TRICHIURA CRATAEGI. 483 



any protection. The larvfe of Trichiura when hatched very speedily 

 separate*, and do not form a general nest, whereas those of Clisio- 

 campa form a general web, which they increase in bulk until it becomes 

 nearly as large as a man's head, and do not separate until they have 

 undergone their final moult. When the lame pupate they make a 

 hard, oval, egg-like cocoon, not a subfusiform double silken web, 

 suffused with a loose powder, as do those of Clisiocampa ; the imago 

 differs from that of the latter genus by having the antennas straight, 

 serrated in the females ; the wings rounded, obtuse, and abbreviated in 

 both sexes ; the legs stout and very pilose ; the abdomen strongly 

 tufted in both sexes, that of the female furnished at its extremity with 

 a downy mass ; the head distinct and very hairy, and the proportions 

 of the palpi different." There is only one known species in the genus 

 — the widely distributed crataegi. The species placed in the genus by 

 Kirby appear, as we have already said, to differ considerably and not 

 to be congeneric. The structural peculiarities of the early stages of 

 Achnocampa ilicis are, at present, a very great desideratum, as its 

 affinities with T. crataegi are by no means clearly made out. Among 

 other things, Aurivillius notes that " nervures 9-10 of the forewings 

 have a long stalk only as long as the free part of the nervure in ilicis, 

 whilst it is more than double as long in crataegi " ; also " in the hind- 

 wing nervures 7-8 are quite free in ilicis, but united into a short stalk 

 in crataegi." He then adds : " The larvas of the two species are very 

 different, and give ground for the erection of a special genus for ilicis. 

 Unfortunately I only know the larva of ilicis from the description and 

 the figures of Eambur and Milliere. According to these, the larva of 

 ilicis differs principally in having the body much narrowed towards the 

 head and in the conical elevation on the 11th segment. Like the larva 

 of crataegi it is provided with warts, but on the arrangement of the 

 warts the authors are silent. If, as I suspect, they are developed in 

 the same peculiar way as in crataegi, it would be a further proof of the 

 near relationship of the species, and the other outward differences 

 might be explained as adaptations to different modes of life. It is 

 further to be remarked that the 11th segment of crataegi also is slightly 

 elevated. The larva of crataegi is almost cylindrical, and thinly clothed 

 all over with short soft hairs ; on the warts are stronger and stiffer hairs ; 

 the warts flattened, little raised. Segments 1-3 have a large wart on each 

 side, with another weakly indicated behind it ; first segment above is 

 without warts, the two next bear two each ; segments 4-11 have each 

 two large dorsal warts, and on each side a small one below and a larger 

 above the spiracle. Pupa red-brown, thin-skinned, naked, with several 

 hooks at blunt anus." 



Trichiura crataegi, Linne. 



Synonymy. — Species : Crataegi, Linn., " Sys. Nat.," 10th ed., p. 502 no. 30 



(1758) ; 12th eel., p. 823, no. 48 (1707) ; "Faun. Suec," p. 299, no. 1126 (1761) 



Poda, " Ins. Mus. Graec," p. 86 (1761) ; Fab., " Sp. Ins.," p. 194, no, 104 (1781) 



" Mant.," ii., p. 126, no. 150 (1787) ; ■' Ent. Syst.," iii., p. 460, no. 166 (1793) 



* There is possibly here some distinct difference of habit, for Milliere (Lep. 

 Alpes-Marilinics, p. 141), says that the young larvae hybernate under a common 

 web fixed to the small branches of Crataegus oxyacantha, and at their last 

 moult (in the spring), separate and live singly. Bacot notes that, in confine- 

 ment, at least, the larva) undergo their first moult in little groups, like those of 

 Eutricha qucrcifoliu. 



E e2 



