408 



DIPTEEA. 



them' by an insoluble cement on the upper surface of the two 

 or three first rings of the body. The eggs hatch often after 

 the caterpillar has gone under ground to transform, and in 

 fifteen to nineteen days, or the last of September, the flies ap- 

 pear. T. (Lydella) doryphorce Biley (Fig. 328) preys on the 



larvae of the Colorado potato 

 beetle. Other species of gen- 

 era allied to Tachina, accord- 

 ing to Dufour, are parasitic on 

 beetles, etc ; thus, Cassidomyia 

 preys on Cassida, Hyalomyia 

 on Brachyderes, and Ocyptera 

 attacks Pentatoma ; and he 

 thinks that Cliartophila floralis 

 feeds either on the food or the 



Fig. 328. 



young itself of Andrena. 



Sarcophaga, the Flesh-fly, has a small head, with the aiitennal 

 bristle plumose or hairy, naked at the tip ; the first posterior 

 cell only slightly opened, or closed, with large tegulse and 

 stout legs. The flesh-fly, Sarcophaga carnaria Linn., is black, 

 the thorax streaked with gray, and the abdomen checkered 

 with whitish. The female is viviparous, that is, the 

 larvae hatch and live within the oviduct. The ova- 

 ries are large, arranged in a spiral manner and con- 

 tain sometimes 20,000 eggs. We have reared Sarco- 

 phaga nudipennis Loew from the cells of Pelopaeus 

 flavipes, the Mud-dauber, which had been stored with 

 spiders, the flies making their appearance on the first 

 of July, a few days before the wasps issued from the 

 cells. The parent flies had probably laid their eggs 

 in the spiders before the cells were closed by the 

 wasps. The nests .were brought from Texas. 

 Fig. 329. Musca has plumose antennae, while in Stomoxys 

 they are pectinated. Dufour states that the allied genera, 

 Echinomyia, Gonia, Dexia and JSiphonia are also viviparous. 

 Musca (Lucilia) Caesar Linn, the Blue-bottle fly, and Musca 

 (Calliphora) vomitoria Linn, the Meat-fly, deposit their eggs 

 (fly-blows) upon meat and decaying animal substances, and 

 during the late war were grievously tormenting to our soldiers, 



