MEANS OF DEFENCE OF INSECTS. 447 



the rest of the body being black, renders it particularly conspicuous. To 

 obviate this inconvenience, it turns its head and tail inwards till they are 

 parallel with the trunk and abdomen, and gives its thorax a vertical direc- 

 tion, when it resembles a rough stone. The species of another genus of 

 beetles (Agathidium) will also bend both head and thorax under the elytra, 

 and so assume the appearance of shining globular pebbles. 



Related to the defensive attitude of the two last-mentioned insects, and 

 precisely the same with that of the Armadillo (Dasyjjus) amongst quad- 

 rupeds, is that of one of the species of woodlouse (^Armadillo vulgaris). 

 This insect, when alarmed, rolls itself up into a little ball. In this atti- 

 tude its legs and the underside of the body, which are soft, are entirely 

 covered and defended by the hard crust that forms the upper surface of 

 the animal. These balls are perfectly spherical, black, and shining, and 

 belted with narrow white bands, so as to resemble beautiful beads ; and 

 could they be preserved in this form and strung, would make very orna- 

 mental necklaces and bracelets. At least so thought Swammerdam's 

 maid, who, finding a number of these insects thus rolled up in her master's 

 garden, mistaking them for beads, employed herself in stringing them on 

 a thread ; when to her great surprise, the poor animals beginning to move 

 and struggle for their liberty, crying out and running away in the utmost 

 alarm, she threw down her prize. ^ The golden-wasp tribe also (^Chrysi- 

 didce), all of which I suspect to be parasitic insects, roll themselves up, 

 as I have often observed, into a little ball when alarmed, and can thus 

 secure themselves — the upper surface of the body being remarkably hard, 

 and impenetrable to their weapons — from the stings of those Hymenoptera 

 whose nests they enter with the view of depositing their eggs in their 

 offspring. Latreille noticed this attitude in Parnopes carnea, which, he 

 tells us, Bembex rostratra pui'sues, though it attacks no other similar insect, 

 with great fury ; and, seizing it with its feet, attempts to dispatch it with 

 its sting, from which it thus secures itself.^ M. Lepelletier de Salnt-Far- 

 geau, to whom entomology is indebted for so many new facts relative to 

 the manners of hymenopterous insects, has given us a striking account of 

 a contest between the art of one of these parasites (Hedychrum regium) 

 and the courage of one of the mason-bees, in endeavoring to defend its 

 nest from its attack. The mason-bee had partly finished one of her cells, 

 and flown away to collect a store of pollen and honey. During her 

 absence the female parasitic Hedychrum, after having examined this cell 

 by entering it head foremost, came out again, and walking backwards, 

 had begun to introduce the posterior part of her body into it, preparatory 

 to depositing an egg, when the mason-bee arriving laden with her pollen- 

 paste threw herself upon her enemy, which, availing herself of the means 

 of defence above adverted to, rolled herself up into a compact ball, with 

 nothing but the wings exposed, and equally invulnerable to the sting or 

 mandibles of her assailant. In one point, however, our little defender of 

 her domicile saw that her insidious foe was accessible; and, accordingly, 

 with her mandibles cut off her four wings, and let her fall to the ground, 

 and then entering her cell with a sort of inquietude, deposited her store 

 of food, and flew to the fields for a fresh supply ; but scarcely was she 



> Hill's Smamm. i. 174. « Ann. du Mus. 1810, 5. 



