866 



INSECTA. 



furnished either with a telescopic, jointed tube, 

 as in the Chrysidida, golden wasps, or with a 

 spiculiferous ovipositor, which is partly retrac- 

 tile within the abdomen, as in the Cynipidee, 

 gall-flies. The former of these insects deposit 

 their eggs either in the cells of other Hymen- 

 optera or in the bodies of active Lepidopterous 

 larvae, before their change to the pupa state, and 

 thus resemble in habits the true Ichneumonida. 

 The Cynipida puncture the leaves or bark of 

 trees and plants, and deposit their eggs, at the 

 same time injecting into the wound a fluid 

 which occasions the growth of galls or excre- 

 scences, the interior of which is both food and 

 habitation for the young larva. In their habits, 

 as Mr. Westwood has well observed, the Cyni- 

 pid& very closely approach the Terebrantia, 

 and seem to form a link of communication be- 

 tween them and the true Ichneumonidts. 



Order VII. STREPSIPTERA. 



Wings four, the anterior ones (pseudelytra) 

 very minute, twisted, and projecting trans- 

 versely from the sides of the meso-thorax like 

 little scales ; posterior pair very large, fan- 

 shaped, with radiating nervures, and plicated 

 when folded. Body linear, abdomen com- 

 pressed, metathorax very large; meso- and pro- 

 thorax very short; head transverse, broader 

 than the pro-thorax; eyes slightly peduncu- 

 lated; antennae inserted into an exca- 

 vation in the front, and terminated by two 

 branches; mouth unfitted for taking food; 

 maxillae minute, projecting, stiliform ; labial 

 palpi very large.* Metamorphosis complete. 



These insects, Stylopidee, are parasitic and 

 exceedingly minute ; they undergo their trans- 

 formations in the bodies of perfect wasps and 

 bees, and pass out between the abdominal seg- 

 ment. Latreille has aptly designated them the 

 CEstri of insects. It is entirely unknown where 

 the eggs are deposited, whether in the body of 

 the wasp or bee, or in that of its larva. Four 

 distinct genera of these minute parasites have 

 already been discovered. Stylops Spencii (Jig. 

 347) is one of the largest species, but is scarcely 



Fig. 347. 



. 



Stylops Spencii, highly magnified. 

 Westwood, Ent. Trans. 



* Kirby in Lin. Trans, vol. xi. p. 86. 

 and Spence, Introduct. vol. iv. p. 378. 



Kirby 



more than two lines in length, while the small- 

 est species yet known, Elenchus Templetonii, 

 WEST.* is not more than two-thirds of a line, 

 or scarcely a line in breadth with its wings ex- 

 panded. 



The anomalous structure of these insects has 

 been a matter of great difficulty to entomolo- 

 gists. Rossi, who first discovered an insect of 

 this order, placed it with the Hymenoptera. 

 Mr. Kirby at first thought that it ought to follow 

 the Coleoptera, on account of its elytra and 

 kind of metamorphosis ; Mr. Mac Leayf placed 

 it between the Coleoptera and Hymenoptera, 

 to both of which, as Mr. Kirby had remarked, 

 it is connected by its metamorphosis. Dr. 

 Leach placed it between the Coleoptera and 

 Dermaptera, while Mr. Newman, who at first 

 thought it belonged to Hymenoptera,:}; afterwards 

 placed it with the Diptera, between which 

 two Orders it was also placed by M. Samo- 

 uelle.|| It has, however, been satisfactorily 

 shown by Mr. Westwood 11 that it is an imper- 

 fectly mandibulated insect, and that if the 

 structure of its oral apparatus, the shortness of 

 its first thoracic segments, and its kind of me- 

 tamorphosis be considered, it ought to be 

 placed between the Hymenoptera and Lepi- 

 doptera, at the end of the Mandibulata, which 

 situation it occupies in Mr. Stephens's arrange- 

 ment.** But the existence of elytra, and the 

 peculiar structure of its wings, ought not to be 

 disregarded, and should any species sufficiently 

 large for minute dissection be hereafter disco- 

 vered, it is not improbable that an examination 

 of its internal organs may lead to a different 

 opinion. 



SUB-CLASS II. HAUSTELLATA. 



Order VIII. LEPIDOPTERA. 



Wings four, covered with minute scales; 

 mouth proboscidal, formed of two elongated 

 organs, approximated laterally to form a tube ; 

 when at rest spirally convoluted. Labial palpi 

 large, hairy. Metamorphosis complete. 



The Order is divided into six sections. 



First the Diurna, day-fliers or butterflies, are 

 distinguished by their long clavated antennae, 

 which in a few are also slightly hooked at the 

 apex. The wings are large and erect when the 

 insect is at rest. The larva or caterpillar has 

 sixteen feet. Pupa quiescent and complete. 



In the second section, Crepuscularia, (Jig. 

 348,) the sphinges or hawk-moths, the antennae 

 are prismatic, and generally thickest in the mid- 

 dle, the body large, and tapering towards its ex- 

 tremity, which is often bearded, and the wings 

 are elongated and slightly deflexed when at rest. 

 The pupa is smooth, and inclosed in a coccoon, 



* Westwood, Transact. Ent. Society, vol. i. 

 p. 169. 



t Horae Entomolog. p. 371. 



| Mag. Natur. Histor. No. 23. 



6 Ent. Mag. vol. ii. p. 326. 



\\ Entomol. Compendium, 1819, p. 288. 



fl Trans. Ent. Society, vol. i. p. 169 et 172. 

 * This is also the place assigned to it by Mr. 

 Westwood. " Introduction," &c. vol. ii. p. 287. 

 June 1, 1839. 



