Calf milk replacers as substitutes for milk in the larval diet of the screwworm (Diptera: Calliphoridae).

The effect of calf milk replacers as substitutes for nonfat dry milk in the larval diet of the screwworm, Cochliomyia hominivorax (Coquerel), was determined in the laboratory. Pupal weight and fecundity of females were significantly greater than the control with some of the formulations tested. Larval crawl-off patterns for all diets were similar. Pupal weights were significantly affected only on day 1 of the 4-d crawl-off period. Among the formulations of calf milk replacer, Gold Label brand products showed the most promise as substitutes for the nonfat dry milk presently used in the screwworm production facility. Use of calf milk replacers would lead to a yearly savings of 39.3% in the cost of the dietary milk component. At a production level of 250 million flies weekly, this substitution would save approximately $338,000 dollars yearly.