INTERACTION OF FOOD AND PHOTOPERIOD IN THE TERMINATION OF LARVAL DIAPAUSE IN CHAOBORUS AMERICANUS (DIPTERA: CULICIDAE)

¹ The University of Michigan, Ann Arbor, Michigan 48104

1. Food and long day photoperiod interact synergistically to effect the termination of larval diapause but the input of food and long day must be simultaneous rather than sequential for the synergistic effect to take place.

2. Daylength does not affect food consumption.

3. Neither food alone nor long day alone is capable of augmenting development initiated by long day with food; likewise, short day without food does not appear to retard development once it has been initiated.

4. Food is nutritionally capable of affecting larval and pupal survivorship for up to several weeks but its capacity to interact synergistically with long day to induce development persists for only a day.

5. The capacity of long day to interact synergistically with food to induce development persists for 1 to 2 days.

6. Food, therefore, is probably acting via some neuroendocrine reflex as an environmental cue independently of its nutritional contribution to the overwintering larva or to the resultant pupa and adult.