Dec. 1, 1885.] 



KNOWLEDGE ♦ 



53 



it is not surprising- that their numbers are very difFereut 

 in different seasons ; in some years, as was the ease in 

 1878 and 1880, they are .so numerous as to be a positive 

 plai;-ue, and in otliers comparatively few are seen. 



In country j'laces, wasps' nests are not unfrequenfly 

 found in thatched roofs or under the eaves of houses, as 

 well as attached to beams in lofts, barns, and out-houses. 

 Even the ground- wasps sometimes .select such situations, 

 and the hoi-net, too, occasionally establishes it.self in a 

 loft or barn. Sometimes amongst thatch are found 

 numbers of the rudimentary nests constructed by the 

 queens only, which have never advanced beyond their 

 primitive condition, having been, for some reason or 

 other, abandoned shortly after their construction. 



The insects themselves are quite omnivorous in their 

 tastes ; one might almost say, " Whatever man can eat, 

 that wasps can eat " ; the swarms that, in a hot summer, 

 crowd the windows of country grocers' and bakers' shops 

 are a pretty good proof of this. Sweets of all kinds, 

 including ripe fruits, are very attractive to them ; but 

 cakes and bread, or even meat, will also be readily de- 

 voured. Living insects, too, they catch in great numbers, 

 especiallj- flies, and it has been well remarked that, while 

 they will at one moment be robbing the butcker by 

 devouring his meat, they will at the next be making- 

 valuable restitaition by devouring the flies that would 

 lay their eggs upon it ; and it is probable that the 

 advantage that accrues to us through their destruction 

 of so many disagreeable insects is more than sufficient to 

 counterbalance any loss we may sustain through their 

 attacks upon our fruit and other stores. In catching 

 their insect prey they are very dexterous. Professor 

 Westwood says, " I have watched the common wasp 

 hovering over and darting hawk-like upon flies upon 

 excrement, careful not to soil its own legs and wings." 

 So, too, they will pick flies off the backs of pigs in their 

 stj-es. They are clever, too, in chasing and dodging 

 insects to catch them on the wing. When the prey is 

 ciught, the wings, head, and legs, being more or less 

 hard and dry morsels, are bitten off, and the rest of the 

 body devoured. Flies, butterflies, and even bees are 

 treated in this way. Unlike the Odyneri, they do not 

 use their stings in giving a quietus to their prey ; the 

 action of their powerful jaws is quite sufficient, without 

 the aid of the more deadly weapon. 



They are most industrious in the obtaining of suppilies, 

 and well they may be, considering the number of hungry 

 mouths they have so constantly to fill ; greedj- grubs, 

 ever on the look-out for something good, demand all the 

 energies of even the large staff of workers that are in 

 continual attendance upon them. Sir John Lubbock 

 records a case of one of his wasps, which paid no less 

 than ninety-four visits to a store of honey in one day. 

 And in the performance of these duties they are not only 

 industrious, but wonderfully persistent, and undaunted 

 by obstacles or dangers. The same diligent observer 

 records several instances in point. One wasp had smeared 

 its wings with the sj-rup on which it was being fed, 

 and so rendered itself incapable of flight ; Sir John, 

 therefore, put it in a bottle of water, and gave it a bath, 

 transferring it then to a dry bottle jilaced in the sun, as 

 the best means of getting it dry. When qiiite recovered, 

 it was allowed to go free, and after thirteen minutes it 

 returned to the .syrup-saucer that had been the scene of 

 its former disaster, and began to sip the liquid with as 

 much avidity as before, evidently quite undeterred 

 by its sad experience. Another was immersed in water 

 till quite insensible, in other words, virtually drowned ; 

 on being taken out, it recovered after a while, and at once 



set to work again at the business of its life, as though 

 there had been no interruption. 



Fig. 1.— Head of Wasp: a, antennse ; c, clypeus ; c, compound 

 eyes ; m, mandible.* ; o, ocelli : .«, coronet spot. 



The head of a wasp (Fig. 1) is a remarkable .structure, 

 and well worthy of a close find attentive examination, 

 if only to see what a variety of adornment is lavished 

 on even minute and otherwise obscure parts of the 

 insect, and to marvel at the number of organs that cr.n 

 be collected into so small a space. The entomologist who 

 wishes to distinguish the different species from one 

 another must pay great attention to the minutia^ of this 

 part of the insect, because some of the best distinguish- 

 ing marks are to be found here. In shape the head is 

 something like a triangular cake with the angles 

 rounded off ; it is set on the body vertically, with the 

 base of the triangle placed horizontall3^, and forming the 

 crown. In front it is slightly convex and behind eou- 

 Ciive, and it is attached to the thorax only by a small 

 junction in the centre of the hinder surface. 



The apex of the inverted triangle is formed by the 

 meeting of the two exceedingly stout and broad jaws, or 

 ntandibles, each furnished on its cutting edge with an 

 inner and an outer row of notches or teeth, separated 

 by a gi-oove. They move laterr.lly, and are in most cases 

 attached by a sort of hinge-joint just below the com- 

 pound eyes. The jaws themselves are yellow, but the 

 teeth black. Occupying the centre of the head, just 

 above the jaws, is an important and conspicuous organ 

 called the clypeus. It is slightly projecting, and is like a 

 broatl pliite with an outline which is curved above and 

 angular below. This, too, is bright yellow, but it carries 

 certain black marks upon it ^vhich varj' in the different 

 species, but iu-e in most cases sufficiently constant in the 

 same to be used as diagnostic characters. 



Just above the clypeus the two antennie are inserted, 

 not very far apart from each other, in the centre of the 

 head. Each consists of a long basal joint, the scape, and 

 a stout, many-jointed terminal part, the flagellum. 

 Between the antenn*, and stretching from the base of 

 one to that of the other, is a remarkable, bright yellow 

 spot of most elegant shape. It usually bears some resem- 

 blance to a sort of coronet, and situated as it is, just 

 above the equally brilliant yellow clypeus, it sucrgests, in 

 conjunction with the latter, the idea of a nobleman's 

 coat-of-arms surmoitnted by his coronet, as though the 

 wasp were carrying the evidence of its rank and identity 

 on its brow ; and it is not a little remarkable that in this 

 coat-of-arms, so to speak — viz., the combined clypeus and 

 coronet — we reallj-do find some of the best distinguishing 

 marks of the species. 



The sides of the head are occupied by the compound 

 eyes, which, being situated just on the bend, of course 

 command the most extensive horizon possible. They are 

 reniforra, or kidney-shaped, there being a deep indenta- 



