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Soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), reached damaging levels in 2003 and 2005 in soybean, Glycine max (L.) Merrill, in most northern U.S. states and Canadian provinces, and it has become one of the most important pests of soybean throughout the North Central region. A common experimental protocol was adopted by participants in six states who provided data from 19 yield-loss experiments conducted over a 3-yr period. Population doubling times for field populations of soybean aphid averaged 6.8 d +/- 0.8 d (mean +/- SEM). The average economic threshold (ET) over all control costs, market values, and yield was 273 +/- 38 (mean +/- 95% confidence interval [CI], range 111-567) aphids per plant. This ET provides a 7-d lead time before aphid populations are expected to exceed the economic injury level (EIL) of 674 +/- 95 (mean +/- 95% CI, range 275-1,399) aphids per plant. Peak aphid density in 18 of the 19 location-years occurred during soybean growth stages R3 (beginning pod formation) to R5 (full size pod) with a single data set having aphid populations peaking at R6 (full size green seed). The ET developed here is strongly supported through soybean growth stage R5. Setting an ET at lower aphid densities increases the risk to producers by treating an aphid population that is growing too slowly to exceed the EIL in 7 d, eliminates generalist predators, and exposes a larger portion of the soybean aphid population to selection by insecticides, which could lead to development of insecticide resistance.

Invasões de Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) no Hemisfério Ocidental: Implicacões para a América do Sul RESUMO -A joaninha, Harmonia axyridis (Pallas), nativa da Ásia, foi recentemente detectada na América do Sul depois de ter invadido a América do Norte e Europa. Essa joaninha é um predador voraz, e portanto, popular e eficaz no controle biológico. Infelizmente, H. axyridis também está relacionada a impactos nocivos (ex., como peste residencial e de frutas temperadas e ameaça a organismos não-alvos). Para fazer prever os possíveis impactos de H. axyridis na América do Sul, a história da sua invasão no Hemisfério Ocidental foi revisada e os vários fatores críticos para futuras invasões (isto é, chegada, estabelecimento e disseminação) em novas áreas da América do Sul foram discutidos. A possibilidade de introduções contínuas de H. axyridis na América do Sul parece alta devido a sua popularidade como agente de controle biológico e através de introduções acidentais. Seu estabelecimento também parece possível em extensas regiões da América do Sul. A similaridade climática com a região nativa sugere que o estabelecimento é possível na região sul da América do Sul. Porém, similaridade de hábitat com a região nativa sugere que o estabelecimento seja mais adequado na região norte da América do Sul. Além disso, a disponibilidade da presa não deve ser um fator limitante para o estabelecimento desse predador. Após o estabelecimento, H. axyridis pode se disseminar pelo próprio vôo e por meios associados ao homem. Concluindo, a invasão de H. axyridis em novas áreas do continente sul-americano é provável. (Colunga-Garcia & Gage 1998, Brown & Miller 1998, Michaud 2002b, Alyokhin & Sewell 2004, Saini 2004, which may be partly due to intraguild predation (e.g., Cottrell & Yeargan 1998, Michaud 2002b, Cottrell 2004, Yasuda et al. 2004. In addition, H. axyridis may impact populations of the monarch butterfly, Danaus plexippus (Koch et al. 2004c, in press b). Second, H. axyridis can be a pest of fruit production (Koch et al. 2004a), particularly as a contaminant during wine production (Pickering et al. 2004, Galvan et al. 2006. Third, H. axyridis can be a nuisance to humans. It can become a household pest when it seeks shelter from winter in homes and other structures (Nalepa et al. 2004(Nalepa et al. , 2005. Once on or in a home, massive aggregations of H. axyridis are a nuisance to homeowners (Nalepa et al. 2004, Huelsman & Kovach 2004 and can cause allergic reactions in humans (Ray & Pence 2004). Similarly, H. axyridis can form autumn aggregations in bee hives, where it apparently does not harm the bees, but is a nuisance to the bee keepers (Caron 1996).The geographic range and impacts (both positive and negative) of H. axyridis are expanding rapidly. Currently, this coccinellid is widely established in North America Can we use what we have learned from the invasion of H. axyridis in North America to predict implications for South America? In this paper, we provide a review of the literature on the histor...

Diverse subdisciplines within entomology recognize the detection of rare individuals as the precursor to effective management of these individuals. Unfortunately, detection methods have often developed on a case-by-case basis, and advances in one subdiscipline have not carried over to similarly related fields. The biology of a particular organism will certainly affect sampling methods, but the underlying principles governing the power of a sampling strategy to detect rare individuals will apply across taxa. Our review of the sampling literature demonstrates the common problem of detecting rare individuals, reviews the fundamentals of probability theory as a foundation for any monitoring program, and discusses the inferences that can be drawn from samples, especially when resources limit sampling efforts. Particular emphasis is placed on binomial-, beta-binomial-, and hypergeometric-based sampling strategies as they pertain to quarantine inspections for exotic pests, veterinary/medical entomology, and insecticide resistance monitoring.

Soybean aphid, Aphis glycines Matsumura, is now widely established in soybean, Glycine max L., production areas of the northern United States and southern Canada and is becoming an important economic pest. Temperature effect on soybean aphid fecundity and survivorship is not well understood. We determined the optimal temperature for soybean aphid growth and reproduction on soybean under controlled conditions. We constructed life tables for soybean aphid at 20, 25, 30, and 35 degrees C with a photoperiod of 16:8 (L:D) h. Population growth rates were greatest at 25 degrees C. As temperature increased, net fecundity, gross fecundity, generation time, and life expectancy decreased. The prereproductive period did not differ between 20 and 30 degrees C; however, at 30 degrees C aphids required more degree-days (base 8.6 degrees C) to develop. Nymphs exposed to 35 degrees C did not complete development, and all individuals died within 11 d. Reproductive periods were significantly different at all temperatures, with aphids reproducing longer and producing more progeny at 20 and 25 degrees C than at 30 or 35 degrees C. Using a modification of the nonlinear Logan model, we estimated upper and optimal developmental thresholds to be 34.9 and 27.8 degrees C, respectively. At 25 degrees C, aphid populations doubled in 1.5 d; at 20 and 30 degrees C, populations doubled in 1.9 d.

Drosophila suzukii Matsumura, often called spotted wing drosophila, is an exotic vinegar fly that is native to Southeast Asia and was first detected in the continental United States in 2008. Previous modeling studies have suggested that D. suzukii might not survive in portions of the northern United States or southern Canada due to the effects of cold. As a result, we measured two aspects of insect cold tolerance, the supercooling point and lower lethal temperature, for D. suzukii summer-morph pupae and adults and winter-morph adults. Supercooling points were compared to adults of Drosophila melanogaster Meigen. The lower lethal temperature of D. suzukii winter-morph adults was significantly colder than that for D. suzukii summer-morph adults, while supercooling points of D. suzukii winter-morph adults were actually warmer than that for D. suzukii summer-morph adults and pupae. D. suzukii summer-morph adult supercooling points were not significantly different than those for D. melanogaster adults. These measures indicate that D. suzukii is a chill intolerant insect, and winter-morph adults are the most cold-tolerant life stage. These results can be used to improve predictions of where D. suzukii might be able to establish overwintering populations and cause extensive damage to spring fruit crops.

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