114 THE CANADIAN ENTOMOLOGIST. 



of a locust, and the present beetle takes the precaution of laying its egg 

 near where the locust has hidden its egg-batches in the ground. Among 

 the Cantharids, whose host is a genus of bee ( Anthophora)^ the beetle 

 oviposits near the bee's nest, but in order that the triungulin may reach 

 the egg of the bee, it has to be carried into the nest by a queen bee ; its 

 instinct impels it to seize the first hair within reach. This frequently 

 proves to be the leg of a drone, and in some cases the triungulin manages 

 to transfer itself to the leg of a queen bee during the nuptial flight, and so 

 reaches its goal, the egg cell in the hive. But hundreds of triungulins 

 must perish from seizing a wrong object, and in order to compensate for 

 this, selection has enormously increased the fertility of the female beetle,, 

 which lays as many as 2,000 eggs. In the Meloe or Oil beetle the instinct is 

 even more imperfect ; the beetle does not lay her eggs near the home of 

 the host, and the triungulin mounts to the top of grass-stems or enters a 

 blossom and waits there for a hair (any hair will do) ; this more often than 

 not proves to be growing on the leg of a fly, or if a bee, the wrong kind^ 

 and thousands of the triungulins, instinctively seizing the first hairy object 

 that offers, are carried into space to perish miserably. All that saves the 

 Meloe from utter extinction is the stupendous fecundity of the female, the 

 clutch of eggs laid by this Apteryx among insects producing a brood of no 

 fewer than 10,000 triungulin chicks. 



Apart from the great Phytophagous group of beetles, easily the best 

 known family of leaf-eaters is the Scarabaeids. One section of this family 

 consists of scavengers pure and simple, the larva being nourished in 

 manure or rotting wood and the female laying her eggs in such material. 

 But an important branch of the family is phytophagous, the larvae feeding 

 on living vegetable matter, usually the roots of grasses and herbaceous 

 plants, and the mature insects often feeding voraciously on leaves of trees 

 or soft vegetable tissue. 



In this family of beetles, structurally so different from the Phytophag- 

 ous Beetles, strictly so called, it is interesting to note how far one group 

 has diverged from another in response to conditions entailed by their 

 chosen food material. Among the Coprini you find the larval stage 

 completed in a few weeks, or at most months, while the life of the mature 

 beetle (as in Scarabceus) extends over a period of two or three years. 

 Among the Melolonthini almost the converse obtains ; the larva takes two, 

 three or even five years to mature, and the beetle after emerging from the 

 ground lives for only a week or two. 



