16 FORMS OF GALLS. 



Cynips glutinosa is a well-known example of this. 

 Giraud (Verh. z.-b. Ges. Wien, 1859, p. 342) relates 

 that this exudation glues small insects to the gall, and 

 this observation is confirmed by Paszlavszky,* who 

 has found Hemiteles (an ichneumon), Torymids, and 

 other gall parasites so attached. In our own country 

 we have an even more interesting case in Andricus 

 Sieboldi, whose galls give out a secretion which, as 

 was first pointed out by Dr. Adler,f is much relished 

 by ants, which, as stated by the same author, cover 

 them with sand and earth, so as not to be caught them- 

 selves when getting the liquid. I have myself noticed 

 the ants at the gall secretion, but the galls were not 

 covered. The spines on galls, as in the American 

 Bhodites bicolor, must also be a protection. From 

 observation, and from a study of the published notes 

 in the rearing of parasites and inquilines, it seems to 

 me clear that the smooth galls have a larger number of 

 parasites than the hairy, rough, or glutinous ones. 



As another means of protection may be mentioned 

 the short duration of some galls on the tree, e. g. 

 Andricus aprilinus ; the falling to the ground when 

 ripe of many bud-galls, where they are lost among the 

 herbage, &c, to which their colour assimilates, being at 

 first green, then becoming brownish ; the dropping 

 to the earth of Nenroterus lenticularis before it is fully 

 grown or the larva mature, thus reducing the period 

 during which it can be attacked by parasites. So, 

 too, the larva chamber in Andricus curvator being 

 loose, and surrounded by a large empty space, may pro- 

 tect it. 



The springing habit of some gall larvae may also do 

 so. This fact was first alluded to by Olivier (Hist 

 Ins., ii, p. 318) ; then a fuller description of the 

 jumping habits of Andricus saliens was given by Kollar, 

 Verh. z.-b. Ges. Wien, 1857, p. 513, and by Giraud, 

 1. c, 1859, p. 352. According to the latter, they can 



* Wiener Ent. Zeit., ii, p. 131. 



f Zeit. f. wissen. Zool., xxxv, p. 172. 



