Interactions between dietary nitrogen and simulated autumn conditions on diet consumption and reproductive development in the boll weevil, Anthonomus grandis

Abstract

ABSTRACT. Dietary nitrogen content and short‐day, cool scotophase temperature were investigated for effects on diet consumption and reproductive development in the female boll weevil, Anthonomus grandis Boheman (Coleoptera: Curculionidae). Experimental weevils were maintained from the day of adult eclosion on cottonseed flour diets on a LD10:14 h, 27:15d̀C cycle. Control weevils were maintained under long‐day conditions (LD13:11) at a constant 27d̀C. Diets containing 4% and 1.7% N were labelled with a 14C‐amino acid mixture and fed to individual females for 24 h to permit determinations of diet consumption rate, amino acid absorption, and reproductive allocation of the assimilated amino acids. Females fed the 1.7% N diet under long‐day, 27d̀C laid 50% fewer eggs than females fed the 4% N diet under the same regimen. Egg production was depressed further by the 1.7% N diet when combined with short‐day, and cool scotophase temperatures. These latter conditions delayed, but did not prevent, attainment of a high rate of egg production by females fed the 4% N diet. The short‐day, cool temperature regimen also stimulated diet consumption but reduced the allocation of absorbed 14C amino acids towards oogenesis.