INSECTA. 



865 



and tarsi with only three joints. The larva 

 and pupa are active, voracious, and aquatic, and 

 like those of the Ephemera, resemble the per- 

 fect insect. Metamorphosis incomplete. 



The fourth section, Termitina, have large 

 and nearly equal sized wings, either disposed 

 horizontally or erect, with the antennae rather 

 long and filiform, as in Hemerobid<e, lace- 

 winged flies, or club-shaped, as in the ant-lions, 

 jMyrmelionidtf. The larvae are active and pre- 

 daceous. The ant-lion lives at the bottom of a 

 minute pit-fall, which it digs to entrap other 

 insects. The Hemerobius lives among crowds 

 of Aphides, plant-lice, upon which it feeds, 

 while the larvae of the Termites, or white ants, 

 live in societies of almost innumerable indivi- 

 duals. The first two of these families undergo 

 a complete metamorphosis, and the insects in 

 the condition of nymphs are inactive in the 

 earlier stages of the pupa state. In the latter 

 family the larva and pupa greatly resemble the 

 perfect insect, and are active at every period of 

 existence. 



The fifth section, Megaloptera, have the pos- 

 terior wings rather larger than the anterior, the 

 head and pro-thorax large and quadrate, and 

 the antennae long and setaceous. Metamor- 

 phosis incomplete. According to Mr. West- 

 wood * the larva and pupa are active, and not 

 inclosed in a case, are aquatic, and greatly re- 

 semble the perfect insect. 



Order V. TRICHOPTERA. 



Wings four, deflexed, hairy, not reticulated ; 

 texture slightly coriaceous ; posterior pair pli- 

 cated, broader than the anterior; antennae very 

 long, setaceous ; ocelli three ; maxillary palpi 

 long ; " mouth unfitted for mastication ; man- 

 dibles rudimental." Metamorphosis complete. 



The perfect insects of this Order, called by 

 fishermen " stone-flies," f are found on water- 

 plants, stems of trees, and palings by the side 

 of rivers. The larvae, the caddis, or case-worms, 

 are aquatic, and reside in little cases which 

 they carry about with them, and construct by 

 uniting bits of wood, minute shells, and frag- 

 ments of stones, which are woven together with 

 threads of fine silk. The pupa is semi-com- 

 plete, and quiescent during the greater part of 

 its period, but becomes active, and creeps out 

 of the water upon the stems of plants before 

 changing to the perfect insect. 



Order VI. HYMENOPTERA. 



Wings four, membranous with large areolar 

 cells ; posterior pair smaller than the anterior ; 

 antennae longer than the head ; eyes large ; 

 ocelli three. Mandibles strong, and generally 

 dentated ; maxillae largely developed ; labium 

 and ligula together forming a long proboscis 

 sheathed by the maxillae. Female armed either 

 with a borer or sting. Metamorphosis com- 

 plete. 



This Order is divided into four sections. 



In the first, Terebrantia, borers, the abdo- 

 men is sessile or united to the thorax by its 



* Introdnct. to Entom. vol. ii. p. 23. 

 t Yarrell's British Fishes, vol. ii. p. 84. 



VOL. II. 



whole breadth. In one family, the saw-flies, 

 (fig. 355, B), the abdomen is armed with two 

 serrated partially concealed plates, with which 

 the insect cuts through the bark or pierces the 

 leaves of plants to deposit her eggs. In ano- 

 ther family, Urocerida, the true borers, the ab- 

 domen is armed with a strong projecting cylin- 

 drical spiculum, which is grooved on its under 

 surface, and contains two smaller dentated spi- 

 cula, analogous to the plates of the saw-fly, 

 with which the insect bores into timber- 

 trees and deposits its eggs. The larvae are 

 active and extremely voracious. Those of the 

 saw-flies, pseudo-caterpillars (jig. 355, A,) de- 

 vour the leaves of plants, and are sometimes 

 exceedingly injurious to the agriculturist, as 

 has been the case with those of Athalia centi- 

 folia to the turnip crops during the last few 

 summers,* while the larvae of Urocerida are said 

 to be equally destructive to living trees.f 



In the second section, Pupophaga, the ich- 

 neumon flies, the body is long and slender, and 

 the abdomen is petiolated, or connected only 

 by a constricted neck with the thorax, and the 

 antennae are long and setaceous. The larvae are 

 apodal, and are parasitic on other insects. 



In the third section, Aculeata, the body is 

 short and pedunculated, and furnished with a 

 true aculeus, which is used as a weapon of de- 

 fence. The larvae are apodal, are fed by the 

 parent or by sterile females, and generally re- 

 side in cells. Some species are solitary, and 

 feed their young with the bodies of other in- 

 sects, CrabronidcE ; others live in society, and 

 are either omnivorous, as the Formicida, ants, 

 and Vespida, hornets (fig. 346) and wasps, or 



Fig. 346. 



Vetpacrabro. The Hornet. (SamoueUe.) 



mellivorous, as the humble and hive bees, 

 (Apida), which feed their young upon a mix- 

 ture of pollen and honey. 



In the fourth section, Tubulifera, the body 

 is short, slightly convex, and often compressed 

 laterally; the posterior wings are almost en- 

 tirely destitute of nervures, and the abdomen is 



* Prize Essay of the Entomological Society on 

 the Anatomy, Habits, and Economy of Athalia 

 centifolia, 1838, by G. Newport. 



t West wood, Introd. &c. vol. ii. p. 119. Mr. 

 Ruddon in Trans. Entomological Society, vol. i. 

 p. Ixxxv. 



3 L 



