174 BRITISH LEPIDOPTEKA. 



the head rounded, with two large black eyes and two slender antennas, 

 the latter at least half the length of the body and terminated by an 

 elongated thickening. The legs are also long, yellowish, of ordinary 

 shape, and terminated by two rather large hooks ; the abdomen is 

 composed of six segments without counting the ovipositor (which forms 

 a sort of tail behind), composed of three segments, capable of being 

 drawn one within the other like the joints of a telescope ; the dorsum 

 is smooth and glassy, but laterally and ventrally are a large number of 

 scale-like hairs, as in ordinary Phalenes ; the 6th abdominal segment 

 with a fringe of long hairs encircling it. These females are sluggish. 

 From a large number of cases collected each year only females have 

 been bred (unless the males are wingless), and from the eggs laid 

 numberless larvae have hatched. 



Pakthenogenesis in S. lichenella. — We have already noted that 

 De Geer and others have recorded the occurrence of partheno- 

 genesis in this insect, and we have further shown (ante, pp. 157- 

 158) that authors have attempted to attach the insect to various 

 species — triquetrella, pineti, &c. One or two other references, perhaps, 

 call for notice. In 1847 Speyer published (Stett. Ent. Zeitung, 1847, 

 pp. 18-21) a paper on " The natural history of Talaeporia lichenella, 

 Zell," He notes that the mode of propagation of the species had long 

 been a matter of controversy, and refers to the observations of Mann 

 and Hering on the mode of copulation of Psyche plumifera and P. stetti- 

 nensis, and to an earlier one in the Ids on that of P. muscella. He then 

 states that having established by accurate observation the propagation 

 of T. lichenella, L. and P. triquetrella, Tr. (? =clathrella, F. v. E.) 

 parthenogenetically (Isis, 1846, p. 29), he had, four years previous to 

 the publication of the paper, collected a further supply of cases in 

 early April, which the larvae had already spun up for pupation on a 

 garden fence, and, having isolated them, found that they produced 

 only females, which, after sitting a short time, began to oviposit with- 

 out copulation, and that after about four weeks larvas hatched from the 

 unfertilised eggs. As it was possible (though very improbable) that 

 the females had already been fertilised, he made further observations, 

 and, in March, 1846, he again collected a number of lichenella cases, 

 some still containing larvae, some pupa?. The imagines, again only 

 2 s, emerged in the second half of April. Four specimens, whose 

 emergence and egg-laying were especially noticed, were selected for 

 separate observation. The larvae came out at the beginning of June, 

 and, to judge from their number, nearly all the eggs must have de- 

 veloped. They were not hard to breed. Some bits of lichen-covered wood 

 from old fences and bark of trees, sprinkled daily with water, but never 

 renewed, sufficed at first for feeding them. Later they were given dead 

 moths, which they devoured with great relish. They ate all parts which 

 were not too hard, and of a Gastropacha populifolia they left nothing but 

 the heap of eggs. They needed but little light and air, grew slowly, and 

 did not reach full size till autumn. They left off feeding in October, 

 remained without moving till March, then got restless and spun up. 

 About 15-20 grew very slowly, so that, in autumn, they were scarcely 

 half the size of the rest, indeed, one couple had reached but little 

 over a line in length. Some of these backward ones died during the 

 winter, the rest re-cOmmenced feeding in March. He t^ok good care of 

 them, but they gradually died off in the summer, without having grown 



