46 INSECT ARTIZANS AND THEIR WORK 



wasps is known to be very acute ; but every beetle 

 selected is bound to be a weevil. It is probable 

 that, to the keen olfactory sense of the wasp, each 

 beetle family has a peculiar clan smell. Cerceris 

 labiata restricts her attentions to one particular 

 species of beetle, a relation of the so-called turnip- 

 flea. See how in these matters a knowledge of 

 entomology would help the farmer and gardener, 

 by enabling them to encourage insects that help 

 them to keep down the numbers of others that are 

 noxious. The species of Cerceris are regarded by 

 gardeners as young specimens of the ordinary wasp, 

 and as such destroyed whenever opportunity offers, 

 whilst weevils and turnip-fleas increase and inflict 

 real injury upon garden produce. The whole of 

 these fossorial Hymenoptera, as a matter of eco- 

 nomics, ought to be religiously protected by all 

 interested in husbandry ; for those that are bees 

 are useful in flower pollination, and the wasps 

 destroy large numbers of plant-eating insects. 

 Some species intimately studied by the Peckhams in 

 North America have yielded most interesting results. 

 " They might be considered the aristocrats 

 in the work of wasps, their habits of reposeful 

 meditation and their calm, unhurried ways being 

 far removed from the nervous manners of the 

 Pompilidae, or the noisy, tumultuous life of Bembex. 

 Their intelligence is shown by their reluctance to 

 betray their nests, and by their uneasiness at any 

 slight change in the objects that surround them. 

 It is not necessarv to attempt to catch them or to 



