280 



MOTIONS OF INSECTS. 



middle,, with a lateral longitudinal fold, but occasionally near 

 the extremity. When they prepare for flight, their antennse 

 being set out, the elytra are opened so as to form an angle 

 with the body and admit the free play of the wings ; and they 

 then fly off, striking the air by the vertical motion of these 

 organs, the elytra all the while remaining immoveable. The 

 Cetonice, however, as noticed by M. Audouin, differ from most 

 if not all other coleopterous insects in keeping their elytra 

 closed during their flight. 1 During their flight the bodies of 

 insects of this order, as far as I have observed them, are always 

 in a position nearly vertical, which gives to the larger sorts, 

 the stag-beetle for instance, a very singular appearance. 

 Olivier, probably having some of the larger and heavier beetles 

 in his eye, affirms that the wings of insects of this order are 

 not usually proportioned to the weight of their bodies, and 

 that the muscular apparatus that moves them is deficient in 

 force. In consequence of which, he observes, they take flight 

 with difficulty, and fly very badly. The strokes of their wings 

 being frequent, and their flight short, uncertain, heavy, and 

 laborious, they can use their wings only in very calm weather, 

 the least wind beating them down. Yet he allows that others, 

 whose body is lighter, rise into the air and fly with a little 

 more ease, especially when the weather is warm and dry ; their 

 flights, however, being short, though frequent. He asserts 

 also, that no coleopterous insect can fly against the wind. 2 

 These observations may hold, perhaps, with respect to many 

 species ; but they will by no means apply generally. The 

 cockchafer (Melolontha vulgaris), if thrown into the air in the 

 evening, its time of flight, will take wing before it falls to the 

 ground. The common dung-chafer ( Geotrwpes stercorarius) — 

 wheeling from side to side like the humble-bee — flies with 

 great rapidity and force, and, with all its dung- devouring con- 

 federates, directs its flight with the utmost certainty, and 

 probably often against the wind, to its food. The root de- 

 vourers or tree-chafers {Melolontha, Hoplia, &c.) support them- 

 selves, like swarming bees, in the air and over the trees, flying 

 round in all directions. The Brachyptera and Donacice, in 

 warm weather, fly off from their station with the utmost ease ; 



1 Ann. Soc. Ent. de France, viii. p. xlviii. 2 Entomol. i. 1. 



