Key Parameter Comparisons of Fungal Induced Mortality in Alfalfa Weevil Larvae (Coleoptera: Curculionidae)

Key parameters of alfalfa weevil larval mortality by Entornophthora phytonorni were compared weekly in three alfalfa fields. Rainfall appeared to be the overriding factor in seasonal larval infection rates

Feeding Preference Studies of Adult \u3ci\u3eNezara Viridula\u3c/i\u3e (Hemiptera: Pentatomidae) Morphs from India and the United States

Nezara viridula (Linnaeus) morphs from India and the United States were studied in a laboratory comparison of feeding preferences for pods of soybeans, Glycine max, and green beans, Phaseolus vulgaris. Adults of a morph from the U.S. apparently selected pods at random, while three sympatric morphs from India generally preferred green bean pods

Epizootiology of the Fungal Pathogen, \u3ci\u3eZoophthora Phytonomi\u3c/i\u3e (Zygomycetes: Entomophthorales) in Field Populations of Alfalfa Weevil (Coleoptera: Curculionidae) Larvae in Illinois

The influence of the fungal pathogen, Zoophthora phytonomi, on larvae of the alfalfa weevil, Hypera postica, was studied in three alfalfa fields in Illinois. Disease epizootics occurred in all three fields and disease onset was ob- served within a fairly narrow range of degree day accumulations. At the height of each epizootic, percentages of infected larvae were between 80 and 100%, and the fungus contributed to the collapse of the weevil population in each field. Percent parasitism by the larval parasitoids, Bathyplectes cur­culionis and B. anurus, was lower in our fields than is common in mid-season alfalfa weevil populations and was sometimes correlated negatively with Zoophthora phytonomi infection levels, strongly implying negative interfer- ence between the parasitoids and the pathogen. Control potential of Zooph­thora phytonomi disease in alfalfa weevil larval populations is addressed

A New Microsporidium in Alfalfa Weevil Populations: Distribution and Characterization

A microsporidium species, not previously reported, was found infecting field populations of the alfalfa weevil, Hypera postica, in Illinois. The pathogen is widely distributed thoughout the state. Percent infection ranged from 1 % to 50% at different collection locations. Characteristics of the microsporidium and possible modes of transmission are presented

Lethal Temperatures of Diapausing \u3ci\u3eBathyplectes Curculionis\u3c/i\u3e (Hymenoptera: Ichneumonidae) a Parasite of the Alfalfa Weevil (Coleoptera: Curculionidae)

Seasonally acclimatized diapausing larvae of Bathyplectes curculionis (Thomson) were exposed to extreme hxgh and low temperatu~es to determine lethal temperatures for this stage of the parasite. The possible effects of relative humidity on high temperature mortality, mortality induced by repetitive exposures to sublethal temperatures, and differential survival between sexes, were also measured. The upper lethal temperature for summer larvae was 60°C (LDSo from 2 to 4 h), and the lower lethal temperature for winter larvae was -25°C (LDSo from 0 to % h). Summer larvae showed significantly increased mortality with repetitive exposures to sublethal temperatures (55OC) whereas winter larval mortality did not increase significantly with repetitive exposures to sublethal temperatures (-20°C). In winter experiments in which the sex of the emerging adult could be measured, no significant difference in survival was found between the sexes. Our results, in conjunction with published field data, strongly suggest that heat kill in the summer may be a significant mortality factor in warmer areas of the parasite\u27s range

Localized Field Migration of the Adult Alfalfa Weevil, Clover Leaf Weevil, and Clover Root Curculio (Coleoptera: Curculionidae), and Its Implication for a Fall Pest Management Program

The migration of the alfalfa weevil, clover leaf weevil and clover root curculio from aestivation sites into adjacent alfalfa fields was monitored with several different trapping systems. It was found that the initial dispersal back into alfalfa fields following aestivation was a slow gradual movement across the soil surface with flight occurring only after the insects had been in the alfalfa for several days

The Marine Microbial Eukaryote Transcriptome Sequencing Project (MMETSP): illuminating the functional diversity of eukaryotic life in the oceans through transcriptome sequencing

International audienceCurrent sampling of genomic sequence data from eukaryotes is relatively poor, biased, and inadequate to address important questions about their biology, evolution, and ecology; this Community Page describes a resource of 700 transcriptomes from marine microbial eukaryotes to help understand their role in the world's oceans

Nitrogen Fixation in Mesoscale Eddies of the North Pacific Subtropical Gyre: Patterns and Mechanisms

Mesoscale eddies have been shown to support elevated dinitrogen (N2) fixation rates (NFRs) and abundances of N2-fixing microorganisms (diazotrophs), but the mechanisms underlying these observations are not well understood. We sampled two pairs of mesoscale cyclones and anticyclones in the North Pacific Subtropical Gyre in 2017 and 2018 and compared our observations with seasonal patterns from the Hawaii Ocean Time-series (HOT) program. Consistent with previous reports, we found that NFRs were anomalously high for this region (up to 3.7-fold above previous monthly HOT observations) in the centers of both sampled anticyclones. In 2017, these elevated rates coincided with high concentrations of the diazotroph Crocosphaera. We then coupled our field-based observations, together with transcriptomic analyses of nutrient stress marker genes and ecological models, to evaluate the role of biological (via estimates of growth and grazing rates) and physical controls on populations of Crocosphaera, Trichodesmium, and diatom symbionts at the mesoscale. Our results suggest that increased Crocosphaera abundances in the 2017 anticyclone resulted from the alleviation of phosphate limitation, allowing cells to grow at rates exceeding grazing losses. In contrast, distributions of larger, buoyant taxa (Trichodesmium and diatom symbionts) appeared less affected by eddy-driven biological controls. Instead, they appeared driven by physical dynamics along frontal boundaries that separate cyclonic and anticyclonic eddies. No examined controls were able to explain our 2018 findings of higher NFRs in the anticyclone. A generalized explanation of elevated NFRs in mesoscale eddies remains challenging due to the interplay of eddy-driven bottom-up, top-down, and physical control mechanisms.This work was funded by the Simons Foundation (Award # 721252 to DMK, 721256 to AEW, 721223 to EFD, 721221 to MJC, 721244 to EVA, 721225 to STD, 329108 to SJ, and 724220 to JPZ) and expedition funding from the Schmidt Ocean Institute for R/V Falkor Cruise FK180310 in 2018.Peer reviewe

Nitrogen Fixation in Mesoscale Eddies of the North Pacific Subtropical Gyre: Patterns and Mechanisms

Mesoscale eddies have been shown to support elevated dinitrogen (N2) fixation rates (NFRs) and abundances of N2-fixing microorganisms (diazotrophs), but the mechanisms underlying these observations are not well understood. We sampled two pairs of mesoscale cyclones and anticyclones in the North Pacific Subtropical Gyre in 2017 and 2018 and compared our observations with seasonal patterns from the Hawaii Ocean Time-series (HOT) program. Consistent with previous reports, we found that NFRs were anomalously high for this region (up to 3.7-fold above previous monthly HOT observations) in the centers of both sampled anticyclones. In 2017, these elevated rates coincided with high concentrations of the diazotroph Crocosphaera. We then coupled our field-based observations, together with transcriptomic analyses of nutrient stress marker genes and ecological models, to evaluate the role of biological (via estimates of growth and grazing rates) and physical controls on populations of Crocosphaera, Trichodesmium, and diatom symbionts at the mesoscale. Our results suggest that increased Crocosphaera abundances in the 2017 anticyclone resulted from the alleviation of phosphate limitation, allowing cells to grow at rates exceeding grazing losses. In contrast, distributions of larger, buoyant taxa (Trichodesmium and diatom symbionts) appeared less affected by eddy-driven biological controls. Instead, they appeared driven by physical dynamics along frontal boundaries that separate cyclonic and anticyclonic eddies. No examined controls were able to explain our 2018 findings of higher NFRs in the anticyclone. A generalized explanation of elevated NFRs in mesoscale eddies remains challenging due to the interplay of eddy-driven bottom-up, top-down, and physical control mechanisms.This work was funded by the Simons Foundation (Award # 721252 to DMK, 721256 to AEW, 721223 to EFD, 721221 to MJC, 721244 to EVA, 721225 to STD, 329108 to SJ, and 724220 to JPZ) and expedition funding from the Schmidt Ocean Institute for R/V Falkor Cruise FK180310 in 2018.Peer reviewe