THE INFLUENCE OF THE DEVELOPMENT RATES OF IMMATURE STAGES OF ERISTALIS-ARBUSTORUM (DIPTERA, SYRPHIDAE) ON ADULT ABDOMINAL COLOR PATTERN

The abdominal colour pattern of Eristalis arbustorum (L.) shows season al variation, with animals emerging in spring being darker than those emerging during summer. One of the most important environmental cues i nfluencing the abdominal colour pattern is developmental temperature. An experiment was carried out to establish which period during the imm ature stages was important in determining final adult colour pattern. The results indicate a good relationship between the length of the pup al period and both the extent of the paler markings on the abdomen and the grey score of these markings. The length of the larval period did not have any effect on adult colour pattern.