THE PRACTICAL ENTOMOLOGIST. 



15 



and slender, the second joint being long and slen- 

 der, hardly thickened, and the joints composing 

 the terminal half of the length are bead-like, being 

 much rounder than those towards the base. The 

 thorax is globular in front of the insertion of the 

 wings, while the abdomen or hind-body is a little 

 longer than the thorax, is broadest on the basal 

 third, but is remarkably flattened from above down- 

 wards, suddenly terminating in an acute tip ; being 

 very flat above, while on the under side it is fuller 

 and rounder; and when the wings are folded, as 

 at rest, flat upon the back, the tip does not reach to 

 their extremities. The color of the entire body is 

 of a uniform black, the surface highly polished and 

 slightly punctured. The shanks are blackish brown, 

 becoming towards the tip very much paler; the 

 tibiae or second joint is of a pale brown, becoming 

 still paler towards the tip, while the tarsal or foot- 

 joints are at base of a very pale honey-yellow, and 

 the terminal joints are rusty-brown. On the three 

 terminal rings of the abdomen are a few scattered 

 hairs; the ovipositor is slightly exserted, being long 

 enough for the insect to bore through the egg-shell 

 of the moth. 



This belongs to a different genus from the spe- 

 cies mentioned by Herrick and Harris as parasitic 

 in the eggs of the Canker worm moth, since it dif- 

 fers in having a much longer and flatter abdomen, 

 and longer and slenderer antennae. But a more 

 extended notice of its structure and affinities should 

 not detain iis here. The question with us now is, 

 how much does it do in killing ofi", and thus re- 

 straining within proper limits, the injurious insect 

 on which it preys. After seeing how many eggs 

 of the Canker worm are destroyed by the minute 

 fly which I have observed in very considerable 

 numbers laying its eggs in those of the Canker 

 worm late in autumn, we cannot easily overestimate 

 the number of worms they destroy in embryo. 



Having introduced and identified our new Lilli- 

 putian ally, what of the story of her life ? In 

 brief it seems thus. Late in June in New Eng- 

 land (earlier, South), just as the moth has finished 

 laying her eggs, numbers of our friendly flies ap- 

 pear and bore through the egg-shell of the moth to 

 deposit within a tiny egg. The egg hatches, and 

 the microscopic grub ensconces itself in a less vital 

 part of the growing tent caterpillar, in the fatty 

 matter on the back of the worm, and gradually ex- 

 hausts the life of the caterpillar, so that it dies be- 

 fore being large enough to hatch. Upon opening 

 the egg in the fall of the year, instead of the young 

 caterpillar just ready to eat its way through the 

 egg shell, we find our insect friend with its head 

 in the largest end of the shell, which faces outward, 

 and in the autumn a few hatch out. But it is pro- 

 bable that a larger number are born in the early 

 summer. It was evident that the whole group of 

 eggs were destroyed by these parasites, as no cater- 

 pillars hatched from them, since on opening the eggs 

 the flies were found within, and many of the eggs 

 were shrivelled up. Cannot some way be found to 

 breed these minute parasites upon our injurious 

 insects in large numbers in our orchards ? 



A correspondent from Bethlehem, Pa., writes that he 

 has an English Elm (of fifteen years' growth and the 

 only one in the city) that is infected with the larva of a 

 small beetle during the months of May, June and July, 

 eating the leaves and leaving nothing but the skeleton. 

 He describes the larva as being about half an inch in 

 length and hairy, and the perfect insect as a beetle, quar- 

 ter of an inch in length, the wing-cases yellow, with black 

 spots. As to methods of destroying the larvse, he writes 

 as follows : 



"I noticed that in the month of July, the time of the 

 transformation of this insect from the larva to the chry- 

 salis state, tjiey descend, creeping down the limbs and 

 trunk of the tree. For the past few years I watched at 

 thjs season and daily took a broom and brushed down all 

 the larvae to be seen; others, having come down previ- 

 ously, are found lying on the ground near the trunk. 

 Gathering all together as much as possible, I took boiling 

 water and scalded them to death. Not being always on 

 the alert, some will naturally escape, and these propa- 

 gate the mischief for the following season. This year I 

 made an e.xperimeut in trapping the larvae. I cut a band 

 of tin about 2i inches in width, to fit the trunk of the tree, 

 encircling it at an angleof about 43 degrees. At the low- 

 est point I made an opening with a short tube to fit into 

 the mouth of a pickle jar. Along the outer edge of the 

 projecting tin I made a ridge of fresh putty. The larvce 

 finding this tin obstruction in their way down the trunk, 

 will follow its course to the lowest point, and drop into 

 the jar or any vessel that may be attached for their recep- 

 tion. Insects generally, having an instinctive dislike for 

 oil will be kept from creeping over the tin by the putty ar- 

 rangement. This must be renewed as soon as the oil has 

 dried off. but instead of renewing the putty, an application 

 of oil to it will answer the same purpose. The jar I used I 

 intended to hold at least five thousand, if not ten thou- 

 sand, of these worms ; it was filled in the course of twen- 

 ty-four hours, on several successive days. How near I 

 succeeded in getting all, the next. season alone can demon- 

 strate, but the arrangement as a trap was a success. I 

 present my e.xperience for what it may be worth; if 

 there is any better, remedy than the one I applied, I shall 

 be pleased to hear from any of your correspondents." 



Remarks. — From the description given of the larva — 

 "about one-half inch in length and hairy" — it is impos- 

 sible for us to say to what insect it belongs, but should 

 judge it to be the larva of a moth; but our correspondent 

 has evidently confounded his friends with those of his 

 enemies, for, we believe, from the description and figure 

 given of the "perfect insect," that it is a species of lady- 

 bird (Coccinellidie), and probably Sippodamta convergcns 

 Guer. — a friend and not a foe — and which no doubt fed 

 upon a species of gall-producing Aphis, peculiar to the 

 Elm. There is, however, a beetle ( Galeruca calmariensis) 

 that is very destructive to the Elms in Europe, the larva 

 of which is said to be a " thick, cylindrical, blackish, six- 

 footed grub," and sometimes so destructive as to wholly 

 denude the Elms of their leaves. It has been introduced 

 into this country, making its first appearance in the city 

 of Baltimore some twenty-five years ago, where it played 

 havoc with the Elms, entirely defoliating them. Dr. 

 Brackenridge Clemens, of Easton, Pa., informs us that 

 the Elms about that city are defoliated by a yellowish 

 grub, spotted with black, each spot giving out a hair; he 

 says that they are sometimes quite numerous, and de- 

 scend from the tree to change to the chrysalis, which is 

 also yellow; the perfect insect is a beetle, which, from the 

 description he gave of it — obscure yellowish with a black 

 stripe on each elyton or wing-case — seems to be the Ga- 

 leruca calmariensis. We trust that if any of our readers 

 have information concerning the larva referred to by the 

 above correspondent, they will make it known through 

 the columns of this Bulletin. — [Eds. 



