and eco2 affected larval development of the luc ... | 2013 | 24273544 |
| worldwide populations of the aphid aphis craccivora are infected with diverse facultative bacterial symbionts. | facultative bacterial endosymbionts can play an important role in the evolutionary trajectory of their hosts. aphids (hemiptera: aphididae) are infected with a wide variety of facultative endosymbionts that can confer ecologically relevant traits, which in turn may drive microevolutionary processes in a dynamic selective environment. however, relatively little is known about how symbiont diversity is structured in most aphid species. here, we investigate facultative symbiont species richness and ... | 2014 | 24233285 |
| widespread selection across coding and noncoding dna in the pea aphid genome. | genome-wide patterns of diversity and selection are critical measures for understanding how evolution has shaped the genome. yet, these population genomic estimates are available for only a limited number of model organisms. here we focus on the population genomics of the pea aphid (acyrthosiphon pisum). the pea aphid is an emerging model system that exhibits a range of intriguing biological traits not present in classic model systems. we performed low-coverage genome resequencing of 21 clonal p ... | 2013 | 23589520 |
| survival to parasitoids in an insect hosting defensive symbionts: a multivariate approach to polymorphic traits affecting host use by its natural enemy. | insect parasitoids and their insect hosts represent a wide range of parasitic trophic relations that can be used to understand the evolution of biotic diversity on earth. testing theories of coevolution between hosts and parasites is based on factors directly involved in host susceptibility and parasitoid virulence. we used controlled encounters with potential hosts of the aphidius ervi wasp to elucidate behavioral and other phenotypic traits of host acyrthosiphon pisum that most contribute to s ... | 2013 | 23565269 |
| predation determines different selective pressure on pea aphid host races in a complex agricultural mosaic. | field assessments were conducted to examine the interplay between host plant and predation in complex agricultural mosaic on pea aphid clover and alfalfa races. in one experiment, we examined the relative fitness on clover race (cr) and alfalfa race (ar) pea aphids on broad bean, red clover and alfalfa alone. but because clover is typically grown in a more complex agricultural mosaic with alfalfa and broad bean, a second experiment was conducted to assess the fitness consequences under predation ... | 2013 | 23409081 |
| predation drives stable coexistence ratios between red and green pea aphid morphs. | we conducted field surveys and experiments to evaluate the hypothesis that predation is an important driving factor determining the degree of coexistence between red and green morphs of the pea aphid acyrthosiphon pisum. theory suggests that the different colour morphs are differentially susceptible to natural enemies and selection by predation which in turn leads to variable relative abundances of red and green morphs among host plants across landscapes. our field surveys on pea and alfalfa rev ... | 2013 | 23294477 |
| genome scans reveal candidate regions involved in the adaptation to host plant in the pea aphid complex. | a major goal in evolutionary biology is to uncover the genetic basis of adaptation. divergent selection exerted on ecological traits may result in adaptive population differentiation and reproductive isolation and affect differentially the level of genetic divergence along the genome. genome-wide scan of large sets of individuals from multiple populations is a powerful approach to identify loci or genomic regions under ecologically divergent selection. here, we focused on the pea aphid, a specie ... | 2012 | 23017212 |
| quantitative genetics of feeding behavior in two ecological races of the pea aphid, acyrthosiphon pisum. | much of the diversity of herbivorous insects stems from the adaptive divergence of populations onto different host plants. this often involves the evolution of specialized patterns of host acceptance that in turn lead to assortative mating for insects that mate exclusively on their hosts. here, we explore the genetic architecture of feeding behavior in a herbivorous insect that has become a model for the study of incipient speciation, the pea aphid (acyrthosiphon pisum). we use crosses between i ... | 2012 | 21897437 |
| frass analysis of diets of aphidophagous lady beetles (coleoptera: coccinellidae) in utah alfalfa fields. | aphidophagous lady beetles enhance their foraging success in natural settings by consuming other types of food in addition to aphids. frass analysis was used to examine natural diets of female lady beetles in fields of alfalfa (medicago sativa l.) in northern utah. the first (spring) alfalfa crop was censused in 2004 and 2005 to determine the diet of female adults of the introduced coccinella septempunctata l., and two native species, c. transversoguttata richardsoni brown, and hippodamia conver ... | 2010 | 20388290 |
| reproductive responses of invasive and native predatory lady beetles (coleoptera: coccinellidae) to varying prey availability. | as adults, many predatory insects must adjust to a constantly changing prey environment while balancing between survival and reproduction. two laboratory experiments were conducted to compare reproductive responses of females of two species of lady beetles, invasive coccinella septempunctata l. and native c. transversoguttata richardsoni (brown), in utah alfalfa fields to varying availability of prey. when both lady beetles were placed immediately on experimental diets after being collected from ... | 2009 | 19689911 |
| host races of the pea aphid acyrthosiphon pisum differ in male wing phenotypes. | the evolution of reproductive isolation without geographic isolation (sympatric speciation) has recently gained strong theoretical and empirical supports. it is now widely admitted that many host-specific phytophagous insect species have arisen through shifting and adapting to new plants. the pea aphid acyrthosiphon pisum has received considerable attention in this context and is now considered as a probable case of incipient sympatric speciation through host specialization. in europe, three hos ... | 2010 | 19323853 |
| population differentiation and genetic variation in performance on eight hosts in the pea aphid complex. | phytophagous insects frequently use multiple host-plant species leading to the evolution of specialized host-adapted populations and sometimes eventually to speciation. some insects are confronted with a large number of host-plant species, which may provide complex routes of gene flow between host-adapted populations. the pea aphid (acyrthosiphon pisum) attacks a broad range of plants in the fabaceae and it is known that populations on trifolium pratense and medicago sativa can be highly special ... | 2008 | 18647340 |
| deterrence and toxicity of plant saponins for the pea aphid acyrthosiphon pisum harris. | plant saponins are widely distributed among plants and have a wide range of biological properties. three alfalfa saponins - zanhic acid tridesmoside, 3glca, 28ararhaxyl medicagenic acid glycoside, and 3glca, 28ararha medicagenic acid glycoside - were tested for their settling inhibition effects on feeding behavior of the aphid acyrthosiphon pisum using the electrical penetration graph method. application of saponins to artificial diets affected the insects' probing behavior. in general, saponins ... | 2007 | 17610116 |
| predator avoidance behavior in the pea aphid: costs, frequency, and population consequences. | induced prey defenses can be costly. these costs have the potential to reduce prey survival or reproduction and, therefore, prey population growth. i estimated the potential for predators to suppress populations of pea aphids (acyrthosiphon pisum) in alfalfa fields through the induction of pea aphid predator avoidance behavior. i quantified (1) the period of non-feeding activity that follows a disturbance event, (2) the effect of frequent disturbance on aphid reproduction, and (3) the frequency ... | 2007 | 17066305 |
| population differentiation and genetic variation in host choice among pea aphids from eight host plant genera. | habitat choice plays a critical role in the processes of host range evolution, specialization, and ecological speciation. pea aphid, acyrthosiphon pisum, populations from alfalfa and red clover in eastern north america are known to be genetically differentiated and show genetic preferences for the appropriate host plant. this species feeds on many more hosts, and here we report a study of the genetic variation in host plant preference within and between pea aphid populations collected from eight ... | 2006 | 17017058 |
| temporal habitat variability and the maintenance of sex in host populations of the pea aphid. | the evolutionary maintenance of sex, despite competition from asexual reproduction, has long intrigued the evolutionary biologists owing to its numerous apparent short-term costs. in aphids, winter climate is expected to determine the maintenance of sexual lineages in the high latitude zones owing to their exclusive ability to produce frost-resistant eggs. however, diverse reproductive modes may coexist at a local scale where climatic influence is counteracted by microgeographical factors. in th ... | 2006 | 17015368 |
| effect of low and high-saponin lines of alfalfa on pea aphid. | pea aphid fed on a high-saponin line of alfalfa showed reduction of reproduction and survival, and disturbance in development of its population. this line negatively influenced aphid probing behaviour, particularly prolonging the non-probing period and probing of the peripheral tissues (epidermis and mesophyll) and shortening the period of phloem sap ingestion. the high-saponin line of alfalfa differed from the low-saponin one by the presence of zanhic acid tridesmoside and a higher level of 3-g ... | 2006 | 16740274 |
| ecological specialization correlates with genotypic differentiation in sympatric host-populations of the pea aphid. | the pea aphid, acyrthosiphon pisum, encompasses distinct host races specialized on various fabaceae species, but the extent of genetic divergence associated with ecological specialization varies greatly depending on plant and geographic origins of aphid populations. here, we studied the genetic structure of french sympatric pea aphid populations collected on perennial (pea and faba bean) and annual (alfalfa and red clover) hosts using 14 microsatellite loci. classical and bayesian population gen ... | 2006 | 16599915 |
| application of dl-beta-aminobutyric acid (baba) as a root drench to legumes inhibits the growth and reproduction of the pea aphid acyrthosiphon pisum (hemiptera: aphididae). | dl-beta-aminobutyric acid (baba) is a non-protein amino acid that is an effective inducer of resistance against a variety of plant pathogens. however, examples of baba-induced resistance against insect herbivores have not been reported. we applied baba as a soil drench to legumes and monitored its effects on the pea aphid acyrthosiphon pisum (harris). on tic bean (vicia faba var. minor), baba increased aphid mortality, caused a reduction in the mean relative growth rate of individual insects and ... | 2005 | 16197565 |
| attraction of two lacewing species to volatiles produced by host plants and aphid prey. | it is well documented that host-related odors enable many species of parasitoids and predatory insects to locate their prey and prey habitats. this study reports the first characterization of prey and prey host odor reception in two species of lacewings, chrysoperla carnea (say) and chrysopa oculata l. 2-phenylethanol, one of the volatiles emitted from their prey's host plants (alfalfa and corn) evoked a significant eag response from antennae of c. carnea. traps baited with this compound attract ... | 2005 | 15812573 |
| aphid infestation causes different changes in carbon and nitrogen allocation in alfalfa stems as well as different inhibitions of longitudinal and radial expansion. | alfalfa (medicago sativa) stem elongation is strongly reduced by a pea aphid (acyrthosiphon pisum harris) infestation. as pea aphid is a phloem feeder that does not transmit virus or toxins, assimilate withdrawal is generally considered as the main mechanism responsible for growth reduction. using a kinematic analysis, we investigated the spatial distributions of relative elemental growth rates of control and infested alfalfa stems. the water, carbon, and nitrogen contents per unit stem length w ... | 2005 | 15778456 |
| reproductive isolation between divergent races of pea aphids on two hosts. ii. selection against migrants and hybrids in the parental environments. | sympatric races of pea aphids on alfalfa and red clover are highly ecologically specialized and significantly reproductively isolated. much of the restriction of gene flow between the specialized populations is due to habitat choice behavior of the winged colonizers (via 1999). here, we document additional pre- and postmating reproductive isolation through selection against migrants and hybrids in the parental environments. first, a group of randomly chosen genotypes from each race that were exp ... | 2000 | 11108590 |
| clones of pea aphid, acyrthosiphon pisum (hemiptera: aphididae) distinguished using genetic markers, differ in their damaging effect on a resistant alfalfa cultivar. | cuf 101, a resistant cultivar of alfalfa, was exposed to 15 clones of acyrthosiphon pisum harris collected from alfalfa fields in three regions of france (east, south, central west) to determine whether the level of resistance varied across the different clones. the survival of alfalfa seedlings infested at the cotyledon stage was assessed using a standardized method. although no difference in seedling mortality was detected between clones grouped by region, there was a significant variation amo ... | 2000 | 10948361 |
| interspecific variation in the escape responses of aphids: effect on risk of predation from foliar-foraging and ground-foraging predators. | a series of laboratory experiments was conducted to determine the effect of interspecific differences on prey defensive behavior on the susceptibility of two aphid species (acyrthosiphon pisum and a. kondoi) to a ground-foraging predator, harpalus pennsylvanicus, and a foliar-foraging predator, coccinella septempunctata. these organisms are representative of a biologically and economically important predator/prey system in alfalfa. the primary defensive behavior of both aphid species toward c. s ... | 1998 | 28308458 |
| variation in aphid alarm pheromone content among glandular and eglandular-hairedmedicago accessions. | pea (acyrthosiphon pisum harris) and blue alfalfa aphid (a. kondoi shinji) deterrency in alfalfa (medicago saliva l.) may result from incorporating higher levels of the aphid alarm pheromone,(e)-β-farnesene relative to(e)-β-caryophyllene. we evaluated five eglandular and two glandular-haired alfalfa accessions for differences in(e)-β-farnesene and(e)-β-caryophyllene content under glasshouse conditions using supercritical fluid extraction and gas chromatography. in addition, pea and blue alfalfa ... | 1996 | 24226476 |
| mitochondrial dna diversity in the pea aphid acyrthosiphon pisum. | the pea aphid acyrthosiphon pisum has been established in north america for at least a century and occurs on a broad range of host plants. despite its importance as a crop pest, there is little understanding of the genetic structure of its populations or the extent of genetic divergence associated with different host plant utilization. this study examined the extent of mitochondrial dna (mtdna) diversity among 35 clones of pea aphids from alfalfa. polymorphisms were detected at only 2 of 126 res ... | 1994 | 8001815 |
| feeding deterrency of some 4-hydroxycoumarins and related compounds: relationship to host-plant resistance of alfalfa towards pea aphid (acyrthosiphon pisum). | a series of 3-acyl-4-hydroxycoumarins, structurally related to dicoumarol, as well as several alfalfa constituents including coumestrol were tested for their feeding deterrency towards the pea aphid. feeding deterrency of the 3-acyl-4-hydroxycoumarins decreased as the size of the 3-acyl group increased. | 1987 | 24302057 |
| routine alfalfa (medicago sativa) cutting program and its influence on pea aphid (acyrthosiphon pisum harris) populations. | 1. cutting does not influence the general features of the pea aphid population trends on alfalfa. 2. cutting significantly influences host plant conditions. 3. by affecting host-plant conditions, cutting may partially influence aphid population density on alfalfa. 4. the plant growth is not always coincident with the increase of aphid numbers. 5. migration of aphids from alfalfa could have basic disruptive effects on the alfalfa field ecosystem in some years. 6. routine alfalfa cutting may be pa ... | 1970 | 28309788 |
| temporary immunity in alfalfa ordinarily susceptible to attack by the pea aphid. | | 1946 | 20991711 |
| cloning and structure-function analyses of quinolone- and acridone-producing novel type iii polyketide synthases from citrus microcarpa. | two novel type iii polyketide synthases, quinolone synthase (qns) and acridone synthase (acs), were cloned from citrus microcarpa (rutaceae). the deduced amino acid sequence of c. microcarpa qns is unique, and it shared only 56-60% identities with c. microcarpa acs, medicago sativa chalcone synthase (chs), and the previously reported aegle marmelos qns. in contrast to the quinolone- and acridone-producing a. marmelos qns, c. microcarpa qns produces 4-hydroxy-n-methylquinolone as the "single prod ... | 2013 | 23963450 |
| adverse effects of herbal medicines: an overview of systematic reviews. | this overview of systematic reviews (srs) aims to evaluate critically the evidence regarding the adverse effects of herbal medicines (hms). five electronic databases were searched to identify all relevant srs, with 50 srs of 50 different hms meeting our inclusion criteria. most had only minor weaknesses in methods. serious adverse effects were noted only for four hms: herbae pulvis standardisatus, larrea tridentate, piper methysticum and cassia senna. the most severe adverse effects were liver o ... | 2013 | 23472485 |
| methylene blue biosorption by pericarp of corn, alfalfa, and agave bagasse wastes. | the presence of dyes in effluent is a matter of concern due to their toxicologic and aesthetical effects. in this research, locally available agro-industrial wastes (zea mays pericarp, zmp; agave tequilana bagasse, atb; and medicago sativa waste, msw) were used as alternative low-cost adsorbents for the removal of methylene blue (mb) from aqueous solutions. the adsorbents were characterized physically and chemically by fourier transform infrared, scanning electron microscopy, potentiometric titr ... | 2014 | 24701903 |
| [heat-responsive mechanisms in plants revealed by proteomic analysis: a review]. | heat stress is a major abiotic stress that limits plant growth and productivity. in recent years, proteomic investigations provide more information for understanding the sophisticated heat-responsive molecular mechanism in plants at systematic biological level. the heat-responsive proteomic patterns in several plants, i. e., model plants (arabidopsis thaliana), staple food crops (soybean, rice and wheat), heat-tolerant plants (agrostis stolonifera, portulaca oleracea, and carissa spinarum), grap ... | 2015 | 26685622 |
| [pb, zn accumulation and nutrient uptake of 15 plant species grown in abandoned mine tailings]. | vegetation restoration field test was carried out in the abandoned lead-zinc tailings for 3 years. the study showed that accumulation of lead (pb), zinc (zn) and nutrient uptake differed with plant species and organs, heavy metals, and planting time. pb was mainly accumulated in tree roots, and its content distribution in tree organs was generally in the order of roots > leaves > stems. but zn concentrations in leaves of several tree species were higher than those in roots and stems. within the ... | 2012 | 22946191 |
| 3'4'7-trihydroxyflavone inhibits rankl-induced osteoclast formation via nfatc1. | 3'4'7-trihydroxyflavone is a flavonoid from ladino clover, alfalfa, and albizzia julibrissin. in the present study, we found that 3'4'7-trihydroxyflavone markedly inhibited the receptor activator of nuclear factor kappa b ligand (rankl) induced osteoclastic differentiation from mouse bone marrow derived macrophages (bmms). 3'4'7-trihydroxyflavone also reduced the mrna expression level of osteoclastic marker genes including calcitonin receptor (ctr), cathepsin k1 v-atpase v0 subunit d2 (atp6v0d2) ... | 2015 | 26601423 |
| short-term digestible energy intake in captive moose (alces alces) on different diets. | moose (alces alces) are regularly described as problematic animals in captivity, mainly because of their particular digestive physiology and resulting feeding demands. according to the literature, moose regularly reject non-browse forages offered in captivity, which may indirectly lead to an overproportional ingestion of easily digestible feeds and thus chronic acidosis, which may in turn be the cause of their low life expectancy in captivity. by feeding experiments in four animals, this study a ... | 2013 | 23801273 |
| molecular cloning and characterization of a gene regulating flowering time from alfalfa (medicago sativa l.). | genes that regulate flowering time play crucial roles in plant development and biomass formation. based on the cdna sequence of medicago truncatula (accession no. ay690425), the lfy gene of alfalfa was cloned. sequence similarity analysis revealed high homology with flo/lfy family genes of other plants. when fused to the green fluorescent protein, mslfy protein was localized in the nucleus of onion (allium cepa l.) epidermal cells. the rt-qpcr analysis of mslfy expression patterns showed that th ... | 2013 | 23670041 |
| honey bee (hymenoptera: apidae) foraging in response to preconditioning with onion flower scent compounds. | onion (allium cepa l.) seed production has long been plagued with yield problems because of lack of pollination by the honey bee, apis mellifera l. to attempt to attract more pollinators to the onion seed production field, honey bees were conditioned to associate onion floral odor components with a reward. isolated nucleus hives of honey bees were fed 30% sucrose solutions scented with a 0.2% solution of onion floral odor compounds. after feeding on these solutions for 6 wk, bees were not found ... | 2003 | 14650525 |
| occurrence of arbuscular mycorrhizal fungi in saline soils of the tabriz plain of iran in relation to some physical and chemical properties of soil. | the abundance and distribution of arbuscular mycorrhizal fungi (amf) were evaluated in the tabriz plain, where soil salinity levels range from 7.3 to 92.0 ds/m. soil and root samples were collected from the rhizosphere of several glycophytes (allium cepa l., medicago sativa l., triticum aestivum l. and hordeum vulgare l.) and halophytes (salicornia sp. and salsola sp.) and were analysed for spore number in soil, root colonization with amf and some physical and chemical soil properties. the numbe ... | 2001 | 24595430 |
| effect of supplementation with linseed or a blend of aromatic spices and time on feed on fatty acid composition, meat quality and consumer liking of meat from lambs fed dehydrated alfalfa or corn. | cross-bred lambs (n=72) were fed finishing diets using a factorial arrangement of treatments: basal diet (alfalfa pellets or corn), supplement (none, linseed or aromatic spices), time on feed (41 or 83days). carcass and meat quality traits, fatty acid composition, color stability and consumer liking were determined. feeding alfalfa improved sensory ratings and fatty acid composition of lamb. however, corn or longer alfalfa feeding would be recommended if heavier and fatter carcasses are sought. ... | 2017 | 28110126 |
| changes in blood profile in sheep receiving raw garlic, garlic oil or monensin. | this study aimed to evaluate the effects of supplementing a basal diet (ctr) with raw garlic (gar) or garlic oil (gao) on blood profile in sheep. monensin (mon, 33 mg/kg dm) was used as positive control. four ruminally fistulated rams were used in three experiments each arranged in a 4 × 4 latin square design with 28-day periods. experiments 1 and 2 differed in the dose of gar (75 vs. 100 g/kg dm) and gao (500 vs. 750 mg/kg dm), while experiment 3 was designed to compare the two doses of each ad ... | 2015 | 24689703 |
| changes in anthropometric measurements, body composition, blood pressure, lipid profile, and testosterone in patients participating in a low-energy dietary intervention. | the purpose of this study was to describe changes in anthropometric measurements, body composition, blood pressure, lipid profile, and testosterone following a low-energy-density dietary intervention plus regimented supplementation program. | 2013 | 23997718 |
| [effect of agroforestry model on inhibition of oncomelania snails in plateau mountainous area of yunnan province]. | to evaluate the effect of agroforestry models on the inhibition of oncomelania snails in the plateau mountainous area of yunnan province. | 2012 | 23373253 |
| early experience with diverse foods increases intake of nonfamiliar flavors and feeds in sheep. | this study determined whether early experiences by sheep with monotonous or diverse diets influence intake of unfamiliar flavors and feeds later in life. thirty 2-mo-old lambs were randomly assigned to 3 treatment diets (n = 10): diverse (div), diverse with plant toxins (div+t), and monotonous (mon). lambs in div received in 9 successive periods of exposure 4-way choice combinations of 2 foods high in energy and 2 foods high in protein from an array of 6 foods: 3 high in energy [beet pulp, oat g ... | 2012 | 22393032 |
| usage patterns, health, and nutritional status of long-term multiple dietary supplement users: a cross-sectional study. | dietary supplement use in the united states is prevalent and represents an important source of nutrition. however, little is known about individuals who routinely consume multiple dietary supplements. this study describes the dietary supplement usage patterns, health, and nutritional status of long-term multiple dietary supplement users, and where possible makes comparisons to non-users and multivitamin/mineral supplement users. | 2007 | 17958896 |
| phytotoxic potential of secondary metabolites and semisynthetic compounds from endophytic fungus xylaria feejeensis strain sm3e-1b isolated from sapium macrocarpum. | bioactivity-directed fractionation of the combined culture medium and mycelium extract of the endophytic fungus xylaria feejeensis strain sm3e-1b, isolated from sapium macrocarpum, led to the isolation of three known natural products: (4s,5s,6s)-4-hydroxy-3-methoxy-5-methyl-5,6-epoxycyclohex-2-enone or coriloxine, 1; 2-hydroxy-5-methoxy-3-methylcyclohexa-2,5-diene-1,4-dione, 2; and 2,6-dihydroxy-5-methoxy-3-methylcyclohexa-2,5-diene-1,4-dione or fumiquinone b, 3. this is the first report of comp ... | 2016 | 27159617 |
| phytotoxic and antimicrobial activity of volatile and semi-volatile organic compounds from the endophyte hypoxylon anthochroum strain blaci isolated from bursera lancifolia (burseraceae). | to evaluate the phytotoxic, antifungal and antioomycete activity; and, determine the chemical composition of the volatile organic compounds (vocs) and semi-volatile metabolites produced by the endophyte hypoxylon anthochroum strain blaci isolated from bursera lancifolia. | 2016 | 27159426 |
| phytotoxic activity and conformational analysis of thymol analogs from hofmeisteria schaffneri. | bioassay-guided fractionation of two phytotoxic extracts (a ch(2)cl(2)-meoh (1:1) and an aqueous) prepared from the aerial parts of hofmeisteria schaffneri led to isolation of thymol analogs 3-5, along with seven known compounds, 1, 2 and 6-10. compounds 3-5 were identified by spectroscopic methods as 1,4-bis(2'-hydroxy-4'-methylphenyl)butane-1,4-dione (3), 2-isopropyl-5-methylphenyl (2z)-2-methylbut-2-enoate (4) and 2-hydroxy-2-(2-hydroxy-4-methylphenyl)propane-1,3-diyl (2z,2'z)bis(2-methylbut- ... | 2008 | 18328513 |
| allelopathic effects of medicago sativa l. and vicia cracca l. leaf and root extracts on weeds. | in this study, the allelopathic potential of different concentration (5, 25 and 50%) of m. sativa and v. cracca leaf and root extracts were evaluated on germination and radicle length of four weed species (amaranthus retroflexus l., lolium perenne l., ipomoea hederacea l. and portulaca oleracea l.) in laboratory condition. as a result, germination and radicle length of all species were reduced by the extract from m. sativa and v. cracca leaf and root at different percentage. increasing the water ... | 2007 | 19086510 |
| effect of petroleum on decomposition of shrub-grass litters in soil in northern shaanxi of china. | the impacts of petroleum contamination on the litter decomposition of shrub-grass land would directly influence nutrient cycling, and the stability and function of ecosystem. ten common shrub and grass species from yujiaping oil deposits were studied. litters from these species were placed into litterbags and buried in petroleum-contaminated soil with 3 levels of contamination (slight, moderate and serious pollution with petroleum concentrations of 15, 30 and 45 g/kg, respectively). a decomposit ... | 2015 | 26141899 |
| [soil organic carbon storage changes with land reclamation under vegetation reconstruction on opencast coal mine dump]. | vegetation reconstruction was an effective solution to reclaim the opencast coal mine dump which was formed in the process of mining. to understand the impact of the vegetation reconstruction patterns' on the mine soil organic carbon (soc) storage was essential for selecting the methods of vegetation restoration and also important for accurately estimating the potential of the soil carbon sequestration. the study area was on the heidaigou opencast coal mine, which was 15 years reclaimed coal min ... | 2014 | 25693392 |
| [genetic diversity of rhizobia isolated from shrubby and herbaceous legumes in shenmu arid area, shaanxi, china]. | legume, with a strong resistance to the adverse environmental conditions, is one of pioneer plants in the desert region and plays an important role in the protection of the ecological environment. in this study, the symbiosis of rhizobia associating with shrubby and herbaceous legumes in shenmu area, shaanxi, china was characterized by the 16s rrna pcr-rflp and sequence analysis of involved genes. a total of 55 strains were isolated and purified, including 30 strains from the shrubby legume amor ... | 2014 | 25223023 |
| [allelopathic effects of the humus soils from betula platyphylla and quercus liaotungensis pure plantations on 9 kinds of common shrubs and herbs]. | the humus soils were collected from betula platyphylla and quercus liaotungensis pure plantations and woodless land separately where the site conditions were basically the same, and taken as medium for potting culture test of 9 kinds of shrubs or herbs in plastic greenhouse to assess the allelopathic effects of humus soils of pure plantations on shrubs or herbs. humus soils from b. platyphylla plantation significantly inhibited the seed germinations of medicago sativa and melilotus officinalis, ... | 2014 | 25223017 |
| gas-liquid chromatographic determination of bromacil residues. | a simple, fast, and accurate method has been developed to determine residues of bromacil (5-bromo-3-sec-butyl-t-methyluracil) herbicide. following sample extraction, filtration, and concentration, the herbicide is determined using a gas chromatograph equipped with a thermionic nitrogen/phosphorus detector. the method has been used to recover 0.04 ppm bromacil added to citrus, pineapple, soil, and water, and 0.1 ppm bromacil added to alfalfa hay. | 1980 | 7380790 |
| digesta retention patterns in geese (anser anser) and turkeys (meleagris gallopavo) and deduced function of avian caeca. | although it is well-known that retrograde transport of urine fills the caeca of birds with fluid and small particles, the function of avian caeca is still not fully understood. we measured mean retention times (mrt) of solute (cobalt-edta, co), small particle (<2mm, chromium-mordanted fibre, cr) and large particle (8mm, cerium-marked fibre, ce) markers in geese (anser anser) and turkeys (meleagris gallopavo) fed alfalfa pellets ad libitum. intake did not differ between species. turkeys had longe ... | 2017 | 27923709 |
| effect of different sources of dietary fibre on growth performance, intestinal morphology and caecal carbohydrases of domestic geese. | 1. the aim of this study was to examine the effects of dietary fibre sources on growth and on the development of the gastro-intestinal tract in growing geese. 2. six-week-old female white roman geese were divided at random into 6 groups with 6 dietary treatments. diets were isoenergetic and isonitrogenous and contained alfalfa meal, barley bran, rice hulls, cellulose, pectin or lignin as the major dietary source of fibre. 3. food intake was significantly higher in the barley bran group than in t ... | 1998 | 9800044 |
| the role of phenolic compounds and nutrients in determining food preference in greater snow geese. | we tested buchsbaum's hypothesis that food palatability in geese is determined by a hierarchy of feeding cues among which deterrent secondary metabolites (mostly phenols) have a primary role (buchsbaum et al. 1984). in preference tests, greater snow goose feeding was slightly depressed when grass was sprayed with ferulic acid but not when grass was sprayed with p-coumaric and tannic acids. extracts of timothy grass, red clover or alfalfa sprayed on grass also failed to depress goose feeding. in ... | 1990 | 28312973 |
| growth, photosynthetic acclimation and yield quality in legumes under climate change simulations: an updated survey. | continued emissions of co2, derived from human activities, increase atmospheric co2 concentration. the co2 rise stimulates plant growth and affects yield quality. effects of elevated co2 on legume quality depend on interactions with n2-fixing bacteria and mycorrhizal fungi. growth at elevated co2 increases photosynthesis under short-term exposures in c3 species. under long-term exposures, however, plants generally acclimate to elevated co2 decreasing their photosynthetic capacity. an updated sur ... | 2014 | 25113447 |
| preliminary evaluation of selected minerals in liver samples from springbok (antidorcas marsupialis) from the national zoological gardens of south africa. | limited information is available on the mineral nutrition of captive antelope in south africa. zoo animals are usually offered a very limited array of feeds, which may result in nutritional imbalances. as a pilot study to investigate the presence of myopathy in antelope at the national zoological gardens of south africa (nzg), stored liver samples from six springbok (antidorcas marsupialis) and seven other antelopes from the nzg, as well as selected food items, were submitted for analysis of sel ... | 2012 | 23327132 |
| toxicologic evaluation of a high-selenium hay diet in captive pronghorn antelope (antilocapra americana). | five captive-raised pronghorn antelope (antilocapra americana) were fed an alfalfa-grass hay diet containing 15 ppm total dietary selenium (se) for 164 days. four additional captive-raised pronghorns fed a similar diet containing approximately 0.3 ppm total dietary se served as controls. none of the pronghorns had clinical signs attributable to the high se hay. plasma se increased more rapidly than blood se concentrations, from baseline concentrations (< 0.15 g/ml) to > 0.40 g/ml within the firs ... | 1996 | 8627943 |
| capulavirus and grablovirus: two new genera in the family geminiviridae. | geminiviruses are plant-infecting single-stranded dna viruses that occur in most parts of the world. currently, there are seven genera within the family geminiviridae (becurtovirus, begomovirus, curtovirus, eragrovirus, mastrevirus, topocuvirus and turncurtovirus). the rate of discovery of new geminiviruses has increased significantly over the last decade as a result of new molecular tools and approaches (rolling-circle amplification and deep sequencing) that allow for high-throughput workflows. ... | 2017 | 28213872 |
| alfalfa leaf curl virus: an aphid-transmitted geminivirus. | the family geminiviridae comprises seven genera differentiated by genome organization, sequence similarity, and insect vector. capulavirus, an eighth genus, has been proposed to accommodate two newly discovered highly divergent geminiviruses that presently have no known vector. alfalfa leaf curl virus, identified here as a third capulavirus, is shown to be transmitted by aphis craccivora. this is the first report of an aphid-transmitted geminivirus. | 2015 | 26109720 |
| identification and characterization of resistance to cowpea aphid (aphis craccivora koch) in medicago truncatula. | cowpea aphid (cpa; aphis craccivora) is the most important insect pest of cowpea and also causes significant yield losses in other legume crops including alfalfa, beans, chickpea, lentils, lupins and peanuts. in many of these crops there is no natural genetic resistance to this sap-sucking insect or resistance genes have been overcome by newly emerged cpa biotypes. | 2012 | 22759788 |
| development, reproduction, and within-plant infestation patterns of aphis craccivora (homoptera: aphididae) on alfalfa. | the goal of this research was to describe developmental rates, reproductive rates, and infestation patterns of aphis craccivora koch on alfalfa (medicago sativa l.). all studies were conducted on the susceptible cultivar ok08 using aphids reared from collections made in oklahoma. to determine thermal requirements for growth of a. craccivora, development from birth to adult was recorded at 7.2, 12.8, 18.3, 23.9, and 29.4 degrees c. the same constant temperature treatments (except for 7.2 degrees ... | 2009 | 20021773 |
| migratory bee hive transportation contributes insignificantly to transgenic pollen movement between spatially isolated alfalfa seed fields. | | 2017 | 28204486 |
| migratory bee hive transportation contributes insignificantly to transgenic pollen movement between spatially isolated alfalfa seed fields. | contracted commercial beekeeping operations provide an essential pollination service to many agricultural systems worldwide. increased use of genetically engineered crops in agriculture has raised concerns over pollinator-mediated gene flow between transgenic and conventional agricultural varieties. this study evaluated whether contracted migratory beekeeping practices influence transgenic pollen flow among spatially isolated alfalfa fields. twelve honey bee (apis mellifera l.) colonies were per ... | 2016 | 27852693 |
| pheromone lure and trap color affects bycatch in agricultural landscapes of utah. | aerial traps, using combinations of color and attractive lures, are a critical tool for detecting and managing insect pest populations. yet, despite improvements in trap efficacy, collection of nontarget species ("bycatch") plagues many insect pest surveys. bycatch can influence survey effectiveness by reducing the available space for target species and increasing trap screening time, especially in areas where thousands of insects are captured as bycatch in a given season. additionally, bycatch ... | 2016 | 27412193 |
| effects of residual novaluron on reproduction in alfalfa leafcutting bees, megachile rotundata f. (megachilidae). | the chitin synthesis inhibitor novaluron can suppress pests that affect alfalfa seed production, but can negatively affect reproductive success in the alfalfa pollinator megachile rotundata. novaluron is considered to be a reduced-risk insecticide because it disrupts ecdysis and is non-lethal to adult insects, but some exposed adults have fewer eggs and suppressed egg hatch. for this experiment, bees nested in field cages where they were exposed to alfalfa that had never been treated with novalu ... | 2017 | 27405042 |
| optimizing fluctuating thermal regime storage of developing megachile rotundata (hymenoptera: megachilidae). | the alfalfa leafcutting bee, megachile rotundata (f.), is the primary pollinator for alfalfa seed production in north america. under current management practice, developing pupae are incubated at 29-30°c until the adults emerge for pollination. if unfavorable spring weather delays peak alfalfa bloom, managers will cool pupae to slow development, which can increase mortality and causes sublethal effects. previously, we demonstrated that exposure to a fluctuating thermal regime (ftr) increases sur ... | 2016 | 26994099 |
| exposure to suboptimal temperatures during metamorphosis reveals a critical developmental window in the solitary bee, megachile rotundata. | metamorphosis is an important developmental stage for holometabolous insects, during which adult morphology and physiology are established. proper development relies on optimal body temperatures, and natural ambient temperature (ta) fluctuations, especially in spring or in northern latitudes, could result in interruptions to development. it is unclear how low-ta exposure may affect insects that are actively developing. to understand how suboptimal ta may affect metamorphosing insects, we used th ... | 2015 | 26658248 |
| assessing honey bee (hymenoptera: apidae) foraging populations and the potential impact of pesticides on eight u.s. crops. | beekeepers who use honey bees (apis mellifera l.) for crop pollination services, or have colonies making honey on or in close proximity to agricultural crops, are concerned about the reductions of colony foragers and ultimate weakening of their colonies. pesticide exposure is a potential factor in the loss of foragers. during 2009-2010, we assessed changes in the field force populations of 9-10 colonies at one location per crop on each of the eight crops by counting departing foragers leaving co ... | 2015 | 26453703 |
| thermoperiodism synchronizes emergence in the alfalfa leafcutting bee (hymenoptera: megachilidae). | alfalfa seed production in the northwestern united states and western canada is heavily dependent upon the pollinating services of megachile rotundata (f.) (hymenoptera: megachilidae). m. rotundata females nest in cavities either naturally occurring or in artificial nesting blocks. because of the physical nature of the nest, m. rotundata brood may have limited to no exposure to photoperiodic cues in order to regulate important circadian functions. therefore, various thermoperiod regimes were use ... | 2016 | 26385932 |
| resource effects on solitary bee reproduction in a managed crop pollination system. | population density may affect solitary bee maternal resource allocation. the number of megachile rotundata (f.), alfalfa leafcutting bee, females released for seed production of medicago sativa l., alfalfa, may limit flower availability for nest provisioning. in turn, pollinator abundance also may affect crop yield. the m. sativa pollination system presents an opportunity to test for effects of density dependence and maternal manipulation on m. rotundata reproduction. a multiyear study was perfo ... | 2015 | 26314057 |
| effects of fungicide and adjuvant sprays on nesting behavior in two managed solitary bees, osmia lignaria and megachile rotundata. | there is a growing body of empirical evidence showing that wild and managed bees are negatively impacted by various pesticides that are applied in agroecosystems around the world. the lethal and sublethal effects of two widely used fungicides and one adjuvant were assessed in cage studies in california on blue orchard bees, osmia lignaria, and in cage studies in utah on alfalfa leafcutting bees, megachile rotundata. the fungicides tested were rovral 4f (iprodione) and pristine (mixture of pyracl ... | 2015 | 26274401 |
| a simple model for pollen-parent fecundity distributions in bee-pollinated forage legume polycrosses. | a simple weibull distribution based empirical model that predicts pollen-parent fecundity distributions based on polycross size alone has been developed in outbred forage legume species for incorporation into quantitative genetic theory. random mating or panmixis is a fundamental assumption in quantitative genetic theory. random mating is sometimes thought to occur in actual fact, although a large body of empirical work shows that this is often not the case in nature. models have been developed ... | 2015 | 26105686 |
| mixed infections reveal virulence differences between host-specific bee pathogens. | dynamics of host-pathogen interactions are complex, often influencing the ecology, evolution and behavior of both the host and pathogen. in the natural world, infections with multiple pathogens are common, yet due to their complexity, interactions can be difficult to predict and study. mathematical models help facilitate our understanding of these evolutionary processes, but empirical data are needed to test model assumptions and predictions. we used two common theoretical models regarding mixed ... | 2015 | 25982695 |
| transcriptional responses to fluctuating thermal regimes underpinning differences in survival in the solitary bee megachile rotundata. | the transcriptional responses of insects to long-term, ecologically relevant temperature stress are poorly understood. long-term exposure to low temperatures, commonly referred to as chilling, can lead to physiological effects collectively known as chill injury. periodically increasing temperatures during long-term chilling has been shown to increase survival in many insects. however, the transcripts responsible for this increase in survival have never been characterized. here, we present the fi ... | 2015 | 25657206 |
| quadrat method for assessing the population abundance of a commercially managed native soil-nesting bee, nomia melanderi (hymenoptera: halictidae), in proximity to alfalfa seed production in the western united states. | alkali bees, nomia melanderi cockerell, are solitary, gregarious, soil-nesting bees native to the western united states that are commercially managed in the walla walla valley of washington state to provide pollination service on alfalfa, medicago sativa l., produced as a seed crop. in 2010 and 2011, we compared two techniques for estimating n. melanderi abundance in commercially managed bee beds. the first technique involved quantifying the abundance of emergence holes in 24 0.5-m2 quadrats on ... | 2014 | 25195464 |
| cell position during larval development affects postdiapause development in megachile rotundata (hymenoptera: megachilidae). | megachile rotundata (f.) (hymenoptera: megachilidae) is the primary pollinator of alfalfa in the northwestern united states and western canada and provides pollination services for onion, carrot, hybrid canola, various legumes, and other specialty crops. m. rotundata females are gregarious, nest in cavities either naturally occurring or in artificial nesting blocks, where they construct a linear series of brood cells. because of the physical layout of the nest, the age of the larvae within the n ... | 2014 | 24914676 |
| changes in respiratory structure and function during post-diapause development in the alfalfa leafcutting bee, megachile rotundata. | megachile rotundata, the alfalfa leafcutting bee, is a solitary, cavity-nesting bee. m. rotundata develop from eggs laid inside brood cells constructed from leaf pieces and placed in series in an existing cavity. due to the cavity nesting behavior of m. rotundata, developing bees may experience hypoxic conditions. the brood cell itself and the position of cell inside the cavity may impact the rates of oxygen diffusion creating hypoxic conditions for developing animals. we hypothesized that bees ... | 2014 | 24819205 |
| risk to pollinators from the use of chlorpyrifos in the united states. | cpy is an organophosphorus insecticide that is widely used in north american agriculture. it is non-systemic, comes in several sprayable and granular formulations,and is used on a number of high-acreage crops on which pollinators can forage,including tree fruits, alfalfa, corn, sunflower, and almonds. bees (apoidea) are the most important pollinators of agricultural crops in north america and were the main pollinators of interest in this risk assessment.the conceptual model identified a number o ... | 2014 | 24723137 |
| extended hypoxia in the alfalfa leafcutting bee, megachile rotundata, increases survival but causes sub-lethal effects. | many insects are tolerant of hypoxic conditions, but survival may come at a cost to long-term health. the alfalfa leaf-cutting bee, megachile rotundata, develops in brood cells inside natural cavities, and may be exposed to hypoxic conditions for extended periods of time. whether m. rotundata is tolerant of hypoxia, and whether exposure results in sub-lethal effects, has never been investigated. overwintering m. rotundata prepupae were exposed to 10%, 13%, 17%, 21% and 24% o2 for 11 months. once ... | 2014 | 24662466 |
| health status of alfalfa leafcutting bee larvae (hymenoptera: megachilidae) in united states alfalfa seed fields. | we conducted a broad geographic survey in the northwestern united states to quantify production losses in the alfalfa leafcutting bee (megachile rotundata (f.), hymenoptera: megachilidae), a solitary pollinator used extensively in alfalfa seed production. viable larvae were found in only 47.1% of the nest cells collected at the end of the season. most of the rest of the cells contained pollen balls (typified by a provision but no larva; 16.7%), unknown causes of mortality (15.5%), or larvae kill ... | 2013 | 24128927 |
| effects of extended prepupal storage duration on adult flight physiology of the alfalfa leafcutting bee (hymenoptera: megachilidae). | the alfalfa leafcutting bee, megachile rotundata (f.), is a solitary, cavity-nesting bee and is the primary pollinator for alfalfa seed production. bee management practices include cold storage during the prepupal stage. fluctuating thermal regimes during cold storage increases survival of cold storage and allows a doubling of the cold storage period with no decrease in survival. however, survival, characterized as successful adult emergence, is not qualitative. in this study, we determined whet ... | 2013 | 23865171 |
| a fluctuating thermal regime improves long-term survival of quiescent prepupal megachile rotundata (hymenoptera: megachilidae). | the alfalfa leafcutting bee megachile rotundata (f.) is the primary pollinator for alfalfa seed production. under standard management conditions, the alfalfa leafcutting bee develops to the diapausing prepupal stage under field conditions, after which they are cold-stored at a static temperature until the following spring, when temperatures are raised and development resumes. we have assessed the effects of a fluctuating thermal regime (ftr) during overwintering cold storage, where bees were exp ... | 2013 | 23865170 |