scholarly journals Long-Term Seasonal Abundance Patterns of Helicoverpa zea and Heliothis virescens (Lepidoptera: Noctuidae) in the Texas High Plains

2004 ◽  
Vol 97 (2) ◽  
pp. 668-677 ◽  
Author(s):  
M. N. Parajulee ◽  
D. R. Rummel ◽  
M. D. Arnold ◽  
S. C. Carroll
1991 ◽  
Vol 26 (2) ◽  
pp. 281-286
Author(s):  
Marion L. Laster ◽  
Earl A. Stadelbacher

The sexual attractancy of female Heliothis virescens (F.) which had been cultured in the laboratory for 40 generations and of hybrid and backcross females (H. subflexa ♀ X H. virescens ♂) was determined and compared with the attractancy of wild female H. virescens. In field tests, females reared (< 1 generation) from field-collected larvae were significantly (P ≤ 0.05) less attractive to wild males than were females reared in the laboratory for 40 generations (HVL-40), but the attractancy of females reared in the laboratory for 1 or 41 generations did not differ significantly. The attractancy of H. virescens females from generations 40, 41 and BC females from generations 41, 42 or 179, 180 did not differ significantly in any of five tests, except in test three, where more wild males were attracted by HVL-40 than by BC-41 females. Continuous backcrossing of the female hybrid (180 generations) did not affect the attractivity of the female to the wild males. The attractancy of lab-reared H. virescens (except for generation 40) or hybrid BC virgin females, regardless of generation, to wild H. virescens males was not significantly different from that of the synthetic female sex pheromone Z-11-Hexadecenal: Z-9-tetradecenal (14.6:1). The data indicate the attractancy of H. virescens and BC virgin females to wild males may be enhanced by continuous laboratory rearing. These findings are important in population dynamic studies in which lab-reared females are used and in determining the ratio of BC to wild H. virescens females needed to suppress a given population of H. virescens.


1998 ◽  
Vol 33 (2) ◽  
pp. 129-135 ◽  
Author(s):  
A. O. Ameen ◽  
J. R. Fuxa ◽  
A. R. Richter

Interactions between formulations of the aizawai and kurstaki subspecies of Bacillus thuringiensis Berliner were evaluated by bioassay in Heliothis virescens (F.) and Helicoverpa zea (Boddie). In preliminary experiments, a formulation of subspecies aizawai, Xentari AS®, had significantly (P < 0.05) higher median lethal concentrations (LC50s) in both insect species than formulations based on subspecies kurstaki. Helicoverpa zea was significantly (P < 0.05) more susceptible than H. virescens to one formulation of subspecies kurstaki (Dipel ES®), but the two insects did not differ in susceptibility to Xentari AS® or to a second formulation of subspecies kurstaki (Dipel 6AF®). In H. virescens, Xentari AS® was additive with Dipel 6AF® and significantly (P< 0.05) antagonistic with Dipel ES® and with a third formulation of subspecies kurstaki, Dipel 48A®. In H. zea, Xentari AS® was significantly antagonistic with all three formulations of subspecies kurstaki. This suggests that certain toxin combinations from B. thuringiensis subspecies might not be effective for managing H. virescens and H. zea populations.


1994 ◽  
Vol 29 (2) ◽  
pp. 192-200 ◽  
Author(s):  
M. R. Bell ◽  
D. D. Hardee

A 9.6-km diam area in the intensive cotton-growing region of the Mississippi Delta was treated with an entomopathogenic virus to determine the effect on populations of adult tobacco budworms, Heliothis virescens (F.), and bollworms, Helicoverpa zea (Boddie), emerging from early season weed hosts. Four aircraft were used to treat ≈ 7,106 ha during 24–28 April at a rate of 100 larval equivalents per ha. Emergence data from cages placed over treated and untreated areas indicated that virus treatments reduced tobacco budworm emergence by 80.6% and bollworm emergence by 46.2%. During the emergence period, tobacco budworm traps in the area surrounding the treated area averaged 11.4 moths per trap per night. Average trap capture per trap per night in the center (6.4 km diam) of the treated area was 6.4 moths, a reduction of 43.9% compared with the untreated area. Correspondingly, reduction in trap counts for bollworm in the center was 21% when compared with the untreated area.


Sign in / Sign up

Export Citation Format

Share Document