The effect of Bt-cotton, i.e. genetically modified cotton that contain genes expressing delta-endotoxin, on aphid, whitefly, chrysopid and coccinellid populations was determined with a two-year field study at a cotton farm near Marble Hall, South Africa. Although Bt-cotton is lepidopteran specific, non-lepidopteran arthropod populations may be indirectly influenced by the endotoxin. Abundance o...

An increasing area of transgenic Bacillus thuringiensis (Bt) cotton is being planted in saline-alkaline soil in China. The Bt protein level in transgenic cotton plants and its control efficiency can be affected by abiotic stress, including high temperature, water deficiency and other factors. However, how soil salinity affects the expression of Bt protein, thus influencing the control efficienc...

Adequate expression of Bt (Bacillus thuringiensis) toxins and purity of seeds of Bt-transgenic cottons are important for controlling bollworms, and thereby increasing the cotton productivity. Therefore, we examined the variability in expression of Bt toxin proteins in the seeds and in leaves of different cotton (Gossypium hirsutum (L.) hybrids (JKCH 226, JKCH 1947, JKCH Durga, JKCH Ishwar, JKCH...

A 6-yr Þeld study assessed the long-term impact of Bt cotton producing the Cry1Ac -endotoxin on 22 taxa of foliar-dwelling arthropod natural enemies inArizona. No chronic, long-term effects of Bt cotton were observed over multiple generations of nontarget taxa. Zero-2 taxa declined signiÞcantly in unsprayed Bt compared with non-Bt cotton each year. In contrast, positive control studies showed t...

1) Moth Trapping. Despite the use of Bt-transgenic cotton on over 98% of the acreage in Tennessee, bollworm and tobacco budworm still compose an important pest complex. Bollworms may cause significant economic damage to Bt cotton fields, and the bollworm/budworm can be even more damaging to non-Bt cotton. More importantly, the threat of tobacco budworm infestations results in high adoption of B...

Background: Cotton with coevolving pests has been grown in India more than 5000 years. Hybrid cotton was introduced in the 1970s with increases in fertilizer and in insecticide use against pink bollworm that caused outbreaks of bollworm. Hybrid Bt cotton, introduced in 2002 to control bollworm and other lepidopteran pests, is grown on more than 90 % of the cotton area. Despite initial declines,...

Insect-resistant cotton was first introduced commercially in 1996. It is commonly referred to as Bt cotton, because it produces an insecticidal protein from the naturally occurring soil bacterium Bacillus thuringiensis (Bt). Global adoption of Bt cotton has risen dramatically from 800,000 hectares in its year of introduction in 1996 to 5.7 million hectares (alone and stacked with herbicide-tole...

The effects of Bt transgenic cottons (Bt-I expressing cry1Ac and Bt-II expressing cry1Ab and cry2Ab or cry1Ab and cry1Fa) and non-Bt cottons on feeding, oviposition and longevity of adults, and development and survival of Liriomyza trifolii larvae were studied under laboratory conditions; and infestation on four Bt and two non-Bt cotton traits were investigated under field conditions. Laborator...

Field studies to assess effects of transgenic crops onnontarget organisms primarily have focused on nontarget abundance and diversity, whereas few have examined effects on nontarget community function. A 5-yr Þeld study in Arizona assessed whether transgenic cotton producing the Cry1Ac toxin of Bacillus thuringiensis (Bt) had an effect on the natural enemy communityÕs impact on three key pests....

Top-down force is referred to arthropod pest management delivered by the organisms from higher trophic levels. In the context of prevalent adoption of transgenic Bt crops that produce insecticidal Cry proteins derived from Bacillus thuringiensis (Bt), it still remains elusive whether the top-down forces are affected by the insect-resistant traits that introduced into the Bt crops. We explored h...