Applying a computer model to evaluate the evolution of resistance by western corn rootworm to multiple Bt traits in transgenic maize.

Western corn rootworm, Diabrotica virgifera virgifera (LeConte) (Coleoptera: Chrysomelidae), is a major pest of maize in the United States. Transgenic maize producing insecticidal toxins from the bacterium Bacillus thuringiensis (Bt) have been used to manage this pest since 2003. Refuges of non-Bt maize have been used to delay resistance to Bt maize by western corn rootworm, and are planted in conjunction with maize producing single or multiple (i.

Effects of combining soil-applied insecticide and Bt corn for integrated pest management and resistance management of western corn rootworm (Coleoptera: Chrysomelidae).

The western corn rootworm, (Diabrotica virgifera virgifera LeConte, Coleoptera: Chrysomelidae), is a serious pest of corn (Zea mays Linnaeus, Cyperales: Poaceae) in the midwestern United States. Management practices for corn rootworm larvae include crop rotation, transgenic corn producing insecticidal toxins from the bacterium Bacillus thuringiensis Berliner (Bacillales: Bacillaceae) (Bt), and soil-applied insecticides. The extent to which combining soil-applied insecticide with Bt corn would be beneficial from the perspective of insect resistance management (IRM) or integrated pest management (IPM) remains uncertain.

Larval density-dependent mortality of western corn rootworm (Coleoptera: Chrysomelidae) in Bt and non-Bt maize and implications on dose calculations.

Background: Transgenic crops producing insecticidal toxins from the bacterium Bacillus thuringiensis (Bt) have been used to manage insect pests for nearly 30 years. Dose of a Bt crop is key to assessing the risk of resistance evolution because it affects the heritability of resistance traits. Western corn rootworm (Diabrotica virgifera virgifera, LeConte), a major pest of maize, has evolved resistance to all commercially available Bt traits targeting it, and threatens resistance to future transgenic traits.

Genetic Structure of Northern Fowl Mite (Mesostigmata: Macronyssidae) Populations Among Layer Chicken Flocks and Local House Sparrows (Passeriformes: Passeridae).

The northern fowl mite (NFM) Ornithonyssus sylviarum Canestrini and Fanzago is a blood-feeding ectoparasite found on many wild bird species and is a pest of poultry in the United States. It is unknown where NFM infestations of poultry originate, which has made it difficult to establish preventative biosecurity or effective control. We used microsatellite markers to evaluate genetic variation within and among NFM populations to determine routes of introduction onto farms and long-term persistence.

Arrhenotoky and oedipal mating in the northern fowl mite (Ornithonyssus sylviarum) (Acari: Gamasida: Macronyssidae).

Background: The northern fowl mite (NFM; Ornithonyssus sylviarum) is a blood-feeding ectoparasite of birds and a major pest of poultry in the United States. Mite populations spread rapidly in commercial flocks, reach peak burdens of >70,000 mites per bird and have developed resistance to many pesticides. Despite decades as a pest in the United States, the reproductive biology of NFM remains unclear.