Consumption by Several Common Arthropod Predators of Eggs and Larvae of Two Heliothis Species1 That Attack Cotton23

Abstract

In laboratory experiments, several common arthropod predators consumed relatively large numbers of eggs and early-instar larvae of the bollworm, Heliothis zea (Boddie), and the tobacco budworm, H. virescens (F.). Predators confined with the hosts in small containers consumed more eggs and/or larvae than those confined with hosts on 10-inch cotton tci initials. However, all species were effective in reducing host populations on the terminals. Also, larval green lacewings (a mixture of Chrysopa Carnea Stephens and (C. rufilabris Burmeister) and adults of a lygaeid bug, Geocoris punctipes (Say), substantially reduced egg and larval populations of caged tobacco budworms. From the cage tests it was estimated that a release of about 420,000 Chrysopa larvae per acre had reduced the peak population of tobacco budworm eggs by 76% at 8 days after moth release. At 13 days, the larval population of the tobacco budworm had been reduced by 96%. A release of about 252,000 G. punctipes adults per acre was not so effective. However, a release of 630,000 G. punctipes adults and 420,000 Chrysopa larvae per acre reduced the egg and larval populations of the tobacco budworm by 88% and 99%, respectively.