LETTERS FBOM DR. STAUDINGER. 139 



send you jive larvae. I had long since noticed the galls on the 

 Pistacia, some of which are very large, and I had even opened some. 

 But I found only thousands of Aphides therein, packed up with white 

 dust, so that I was soon disgusted. But to-day I have examined 

 these galls with fresh zest, although it was very dirty work, many 

 of them being sticky with resin. I found in them two kinds of larvae, 

 living amongst hundreds of Aphides, on which they probably feed, as 

 I did not find that the inner walls of the galls had been gnawed*. 

 One was a large knot-horn larva, which will not, therefore, interest 

 you; the other, a small white larva,. is that of the Staihmopoda 

 Querinii ; of this I also found some pupae, and in one gall which was 

 completely closed I found a recently developed specimen of the per- 

 fect insect. On the Pistacia there are three kinds of galls : the 

 largest of these is at the ends of the branches ; these have an elon- 

 gate pod-like form, yet they vary very much both in shape and size : 

 I found one which was nearly a foot in length. It is only in this 

 kind of gall that I have met with Stathmopoda Guerinii, and, I may 

 say, principally in the smaller of this sort of galls. The larva con- 

 structs a firm cocoon, covered with grains of its excrements, and 

 attaches it to the inner wall of the gall. Generally there is an 

 opening formed through which the imago may escape ; but I found 

 some galls where this was not the case, and where consequently the 

 moth must develope in the interior of the gall. Thus in some galls 

 which had no openings I found moths which had emerged and there 

 died, having no means of escape. 



" I generally found these larvae in the galls along with many 

 Aphides ; yet in some very small galls, only an inch or two in length, 

 I found no trace of Aphides ; perhaps they had all been devoured 



" In very many galls, especially the larger and fresher ones, one 

 finds Aphides only, and no trace of any larvae ; so that I believe the 

 galls are caused in the first instance by the Aphides, and then the 

 moths deposit their eggs on the galls " 



" Celles-les-bains, pres de la Voulte, 

 "Dep. Ardeche, October 13th, 1866. 



" I now send you a box containing six sorts of larvae : 

 " 1. Two or three larvae of a Gelechia?, feeding on Helichrysum in 



woolly tubes. 



" 2. Three mines of a Lithocolletis on Cytisus ? 

 *' 3. Five mines of a Cemiostoma on Cytisus ? 

 " 4. Two larvae of a Gelechia on Cytisus? between united leaves ; I 



have only found one other. 

 " 5. Two larvae of Gelechia terebinthella ? between leaves of the 



Pistacia ; these are all I could find of them. 

 " 6. A larva of a Gelechia ? in the leaves of a white-flowered 



Scabious ; the only one I have found." 



(The first four of these duly reached me, but of the 5th and 6th I 



* In a subsequent letter Dr. Staudinger remarks, " the larvsc- eat the inner 

 walls of the galls." 



