106 Observations on the vaiHous Insects 



has a stout spine. It remains from a week to a fortnicrht in this 

 state, and the flies are often exceedingly abundant in the autumn. 



Two lar^e flies belonging- to the Family Muscid^ 1 also bred 

 from a single potato, as previously stated. There were 48 speci- 

 mens of one which was named by Fallen 



34. Musca stabulans.* The male is 3| lines long, and the 

 wings expand ^ an inch : it is of an ash-colour, and clothed with 

 black bristles; the feelers are ferruginous ; the antennae drooping, 

 5-jointed and rust-coloured, pitchy at the base, 3rd joint elliptical 

 and hoary, except at the base, the seta black and feathery, the 

 basal joint minute: eyes large, approximating, naked, and chest- 

 nut colour, the margins silvery white, as well as the face, with a 

 black stripe tapering from the antennae to the 3 ocelli on the 

 crown: thorax hoary, with 4 black longitudinal stripes before, the 

 2 central ones the longest, with a spot on each side beyond the 

 centre ; scutel hoary, with a dark stripe at the base, ferruginous at 

 the tip : abdomen ashy-ochreous, shining, the back variegated 

 with brown patches : wings with the apical cell not angulated, 

 but suddenly rounded, scales at the base with pale tawny mar- 

 gins, and concealing the ochreous clubbed balancers: legs black, 

 apex of thighs and tibiae ferruginous; pulvilli at the extremity of 

 the feet elongated. Female similar, but the eyes do not approxi- 

 mate, the face has a yellow tinge, and the stripe on the crown is 

 broad and elliptical : the abdomen is broader, with an oviduct at 

 the tail, and the pulvilli are small (fig. 54 ; w, the natural size). 



The maggots had bred and accumulated amongst the slimy 

 matter of the rotting potato just as meat-maggots are found, toge- 

 ther with the horny pupae. Indeed, the largest maggots were 

 exceedingly like those of the flesh-flies, being fat and whitish, the 

 ochreous food and white lines of viscera shining through the 

 transparent skin : the head was pointed with a black proboscis 

 formed of 2 horny claws, and the two spiracles at the blunt tail 

 were like 2 black horny knobs (fig. 55). The tough and oval 

 pupae were of a bright chestnut colour, the segments slightly 

 marked, the head end rounded and wrinkled to a point, the tail 

 furnished with 2 black spiracular tubes (fig. 56). 



Of the other fly I bred 58 specimens from the same potato 

 the middle of August. The larvae escaped my notice at first 

 from being so very like the earth in colour, and they are still 

 more difhcult to detect from their sluggishness. They must be 

 in the greatest force in July, but I have met with them in rotten 

 potatoes the end of November. The group of flies with these 

 singular spiny larvae have been formed by Bouche into a Genus 



* Meigen's »Syst. Besch. Europ, zweif. Inseck., vol. v. p, 75, and Curtis's 

 Guide, Genus 1286, No. 23. 



