Behavioral characteristics of neonate European corn borer, Ostrinia nubilalis, on Bt corn (original) (raw)

DiPel-selected Ostrinia nubilalis larvae are not resistant to transgenic corn expressing Bacillus thuringiensis Cry1Ab

Journal of economic entomology, 2007

The survival of KS-SC DiPel-resistant and -susceptible European corn borer, Ostrinia nubilalis (Hübner), was evaluated on different tissues from corn, Zea mays L., hybrids, including a nontransgenic and two transgenic corn plants (events MON810 and Bt11) expressing high doses of Bacillus thuringiensis (Bt) Cry1Ab. The survival of Bt-resistant and -susceptible third instars was similar after a 5-d exposure to transgenic plant tissues. Survivors eventually died when returned to Bt corn tissues, but many were able to continue development when transferred to non-Bt corn tissues. Survival of resistant and susceptible larvae also was evaluated in bioassays with dilutions of leaf extracts from the three corn hybrids incorporated in an artificial diet. In these assays, survival was significantly higher for resistant O. nubilalis neonates at three of the five dilutions compared with the susceptible strain, but the resistance ratio was only 2.2- and 2.4-fold for MON810 and Bt11, respectively....

Optimum Timing of an Application of Corn Oil and Bacillus thuringiensis to Control Lepidopteran Pests in Sweet Corn

HortTechnology

Corn oil and Bacillus thuringiensis ssp. kurstaki (Bt) applied directly into the silk channel of a corn ear has been shown to be an effective pesticide against corn earworm, Helicoverpa zea (CEW), and european corn borer, Ostrinia nubilalis (ECB). Field studies were conducted in 2000 and 2001 to determine the influence of application timing on ear quality at harvest. Two blocks of corn were planted during each year to observe treatment effects under varying populations of the two insect species. The treatment consisted of 0.5 mL (0.017 floz) of food grade corn oil containing a suspension of Bt at 0.08 g (0.003 oz) a.i. per ear applied directly into the silk channel at the husk opening. One treatment application was made on each silk day 3 through 11 from first silk; silk day 1 was the first day that 50% or more of ears had 2.5 cm (1 inch) of silk protruding from the husk. One treatment did not receive the oil + Bt suspension. All ears were harvested at milk stage, on silk day 25. Th...

Impact of transgenic Bt corn on European corn borer (Ostrinia nubilalis Hübner) in Lower Silesia, Poland. Preliminary results

The aim of this preliminary study performed in Lower Silesia, Poland, was to determine the impact of transgenic Bt corn (MON 810) on its target pest, the larvae of the European corn borer (ECB), as compared to a non-transgenic isoline control. Abundance of the pest as well as non-target organisms (data not included here) was monitored once a week, from the beginning of moth flight until the end of the corn growing season. At the end of the season, 100 plants from each treatment were taken to the laboratory for further analysis. Apparently higher level of damage caused by ECB larvae was recorded on conventional corn stalks and cobs when compared to transgenic Bt-corn. The differences were noticed throughout the whole growing season. Positive effects of the transgenic cultivar in comparison to non-Bt corn on different parameters of plant damage caused by ECB larvae were confirmed by the laboratory analysis.