Insecticides continue to be the primary means of control for ectoparasites on livestock. Intensive use of these materials has led to resistance to organochlorines, organophosphates and pyrethroids among populations of Haematobia irritans irritans, H. irritans exigua and Lucilia cuprina. Similarly, use of acaricides has led to resistance in one-host Boophilus ticks to all currently-used organoph...

tandem with transgenic technology, while also questioning the validity of OCT performance data. Cotton (Gossypium hirsutum L.) cultivars transgenically enhanced A key role of cultivar testing is to provide unbiased to impart herbicide resistance to either bromoxynil [3,5-dibromoagronomic performance in a defined environment while 4-hydroxybenzonitrile; BXN (Bayer Advanced, Peoria, IL)] or glyph...

To delay evolution of pest resistance to transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt), the "pyramid" strategy uses plants that produce two or more toxins that kill the same pest. In the United States, this strategy has been adopted widely, with two-toxin Bt cotton replacing one-toxin Bt cotton. Although two-toxin plants are likely to be more durable than one...

Several studies have been conducted on resistance sources to improve the genetic resistance of farm-grown tomatoes to arthropod pests, including phytophagous mites. In the present study, we evaluate the behavior of the two-spotted spider mite on different cherry tomato accessions to identify possible sources of resistance (repellent effect) to this pest. Sixty-four accessions of cherry tomatoes...

Herbicide resistance is a growing threat to agriculture and has parallels to resistances to fungicides and insecticides. However, there are many reasons to treat the resistance to herbicides differently. To highlight these similarities and differences, three pests, a weed, an insect, and a disease that have shown the ability to rapidly develop resistance to a variety of products and product cla...

Industry and scientists have worked to develop a high-dose refuge management plan that can effectively delay European corn borer (ECB) resistance to new genetically modified pesticidal corn. For a high dose, the corn expresses enough pesticide to kill all but the most resistant corn borers. For refuge, producers plant a traditional corn variety that allows susceptible corn borers to thrive and ...

Transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt) kill some key insect pests, but evolution of resistance by pests can reduce their efficacy. The main approach for delaying pest adaptation to Bt crops uses non-Bt host plants as "refuges" to increase survival of susceptible pests. To delay evolution of pest resistance to transgenic cotton producing Bt toxin Cry1Ac...

The red flour beetle is a cosmopolitan pest of stored grain and stored grain products. The pest has developed resistance to phosphine, the primary chemical used for its control. The reproductive output of survivors from a phosphine treatment is an important element of resistance development but experimental data are lacking. We exposed mated resistant female beetles to 0.135 mg/L of phosphine f...

The occurrence of resistance in Varroa mite populations is a serious threat to the beekeeping industry and to crops that rely on the honey bee for pollination. Integrated pest management strategies for control of this pest include the judicious use of insecticides. To monitor field populations of Varroa mite for insecticide resistance, a glass vial bioassay procedure was developed to use in the...

Genetically modified plants expressing insecticidal proteins from Bacillus thuringiensis (Bt) offer valuable options for managing insect pests with considerable environmental and economic benefits. Despite the benefits provided by Bt crops, the continuous expression of these insecticidal proteins imposes strong selection for resistance in target pest populations. Bt maize (Zea mays) hybrids hav...