| total hemocyte counts of honey bee larvae (apis mellifera l.) from various elevations. | | 1970 | 5483357 |
| role of honey bees (hymenoptera: apidae) in the pollination biology of a california native plant, triteleia laxa (asparagales: themidaceae). | a central focus of pollination biology is to document the relative effectiveness of different flower visitors as pollinators. ongoing research seeks to determine the role that introduced honey bees (apis mellifera l.) play in the pollination of both invasive and native plants. here we report on the importance of a. mellifera as pollinators of a california native plant, triteleia laxa bentham. in observation plots and transect censuses, a. mellifera overwhelmingly dominated the t. laxa flower vis ... | 2008 | 18559188 |
| range and frequency of africanized honey bees in california (usa). | africanized honey bees entered california in 1994 but few accounts of their northward expansion or their frequency relative to european honey bees have been published. we used mitochondrial markers and morphometric analyses to determine the prevalence of africanized honeybees in san diego county and their current northward progress in california west of the sierra nevada crest. the northernmost african mitotypes detected were approximately 40 km south of sacramento in california's central valley ... | 2015 | 26361047 |
| wildflower plantings do not compete with neighboring almond orchards for pollinator visits. | the engineering of flowering agricultural field borders has emerged as a research and policy priority to mitigate threats to pollinators. studies have, however, rarely addressed the potential that flowering field borders might compete with neighboring crops for pollinator visits if they both are in bloom at the same time, despite this being a concern expressed by growers. we evaluated how wildflower plantings added to orchard borders in a large (512 ha) commercial almond orchard affected honey b ... | 2017 | 28379320 |
| nontarget effects of the mosquito adulticide pyrethrin applied aerially during a west nile virus outbreak in an urban california environment. | in august 2006, a pyrethrin insecticide synergized with piperonyl butoxide (evergreen crop protection ec 60-6, mclaughlin gormley king company, golden valley, mn) was sprayed in ultralow volumes over the city of davis, ca, by the sacramento-yolo mosquito and vector control district to control mosquitoes transmitting west nile virus. concurrently, we evaluated the impact of the insecticide on nontarget arthropods by 1) comparing mortality of treatment and control groups of sentinel arthropods, an ... | 2007 | 17939516 |
| regional distribution of paenibacillus larvae subspecies larvae, the causative organism of american foulbrood, in honey bee colonies of the western united states. | we examined honey bee, apis mellifera l., colonies pollinating almonds in california during february 2003 for paenibacillus larvae subsp. larvae, the causative organism of the virulent brood disease american foulbrood. colonies originating from the rocky mountain area and california had significantly higher numbers (p < 0.05) of bacterial colony-forming units (cfus) (408 and 324 per 30 adult bees, respectively) than colonies from the upper midwest (1.28). colonies from the northwestern, central, ... | 2005 | 16156557 |
| update on the status of africanized honey bees in the western states. | the africanized honey bee (ahb), apis mellifera scutella--perhaps better known as the "killer bee"--has arrived in the western united states and in southern california, following a nearly 50-year north-ward migration across south and central america. first detected near hidalgo, texas in october 1993, the bees continue to advance 100 to 300 miles per year by colonizing existing hives or forming new hives in the wild. although the ahb's "killer" reputation has been greatly exaggerated, the presen ... | 1999 | 10344176 |
| helical, motile mycoplasmas associated with flowers and honey bees in california. | spiroplasmas were cultured from nonsurface-sterilized flowers of magnolia tree (magnolia grandiflora l.) and tulip tree (liriodendron tulipfera l.) in alameda, solano, and yolo counties in california. spiroplasmas were also isolated from honey bees (apis mellifera l.) collected in the vicinity of davis and berkeley, ca. most of the isolates grew relatively slowly at 31 or 37 degrees c reaching maximum population at 31 degrees c in 8-10 days. the flower isolates were serologically indistinguishab ... | 1981 | 7214240 |
| effects of captan on apis mellifera brood development under field conditions in california almond orchards. | three almond field trials were conducted during 2003 and 2004 at two locations in central (fresno county) and northern (yolo county) california to evaluate the potential effects of commercial applications of captan on honey bees, apis mellifera l. captan was applied at 5.0 kg (ai)/ha during bloom. hives were evaluated for hive health and brood development parameters for approximately 2 mo after application. this study showed that the application of captan was not harmful to foraging honey bees o ... | 2009 | 19253613 |
| effect of a fungicide and spray adjuvant on queen-rearing success in honey bees (hymenoptera: apidae). | commercial producers of honey bee queens (apis mellifera l.) have reported unexplained loss of immature queens during the larval or pupal stage. many affected queen-rearing operations are situated among the almond orchards of california and report these losses in weeks after almond trees bloom. almond flowers are a rich foraging resource for bees, but are often treated with fungicides, insecticides, and spray adjuvants during bloom. anecdotal reports by queen producers associate problems in quee ... | 2013 | 24224234 |
| honey bee (apis mellifera) colony health and pathogen composition in migratory beekeeping operations involved in california almond pollination. | honey bees are important pollinators of agricultural crops. pathogens and other factors have been implicated in high annual losses of honey bee colonies in north america and some european countries. to further investigate the relationship between multiple factors, including pathogen prevalence and abundance and colony health, we monitored commercially managed migratory honey bee colonies involved in california almond pollination in 2014. at each sampling event, honey bee colony health was assess ... | 2017 | 28817641 |
| complex interactions among biocontrol agents, pollinators, and an invasive weed: a structural equation modeling approach. | herbivores, seed predators, and pollinators can exert strong impacts on their host plants. they can also affect the strength of each other's impact by modifying traits in their shared host, producing super- or sub-additive outcomes. this phenomenon is especially relevant to biological control of invasive plants because most invaders are attacked by multiple agents. unfortunately, complex interactions among agents are rarely studied. we used structural equation modeling (sem) to quantify the effe ... | 2012 | 23387114 |
| synergistic effects of non-apis bees and honey bees for pollination services. | in diverse pollinator communities, interspecific interactions may modify the behaviour and increase the pollination effectiveness of individual species. because agricultural production reliant on pollination is growing, improving pollination effectiveness could increase crop yield without any increase in agricultural intensity or area. in california almond, a crop highly dependent on honey bee pollination, we explored the foraging behaviour and pollination effectiveness of honey bees in orchards ... | 2013 | 23303545 |
| local bumble bee decline linked to recovery of honey bees, drought effects on floral resources. | time series of abundances are critical for understanding how abiotic factors and species interactions affect population dynamics, but are rarely linked with experiments and also scarce for bee pollinators. this gap is important given concerns about declines in some bee species. i monitored honey bee (apis mellifera) and bumble bee (bombus spp.) foragers in coastal california from 1999, when feral a. mellifera populations were low due to varroa destructor, until 2014. apis mellifera increased sub ... | 2016 | 27539950 |