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: