32 PROCEEDINGS OF THE NATIONAL MUSEUM vol.80 



Male. — Similar to the female ; antennae of allotype 44-segmented. 



Type.— U.S.N.M. No. 43501. 



Type locality. — ^Whitesbog, N. J. 



Host. — Ancylis^ species near comptatui Frolich. 



Remarks. — ^Described from nine female and six male specimens 

 reared by H. B. Scammell July 30 to August 8, 1916, in the Bureau 

 of Entomology under Quaintance No. 12782. I have seen one other 

 specimen, not part of the type series, which is in the collection of 

 the gipsy moth laboratory and which was taken at North Saugus, 

 Mass., June 14, 1906, by E. A. Back. 



21. MACROCENTRUS ANCYUVORUS Rohwer 



Macrocentrus ancylivora Rohweb, Proc. Ent. Soc. Washington, vol. 25, p. 168., 

 1923. 



Type. — In the United States National Museum. 



This species is of particular interest to economic entomologists at 

 the present time owing to the apparent importance it has assumed 

 as a parasite of the introduced oriental fruit moth {Laspeyresia 

 molesta Busck). It is, however, only one of several species of 

 Macrocentrus that are being obtained from the larvae of that pest in 

 the eastern part of the United States, and because of the variation 

 occurring within species and the little attention that has been given 

 to the classification of the species of Macrocentrus^ some uncertainty 

 has existed regarding the identity of specimens reared from L. 

 molesta. 



From delicatus, which in some areas appears to be at least as im- 

 portant a parasite of the fruit moth as ancylivortis, the latter is easily 

 distinguished by having the first tergite more or less impressed at 

 base, with the spiracles not beyond the basal fourth, while in delicatus 

 there is not even a suggestion of an impression at base of first tergite 

 and the spiracles are much beyond the basal fourth ; in addition, the 

 stigma of delicatus is always pale yellow, the radius arises from 

 much beyond the middle of stigma, the nervulus is usually postfurcal 

 by as much as its own length, and the antennae are usually 48 to 55 

 segmented; ancylivorus has the stigma usually brown, with a large 

 pale spot at base, the radius arising from only slightly beyond middle 

 of stigma, the nervulus never postfurcal by as much as its own 

 length, and the antennae usually 42 to 48 segmented. 



From instdbilis and laspeyresiae.^ which are rather less commonly 

 reared from L. molesta.^ ancylivorus is sometimes less easily dis- 

 tinguished. It differs from both species, however, in the shorter 

 palpi, the longest segment of maxillary palpus being no longer, 

 usually shorter, than the second segment of the antennal flagellum, 



