17> 



THE ENTOMOLOGIST. 



DESCRIPTIONS OF OAK-GALLS. 

 Translated from Di". G. L. Mayr's ' Die Mitteleuropaischen Eichengallen. 



By Edward A. Fitch. 



(Continued from p. 1G2.) 



Via. C!). 



-N. MiNUTUi.us Fig. GiS. — N. saliens. 

 (and magnified). 



68. Neuroierus saliens, Koll. (= N. saltans, Gir.). — This 

 gall, which is very nearly related to the former species, may 

 be found in the second half of September on the under side 

 (rarely on the upper side, or on the petiole) of the leaves of 

 Quercus cerris: it breaks forth from a longitudinal rent in 

 the midrib. Whilst we generally find but one or two galls 

 of N. ostrens on a leaf, those of N. saliens are gregarious, and 

 often occur in such a manner that the galls, placed behind 

 one another, form a continuous line. It is hairless, smooth, 

 slightly glossy, at first green, then reddish brown, and is of a 

 splindle-shaped form, with a length of 3 millimetres, and a 

 breadth and height of 1'2 millimetre ; on the side next to the 

 leaf it is fastened to the cleft in the midrib throughout its 

 entire length by means of a narrow adhej»ent clasp or border, 

 whilst the gall of N. osireus is only attached to the midrib at 

 one point. This species is of great interest, as the detach- 

 ment of the ripe gall from the leaf depends on the will of the 

 contained larva. Collected galls, as yet attached to the leaf, 

 at the beginning of October burst from it, jump and twist 

 themselves, without the gall itself undergoing any change of 

 form. This peculiar movement is occasioned thus: the 

 larva, lying in the roomy cell, bends itself in a circular 



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