243 



Only four species are recorded from the United States, two of which, 

 alternata Say and punctatus Fabricius, occur commonly in Illinois. 



Rhyphus punctatus Fabricius 



Ehagio punctatus Fabricius, Mantissa Insectorum, Vol. 2, p. 333. (1787) 



Larva. — Length, 9-10 mm., diameter, .75 mm. Yellowish white, 

 with the greater portion of each segment marked with fuscous brown, 

 the dark portion containing a number of rounded or elongate pale 

 spots. 



Head larger and more tapered anteriorly than in Mycetobia, the 

 dorsal aspect as in Figure 4, Plate XXXVI ; eye-spots distinct ; anten- 

 nae smaller than in Mycetobia; mandibles as in Figure 5, their apices 

 blunt, without well-developed teeth, and obscured apically by long and 

 dense hairs ; maxillary palpi small ; maxillae hairy ; labium as in 

 Figure 12, centrally with a deep incision. Thoracic segments sub- 

 equal in length; prothoracic spiracles of moderate size, situated on 

 side, about one third from posterior margin of segment. All abdom- 

 inal segments with a distinct constriction about one fifth from the 

 anterior margin; apical segment with a large smooth plate on ventral 

 surface, the tip of segment with 5 short processes round margin of 

 spiracular disc (Fig. 2). 



Pupa. — Length, 6—8 mm. Of the same color as the larva. 



Head with the same armature and general structure as Mycetobia. 

 Thoracic respiratory organs much less elevated than in that genus, 

 their apices not reaching nearly as far as anterior margin of antennae 

 when seen in profile. Legs and wings as in Mycetobia, the principal 

 difference, apart from the thoracic respiratory organs, lying in the 

 armature of the abdominal segments, as indicated in kev to genera and 

 in Figures 8 and 9, Plate XXXVI. 



I have before me larvae and pupae that I obtained June 24, 19 16, 

 from horse-dung at White Heath, 111., and similar material submitted 

 by J. A. Hyslop, obtained at Hagerstown, Md., from cow-dung. 



The species is found in Europe and North America, and is usual- 

 ly very common throughout the warmer portion of the year. The 

 larvae feed in decaying vegetable matter, manure, and occasionally in 

 sewage or foul water. The imagines occur very often upon windows 

 of houses and outbuildings, but are quite frequently found at rest 

 upon tree-trunks. They feed upon exuding sap of trees and upon 

 nectar of flowers. 



