Nepid.e.- 



-INSECTS.- 



-IIoMilPTERA. 



267 



from every bush and every heap of ruins, and so filled 

 our cabins as to be scarcely endurable . . The mighty 

 army settled on the wet paint of the ceiling, and remained 

 there black and stinking until the ants devoured them. 

 These last swarm in my presence; they have eateu up no 

 inconsiderable portion of my provisions, and have taken, 

 I trust to their benefit, a whole box of blue pills; but 

 as they do their best to clear it of all other vermin, I 

 cannot hut look on them with some degree of favour."* 



Family— NEPID^E. 



The insects of this family are pre-eminently carni- 

 vorous, if that title can be given to tlie larvae of water 

 insects, and to small fish and reptiles. The largest 

 species of the group belongs to the genus Belos- 

 toma, from Brazil. The antennie are very short, and 

 have four joints ; the terminal three being more or less 

 branched, while the tarsi are two-jointed. It is re- 

 stricted to the warmer parts of the world, is aquatic, 

 and eminently rapacious. Dr. Leidy describes another 

 genus, under the name of Perthnstoma. The beak is 

 short, strong, and pointed, and the bite is exceedingly 

 venomous to the smaller animals; 



The insects are found in lakes, ponds, ditches, or 

 tranquil waters, where they reign undisputed monarchs 

 over insects and small fry. Mollusca, the smaller Crus- 

 tacea, and even small frogs and fish, become an easy 

 prey to them. 



The insects of these genera quit the water when it 

 is nearly dried up, or is depopulated through their 

 voracious appetite. 



The female of Perthostoma, according to Leidy, car- 

 ries about one hundred and thirty eggs on her back 

 until the larvae are nearlj' in a condition to make their 

 escape. When the ova have aiTived at maturity, the 

 insect casts the mass from her back, when they lie at 

 the bottom of the water until the young burst from 

 their confinement. 



Plate 8, fig. 9, represents the Naucoris cimkoides, 

 a British species. There are three British species. 

 The genus Ranatra is long and filiform; Nepa, or the 

 Water-scorpion, is broad and fiat, and lias two long 

 anal setse. 



Family— NOTONECTIDjE ( Water-boatmen). 



These insects are true swimmers ; their hind legs 

 are greatly elongated, and edged with strong hairs. 



close together, and forming a blade, as it were, to the 

 oar-like propelling leg. 



Plate 8, fig. 6, exliibits the curious Notonecta 

 glauca, or Water-boatman. The name Notonecta, or 

 swimmer on the back, alludes to the habit of the in- 

 sects which swim in this way. Their beak is sharp; 

 they prick very severely with it. There are thirteen 

 or fourteen species of this family, in four genera ; 

 Corixa (separated with Sigara by some authors and 

 placed in a family apart under the name Corixidce) 

 Plea, and Notonecta. 



A strange use is made in Mexico of the eggs of 

 some of the aquatic Hemiptera. The natives of 

 Mexico cultivate a species of sedge called " toule," 

 on which the aquatic insects deposit their eggs, the 

 place being one of those great marshy lakes called the 

 Lagune of Clialco. These sedges are collected into 

 bundles and floated on the water, where the insects 

 are attracted to tbom as places on which to deposit 

 their eggs. The bundles lie for about a month in the 

 lake, when they are removed from the water and dried. 

 The myriads of eggs are beaten from them into a large 

 cloth. These eggs are cleared, and sifted, and put 

 into sacks, and sold to the people, who make of them 

 a kind of cake or biscuit, which they call "hautle." 

 It is described by M. Craveri as being tolerably good, 

 but somewhat fishy in flavour, and with an acid taint. 

 The bundles of sedge are again put into the lake, and 

 a fresh supply of eggs obtained. The insects which 

 deposit these eggs are chiefly two species of Corixa ; 

 one of them being new, he names it Corixa femorata ; 

 the other was described by Say, the American entomo- 

 logist, in 1831, under the name of Corixa mcrcenaria. 



Family— GALGULID^. 



A very curious group of insects; rough on the njiper 

 side; and with a broad transverse head, and pedun- 

 culated eyes. There is no British representative of the 

 family. 



Family— HYDEOMETPvID.E. 



Who has not watched them speeding by fits and starts, 

 like skaters on ice, across the surface of our quiet waters 

 — " fearless walkers," as Hugh INIiller observes, " that 

 with true faith in the integrity of the implanted instinct 

 never made shipwreck in the eddy or sank in the pool." 

 On Plate 8, figs. 7 and 8, the Gerris lacuslris and 

 Hydrometra stugnorum ai'e figured. 



Sub-order— IIOMOPTERA. 



This is a very extensive set of insects, in which the 



upper and lower wings are generally homogeneous. The 



antennae are in most of them very short and bristly. 



List of families and genera of British Homoptera : — 



Sect. 1. — Trimeea. Three -jointed tarsi. 

 F.imily 1. — Cicadidte. Cicada 1. 



Family 2. — hulgoridce. Ps&idophana 1; Issus\\ Cixtus 21; 

 Asiraca 4; Ddphax 19. 



• Bishop Helier's Indian Joinnal, vol. i. p. 72. Murray, 1849. 



Family 3. — Cercopidw. Smiliu 1 ; Cenlroliis 1 ; Ledra I ; 

 Eupellx 1 ; Paropia 2 ; Ulopa 3 ; Cercopis 1 ; Aphro- 

 phura 2; Phjela 5; Aaicephalits 11; Aphrodes il ; 

 I'hrynomorphus 1 ; Eiiacanthus 7 ; Ti/pliloci/ba 30 ; 

 Batracomorplms 1 ; PentUmia 1 ; AtjuUia 4 ; Idioce- 

 rus 5 ; Macropsis 1 ; Oncopsis 1 ; Jassus 1. 



Sect. 2. — Dimeba. Two-jointed tarsi. 



F:\mUy I.— Psi/!l!dai. Psi/fia 27 \ LwUla 1 ; Livia 1. 



Family 2. — Aphida. Aphis 21; Lnchnus 35; Atheroides 2 \ 



' Eriosoma 11 ; Adelycs 22; Brysocrypta 1 ; Phylloxera 



1 ; T/ielaxes 3 — in all, ninety-six species. In Mr. 



