THE EFFECTS OF DIFFERENT COMPONENTS OF AN ARTIFICIAL FOOD ON ADULT GREEN LACEWING (CHRYSOPERLA-CARNEA) FECUNDITY AND LONGEVITY

Artificial foods comprising yeast products, sugar and water are often sprayed in the field to increase numbers of naturally occurring lacewi ng populations. The relative importance of the components of these foo ds for green lacewing (Chrysoperla carnea Stephens) fecundity and long evity is investigated in this paper. In laboratory experiments insects receiving only sugar solution lived significantly longer than those r eceiving diets containing both sugar and yeast (P<0.05). The inclusion of yeast is required for egg production, but few eggs are produced on yeast solution alone. For maximum egg production, food containing yea st and sugar must be offered on more than one occasion. Compared with insects given a diet comprising yeast autolysate, sugar, and water in the ratios 4:7:10, small but significant reductions in egg production rate were noted when the amount of either the yeast, or both the yeast and the sugar, was halved. The implication of these findings for the field is that viscous foods must be offered on a regular basis for max imum effectivity.