450 Some Account of the Wheat Fly, 



appearance, being of deeper orange, and thicker in the body. 

 One of these flies was secured on the 27th of July ; it proved on 

 examination a male, which has not been described before, and 

 the hues of its wings were remarkably brilliant. 



The eggs of the fly are generally found in clusters, varying 

 in number from two to ten, upon the inner chaff', in which the 

 furrowed side of the grain is embedded, and are also occasion- 

 ally to be seen in the interior parts of the flower and chaffl 

 The eggs are deposited by means of a long slender tube (see 

 fig. 91. Vol. I.), and fixed with a glutinous substance possessed 

 by the fly. A thread of glutinous matter frequently connects 

 a cluster of eggs with the style, where the larvae seem to sub- 

 sist on the pollen ; in one instance, fifteen eggs were numbered 

 on such a thread, several of which were suspended on the por- 

 tion extending between the chaff" and the style. The fly not 

 only seems thus to provide a conveyance for the larvae to the 

 style, but also food for their support. The anthers are pre- 

 vented from leaving the style, in consequence of being gummed 

 down by the glutinous matter of the fly, and the pollen thereby 

 detained for the use of the larvae, which otherwise would, in 

 part, be carried out of the glumes by the expansion of the 

 filaments.* In the exertion of gumming down the anthers, 

 many of the flies are entangled in the vascules of the corolla, 

 and thus become a sacrifice to their maternal affection. 



The larvae are produced from the eggs in the course of 

 eight or ten days : they are at first perfectly transparent, and 

 assume a yellow colour in a few days afterwards. They travel 

 not fi'om one floret to another, and forty-seven have been 

 numbered in one. Occasionally there are found in the same 

 floret larvae and a grain, which is generally shrivelled, as if 

 deprived of nourishment; and although the pollen may fur- 

 nish the larvae with food in the first instance, they soon crowd 

 around the lower part of the germen, and there, in all pro- 

 bability, subsist on the matter destined to have formed the 

 grain. 



The larvae are preyed on by a host of enemies, ^the most 

 numerous and active of which is an ichneumon fly (figured in 

 the London Linnean Transactions). Upon presenting four 

 larvae to an ichneumon, it soon stung, or, according to Mr. 

 Kirby, deposited an egg in each of their bodies, and stung 

 one of them a second time. The maggot writhed in seeming 

 agony, and straggled on to my thumb nail, where it was again 

 stung three times by the same fly ; and, in a second struggle, 



* By the expansion of the filaments, the anthers of the wheat plant are 

 forced out of the glumes, and known to farmers by the term bloom. 



