2430 Tee Zoologist — January, 1871. 



been published that it is herbivorous, and thus different from all or 

 nearly all other Chalcidiae, for they are carnivorous in the larva 

 state. The following extract from Nees von Esenbech's ' Hynien- 

 opterorumlchnenmonibus aflBnium Monogvaphia,' voh ii., indicates 

 that the species mentioned (Isosoraa verticilkxta) forms galls on the 

 rose-bush or is parasitic on a gall-maliing insect: — " Feminam, in 

 galla parva globosa sanguinea folii Rosa3 insidentem, misit CI. 

 Gravenhorst, hoc situ a sese prope Brunsvicum captam." One 

 species is said to be very injurious to corn and another to the 

 grape. 



From 'The Practical Entomologist' (vol. i., Philadelphia, 

 18G5) : — "For many years back it has been known that whole 

 fields of wheat, rye and barley have been destroyed in the Slates 

 bordering on the Atlantic by a minute insect popularly called the 

 ' joint-worm.' All accounts agree in slating that this so-called 

 'worm' is found in considerable numbers imbedded in a small, 

 gall-like swelling in or immediately above the second joint of the 

 straw, or at all events some joint not far from the grotnid; and 

 that, in consequence of its operations, the ])ortion of straw above 

 the gall-like sn'cUing withers and comes to nothing. Both Dr. Fitch 

 and Dr. Harris were originally of opinion that the joint-worm was 

 the larva of a Cecidomyia or gall-gnat, the same genus of insects 

 to which appertain the common Hessian fly and the wheat-midge. 

 Subsequently, however, because from a large quantity of the 

 diseased straw they never bred anything but Chalcis flies, they 

 both of them came to the conclusion that it must be the Chalcis 

 flies that were the cause of the disease. We have referred this 

 subject to Mr. Benj. D. Walsh, of Rock Island, Illinois, who has 

 paid special attention to the natural history of galls, and has pub- 

 lished papers in our Proceedings on the galls of the willow and the 

 oak. He answers as follows : — ' I strongly incline to believe that 

 the joint-worm must be the larva of some gali-gnat, and not, as 

 certain authors have supposed, of a Chalcis fly, for the following 

 reasons,'" &c. 



Dr. Walsh subsequently published a detailed history of the joint- 

 worm in the 'American Entomologist,' vol. i. p. 149 (April, 1869), 

 from which the following are extracts; — 



" In certain years, and in particular Stales, the crops of wheat, 

 of barley, or of rye, are observed to be greatly injiiied by a minute 

 maggot, popularly known as the 'joint-worm.' It inhabits a little 



