372 



HABITS OF LARVAE 



The larvae are predaceous, and are usually found in decaying 

 wood, where their food consists principally of the larvae of wood- 

 boring Coleoptera. 



HABITS OF IMAGINES 



The imagines of Mydas clavatm are found upon flowers of milk- 

 weed principally, and although stated to be predaceous I have never 

 found them with any prey. They fly most readily on bright, sunny 

 days, and select the most exposed situations. 



Mydas ceavatus Drury 



Musca clavatus Drury, Illustrations of Natural History, Vol. 1, p. 103. (1770) 



Larva (PI. LIII, Fig. 4). — Length, 45-50 mm. White, head and 

 spiracles black. 



Head as in Figure 5 ; maxilla as in Figure 2. Apical segment 

 slightly carinated on upper posterior margin. 



Pupa (PI. LIII, Fig. 3). — Length, 34-38 mm. Reddish brown, 

 subopaque. 



A strong upwardly directed pair of slightly divergent thorns on 

 upper surface of head; antennal sheath with 2 strong downwardly 

 and slightly outwardly directed thorns; a pair of short thorns, on a 

 common base, at base of middle leg on margin of thorax and another 

 pair above base of wings ; apices of middle legs not extending to apices 

 of wings. Armature of abdomen consisting of strong, flattened 

 thorns, those of first segment directed forward, the others backward 

 and slightly upward ; apical segment ending in a pair of conical 

 processes. 



The above descriptions and the illustrations accompanying were 

 made from three larvae and two pupae in our Laboratory collection. 

 The larvae were obtained in Illinois, two being without data, the other 

 having been taken at Pulaski, June 9, 1907. The pupal exuvia bear 

 the following data: White Heath, 111., May 26, 1910, larva found 

 in rotten stump; and Quiver Lake, Havana, June 19, 1894. 



The drawing of the larval head is incomplete anteriorly, the speci- 

 men being in bad shape, and showing neither maxillary palpi nor an- 

 tennae. The general appearance of the larva is, however, sufficient 

 to enable one to recognize it. 



Walsh has described a species under the name fulvipes. The larval 

 and pupal descriptions are very general and agree with the above as 



