422 



Marvels of Insect Life. 



mav serve as food for their young during the helpless grub stage. There is a family 

 of wasps, represented in this country by two small species, but which in warmer 

 countries includes some of the largest and most powerful of the wasps, whose limbs 

 are stout and well formed for digging, but they adopt methods different from those 

 of the miners. They burrow^ in the earth, but they construct no definite shaft. 

 They make proper provision for the welfare of their progeny, but thev make no cells. 

 They are hairy wasps of black colour save for several relieving spots or bands of red 

 or yellow, true to the wasp principle of advertising their dangerous character to 

 all whom it may concern. As usual, the females, who do all the work, are much 

 larger than the males. Several of the larger species are found as near to us as 

 France, where they have been studied bv Fabre and others. Unfortunatelv, they 

 have no English name by which to distinguish them from other wasps, but we will 

 call them beetle-eating wasps, ^ though it must be understood that the beetles 

 they destroy are always in the grub stage, and that it is the wasp's grub that does 

 the eating. 



Now it is remarkable that these beetle-eating wasps should restrict their 



attentions to the grubs of a par- 

 ticular family of beetles — at first 

 sight not so remarkable, when we 

 remember that other of the solitary 

 wasps show similar exclusive pre- 

 ferences for particular kinds of 

 prey ; but in those cases the 

 selection takes place in daylight, 

 above-ground. The marvellous 

 thing in connection with the beetle- 

 eating wasp is that her victims are 

 hidden from sight underground. 

 They are all grubs of leaf-horned 

 beetles, such as the rose-chafer, the 

 rhinoceros-beetle, etc., each species of beetle-eating wasp keeping to one 

 genus of beetles. These grubs are large and fat, not very active, and 

 lie on their sides, feeding upon decaying vegetable matter underground. 

 Now the task for the beetle-eating wasp, flying over the ground, is 

 to determine where one of these beetle-grubs is feeding below. As 

 they were hatched from the egg underground, there is no clue afforded by the 

 entrance to a burrow, and the task of the wasp seems to be as hopeless as that of 

 the self-styled water-diviner, who claims bv a special sense to be able to locate 

 hidden underground water-channels. Whether the beetle-eating wasp is the 

 possessor of a special sense for her purpose we cannot say, but it looks much like it. 



The curious habits of these wasps were made known as far back as 1840, when 

 an Italian entomologist named Passerini published an account of the yellow-faced 

 beetle-eating wasp.^ He found that the mother-wasp hunted for the fine large 

 grub of the rhinoceros-beetle,^ whi-^h is coir.mon on the Continent in spent-tan, and 

 when found placed an egg on its chest. When the egg hatched, the tiny wasp-grub 



> Scoli.i. - S. flavitrons. ^ Orvctes nasicornis. 



Photo by] 



Yellow-faced Beetle-Wasp. 



[£. Step, F.L.S. 



Thickly clothed with long hairs, this yellow-spotted black wasp suggests a 

 parallel with burly carpenters of the bee tribes. Its sagacity in discovering 

 its hidden prey is remarkable. Natural size. 



