Nov., '03] ENTOMOLOGICAL NEWS. 283 



Through August the pupae of the Diplosis are destroyed in 

 great numbers by two species of Chalcid-flies. Of the first 

 one, a Pteromalid {Sy7itasis diplosidis sp. nov.), I secured 

 numbers of the larvae, pupae and adults, and append a descrip- 

 tion of the adult at the end of this paper. The larva when 

 grown is three millimeters in length, yellowish-white, the skin 

 in very fine transverse ridges. At the articulations between 

 the segments, the ridge is emphasized, and from it grow fine 

 long bristles ventrally, or completely around on a few of the 

 segments (Fig. 6). 



There is but one Syntasis in each larval skin which remains 

 white. The younger ones are attached externally to the Diplo- 

 sis pupae, but when they are fully grown no trace of the pupae 

 remains, not even the tough pupal integument. The parasites 

 lie at the inner end of the larval skin, where the departed 

 host lay. There they pupate, and the adults escape through 

 the tube-like larval skin, just as the host would have done. 

 A whole group of larval skins sometimes changes inhabitants 

 iij this way in August, and whenever a group is invaded by. 

 the Chalcis-fly, the undestroyed pupae will be found dead. 

 When the intruder is present the bark is undermined and brit- 

 tle and the wood friable. Have these things anything to do 

 with the entrance of the parasites ? No larvae or adults ap- 

 peared in my material before August. 



The second species of Chalcid-fly, of which I obtained only 

 a few specimens is a species belonging to the genus Eiipehmis. 

 As the species of Syntasis is an undescribed form,* I give 

 here its description. 



Syntasis diplosidis sp. nov. 



Female. — Length 3.5 mm. — Metallic blue-green, the blue predominat- 

 ing, antennae black except at the base, legs dark at base, yellowish at 

 the tips. 



Head three times as wide as long, rather coarsely confluently punctate, 

 shagreened between the punctures ; lateral ocelli as far from the eye as 

 from the median ocellus ; mandibles yellow, the four teeth at the apex 

 black ; palpi yellow. Antennae twice as long as the head height ; scape 



* Mr. Ashmead, to whom specimens were sent, writes that it is new, 

 and has suggested that it be described in this paper which contains the 

 account of its habits. 



