MOTIONS OF INSECTS. 471 



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 bodies are 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. 1 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 (Geotrupes stercorarius) wheeling 

 from side to side like the humble-bee flies with great rapidity and force, 

 and, with all its dung-devouring confederates, directs its flight with the 

 utmost certainty, and probably often against the wind, to its food. The 

 root devourers or tree-chafers (Melolontha, Hoplia,&c.') support themselves, 

 like swarming bees, in the air and over the trees, flying round in all direc- 

 tions. The Brachyptera and Donacus, in warm weather, fly off from their 

 station with the utmost ease ; their wings are unfolded, and they are in 

 the air in an instant, especially the latter, as I have often found when I 

 have attempted to take them. None are more remarkable for this than 

 the Cicindelfs, which, however, taking very short flights, are as easily 

 marked down as a partridge, and afford as much amusement to the ento- 

 mologist as the latter to the sportsman. It is to be observed that many 

 insects in this order have no wings, and the female glow-worms neither 

 wings nor elytra. 



Many persons are not aware that the insects of the next order, the 

 Dermaptera, can fly; but earwigs (Forficula), their size considered, are 

 furnished with very ample and curious wings, the principal nervures of 

 which are so many radii, diverging from a common point near the an- 

 terior margin. Between these are others, which, proceeding from the oppo- 

 site margin, terminate in the middle of the wing. These organs, when at 

 rest, are more than once folded both transversely and longitudinally. 



Wings equally ample, forming the quadrant of a circle, and with five or 

 six nervures diverging from their base, distinguish the Strepsipterous tribe. 

 When unemployed, these are folded longitudinally. 2 



Probably in the next order (Ort/toptera) the tegmina, or wing-covers 

 since they are usually of a much thinner substance than elytra assist 

 them in flying. They are, however, quite covered by irregular reticulations, 

 produced by various nervures sent forth by the longitudinal ones, and 

 running in all directions. When at rest, the inner part of one laps over 

 that of the other ; but in different genera there is a singular variation in 

 this circumstance. Thus in Blatta, Phasma, and male Acridtz, and generally 

 speaking, but not invariably, in Locusta and Truxalis, the left elytrum laps 

 over the right j but in Mantis, Mantispa, some female Acrida, Gryllus, and 



1 Entomol. i. 1. 



2 It has been ascertained that the spurious elytra of these insects are serviceable 

 in their flight. As M. Latreille now allows this, he ought to have restored its ori- 

 ginal name, which he had altered, to this order. 



H H 4 



