CHAPTER V 

 JOINTED ANIMALS continued 



INSECTS concluded 

 Orders NEUROPTERA, ORTHOPTERA, RHYNCHOTA, etc. 



Characteristics THE Neuroptera form the last order of insects which undergo a 

 of the Neu- complete metamorphosis in the course of their development. In this 

 roptera order it was formerly usual to include certain groups of insects, such 

 as the dragon flies, May flies, white ants, etc. , none of which pass through a period 

 of prolonged inactivity, or pupal stage, before reaching the perfect condition. But 

 although it is largely a matter of convenience whether these groups be placed, as 

 they are in this work, in the order Orthoptera, or arranged in a series of separate 

 orders, no one, taking into consideration the great difference in their mode of devel- 

 opment, would now think of associating them in the same order with the true Neu- 

 roptera. The adult insects of the present order have their mouth organs, when 

 fully developed, adapted to biting and grinding, and never formed for piercing or 

 sucking; in which respect they differ from three of the other orders of the meta- 

 bolous insects, namely, the Hymenoptera, Diptera, and Lepidoptera. From the 

 Coleoptera they are easily distinguished by the structure of their fore-wings, which 

 are never hard and horny like the wing cases or elytra of the latter. Both pairs of 

 wings are membranous, and usually traversed by numerous, more or less closely 

 reticulating, veins; whence the name of Neuroptera given to the order. The hind- 

 wings are often very similar to the fore-wings, but sometimes differ considerably in 

 size and shape. In one section the caddice flies they are capable of being folded 

 like a fan, but in the other section (Planipennia) they always remain flat, and are 

 spread horizontally or obliquely in repose. 



CADDICE FLIES SUBORDER Trichoptera 



The caddice flies, forming the first of the two great divisions of the order, are in 

 general appearance rather like some of the smaller kinds of moths; and since they 

 differ a good deal from the typical Neuroptera, they are often treated as a distinct 

 order. In their adult state they have two pairs of wings, in which the neuration 

 is comparatively simple, with few transverse nervures. The wings are generally 

 clothed with hairs, and the hind-wings usually shorter, broader, and less hairy than 

 the front pair. When at rest, the hind-wings are folded fan-wise, with the fore- 

 wings covering them over like a roof. The caddice flies have a rather small head, 

 which bears two long, tapering, and many-jointed antennae. They have round and 

 (3124) 



