THE AMERICAN ENTOMOLOGIST. 



151 



middle of Jnue, and in southern latitudes in 

 the middle of May. From a large lot of galls 

 that had been found upon barley, obligingly 

 furnished to us by Mr. J. Pettit, of Grimsby, 

 Canada West, the first flies came out June 9th, 

 and they continued coming out in very large 

 numbers till June IGth and subsequently. As 

 is usual with most insects, the males came out 

 first, and not a single female appeared until 

 June nth; whereas from and after Juno l.Jth 

 there were nothing but females to bo met with, 

 the whole number of females, however, greatly 

 exceeding that of the males. Tlie cause of tliis 

 singular phenomenon of the males preceding 

 the females by several days — which has been 

 noticed by other writers in the case of other 

 insects, and which we believe to be a very 

 general law — has never been explained. -But it 

 i.s probably due to the desire of nature, that the 

 males may have time to gain their full strength 

 and vigor, before the females come into the 

 world and require their ininicdiatc attentions. 

 He this question as it may, after coupling in the 

 usual manner, the female Joint-worm Fly 

 proceeds to lay her eggs in the stems of the 

 growing grain. The following excellent ac- 

 count of this operation, from the pen of Mr. 

 Pettit, we extract from the Canada Fanner for 

 18G7, page 268: 



About the 8th of June of the l)l■c^sellt year the 

 pertect insects began to make their way out of the galls. 

 e s- * a s ijcing desirous of knowing more of their 

 habibi, I watehed the growing barley, and on the luth 

 of June found them actively at work ovipositing in the 

 Iketi health;! slaUs of the plant. Before commencing 

 operationsthey walk leisurely up one side of the plant 

 as far as the last leaf, anil then down the other, appa- 

 rently to make sure that it lias not alrt-aily been 

 oviposited in. Head downwaiil. tln'v lli'ii lH"j;in by 

 bending the abdomen downward 1. and iiln in- i In- tip of 

 the ovipositor on the straw at li.ulit aiiLii - with the 

 body, when the abdomen rusuinrs it^ mtuial iMisiiiou, 

 and the ovipositor is^radually worked into the plant to 

 its full e.xtent. With the aid of a good lens, and by 

 pulling up the plants on which they were at work 

 (which did not appear to disconcert them in the least) , 

 I could view the whole operation, which, in some 

 cases, was accomplished in a few minutes, and in others 

 was the work of an hour or two. When a puncture 

 was completed, they usually backed up a little and 

 viewed it for a few seconds, and then apparently satis- 

 fled, moved to one side and commenced another. 



Very shortly after this time, the egg must 

 hatch out. For, upon July 3rd, wc examined 

 a large lot of the green barley-galls, which had 

 been obligingly forwarded to us by Mr. Pettit, 

 and found the larva of the Joint- worm Fly 

 almost half-grown, that is from 0.004 to O.OOG 

 inch long, and about Ave times as long as wide. 

 In these green galls, upon the most careful 

 search, we could And no Gall-gnat larvte, nor 

 any vestiges of any such larvse. So that we are 

 now fully persuaded, that the idea originally 

 entertained by Dr. Haiuls and Dr. Fitch, and 



subsequently favored by the Senior Editor of 

 this JouRXAL, namely, that those galls are in 

 reality made by some undiscovered Gall-gnat, 

 upon which the so-called Joint-worm Fly that 

 has been ligured above is a parasite, is a false 

 and fallacious one. Otherwise, if the so-called 

 Joint-worm Fly were really a parasite, we must 

 certainly have discovered, at this early period 

 in the year, a few specimens of the larva; upon 

 which it was parasitic, or at all events some 

 traces of their handiwork. Both Harris and 

 Fitch afterwards became of opinion, that the 

 Joint-worm Fly was the rdal author of these 

 galls; and we think it right to bear this public 

 testimony to the correctness of their entomo- 

 logical inferences. AVe w'rite for truth, and not 

 for victory, and have never claimed to be 

 infallible.* 



By the beginning of September, the iut'ostcd 

 grain having ripened long before this period, 

 the galls arc already dry and hard, and the lar- 

 v;e contained in them full grown, measuring 

 now about 0.13 inch in length. The great ma- 

 jorit)' of these larvre are destined to remain in 

 that state, enclosed in their little cells, until the 

 succeeding spring; but — as happens with many 

 difl'i'i-pnt insects — a small percentage of them 

 stem to pass into the pupa, and thence into the 

 period state, the same summer that the eggs are 

 deposited. For, out of a lot of 124 barley-galls, 

 received September lOth from Mr. Pettit of 

 Upper Canada, 39 galls, or very nearly one- 

 thud part, were already bored with the same 

 kind of small round holes as are made in the 

 succeeding spring by the escaping Joint-worm 

 Flies, some galls containing six such holes, but 

 most of them about three. It is true that wo 

 are not personally cognizant of the fact, that 

 those holes arc bored ty the same Joint-worm 

 Fly, that escapes from similar holes in such 

 profuse abundance in the following June ; but 

 Prof. Cabell, of Virginia, stated to Dr. Harris 

 ■with reference to the wheat-inhabiting -Joint- 

 worm, that he had known a few flics to leave 

 the straw the first year, but in each instance the 



•The Senior Ertitur of this Journal inibHslicd in (hi' Caiinda 

 ski-micisni l.i- -ivai Im ll,. \\ nrM ia tin- I'raelicnl Knlomolo- 



to the genus Eurytoma, although 

 I the Euriitoma srouo . ' ' 



the Eurijtoma group 



