326 



JOURNAL OF ECONOMIC ENTOMOLOGY 



\yo\. 8 



twenty da3^s later and the pupal period ranges from three to twenty- 

 seven days. The total developmental period from egg to adult has been 

 found to vary from nine to thirty-nine days. None of these records 

 were made on infestations in living animals. Breeding proceeds con- 

 tinuously throughout the summer, and no doubt from ten to fourteen 

 broods are produced in one season in southern Texas. Considering the 

 reproductive capacity of this species it is not surprising to note the 

 millions of flies present about decaying animal matter in mid-summer. 

 By rather careful estimation we judge that a single carcass may pro- 

 duce upwards of a million flies of this species. 



We have observed a ver}^ marked tendenc}' of this fly to breed in 

 animals which have died recently rather than in old carcasses. This 

 habit probably is related to that of the species depositing in living 

 animals. Although some observers have found this species commonly 

 deposits living young in the more northern latitudes, we have failed 

 to observe this phenomenon in connection with our work. This species 

 occurs normally in all sorts of situations in the Southwest, but w^e have 

 observed a marked tendency for it to be found in great numbers far 

 from any habitation. In such situations often no other species of 

 meat-infesting flies is to be seen, while in cities the two species of 

 Lucilia often outnumber the one under discussion. 



Lucilia sericata. — Our experiments indicate that this species nor- 

 mally passes the winter in the larval and pupal stages. It is usually 

 seen flying about or breeding early in the spring before Chrysomyia 

 macellaria has appeared. Breeding takes place in decaying animal 

 matter, although the adult flies are often seen frequenting all sorts of 

 places in search of food. The first oviposition occurs, in summer time, 

 within five to nine days after the adults emerge from the puparia. 

 The incubation period varies greatly with the temperature. In sum- 

 mer, hatching takes place in less than twenty-four hours while in 

 autumn we have a record of seven days. Pupae are formed in three to 

 nine days after hatching, and adults emerge within three to thirteen 

 days after pupation. The developmental period, from egg to the emer- 

 gence of the adult, ranges from nine to twenty-one da^s. These 

 records were made during comparatively warm weather. 



Lucilia cossar. — This species, like the one just discussed, winters in 

 the larval and pupal stages, the adults appearing on the first warm days 

 of spring or even during warm periods in mid-winter. We have ob- 

 served a preoviposition period in this species of six to twenty days. 

 The eggs usually haj:ch in less than twenty-four hours, the larvae 

 begin migrating from the food two to five days later. Pupse are formed 

 three to twelve days after hatching. The pupal period ranges from 

 five to sixteen days and the total developmental period from eleven to 



