80 THE BOOK OF THE FLY 



be competitors often have to be content with laying 

 their eggs in less rich food materials. The blue-bottle 

 can withstand temperatures a few degrees colder than 

 can those flies to which she is nearest akin ; and she 

 seems capable somehow of sheltering herself better. 

 Even as late as the middle of winter, sometimes, a dead 

 bird may be found to be fly-blown under circumstances 

 which indicate that the eggs must have been laid in 

 frosty weather, when flies are not seen at large. The 

 explanation is that the blue-bottle will for a short time 

 awake, and venture outside her retreat in a sheltered 

 south wall, warmed by a few hours of winter sun. She, 

 does not hibernate in early winter in such a continuous 

 state of rigid torpor as, for instance, does the queen 

 wasp ; probably few or none survive the winter by a 

 real hibernation, the progenitors of the first spring 

 broods emerging at a date no earlier than do their 

 rivals and congeners. 



As a bird food or a fishing bait gentles are superior 

 to the maggots of any other dipterid insect. So-called 

 ants' eggs and meal-worms are more highly appreciated 

 by the fancier for bird food, but they are expensive. 

 The pupae called "ants' eggs" can only be had fresh 

 for a short period of summer, and dried stock for the 

 rest of the year requires much labour to obtain and 

 prepare. Meal-worms are the cleanest and the easiest 

 to propagate of all similar larva; ; but they are very slow 

 growing compared with gentles ; in the natural state 

 the life-cycle from the egg to the feeding worm, then 

 the pupa or chrysalid, and finally the bettle, Tenebiio 

 molitor, occupies a twelvemonth's time ; but, like many 

 other insects which have accommodated themselves to 



