larva of the Tentliredinidoz. 197 



means of the flexible abdomen, and others, as we shall see, 

 have especial means of protection. 



Take, for example, the larvas of Trichiosoma ; these are 

 among the largest in the family. They are white, Avliich 

 contrasts well with the green of the leaf, and, as they feed 

 openly, they are readily observed. They have the facnlty 

 of ejecting from lateral pores an acid greenish liquid to 

 some distance and in some quantity. I have no doubt 

 that this is as much a protection against ichneumons as 

 against birds. We know, indeed, from the observations 

 of Lewis (quoted by Westwood, Intr. ii. 108), that the 

 larva of Perga (an Australian genus closely allied to the 

 Cimbicides) carries in its mouth a yellowish gummy 

 matter, which it can vomit in some quantity when there 

 is any occasion for it. That it is of some protection 

 against ichneumons is shown by Lewis finding an ich- 

 neumon Avhich preys on the larvas with its legs and 

 wings covered and glued together by this gummy matter. 



Most of the larvfe of the Cimbicina feed on trees 

 during the day, and they hold on very firmly to the leaf. 

 They are in coloration white or greenish-white, without 

 any distinct marks, and in some cases are covered with a 

 whitish exudation. An exception to this rule is found in 

 Abia scricea, which is found on Scabiosa succisa, usually 

 in the evening. It is of a drab colour, with orange 

 lateral marks. When alarmed it drops at once to the 

 ground * in the form of a ball. I always, Avhen searching 

 for this larvEe, was much puzzled to find it when it had 

 dropped down to the ground. Frequently when found I 

 have lost it again by removing my eye for a moment, and 

 yet it could not have changed its position. Indeed, most 

 larvaj which fall readily to the ground in the form of a 

 ball are difficult to find.f 



It is curious to see how difierent the larvse are in the 

 same genus — even a small one — and how interesting it is 

 to find that these differences are explained by their habits, 

 and especially as regards their means of protection. 

 Take, for instance, the genus Croesus. Two of our 

 species have very distinctly-marked larvas. C. varus, on 

 the contrary, although it has the form and habits of 



* It feeds also on the under side of the leaf, while the tree-feeders rest 

 on the upper side. 



f This habit of falling down to the ground and remaining there motion- 

 less, rolled up into a ball, is analogous to the "shamming dead" of perfect 

 insects. 



