/EGERI1D/C OR SESIID/E. 



tinned existence, it crawls out and bores in a larger branch. 

 Larval life takes nearly two years. Pupation occurs about 

 May in the last larval burrow and adults emerge during 

 June and July. Each female places well on to a thousand 

 eggs in soft, young wood and in crevices of old bark. 



We also have native species of Cossidae, the commonest 

 probably being Prionoxystus robinice. Its larvae bore 

 chiefly in oaks but also in chestnut, poplar, willow, maples, 

 ash, and, as its name indicates, locust. Lugger says the 

 larva is bad smelling, reaches a length of 2.5 inches, and 

 after about three years of eating wood spins a loose cocoon 

 in its burrow. The adult female's wings expand about 

 2.5 inches; they are gray with irregular black lines and 

 spots. The male is hardly more than half as large; his 

 front wings are darker than the female's, and his hind 

 wings are yellowish. 



It is sad, but apparently true, that Sesiidae, the com- 

 monly used name of this family, must, according to the 

 rules of the game, give way to ^geriidse. Those of you 

 who are just starting are fortunate in not having to un- 

 learn that, at least, old name. The wings of the ^geriidas 

 are usually more or less transparent and the adults depart 

 from the usual habits of moths in that they fly by day 

 (see also Hemaris). Please do not take "protective mimi- 

 cry" too seriously but I quote Lugger in order to give the 

 idea. "Many of the species of moths belonging here are 

 very beautiful, and most of them are remarkable on account 

 of the protective mimicry exhibited by them. This close 

 resemblance to insects of different orders was observed 

 long before the significance of protective mimicry was 

 understood. The majority of the Sesiidas mimic bees, 

 wasps, and flies. We all know from experience that bees 

 and wasps can advance some very pointed arguments to be 

 left alone, and any other insect that closely mimics such 

 well armed warriors is very apt to be left unmolested. 

 This mimicry is not simply a superficial one, since even 

 their motions, if captured or disturbed, are like those of 

 the insects imitated. Their attitude when resting, the 



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