THE AMERICAN ENTOMOLOGIST. 



137 



ments, tlie latter correclly remarking tliat "none 

 bnt social insects feed their larva? periodically.* 

 Strictly speaking, the Digger Wasps do not feed 

 their larva' at all. They collect suitable food 

 into a suitable nest, lay au egg therein, close up 

 the nest, aud then leave it forever. As a general 

 rule, it is only the higher animals that feed and 

 tend their young after they are born. All inani- 

 inals, and almost all birds do this, while it is done 

 by but very few reptiles and by still fewer tislies. 

 Consequently, as the Social Insects (Honey-bees, 

 Hornets, Yellow-jackets, Ants and White Ants) 

 have this propensity, and, as any one may see 

 by disturbing au Ant's nest, are as much attached 

 to their larva? as a mother is to her child, we 

 may justly, so far as this character goes, consider 

 them as superior to other insects. But any mode 

 of classification, founded excliisiveti/ upon this 

 one single character, would be open to the same 

 objection as certain modern Systems of Classifi- 

 cation broached of late years in this country, and 

 founded exclusively upon a single character; 

 namely, that they are artificial and not natural 

 systems. 



It may not be amiss to remark here, that 

 (here is a small group of Digger Wasps {Mutilln 

 sub-family), the females of which have not even 

 (he slightest vestiges of wings, and strongly re- 

 semble ants, for which tliey are often mistaken 

 by young entomologists. They may be distin- 

 guished, however, at ouce from any of the Ants 

 by their antennas not being flail-shaped, or"geni- 

 culate " as it is technically termed. From the 

 great dissimilarity of the females to the males, 

 some excellent entomologists were foruierly in 

 certain cases deceived into referring the two 

 sexes, not only to distinct species but to distinct 

 genera ; and the very same thing has occurred 

 with another genus (Jfyzine) belonging to au ^ 

 allied group {Sco/ia family), where the sexes 

 are indeed both of them winged, bift difl'er 

 widely from each other in certain structural 

 peculiarities. Through the kindness of Dr. 

 Phimmer, of Rock Island, Ills., who served in 

 the medical corps of our army during the late 

 war, we received several years ago from the 

 8tate of Jlississippi a large scarlet and black 

 species of this sub-family, about three-quarters 

 of an inch long {MutiUa coccinea, Fabr.), thei/ 

 sting of -which is said to be peculiarly powerful 

 and virulent in its eft'ects. The females of those 

 species, Avhich iiave been seen by us when alive, 

 arc always found in sandy localities running 

 about like ants; and such is said to be the gen- 

 eral habit of the whole group. The -males 



* Woftitwooil, Introduction, t'^^ , II., |i. 207 ; St Fjirg'ean, 

 llilinenopt. II., \i. 5(i'.1, 



occur on flowers and shrubbery, and are ver\- 

 difficult to identify with their appropriate fe- 

 males, unless actually taken in copulation. 



Although so snugly secluded from the world 

 — each in his own private and peculiar cell, and 

 with an abundant supply of delicious insect- 

 meat close to his very mouth — the larvre of the 

 Digger AVaspsdo not escape the attacks of those 

 universal marauders, the Ichneutno?i-flies and 

 their allies. For example, besides the two 

 parasites already referred to above as infesting 

 the little mud-daubers {Ayenin), a beautiful 

 Ichneumon-fly (Gryptus jiinceiis, Cresson) — 

 represented in Figure 109 ( $ ) and remarkable 

 for having when alive the peculiar and to us verv 



[Fig. lOH.] 



agreeable smell 

 of a Humble-bee 

 (liomliKs) — oft- 

 en pierces with 

 its long tail-like 

 ovipositor our 

 common large 

 " mud - dabs, "' 

 aud deposits an 

 egg in the car- 

 cass of the un- 

 fortunate larva 

 of the Mud-dau- 

 (Jolms-Bliick and yellow ber. From this 



egg the larva very soon afterwards hatclies out 

 and finally, as usual, consumes the vitals of its 

 victim, and subsequently spins itself up in a co- 

 coon. We have ourselves bred the above Ichneu- 

 mon-fly from these ''mud-dabs,'' aud have repeat- 

 edly found its thin white silken cocoon, w ith the 

 larva inside it, in the clay-cell of the Mud-dauber. 

 Thus the spider preys upon flies, the mud-dau- 

 ber upon the spider, and the ichneumon-fly upon 

 the mud-dauber. " Kill and be killed ; eatand 

 be eaten." This is the great universal law of 

 Nature. Every insect is checked and controlled 

 by the attacks of others. None, as a general 

 rule, except when man by his artificial processes 

 interferes with the wise arrangements of 

 Nature, is ever allowed to become unduly nu- 

 merous. Every being in the world, not exclud- 

 ing even the human species, exists, not only for 

 its own pleasure and benefit, but for the plea- 

 sure and benefit of other and often very inferior 

 animals. Nothing in nature exists for itself 

 alone; nothing is wasted. Even the dried up 

 remains of the doomed spiders, upon which the 

 larva of the Mud-dauber has fed, are not allowed 

 to go to waste ; but are preyed upon quite ex- 

 tensively by the larva of a small beetle ( Tro 

 yoderma ornaticin, Say), belonging to a 

 Family (Dermestes) , several species of which 



