THE STABLE FLY. 35 



blossom. They average 15 to 30 in number. Miss Ormerod ] mentions 

 that the females " may be seen laying their eggs, and are noted as 

 being busiest at work about 8 o'clock in the evening. In the morning 

 they may be found resting on the lower part of the culm of the wheat, 

 with their heads downwards, flying about, however, in great numbers 

 near the ground when the stems are shaken," which habits I can 

 corroborate. 



The larvae hatch in nine or ten days (a few took twelve days). 

 They are almost transparent at first, gradually turning yellow, and 

 then changing to an orange-red. When full-fed some of the larvae 

 leave the ears of the corn and fall to the ground ; here they bury them- 

 selves in the soil, and remain as larvae for a fortnight or even more, 

 ultimately changing to pupae. Some of the larvae remain in the corn. 

 The pupae are enclosed in filmy cases, and are reddish in colour. 



In addition to attacking wheat, this species attacks rye, oats, barley, 

 couch and other grasses. It has been thought by some writers that the 

 female first lays her egg on couch, meadow foxtail, wild oat, and other 

 grasses, and that the wheat is infested from broods from this source. 

 There are probably two or three broods in a year, but I do not think 

 that the first is confined to couch and wild grasses. 



PREVENTIVE AND REMEDIAL MEASURES. 



All wild grasses near to cornfields, such as those mentioned above, 

 should be destroyed. 



The destruction of all chaff and dust from the threshing machine 

 is an important matter, for when thrown on one side it forms an admir- 

 able breeding ground for the Midge, clouds of which come out in the 

 following May or June ready to infest the wheat. 



As with other species of flies belonging to this family, the proper 

 treatment on the field is fo bury the surface soil. This has proved 

 effective in Canada and elsewhere. 



THE STABLE FLY. 



Stomoxys calcitrans, Linn. 



Numerous specimens of this insect have been sent in for identifica- 

 tion by various correspondents. Newstead 2 has recently given a very 

 full account of its life-history, from which this is taken. He states 

 farmyards and stables are evidently the favourite haunts of this fly ; it 

 occurs also in the fields, parks, and open woods, especially where cattle 

 are grazing, but is much less numerous in such places. It is evidently 



1 Manual Inj. Insects, 1890, p. 89. 



2 Journ. Econ. Biology, 1907, vol. i, pp. 



