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.