|9a$ular JDutt'onarg ot &mmatcfr 



isi 



are found in Western Africa, India, and the 

 Indian islands, some of the species being of 

 considerable size. One species, the Diopsis 

 Xykrsii, was observed by the distinguished 

 Indian statistician and naturalist after whom 

 it is named by Mr. G. K. Gray, in countless 

 multitudes in one of the Indian vallies. 

 Hence it is not improbable that the habits 

 of the numerous species composing the genus 

 are similar. It is one of those well-marked 

 and remarkable groups of insects, all the 



species of whi 



le grou 

 ch hav 



e been described and 



figured by Mr. Westwood. They are, how- 

 ever, rare in collections; the British Museum 

 possessing many curious species. 



DIPLOPTEBA, or DIPLOPTERYGA. 



roup of Ily 

 third divisi 



menopterous insects, forming 

 on of the subsection Prve- 



uite naked, or very slightly 

 the legs are of moderate 



r qute 

 ith hairs : 



dones. These wasps obtain their name from 

 the wings being folded throughout their 

 entire length when at rest. The antennae 

 are generally elbowed, and either filiform or 

 thickened at the tips; the palpi are short 

 and filiform ; the maxillae are long, cori- 

 aceous, and compressed ; the thorax is oval 

 and entire ; and the collar extends laterally 

 to the base of the wings. The body is gene- 

 rally black, more or less spotted with buff, 

 and either 

 clothed 



length, not furnished with organs fitted for 

 the collection of pollen ; and the abdomen 

 is ovate. The sting of the females and 

 neuters is very powerful, and has occasion- 

 ally caused the death of those persons who 

 have been attacked by these insects. This 

 division forms two families, Eumenidce and 

 Vespidee. [See WASP.] 



DIPSAS. A genus of serpents, placed by 

 Cuvier under the head Coluber. 



DIPTERA. An order of two-winged in- 

 sects ; of which the common house-fly and 

 blue-bottle fly afford familiar examples. 

 There are, however, some dipterous insects 

 which are destitute of wings : hence it is 

 necessary to notice other peculiarities be- 

 longing to this order. Some possess a pro- 

 boscis and sucker : others have a proboscis 

 and no sucker. They have six legs, furnished 

 with five-jointed tarsi, two palpi, two an- 

 tennae, and three ocelli. The mouth in the 

 insects of this order is formed for suction ; 

 but there are considerable varieties in the 

 mode in which this is accomplished. Behind 

 the wings are placed a pair of movable 

 slender bodies, termed halteres, or balancers, 

 which are kept in continual motion, and are 

 usually present even when the true wings 

 are not developed. The wings are generally 

 horizontal in their position, and transparent ; 

 the eyes are generally large, often occupying 

 nearly the whole head. The Diptera all 

 undergo a complete metamorphosis, as far 

 as respects the comparative structure of the 

 larva and the perfect insect ; the former 

 being generally cylindrical footless grubs. 



The two-winged insects, though mostly of 



multitudes. Flies are destined to live wholly 

 on liquid food, and are therefore provided 

 with a proboscis, enclosing hard and sharp- 

 pointed darts, instead of jaws, and fitted for 

 piercing and sucking ; or ending with soft 

 and fleshy lips, for lapping. In our own 

 persons we suffer much from the sharp 

 suckers and bloodtliirsty propensities of 

 gnats and mosquitos (Cttticidce), and also 

 from those of certain midges (Ceratopoyon 

 and Simulium), including the tormenting 

 black flies (Simulium molcstum) of America. 

 The larvae of these insects live in stagnant 

 water, and subsist on minute aquatic ani- 

 mals. Horse-flies and the golden-eyed forest 

 flies (Tabanidce), whose larvae live in the 

 ground, and the stinging stable-flies (5to- 

 moxys\ which closely resemble common 

 house-flies, and in the larva state live in 

 dung, attack both man and animals, goading 

 the latter sometimes almost to madness by 

 their severe and incessant punctures. The 

 winged horse-ticks (Hipppboscce\ the bird- 

 flies (Ornithomyice), the wingless sheep- ticks 

 (MelopJtagi). and the spider-flies (Nycteri- 

 Uce.\ and bee-lice (Brattice), which are also 

 destitute of wings, are truly parasitical in 

 their habits, and pass their whole lives upon 

 the skin of animals. Bot-flies or gad-flies 

 (CEstridce), as they are sometimes called, ap- 

 pear to take no food while in the winged 

 state, and are destitute of a proboscis ; the 

 nourishment obtained by their larvae, which, 

 as is well known, live in the bodies of horses, 

 cattle, sheep, and other animals, being suffi- 

 cient to last these insects during the rest of 

 their lives. Some flies, though apparently 

 hannless in the winged state, deposit their 

 eggs on plants, on the juices of which their 

 young subsist, and are oftentimes productive 

 of immense injury to vegetation ; among 

 these the most notorious for their depreda- 

 tions are the gall-gnats (Cecidomyice), in- 

 cluding the wheat-fly and Hessian-fly, the 

 root-eating maggots of some of the long- 

 l 



fl 



flies and fruit flies (Ortalidfs). To this list 

 of noxious flies, are to be added the common 

 house-flies (Muscoe), which pass through the 

 maggot state in dung and other filth, the 

 blue-bottle or blow-flies, and meat-flies 

 (LucUiae and Callipkorce), together with the 

 maggot-producing or viviparous flesh-flies 

 (Sarcophaga andCywo/j/7'<t), whose maggots 

 live in flesh, the cheese-fly (I'iophOa), the 

 parent of the well-known skippers, and a 

 few others that in the larva state attack our 

 household stores. Some are entirely harm- 

 less in all their states and many are emi- 

 nently useful in various ways. Even the 

 common house-flies, and flesh-flies, together 

 with others for which no names exist in our 

 language, render important services by feed- 

 ing, while larvae, upon dung, carrion, and all 

 kinds of filth ; by which means, and by simi- 

 lar services, rendered by various tribes of 

 scavenger-beetles, these offensive matters 

 speedily disappear, instead of remaining to 



egged gnats (Tipulce), those of the flower- 

 ies (AnlhomyuK), and the two- winged gall- 



moderate or small size, are not only very 

 numerous in kinds or species, but also ex- 

 tremely abundant in individuals of the same j larvje live in stagnant water, such as gnats 

 kind, often appearing in swarms of countless (Culiciche), the soldier-flies (Stratiomyadce), 



decay slowly, thereby tainting the air and 

 rendering it unwholesome. Those whose 



