| impact of an exotic parasitoid on plutella xylostella (lepidoptera: plutellidae) population dynamics, damage and indigenous natural enemies in kenya. | diadegma semiclausum (hellén) (hymenoptera: lchneumonidae), an exotic diamondback moth parasitoid, was released in two pilot areas (werugha in coast region and tharuni in central province) in kenya. fifteen month before release, observations on the diamondback moth, plutella xylostella (linnaeus), and local natural enemy population dynamics and pest damage were initiated in both areas and continued for three years after release. the p. xylostella population was bimodal with higher records during ... | 2007 | 17645815 |
| interspecific competition between diadegma semiclausum hellen and diadegma mollipla (holmgren), parasitoids of the diamondback moth, plutella xylostella (l), feeding on a new host plant. | interspecific competition between an introduced parasitoid species aimed at controlling a herbivorous pest species and a native parasitoid parasitising the same host may influence the success of classical biological control programmes. in kenya, interspecific competition between an introduced and a local parasitoid on two diamondback moth populations (dbm, plutella xylostella) was investigated on two different host plants. we tested simultaneous and delayed competition of the local parasitoid di ... | 2008 | 18062837 |
| oogenesis of diadegma semiclausum (hymenoptera: ichneumonidae) and its associated polydnavirus. | we present a detailed ultrastructural analysis of ovary and calyx cell differentiation of diadegma semiclausum. numerous gametangia in various developmental stages were examined with electron microscopy to characterize the ultrastructure features of oogenesis, the most important of which is the development of nurse cells. in the germarium, the undifferentiated germ cells diversify, and one of the central cells of the cluster differentiates into an oocyte while the remaining become nurse cells. g ... | 2008 | 18454475 |
| Deep sequencing-based transcriptome analysis of Plutella xylostella larvae parasitized by Diadegma semiclausum. | Parasitoid insects manipulate their hosts' physiology by injecting various factors into their host upon parasitization. Transcriptomic approaches provide a powerful approach to study insect host-parasitoid interactions at the molecular level. In order to investigate the effects of parasitization by an ichneumonid wasp (Diadegma semiclausum) on the host (Plutella xylostella), the larval transcriptome profile was analyzed using a short-read deep sequencing method (Illumina). Symbiotic polydnavirus ... | 2011 | 21906285 |
| the herbivore-induced plant volatile methyl salicylate negatively affects attraction of the parasitoid diadegma semiclausum. | the indirect defense mechanisms of plants comprise the production of herbivore-induced plant volatiles that can attract natural enemies of plant attackers. one of the often emitted compounds after herbivory is methyl salicylate (mesa). here, we studied the importance of this caterpillar-induced compound in the attraction of the parasitoid wasp diadegma semiclausum by using a mutant arabidopsis line. pieris rapae infested atbsmt1-ko mutant arabidopsis plants, compromised in the biosynthesis of me ... | 2010 | 20407809 |
| jasmonic acid-induced volatiles of brassica oleracea attract parasitoids: effects of time and dose, and comparison with induction by herbivores. | caterpillar feeding induces direct and indirect defences in brassicaceous plants. this study focused on the role of the octadecanoid pathway in induced indirect defence in brassica oleracea. the effect of induction by exogenous application of jasmonic acid (ja) on the responses of brussels sprouts plants and on host-location behaviour of associated parasitoid wasps was studied. feeding by the biting-chewing herbivores pieris rapae and plutella xylostella resulted in significantly increased endog ... | 2009 | 19451186 |
| the complete mitochondrial genome of diadegma semiclausum (hymenoptera: ichneumonidae) indicates extensive independent evolutionary events. | few complete mitochondrial genomes representing limited families in the order hymenoptera have been sequenced. here, we sequenced the complete mitochondrial genome of diadegma semiclausum (hymenoptera: ichneumonidae). this genome is 18 728 bp long, the second largest hexapod mitochondrial genome sequenced in its entirety and that with the highest a+t content at 87.4%. four trnas are rearranged compared with the ancestral arrangement. gene rearrangement mechanisms are different among all three re ... | 2009 | 19370087 |
| diversity, distribution and role of wild crucifers in major cabbage and kale growing areas of kenya. | an investigation of the diversity and distribution of wild crucifer species and their importance for cultivated crucifers was conducted during 2005 and 2006 in the highland and mid-altitude semi-arid areas of kenya. thirteen species of wild crucifers in nine genera were recorded: raphanus raphanistrum, erucastrum arabicum, sisymbrium officinale, crambe kilimandscharica, capsella bursa-pastoris, rorippa nudiuscula, ro. micrantha, ro. microphylla, lepidium bonariense, coronopus didymus, brassica r ... | 2009 | 19063754 |
| isoprene interferes with the attraction of bodyguards by herbaceous plants. | isoprene is the most abundant volatile compound emitted by vegetation. it influences air chemistry and is part of plant defense against abiotic stresses. however, whether isoprene influences biotic interactions between plants and other organisms has not been investigated to date. here we show a new effect of isoprene, namely its influence on interactions between plants and insects. herbivory induces the release of plant volatiles that attract the herbivore's enemies, such as parasitic wasps, as ... | 2008 | 18987312 |
| parasitic castration of plutella xylostella larvae induced by polydnaviruses and venom of cotesia vestalis and diadegma semiclausum. | in the present study, we used gamma-ray to irradiate the female parasitoids to make wasp eggs infertile, resulting in pseudoparasitization, which allowed the analysis of maternal secretions such as polydnaviruses (pdvs) and venom in the absence of larval secretions or teratocytes by the growing parasitoids. we then investigated the spermatogenesis and components of testicular proteins of male plutella xylostella larvae pseudoparasitized by two endoparasitoids (cotesia vestalis and diadegma semic ... | 2009 | 18949808 |
| characterization of midgut trypsinogen-like cdna and enzymatic activity in plutella xylostella parasitized by cotesia vestalis or diadegma semiclausum. | protein digestion in insects is a result of the action of a complex of proteinases present in the midgut. in this report we describe the cloning and sequencing of a trypsin cdna from larvae of the lepidopteran herbivore plutella xylostella. we investigated the expression of this gene and enzymatic activity of its translation product with n-a-benzoyl-l-arginine p-nitroanilide (bapna) as substrate in p. xylostella larvae that were either unparasitized or parasitized by cotesia vestalis or diadegma ... | 2009 | 18618770 |
| time allocation of a parasitoid foraging in heterogeneous vegetation: implications for host-parasitoid interactions. | 1. changing plant composition in a community can have profound consequences for herbivore and parasitoid population dynamics. to understand such effects, studies are needed that unravel the underlying behavioural decisions determining the responses of parasitoids to complex habitats. 2. the searching behaviour of the parasitoid diadegma semiclausum was followed in environments with different plant species composition. in the middle of these environments, two brassica oleracea plants infested by ... | 2007 | 17714262 |
| detection of parasitism in diamondback moth, plutella xylostella (l.), using differential melanization and coagulation reactions. | diamondback moth (dbm), plutella xylostella, is known for causing damage to brassica crops and developing resistance to chemical and biological pesticides; it has become one of the most difficult pests to manage in many regions around the world. the only way to reduce reliance on pesticides is to maximize the role of natural control agents for integrated pest management programs and be able to incorporate the mortality from control agents into pest control decision-making. more than 90 hymenopte ... | 2007 | 17645821 |
| variation in plant volatiles and attraction of the parasitoid diadegma semiclausum (hellén). | differences in allelochemistry of plants may influence their ability to attract parasitoids. we studied responses of diadegma semiclausum (hellén), a parasitoid of the diamondback moth (plutella xylostella l.), to inter- and intraspecific variation in odor blends of crucifers and a non-crucifer species. uninfested brussels sprout (brassica oleracea l. gemmifera), white mustard (sinapis alba l.), a feral brassica oleracea, and malting barley (hordeum vulgare l.) were compared for their attractivi ... | 2005 | 15898495 |
| experimental analysis of the influence of pest management practice on the efficacy of an endemic arthropod natural enemy complex of the diamondback moth. | maximizing the contribution of endemic natural enemies to integrated pest management (ipm), programs requires a detailed knowledge of their interactions with the target pest. this experimental field study evaluated the impact of the endemic natural enemy complex of plutella xylostella (l.) (lepidoptera: yponomeutidae) on pest populations in commercial cabbage crops in southeastern queensland, australia. management data were used to score pest management practices at experimental sites on indepen ... | 2004 | 15666732 |
| infection of the immature stages of diadegma semiclausum, an endolarval parasitoid of the diamondback moth, by beauveria bassiana. | interactions between the immature stages of diadegma semiclausum, an endolarval parasitoid of plutella xylostella, and the fungal entomopathogen beauveria bassiana were investigated in the laboratory. detrimental effects of b. bassiana on d. semiclausum cocoon production and adult parasitoid emergence increased with increasing pathogen concentration and some parasitoid larvae became infected by b. bassiana within hosts. the negative impact of b. bassiana on d. semiclausum cocoon production decre ... | 2004 | 15145252 |
| conflicts between a fungal entomopathogen, zoophthora radicans, and two larval parasitoids of the diamondback moth. | zoophthora radicans (zygomycetes: entomophthorales), diadegma semiclausum (hymenoptera: ichneumonidae), and cotesia plutellae (hymenoptera: braconidae) are all natural enemies of the diamondback moth, plutella xylostella (lepidoptera: yponomeutidae). adult c. plutellae are not susceptible to z. radicans infection but the pathogen can infect and kill adult d. semiclausum. infection of adult d. semiclausum prior to exposure to p. xylostella host larvae significantly reduced the number of parasitoi ... | 2000 | 11023731 |
| interactions between the fungal entomopathogen zoophthora radicans brefeld (entomophthorales) and two hymenopteran parasitoids attacking the diamondback moth, plutella xylostella l. | treatment of the hymenopteran parasitoids diadegma semiclausum and cotesia plutellae with a strain of the entomopathogenic fungus zoophthora radicans, which was initially isolated from plutella xylostella, showed that d. semiclausum was susceptible to the pathogen but that c. plutellae was not. in leaf shower bioassays, the susceptibility of d. semiclausum adults to z. radicans was 70- and 133-fold less than the susceptibility of p. xylostella larvae and adults, respectively. when adult d. semic ... | 1996 | 8812558 |
| developmental responses of the diamondback moth parasitoid diadegma semiclausum (hellén) (hymenoptera: ichneumonidae) to temperature and host plant species. | effects of constant rearing temperature and the plant species fed upon by its hosts were investigated for several developmental parameters of diadegma semiclausum (hellén), an important parasitoid of the diamondback moth, plutella xylostella (l.). temperature had highly significant effects on all developmental parameters measured, and effects were usually both linear and quadratic with increasing temperature. host plant species, comprising brassica napus l., brassica rapa l. ssp. pekinensis and ... | 2011 | 22127052 |
| natural variation in herbivore-induced volatiles in arabidopsis thaliana. | to study whether natural variation in arabidopsis thaliana could be used to dissect the genetic basis of responses to herbivory in terms of induced volatile emissions, nine accessions were characterized upon herbivory by biting-chewing pieris rapae caterpillars or after treatment with the phytohormone jasmonic acid (ja). analysis of 73 compounds in the headspace showed quantitative differences in the emission rates of several individual compounds among the accessions. moreover, variation in the ... | 2010 | 20488836 |
| multidisciplinary approach to unravelling the relative contribution of different oxylipins in indirect defense of arabidopsis thaliana. | the oxylipin pathway is commonly involved in induced plant defenses, and is the main signal-transduction pathway induced by insect folivory. herbivory induces the production of several oxylipins, and consequently alters the so-called 'oxylipin signature' in the plant. jasmonic acid (ja), as well as pathway intermediates are known to induce plant defenses. indirect defense against herbivorous insects comprises the production of herbivore-induced plant volatiles (hipvs). to unravel the precise oxy ... | 2009 | 19798534 |
| changes in hemocytes of plutella xylostella after parasitism by diadegma semiclausum. | we examined the changes of hemocytes in the diamondback moth, plutella xylostella (lepidoptera: plutellidae), due to parasitism by the endoparasitoid diadegma semiclausum (hymenoptera: ichneumonidae). necrosis of prohemocytes in different stages was observed while cell death was absent in the mature hemocytes in the parasitized larvae, which was related to the declined total hemocyte count per microliter (thc). thc in the host hemolymph declined sharply by 12 h post-parasitization and then remai ... | 2009 | 18949799 |