252 THE ENTOMOLOGIST. 



ASPHONDYLIA ULICIS, Traill. 

 By T. a. Chapman, M.D., F.E.S. 



I HAVE not been able to find any original notes on this 

 species beyond those of Mr. Verrall. I found the species very 

 abundant here this August. It probably is, in many places, very 

 often, if looked for, as Mr. Verrall suggests. What led me to 

 take an interest in it was the dimorphism, if that word is cor- 

 rectly applicable, of the galls. Mr. Verrall notes that they 

 resemble the flower-buds, but are larger. As a matter of fact, 

 one form of them are the flower-buds, and the gall is often easily 

 separated into the two divisions of the calyx ; at its base are the 

 two floral bracts. The larva, in fact, occupies the cavity of the 

 calyx, and the inner parts of the flower are wanting, how dis- 

 appearing I do not know. But, as well as this, the gall has 

 another form, which is the seed-vessel, not very much altered in 

 appearance. They remain rather soft, are rather swollen basally 

 (the gall) and dwindled a little at the apex. The two valves of 

 which they consist are nearly as distinct as in a normal seed- 

 vessel ; they equally terminate in the remains of the style, and 

 are surrounded in the same way by the dead and dry calyx and 

 corolla. There seems no very definite reason why the apical 

 portion of the seed-vessel should not contain some traces of a 

 seed, but, as a matter of fact, I cannot find such an example. 



Those in the seed-vessels are about a week later in emerging 

 than those in the buds. In mid August, when I found them, the 

 enlarged buds were very conspicuous, there being no normal 

 buds on the plant, indeed, all the normal inflorescence was in 

 the form of seed-pods already black or blackening, but not ripe. 

 The galls, formed of seed-pods, were less conspicuous, because 

 hidden to some extent by the dried floral envelopes, but when 

 seen were really conspicuous, from being quite green, and so 

 differing from the ordinary pods. 



I know too little of gall-midges to know whether this varia- 

 tion in the situation of the galls is common ; it was new to me. 

 Is there some other name for these than galls ? If galls be 

 typically those of the Cynipidae, the residence of the larva in a 

 "gall" is actually in the plant tissues. In most gall-midges I 

 know, the larva is outside the plant, i. e. the inside of the gall is 

 naturally an external surface of the plant, and not a morbid 

 cavity in the tissues. This is true morphologically of the cavity 

 of a seed-vessel, as in Asphondylia ulicis. 



Betula, Reigate : September, 1903. 



