Figure 1.

(a) Partial Cytochrome c oxidase subunit I (COI, 511 bp) RFLP pattern (digested with BstZ17I) of Helicoverpa armigera and Helicoverpa zea, with bands separated on 2% agarose Gel. M = DNA ladder; (b–d) Helicoverpa larvae were found attacking leaves and pods in (b) soybean; (c) leaves, flowers and bulbs in cotton; and (d) maize ears. In soybean and cotton crops, only H. armigera was found, but in maize both Helicoverpa species were found, indicating possibilities of hybridization. For cotton and soybean, H. armigera was also found in Bt crops.