584 THE PEAK FLY. 



which caused the fruit to fall off even at that early period. I at 

 once placed them in a glass and covered them over, and on open- 

 ing it in February last I found two flies had been produced, u 

 male and female, which I will endeavour briefly to describe. 



" The female is about three-eighths of an inch long, appearing 

 to the naked eye of a pale grey colour, and in general formation 

 like a common house-fly ; but under a lens its distinctive characters 

 are at once perceptible. Head semi-orbicular, dingy white, with 

 a black velvety mark in front reaching down to the antennae, and 

 terminating at the back in form of a crescent ; antennae dark, set 

 with short spines and slightly curved inwards ; eyes rich brown, 

 oval, widely separated; thorax ovate, angular at the base; with 

 five remarkable black spots, one on each shoulder and three 

 below, divided by a scarcely perceptible suture ; several small 

 black dots between the larger spots, out of which stiff setae issue, 

 the whole bearing a close resemblance to ermine ; scutellum 

 semi-ovate, centre white, with an angular black spot on each side, 

 ending in a point Avith a stiff seta ; abdomen four-jointed, dingy 

 white, with three black spots on each joint, the centre one 

 angular; wings dusky, long oval, with five principal nervures and 

 several transverse, as I have endeavoured to show in the accompany- 

 ing sketch ; legs black. Under a lens this is a very pretty fly, 

 belonging to the family muscidse, of which Mr. Curtis enumerates 

 forty-nine species in British entomology ; but in the absence of 

 figures and description I cannot identify it with any of them. It 

 appears, however, to correspond with ' Dexia nigripes,' figured 

 by Walker, 'Diptera,' pi. 12, fig. 11, although he describes the 

 thorax as quadri-maculata, yet shows five spots upon it exactly 

 according with my specimen. The male is smaller, of a more 

 common dingy colour and not handsomely spotted. The maggots 

 are very similar to those of the blow-fly, but smaller. At what 

 time the eggs were deposited, or in what part, cannot be precisely 

 stated, but most likely when the pear was in blossom, or very 

 soon afterwards, as I have frequently discovered the larvae of 

 Lepidoptera in the blossoms of other trees, and bred them until 

 they arrived at the perfect state. I think it would be almost 

 impossible to destroy these mischievous larvse or the flies at this 

 time ; but if every gardener who is made aware of their destructive 

 effects were carefully to collect the fruits which they have caused 

 to fall abortive to the ground, and burn them, the species above 

 described might easily be kept under ; and by adopting the same 

 plan throughout the season, many other equally injurious insects 



