138 MISC. PUBLICATION 631, TJ. S. DEPT. OF AGRICULTURE 



MUSCINA PABULORUM (Fallen) 



Geographical Distribution. — Palaearctic Region: Scotland, England, Spain, 

 France, Netherlands, Corsica, Norway, Sweden, Finland, Denmark, Germany, 

 Poland. Czechoslovakia, Austria, Yugoslavia, Rumania, Russia, Canary Islands, 

 Madeira, Egypt, Palestine, East China, Japan. 



Pathogenesis. — This species is normally saprophagous or carnivo- 

 rous ; there is one record of it as a sheep maggot in Scotland. 



The Genus MUSCA Linnaeus 



The genus Musca is used here in the sense emloyed by Patton and 

 by Van Emden; so for the present purposes such generic names as 

 Byomya, Philaematomyia, Eumusca, and Viviparomusca must be 

 considered as synonyms. The genus is practically of world-wide dis- 

 tribution, although the species that dominates as a household pest 

 will vary from one region to another. 



Members of this genus are black to blackish flies, more or less 

 covered with grayish pollen, and with the abdomen often extensively 

 yellow or orange, sometimes wholly so. The pollen of the mesono- 

 tum may leave two or four black vittae, although in some species the 

 mesonotum is wholly black. The arista is characteristically formed ; the 



Figure 80. — Posterior spiracles of mature larva : A, Musca domestica; B, M. 

 sorbens; C. M. crassirostris. (After Patton {105).) 



terminal segment is strongly thickened basally and its plumosity is 

 very long, the longest rays being usually half the length of the 

 arista or longer. The peteropleura are hairy. Vein m 1+2 is strongly 

 bent forward, is angular at its bend, and reaches the costa before the 

 wing apex; vein r t is bare; the anal vein does not reach the wing 

 margin. 



Life Histories. — Within the genus the life histories vary consider- 

 ably. Most species are oviparous, but in some the females deposit 

 maggots which are in the second or even the third stage. Breeding 

 grounds are varied and commonly include excrement of different 

 types. Development is rapid, and there are several annual genera- 

 tions in temperate climates; in the Tropics breeding may be con- 

 tinuous. The adults of some species, notably M. domestica, M. vicina, 

 and M. sorbens, are common household pests, but some species live 

 habitually away from human habitations. Adults of other species 

 are haematophagous, either making their own lesions by means of 

 rasping labella or lapping blood from around wounds or punctures 

 made by the true bloodsucking Dipt era. 



Larva. — The larva is a glossy whitish maggot of the common mus- 

 coid type. The posterior end is rounded and without noticeable 

 tubercles; the posterior spiracles in the third-stage larvae are D- 

 shaped, the straight side being inward and provided with three 

 strongly sinuous slits (fig. 80) . 



Literature.— The works of Patton (104, 105, 108, 109) will be found 

 useful for the biology, immature stages, and taxonomy of the adults, 



