252 



SlAl,ID.£.- 



-raSECTS.- 



-Trichoptera. 



oval, and of close-spun silk. The species are from 

 three to four lioes in expanse. 



In the family Sialidce, which includes Raphidia, Dr. 

 Hagen quotes five species as iadigenous to our island, 

 and characterizes the family as having the wings 

 deflexed ; the snbcosta unites with the costa before the 

 apex of the wing; the labial palpi are three-jointed; 

 the anal area is present, though in Eaphidia it is very 

 small. The larva has tlie mouth formed for biting, 

 and is always carnivorous. 



Family— SIALID^. 



The Sialis liitarius is a dingy, blackish insect, very 

 common on the banks of ponds and streams. They 

 deposit their eggs in patches on the rushes. The ilies 

 must afford great store of food to many of the smaller 

 fresh-water fish. Anglers who use artificial flies in 

 pursuing their sport, frequently imitate the general 

 appearance and form of the Sialis. Its brownish wings 

 have a multiplicity of veins; the fore-wings are yellow- 

 ish at the base. 



Raphidia, four species. In this family comes the 

 great long-jawed Corydalis cornuta. Our figure is 

 that of Raphidia ophiopsia var nolata (Plate 6, fig. 4). 

 In the family Panorpidce, Dr. Hagen quotes five species 

 as British. The family ia thus characterized : — The 

 wings are horizontal, narrow ; tlie subcosta unites with 

 the costa before the tip of the wings, the mouth is pro- 

 longed like a beak, the labial palpi are two-jointed ; 

 the anal area is wanting. The larva lives underground, 

 and feeds on plants ; the pupa is quiescent, and is with- 

 out a proper cocoon. In the genus Boreus the wings 

 iro wanting; in Panorpa they are present. 



HorAK^ hyemalii, is sometimes found on snow. 



Panorpa, four species. Our figure shows the Pan- 

 orpa communis or common Scorpion-fly (Plate 6, 

 fig. 7). 



The Scorpion-fly can lord it over the Dragon-fly. 

 Lyonet mentions that he saw a scorpion- fly attack a 

 dragon-fly ten times larger than itself. The Panorpa 

 brought him to the ground, pierced him repeatedly with 

 his proboscis; and but for the eagerness of the naturalist 

 who parted them, there was no doubt but that tlia 

 Scorpion-fly would liave destroyed the Libellula. In 

 tills family comes the strange genus Nemoptera, one 

 of the species of which ia figured on Plate 6, fig. 6, 

 Nemoptera filipennis ; the figure, as in several other 

 instances, is copied from one of Mr. Westwood's, In 

 this family, too, comes the genus Bittacus, with its long 

 legs and very great raptorial tarsi. These insects seize 

 and hold other insects with their great claws. 



Family— MANTISPID^. 



A family with raptorial fore legs, looking like a 

 miniature Mantis. 



On lately opening a nest of the curious Wasp, My- 

 rapetra scutellaris, from Monte Mdeo, I was much 

 delighted to get a considerable number of a curious 

 Mantispa alive. In the former nest which I had 

 described, wings of this species, which I alluded to as 

 Hemerohius, occurred. These Mantispse jerked and 

 jumped about in the strangest manner ; when they fell 

 on their backs they righted themselves most curiously. 

 They eagerly ate any small insects oflered to them. 

 They were evidently parasitic in the nest, as they 

 occurred in great numbers. I described this insect at 

 a meeting of the Entomological Society of Loudon, 

 December 2, 18C1. 



Sub-order— TRICHOPTERA ( Caddis-worm flies). 



Thi3 group of mseets was regarded by Kirby as 

 forming a distinct order from the Neuroptera, to 

 which he gave the name of Ti-ichoptera, or hairy wings, 

 from the hairs with which they are usually covered. 

 Westwood and other authors regard them also as 

 distinct from the Neuroptera ; we follow Dr. Hagen 

 in considering them merely as a subdivision of that 

 order. 



Trichoptcra in their early stages are aquatic, and 

 inhabit cases which are constructed of various mate- 

 rials, according to the species or genus of the order. 

 Some employ grains of variously coloured sand to 

 cover these cases ; others use small fresh-water shells, 

 and thus carry about with them a little museum of the 

 coverings of aquatic mollusca of different kinds ; others 

 form tlie outside lining of their case with small frag- 

 ments of branches or reeds. These cases are usually 

 open at the ends. In their pupa state they become 

 torpid ; but before becoming pupse, the larvie, to keep 

 out their enemies, and at the same time to allow free 

 ingress to water, so necessary for their very existence, 

 form a grate across the mouth of the case. This port- 

 cullis, as it has been well called, is spun across each 



end, and is formed of a silk spun from the anua of tha 

 larva. Degeer has described one of these grates. It 

 is formed by a small, thickish, circular lamina of a 

 dark-coloured silk, which becomes hard, and exactly 

 fits the end of the case, being fixed a little within its 

 margin. It is pierced all over with holes, arranged in 

 concentric circles, and separated by ridges which run 

 from the centre to the circumference, somewhat like 

 the spokes of a wheel. Although for a considerable 

 time quiescent in their pupa state, about the close of 

 it they can move ; they are furnished with an appa- 

 ratus to pierce through the grating which imprisons 

 them, otherwise they must perish in the water. The 

 head of the pupa is furnished in front with two hooks ; 

 with these, before their last change, they make an 

 opening in the grate. Having escaped from this, the 

 pupa mounts in the water to the surface, and emerges 

 from it. She then creeps up some plant, her antennae 

 and legs each inclosed in a separate envelope ; tlie 

 perfect insect then gradually bursts from her case. 



Plate 6, fig. 10, shows one of the Trichoptera with 

 the Caddis-worm. 



In North America, Brazil, Australia, New Zealand, 



