On Certain Seed-Infesting Chalcis-Flies, 381 



males reared are much darker than the females. The face and cheeks 

 are yellow; the legs dull yellowish and the antennae more yellowish 

 than in female. Head and thorax black except a small spot on each 

 side between the ocelli and the eyes and an area on the lateral aspect 

 of the prothorax, which are brownish yellow. 



Abdomen compressed, seen from the side, elongate triangular, rounded 

 behind, brown-black above and yellowish brown beneath and at apex. 



The larva is white, smaller than the larva of the Apple-seed Chalcis, 

 and may be distinguished by having the mandibles with four teeth on 

 the inner margin (Figs. 78 and 79) and by lacking the brown tubercles on 

 the face. 



In addition to rearing the adult insect at Ithaca, infested berries of 

 the Mountain Ash have been found at Weedsport, Jamesville and Way- 

 land, N. Y. 



THE ROSE-SEED MEGASTIGMUS 



{Megastigmus aculeatus Swederus) 



This is a common enemy of rose-seed in Europe, where it has been 

 known for over a century. It was first described in 1795 by N. S. 

 Swederus," but owing to the common belief that all Chalcids are parasitic 

 on other insects its true life history was not established until the publica- 

 tion of Wachtl's observations in 1884. Ratzeburg," in 1848, reported 

 that it had been reared by Bouche from the larva of a Trypcta fly that 

 infests the flesh of the rose-fruit. In 1857, Reinhard'* reared them in 

 numbers and noted the significant fact that while the fly larvae are known 

 to go into the ground in the fall the Megastigmus remains in the fruit 

 over winter. He had also seen it ovipositing in the rose-hips. In 

 1876, Perris^^ published the results of four years' experience in rearing 

 the adults. He first noted that the rose-hips which he collected had 

 the pulp intact and contained no insects on which the Megastigmus 

 could be a parasite. He then discovered the exit holes in the seeds 

 through which the adults had escaped. In conclusion he asks, "Must 

 we conclude from these facts that this is a seed-eating insect ? ' ' and 

 answers, "It is more than probable. I shall continue my dissections 

 and rearings. ' ' Unfortunately he never published any further obser- 

 vations on the subject. 



" Vetensk. Acad, nya Handl., XVI., p. 221, 1795. 

 "^Ichneum. Forstinsect., II., p. 182. 

 " Berl. Ent. Zeitschr.. I., p. 76. 

 ^*Ann. Soc. Ent. Fr.. 1876, p. 222. 



