SuBFAMILY CHRYSOMYINAE 147 
eges making up such masses found during summer months had 
probably been deposited by macellaria. 
The total developmental period varies from 9 to 39 days, ac- 
cording to Bishopp, (1915, p. 326), depending upon the tem- 
perature and humidity. 
The numbers of adult macellaria usually increase from early 
spring until frost although a normal decrease in their abundance 
usually occurs during midsummer when the weather is hot and 
dry. Rainy periods are apparently productive of the greatest 
abundance, for a warm humid atmosphere is best suited to the 
rapid development of the species. The number of these flies is 
limited mainly by weather conditions and by available ear- 
easses. Bishopp (1917) judged by rather careful estimation that 
one carcass might produce upwards of a million flies of this 
species. 
This species occurs in southern Florida and southern Texas 
during the entire year. In South Carolina during the winter of 
1931 adults were collected throughout the winter in the neigh- 
borhood of the Charleston city dumps. Deonier (1940) observed 
ecopulating and ovipositing adults in Texas when atmospheric 
temperatures were 58° EF. and he reported the minimum tempera- 
ture for activity for adults to be from 50-60° F. Bishopp (1915, 
pp. 325-326) stated that from 10 to 14 broods are produced in 
southern Texas. The species seldom becomes abundant in north- 
ern United States. It is apparently killed by early frosts. In 
the extreme northern part of its range it appears about June 1-15 
in Ohio along the southern shore of Lake Erie. It is not abundant 
in the northern Middle West but most carrion there seems to 
have its peak population of macellaria during the month of Au- 
gust. The species practically disappears in Ohio by late Septem- 
ber, although a few individuals may be found as late as Novem- 
ber first. 7 
The average life of the adults is comparatively short, ranging 
from two to six weeks. In nature they feed upon a variety of 
foods, ranging from garbage refuse to the nectar of certain 
flowers'. Much of the life of this species is spent about carrion; 
vegetation surrounding a carcass may swarm with thousands of 
adult macellaria. The obvious predilection for decaying meat ex- 
hibited by this species has played a conspicuous part in attempts 
to control it. 
Bishopp and Laake (1921, p. 765) found that adults of ma- 
cellaria would migrate as far as 8 miles in 24 hours and 10 miles 
*Wild parsnip (Pastinaca sativa); also flowers which give off an odor 
resembling that of carrion, i.e. Aristolochia spp. 
