Ceecopid.e.- 



-INSECTS.- 



-Antiu.E. 



269 



Family— CERCOPID^. 



In this very extensive family the antennas are three- 

 jointed ; the head has two ocelli. If strange variety 

 of form, in fact if the most outrfe and bizarre shapes, be 

 the object of admiration, this family will supply ample 

 material. Plate 8, fig. 15, shows the Membracis 



Fig. 169. 



Fig. 170. 



Bocyiliiira gl'jbulare. 



CEda iiiflata. 



foliacea, one of the group, with its curious flattened 

 knife-like expansion of form. There are many fine 

 and prettily-marked species. The genera Hderonotus 

 Cenirotus and others are full of the most strange 

 forma. Fig. 1G9 shows a Brazilian insect named 

 Bocydium glohulare, with a series of pretty round 

 balls, attached by a common pedicel to the thorax. 

 Mr. Miers told me he found it once abundant. Some 

 have curiously inflated appendages over them, quite 

 concealing the rest of the insect. These, too, are Bra- 

 zilian. Fig. 170 shows a marked and beautiful species 

 of (JSda, a very singular genus. It is named CEda 

 inflata. 



We now come to Cercopidce proper. These and 

 the Tdtigonm, a very extensive, beautifully coloured 

 set of long, rather parallel insects, abound in South 

 America and in Asia. The Cercopis and the allied 

 genera are largish insects, strongly and broadly marked. 

 We have but one small species in this country. Our 

 little species of Typhlocyba, Evacantlms, and Jassus 

 are extremely beautiful little creatures. 



Of the common Frog-hopper(^/;/(ro^7(ora<S^)wrearia), 

 in our little town gardens, how often are we annoyed 

 to see our plants infested by the larva, which carries on 

 its depredations on their juices, concealed by an enve- 

 lope of white froth closely resembling saliva I The 

 insect has derived its name of Frog-spittle from this 

 frothy exudation, which is secreted by peculiar organs 

 in the tail of the larva. This exudation protects from 

 the heat of the sun the soft body of the larva, which 

 but for this would soon shrivel up ; and also conceals 

 it from birds and many insects which would otherwise 

 prey upon it. Notwithstanding the concealment, wasps 

 often get at these larvK and carry them off. Few know 

 that the little broad-headed brownish-grey jumping 

 insect, so common on plants, is the frog-spittle insect 

 in its perfect state. By many these insects are regarded, 

 along with (he Aphides, as species of the very compre- 

 hensive though most unscientific genus, vulgarly called 

 " Blight." 



Family— rSYLLID^. 



Unlike other Ilomoptcra, these insects and the Aph- 

 ides have long antennae. They are very destructive to 

 plants, diverting the sap. The box of our gardens is 

 often much injured by the Psylla Buxi, w-hile the 

 Psylla Pyri, and a Chcrnies found on the apple, de- 

 stroy the young shoots and leaves of the pear and 

 apple. Many of these insects in their larva state, are 

 covered with a cottony secretion. 



Leuckhart,* in his work on the •' Alternation of 

 Generations," has proved that a spontaneous evolution 

 of eggs takes place in the Coccidse. He ascertained 

 that all the individuals of the wingless generation of 

 the genus Chermes, or Bark-lice, were of the female 

 sex, and that they laid eggs capable of evolution with- 

 out the intercourse of males. 



The common Fir-louse (^Chermes bietis) passes the 

 winter in the wingless state, in the form of a plump in- 

 sect not larger than a grain of sand, under the covering 

 of a woolly coat, at the base of the scaly young buds 

 of the fir. Leuckhart has convinced himself that the 

 reproduction of the Fir-lice takes place in both genera- 

 tions by a parthenogenetic process, by the spontaneous 

 development of the eggs. Leuckhart, who examined 

 fully two hundred of the Chermes, never met with a 

 male among them; he has no doubt that the Fir- lice 

 generally propagate without males. He leaves it unde- 

 cided whether males are entirely wanting, or whether 

 they merely make their appearance from time to time, 

 under certain favourable circumstances, and then fecun- 

 date the females ; yet, he adds, " It almost appears to 

 me as if certain anatomical conditions rendered the 

 first supposition to a certain extent credible." 



Fajiily— APHID..E (Plant-lice) . 



The Aphides are perhaps the greatest enemies of 

 the vegetable world, and, like the locusts, they have 

 been known to swarm at times in such myriads as to 

 darken the air. We might here quot^ from the writ- 

 ings of Kaltenbach and Professor Huxley, who have 

 recently paid considerable attention to their history, 

 and who bear out Reaumur's assertions of the infinite 

 and almost incredible powers of multiplication pos- 

 sessed by these feeble-looking Plant-lice. That author 

 calculates that a single Aphis may in five generations 

 be the progenitor of 5,904,900,000 descendants; and 

 he believes that in a single year there may be twenty 

 generations. Kirby and Spence show that the Aphides 

 which attack wheat, oats, and barley, seldom multiply 

 so fast as to prove very injurious to these cereal plants. 

 The species of Aphis which attack pulse spread so 

 rapidly, and cover the plants so completely, that the 

 crops of pease and beans are often greatly injured, and 

 sometimes even destroyed by them. These writers 

 state that this was particularly the case with the crop of 

 pease in 1810. In that year the produce did liltle more 

 than equal the seed sown, and many farmers turned 

 their pigs into the fields. This failure was univerBS. 



* See Dnllas' Translation of Paper by Leuckhart, in Aunals 

 of Natural History, p. 321 ; 1859. 



