780 RECORD OF CURRENT RESEARCHES RELATING TO 



that the most extreme varieties resulted from larv^ which had been 

 kept in the cellar (i. e. at a low temperature) during their period of 

 pupation ; but from his other experiments, and from some recorded 

 by Professor Weissmann, he is now inclined to believe that this 

 critical period occurs, not at the time of the pupation itself, but 

 immediately after it. 



With regard to the known sensitiveness of Lepidoptera to low 

 temperatures while entering the pupa stage, he states that larvae of 

 Arctia caja need at least 9° to 10° R. for this operation ; some kept 

 at a degree varying between 8° and 10° took from twenty -four to 

 thirty days to make the change after spinning up, and then only 

 produced somewhat deformed images ; those kept below that tem- 

 perature perished. 



Protective Attitude of the Caterpillar of the Lobster Moth.* — 



Most entomologists have admitted that the grotesque attitude of those 

 caterpillars forming Newman's " Cuspidate " group was in some way 

 protective, but it is only quite recently that Dr. Hermann Miiller 

 has made known the results of his observations on the caterijillar of 

 Stauropus Fagi, which observations now for the first time tend to 

 show the true meaning of this attitude in the species in question. 



When sitting on a twig in its natural position the head and first 

 five segments are held erect, and the greatly lengthened legs of the 

 Becond and third segments held outstretched ; thus, when seen from 

 the front, the whole aspect of the insect, both in form and colour, is 

 most spider-like, and when alarmed it immediately raises its four long 

 legs and moves them irregularly, after the manner of a spider attacking 

 its victim. This spider-like appearance is believed to be a special 

 protection against ichneumons which may approach it from the front. 

 According to the experience of H. Miiller ichneumons are especially 

 afraid of spiders, and he states, on the authority of Fleddermann, an 

 experienced breeder of insects, that the larva oi S. Fagi was never found 

 to be attacked by ichneumons, whilst, according to Treitschke, the 

 nearly allied Hyhocampa Milliauseri is often attacked by them, although 

 a much rarer species, which rarity may perhaps be attributable to 

 the complete absence of such protection as that possessed by S. Fagi. 



So much for the front aspect of the caterpillar under consideration. 

 When approached from the rear there is nothing to be seen but the 

 erect, hard shield-like surface of the last segment surmounted by two 

 black horns, and presenting an appearance totally unlike that of a 

 caterpillar. When a side view of the larva is presented, there is 

 seen on the fourth and fifth segments a small black depression just 

 below the spiracles, and giving the appearance of a caterpillar ivhich 

 has been stung hy an ichneumon, so that one of these foes approaching 

 from the side would be deceived and abandon it without depositing 

 its eggs. 



Odoriferous Apparatus of Sphinx ligustri.t — This has been 

 lately discovered by Von Eeichenau, who found, while stuflSng the 



* ' Kosmos,' 1879, p. 123. See ' Trans. Entom. Soc. Lond.,' 1880, ' Proe.,' p. iii. 

 t ' Entomol. Naclir.,' vi. (1880) p. 141. 



