105 



CHAPTER XIII. — The Plum Moth. (Semasia prunivcra, Walsh.) Fig. 3. 



On July 28, 1867, I was cutting into a number of plums infested 

 by the Plum Curculio and the Plum Gouger, when to my great surprise 

 I discovered in one ol' them what was evidently the larva (fig. 3b) of 

 some small moth. On comparing this figure with that of the larva 

 of the Plum Curculio (fig. 3c) — which scarcely differs in outline from 

 that of the Plum Gouger — the difference will be seen at a single 

 glance. The plum in which it occurred bore the crescent slit of the 

 Curculio; but what had been the history of the egg deposited by the 

 mother Curculio — whether it had failed to hatch out — or whether it 

 had hatched out and shortly afterwards perished — or whether it had 

 hatched out and reached maturity in the plum, and then gone under- 

 ground — I did not ascertain. In the year 1868 I hope to clear up all 

 such points as these; upon which depend a variety of interesting 

 questions in the history of the moth-larva that accompanied the egg- 

 slit of the Curculio. 



About a month afterwards, from a lot of infested plums gathered 

 July 27th, the details of which have been given above (p. 91,) there 

 commenced coming out the small moth figured and described herewith 

 as the Plum Moth (fig. 3;) and specimens continued to come out 

 from time to time until the middle of September, amounting in all 

 to 13. Evidently all these moths must have proceeded from larvas, 

 such as that which 1 had found in the plum at the end of July. 



In the preceding year, and at the same period of the year, from 

 the well-known Black-knot — a fungoid excrescence on the branches 

 and twigs of the Plum-tree, which is infested by the larvae of the 

 Curculio to nearly as great an extent as the Plum itself — I bred sev- 

 eral specimens of this same moth; and in this same Black-knot 

 I had previously met with many of its larvae burrowing in the sub- 

 stance of the Black-knot. I bred two other specimens of the same 

 moth nearly a month earlier in the season from a cockscomb-like 

 hollow gall {ulmicola. Fitch) on the loaf of an elm, which is pro- 

 duced and inhabited by Plant-lice, having previously found its larva 

 inside the gall and among the Plant-lice. And lastly, I had bred on 

 September 2d, 1866, a single specimen of this very same moth from 

 a sessile, hollow gall about the size and shape of a large pea or a small 

 cherry, on the leaf of the Red Oak (Quercus rubra,) which has been 

 named and described by Mr, Bassett, (Quercus singularis, Bassett'.*) 



*I formerly supposed that this gall Avas the nubilipennis of Harris. It 

 is clearly the nuhilipennis of Fitch. But I rather believe that the Quercus- 

 sculpla of Bassett — a flesliy, juicy, subacid, grape-like, eatable gall growing 

 indift'erently on the Black Oak (Quercun tinctoria) and the Red Oak — is the 



