Geographic Distribution of Soybean Aphid Biotypes in the United States and Canada during 2008–2010

Soybean aphid (Aphis glycines Matsumura) is a native pest of soybean [Glycine max (L.) Merr.] in eastern Asia and was detected on soybeans in North America in 2000. In 2004, the soybean cultivar Dowling was described to be resistant to soybean aphids with the Rag1 gene for resistance. In 2006, a virulent biotype of soybean aphid in Ohio was reported to proliferate on soybeans with the Rag1 gene. The objective was to survey the occurrence of virulent aphid populations on soybean indicator lines across geographies and years. Nine soybean lines were identified on the basis of their degree of aphid resistance and their importance in breeding programs. Naturally occurring soybean aphid populations were collected in 10 states (Kansas, Illinois, Indiana, Iowa, Michigan, Minnesota, North Dakota, Ohio, South Dakota, and Wisconsin) and the Canadian province of Ontario. The reproductive capacity of field-collected soybean aphid populations was tested on soybean lines; growth rates were compared in no-choice field cages at each geographic region across 3 yr. The occurrence of soybean aphid biotypes was highly variable from year to year and across environments. The frequency of Biotypes 2, 3, and 4 was 54, 18, and 7%, respectively, from the 28 soybean aphid populations collected across 3 yr and 11 environments. Plant introduction (PI) 567598B, a natural gene pyramid of rag1c and rag4, had lowest frequency of soybean aphid colonization (18%). Several factors may have contributed to the variability, including genetic diversity of soybean aphids, parthenogenicity, abundance of the overwintering host buckthorn (Rhamnus spp.), and migratory patterns of soybean aphids across the landscape

Pollen Feeding Reduces Predation of Northern Corn Rootworm Eggs (Coleoptera: Chrysomelidae, Diabrotica barberi) by a Soil-Dwelling Mite (Acari: Laelapidae: Stratiolaelaps scimitus)

Landscape diversification with flowering plants can benefit pollinators and natural enemies, although insect pests can also use floral resources for nutrition and chemoprotection. Corn rootworms (Coleoptera: Chrysomelidae, Diabrotica spp.) are major pests of corn (Zea mays L.), and while subterranean larvae primarily feed on corn roots, adult rootworms commonly consume floral resources from other plant species. We quantified the species, density, and sex of adult corn Diabroticite rootworm beetles on wild and cultivated sunflower, corn, and squash, quantified pollen within the bodies of adult northern corn rootworms [NCR, D. barberi (Smith & Lawrence)], and investigated how consumption of sunflower and corn pollen by NCR adults impacted predation of their eggs by two soil-dwelling mites with different feeding specialization. NCR were the most common Diabroticite species on sunflower inflorescences and western corn rootworm (WCR, D. v. virgifera LeConte) were more abundant in corn and squash blossoms. Pollen feeding by NCR adults did not impact egg predation by omnivorous Tyrophagus putrescentiae (Schrank) (Acari: Sarcoptiformes, Acaridae), but predatory Stratiolaelaps scimitus (Womersley) (Acari: Mesostigmata, Laelapidae) ate eggs less frequently and took longer to feed on eggs from NCR females that had fed on sunflower pollen. This research suggests pollen feeding by adult NCR can impact predation of their eggs. While increasing plant diversity can benefit natural enemies and pest control within agroecosystems, it is important to consider how floral resources alter dietary preferences of biocontrol agents

Fireflies in Art: Emphasis on Japanese Woodblock Prints from the Edo, Meiji, and Taishō Periods

Examining how insects are represented in artwork can provide insight into people’s perceptions and attitudes towards arthropods, as well as document human–insect interactions and how they change through time. Fireflies are well-known bioluminescent beetles (Coleoptera: Lampyridae) of great cultural significance, especially in Japan. A selection of online museum collections, art databases, and dealer websites were used to find artwork featuring fireflies, with an emphasis on Japanese ukiyo-e wood block prints from the Edo, Meiji, and Taishō time periods (1600–1926). Quotes from early twentieth century texts were used to provide additional historical context. Over 90 different artists created artwork featuring fireflies, including several renowned masters. Artists depicted adult fireflies in a variety of ways (e.g., relatively accurately, more generalized, symbolic or abstract, yellowish dots) in the absence and presence of people. Most images were set outdoors during the evening near water, and primarily featured women and children, groups of women, and large parties catching fireflies or observing caged fireflies. ‘Beauties’, geisha, courtesans, kabuki actors, and insect vendors were also common subjects. Various types of collecting tools and a diversity of cages were featured, as well as insect vendors. The artwork highlights the complex connections between fireflies and humans. Insect-related art can contribute to education and conservation efforts, particularly for dynamic insects such as fireflies that are facing global population declines

Beyond Focal Pests: Impact of a Neonicotinoid Seed Treatment and Resistant Soybean Lines on a Non-Target Arthropod

Integrated pest management (IPM) tactics may effectively control focal pests, but it is also important to test the compatibility of different tactics, and consider non-target organisms. We investigated the effects of a neonicotinoid seed treatment and Rag resistance genes used for soybean aphid (Aphis glycines Matsumura) control on reproduction of a non-target herbivore (twospotted spider mite, Tetranychus urticae Koch) in short-term greenhouse experiments. We also examined interactions between spider mites and a specialist phytoseiid mite [Ambylseius fallacis (Garman)] and assessed the effects of a co-occurring opportunistic omnivore [Frankliniella occidentalis (Pergande)] by including thrips density as a covariate. There were no interactive or main effects of the presence of Rag genes on the densities of any of the arthropods. Overall, effects of the seed treatment on spider mite densities varied, with no difference when mites were confined in clip cages, and higher populations on seed-treated plants when on whole plants. Predatory mites had a consistent negative impact on spider mites, and densities of A. fallacis immatures were similar between seed treated and non-seed treated plants. However, the relationship between spider mite and thrips densities was different between these two plant types, but only in the clip cage experiment lacking predatory mites. This research highlights the importance of considering how IPM tactics might affect non-target organisms

Home on the Range: Establishment of a Canada Thistle Biocontrol Agent

Invasive weeds are one of the worst scourges within rangelands, and it is often difficult to control them using conventional approaches such as herbicides or mowing. But all is not lost—insect allies can help us combat these noxious plants! We are talking about insect biocontrol agents, or plant-eating bugs that feed on weeds. However, there are hurdles these insects must overcome to successfully control weed populations; the first is establishing a viable population after being released. In this article we focus on one such ecological drama, which is the biocontrol of Canada thistle in North Dakota with a stem-mining weevil. The Rangelands archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform March 202

Impact of multiple soil microbial inoculants on biomass and biomass allocation of the legume crop field pea (Fabaceae: Pisum sativum L.)

Abstract Introduction Food production is a global challenge and consequently there is considerable interest in manipulating the rhizobiome using microbial inoculants (MI) to support sustainable agriculture. The effectiveness of MI needs to be evaluated under diverse environmental conditions, especially for nitrogen‐fixing legume crops, for which interactions between their associated bacteria and other soil biota may be particularly important. Materials and Methods We investigated how three commercially available types of plant growth‐promoting MI, alone and in combination (B5: five species of Bacillus bacteria, GP: four species of Trichoderma fungi, N2: Paenibacillus polymyxa bacteria) impacted field pea (Fabales: Fabaceae, Pisum sativum L.) in the greenhouse and a 2‐year field experiment. Results In the greenhouse, we found that effects of MI on plant performance varied, with positive effects of MI only apparent when plants were grown in the winter and likely under greater stress, because they lacked nodules. Plants grown in the summer had nodules and 2‐week‐old MI plants had less root biomass and total plant weight than noninoculated controls, but the weight of 4‐week‐old MI plants was similar to or greater than that of the controls. In the field, the root‐to‐shoot biomass ratio was highest in noninoculated controls and positive effects of N2 on shoots and B5 on shoots and pod densities did not translate into differences in pod weight or total plant weight. In most cases, plants inoculated with all three inoculants performed similar to those receiving a single inoculant, whereas root colonization by arbuscular mycorrhizal fungi was higher for B5 plants than plants in the other treatments. Conclusions Overall, B5 was the inoculant most often associated with increased plant biomass. This research underscores the need to consider microbial and environmental context when evaluating MI

Predatory and Parasitic Insects Associated with Urophora cardui L. (Diptera: Tephritidae) Galls on Canada Thistle, Cirsium arvense L. (Asterales, Asteraceae) in North Dakota

We surveyed the insect fauna associated with Urophora cardui L. (Diptera: Tephritidae) galls on Canada thistle, Cirsium arvense L. (Asterales, Asteraceae), in parts of the northern Great Plains, U.S., by field-collecting galls and rearing or dissecting out the insects. We also examined the relationships between gall biomass and insect density and biomass. Urophora cardui were widespread, and the gall biomass was positively correlated with fly density and fly biomass. We recovered Isohydnocera tabida (LeConte) (Coleoptera: Cleridae) from galls in two counties, which represents a new host record and provides vital information on the little-known immatures of this predatory species. Pteromalus elevatus (Walker) (Hymenoptera: Pteromalidae) was the dominant parasitoid that emerged from the U. cardui galls. Individual galls typically only had one insect species, and occasionally both U. cardui and P. elevatus were present, but it was rare for other insects to be present in galls housing I. tabida. This study adds to the taxonomic literature of gall-inhabiting insect species and provides new information on the predators of U. cardui, specifically a little-known clerid beetle species