ENTOMOLOGY.
[Footnote: From the American Naturalist, November, 1882.]
THE BUCKEYE LEAF STEM BORER.--In our account of the proceedings of the entomological sub-section of the A.A.A.S., at the 1881 meeting (see American Naturalist, 1881, p. 1009), we gave a short abstract of Mr. E.W. Claypole's paper on the above insect, accepting the determination of the species as Sericoris instrutana, and mentioning the fact that the work of Proteoteras æsculana Riley upon maple and buckeye was very similar. A letter recently received from Mr. Claypole, prior to sending his article to press, and some specimens which be had kindly submitted to us, permit of some corrections and definite statements. We have a single specimen in our collection, bred from a larva found feeding, in 1873, on the blossoms of buckeye, and identical with Mr. Claypole's specimens, which are in too poor condition for description or positive determination. With this material and with Mr Claypole's observations and our own notes, the following facts are established:
1st. We have Proteoteras æsculana boring in the terminal green twigs of both maple and buckeye, in Missouri, and often producing a swelling or pseudo-gall. Exceptionally it works in the leaf-stalk. It also feeds on the samara of maple, as we reared the moth in June, 1881, from larvæ infesting these winged seeds that had been collected by Mr. A.J. Wethersby, of Cincinnati, O.
2d. We have an allied species, boring in the leaf-stalk of buckeye, in Ohio, as observed by Mr. Claypole. It bears some resemblance to Proteoteras æsculana, but differs from it in the following particulars, so far as can be ascertained from the poor material examined: The primaries are shorter and more acuminate at apex. Their general color is paler, with the dark markings less distinctly separated. No distinct tufts of scales or knobs appear, and the ocellated region is traversed by four or five dark longitudinal lines. It would be difficult to distinguish it from a rubbed and faded specimen of æsculana, were it not for the form of the wing, on which, however, one dare not count too confidently. It probably belongs to the same genus, and we would propose for it the name of claypoleana. The larva is distinguished from that of æsculana by having the minute granulations of the skin smooth, whereas in the latter each granule has a minute sharp point.
3d. Sericoris instrutana is a totally different insect. Hence our previous remarks as to the diversity of food-habit in this species have no force--C.V.R.
DEFOLIATION OF OAK TREES BY DRYOCAMPA SENATORIA IN PERRY COUNTY, PA.--During the present autumn the woods and road-sides in this neighborhood (New Bloomfield) present a singular appearance in consequence of the ravages of the black and yellow larva of the above species. It is more abundant, so I am informed, than it has ever been before. In some places hardly any trees of the two species to which its attack is here limited have escaped. These are the black or yellow oak (Q. tinctoria) with its variety (coccinea), the scarlet oak and, the scrub oak (Q. ilicifolia). These trees appear brown on the hill-sides from a distance, in consequence of being altogether stripped of their leaves. The sound of the falling frass from the thousands of caterpillars resembles a shower of rain. They crawl in thousands over the ground, ten or twelve being sometimes seen on a square yard. The springs and pools are crowded with drowned specimens. They are equally abundant in all parts of the county which I have visited during the past week or two--the central and southeastern.--E. W. Olaypole, New Bloomfield, Pa.
EFFICACY OF CHALCID EGG-PARASITES.--Egg-parasites are among the most efficient destroyers of insects injurious to vegetation, since they kill their victim before it has begun to do any damage; but few persons are aware of the vast numbers in which these tiny parasites occasionally appear. Owing to the abundance of one of them (Trichogramma pretiosa Riley), we have known the last brood of the cotton-worm to be annihilated, and Mr. H.G. Hubbard reported the same experience at Centerville, Fla. Miss Mary E. Murtfeldt has recently communicated to us a similar experience with a species of the Proctotrupid genus Telenomus, infesting the eggs of the notorious squash-bug (Coreus tristis). She writes: "The eggs of the Coreus have been very abundant on our squash and melon vines, but fully ninety per cent. of them thus far [August 2] have been parasitized--the only thing that has saved the plants from utter destruction."
ON THE BIOLOGY OF GONATOPUS PILOSUS Thoms--Professor Josef Mik, in the September number of the Wiener Entomologische Zeitung (pp. 215-221, pl. iii), gives a most interesting account of the life history of the curious Proctotrupid, Gonatopus pilosus Thoms., which has not before been thoroughly understood. Ferris, in his "Nouvelles excursions dans les grandes Landes," tells how, from cocoons of parasitic larvae on Athysanus maritima (a Cicadellid) he bred Gonatopus pedestris, but this he considered a secondary parasite, from the fact that it issued from an inner cocoon. It appears from the observations of Mik, however, that it was in all probability a primary parasite, as with the species studied by the latter (G. pilosus) the larva spins both an outer and an inner cocoon. The larva of Gonatopus pilosus is an external parasite upon the Cicadellid Deltocephalus xanthoneurus Fieb. The eggs are laid in June or July, and the larvae, attaching themselves at the junction of two abdominal segments, feed upon the juices of their host. But one parasite is found upon a single Cicadellid, and it occasionally shifts its position from one part of the abdomen to another. Leaving its host in September, it spins a delicate double cocoon in which it remains all winter in the larva state, transforming to pupa in May, and issuing as an imago in June.
It will be remembered that the female in the genus Gonatopus is furnished with a very remarkable modification of the claws of the front tarsi, which are very strongly developed, and differ somewhat in shape in the different species. It has usually been supposed that these claws were for the purpose of grasping prey, but Professor Mik offers the more satisfactory explanation that they are for the purpose of grasping the Cicadellids, and holding them during the act of oviposition.
It is interesting to note that there is in the collection of the Department of Agriculture a specimen of Amphiscepa bivittata Say, which bears, in the position described above, a parasitic larva similar to that described by Mik. It left its victim and spun a white cocoon, but we failed to rear the imago. It is probably the larva of a Gonatopus, and possibly that of the only described American species of the genus, Gonatopus contortulus Patton (Can. Ent., xi p. 64).
SPECIES OF OTIORHYNCHIDAE INJURIOUS TO CULTIVATED PLANTS--Of our numerous species of this family, we know the development and earlier stages of only one species, viz, Fuller's rosebeetle (Aramigus Fulleri[1]). A few other species have attracted attention by the injury caused by them as perfect insects. They are as follows: Epicoerus imbricatus, a very general feeder; Pachnoeus opalus and Artipus floridanus, both injurious to the orange tree. Of a few other species we know the food-plants: thus Neoptochus adspersus feeds on oak; Pachnoeus distans on oak and pine; Brachystylus acutus is only found on persimmon; Aphrastus toeniatus lives on pawpaw (but not exclusively); Eudiagogus pulcher and rosenschoeldi defoliate the coffee-weeds (Cassia occidentalis and other species of the same genus). Two very common species, Pandeleteius hilaris and Tanymecus confertus, appear to be polyphagous, without preference for any particular plant. Very recently the habits of another species, Anametis grisea Horn, were brought to our knowledge by Mr. George P. Peffer, of Pewaukee, Wis., who sent us specimens of the beetle accompanied by the following communication: "The larger curculio I send you is working around the roots of apple and pear trees, near the surface of the ground or around the union where grafts are set. I found fifteen of the larvae on a small tree one and a half inches in diameter. The beetle seems to lay its eggs just where the bark commences to be soft, near or partly under the ground. The larvae eat the bark only, but they are so numerous as to girdle the tree entirely in a short time."--C. V. Riley.
[Footnote 1: Vide Annual Report Department of Agriculture, 1878, p. 257.]
BOMBYLIID LARVAE DESTROYING LOCUST EGGS IN ASIA MINOR.--The eggs of locusts in Cyprus and the Dardanelles, as we learn from the Proceedings of the London Entomological Society, are much infested with the parasitic larvae of Bombyltidae, though these were previously not known to occur on the island. This fact shows that the habit which we discovered among some of our N. A. Bombyliids recurs in other parts of the world, and we have little doubt that careful search among locust eggs will also reveal the larval habits of some of the Meloïdae in Europe and elsewhere. Indeed, notwithstanding the closest experiments of Jules Lichtenstein, which show that the larva of the Spanish blister-beetle of commerce will feed on honey, we imagine that its more natural food will be found in future to be locust eggs. The particular Bombyliid observed by Mr. Frank Calvert destroying locusts in the Dardanelles is Callostoma fascipennis Macq., and its larva and pupa very closely resemble those of Triodites mus. which we have studied and figured (see Vol. XV., pl. vi.). We quote some of Mr. Calvert's observations:
"On the 24th of April I examined the larvae in the ground; the only change was a semi-transparent appearance which allowed of a movable black spot to be seen in the body. On the 8th June about fifty per cent. of the larvae had cast a skin and assumed the pupal state in their little cells: the color yellowish-brown, darkening to gray in the more advanced insect. About one per cent. of the cells, in which were two skins and an aperture to the surface, showed the perfect insect to have already come out of them. A gray pupa I was holding in my hand suddenly burst its envelope, and in halt a minute on its legs stood a fly, thus identifying the perfect insect.... I found the fly, now identified, sucking the nectar of flowers, especially of the pink scabious and thistle, plants common in the Troad. (Later on I counted as many as sixteen flies on a thistle-head.) The number of flies rapidly increased daily until the 13th, when the ground appeared pitted all over with small holes from whence the parasite had issued. A few pupae were then still to be found--a larva the rare exception. The pupal state thus seems to be of short duration. It was very interesting to watch the flies appearing above ground; first the head was pushed out; then, with repeated efforts, the body followed; the whole operation was over in two or three minutes; the wings were expanded, but the colors did not brighten until some time after. Occasionally a pupa could not cast off its envelope, and came wriggling out of the ground, when it was immediately captured by ants. Unfortunate flies that could not detach the covering membrane adhering to the abdomen, also fell a prey, as indeed many of the flies that could not get on their legs in time. The flies for the first time 13th June, were seen to pair, but this rarely."