ART. 23 REVISION OP MACROCENTRUS MUESEBECK 21 



11. MACROCENTRUS AMICROPLOIDES Viereck 

 Macrocentrus cmiicroploides Viebex:k, Proc. U. S. Nat. Mus., vol. 43, p. 579, 1912. 



Type. — In the United States National Museum. 



This species, which is a common gregarious parasite of various 

 leaf-rollers, is relatively easily distinguished from all related forms 

 by having the base and apex of stigma conspicuously pale, by the 

 larger eyes and ocelli, b}^ the narrower face, and by the color of the 

 head and thorax. Eyes large; malar space usually less than basal 

 width of mandible; face but very little or no broader than long; 

 ocell-ocular line hardly one and one-half times as long as diameter 

 of a lateral ocellus ; longest segment of maxillary palpus a little longer 

 than second segment of antennal flagellum ; antennae normally 42 to 

 48 segmented ; male scape somewhat swollen ; propodeum finely rugu- 

 lose; metapleura roughened j)osteriorly ; apical teeth of trochanters 

 minute, indistinct; radius arising from very slightly beyond middle 

 of stigma; submedian cell closely hairy, not glabrous apically; medi- 

 ella twice the lower abscissa of basella, the latter distinctly longer 

 than nervellus ; abdomen very slender, first, second, and usually most 

 of third, tergites closely longitudinally striate ; the first deeply exca- 

 vated at base; second tergite much longer than broad, the lateral 

 depressed margins very narrow; third tergite usually longer than 

 broad, at least in the female; ovipositor sheaths slightly longer than 

 the body. 



In color the species is extremely variable. The color of the head 

 ranges from entirely yellow to mostly black; nearly always at least 

 occiput and vertex are blackish, the face more or less brownish and 

 never entirely black; the thorax also varies from entirely testaceous 

 to mostly black, but the sternum and lower part of pleura are vir- 

 tually always pale, with the pronotum never blackish even in the 

 darkest specimens; dorsum of abdomen most frequently black, al- 

 though sometimes mostly yellowish; in the darkest specimens the 

 sternites, too, are blackish ; legs entirely yellow ; wings hyaline, veins 

 brownish, stigma brown, conspicuously pale at base and at apex and 

 usually along anterior margin. 



The national collection contains many specimens representing a 

 range in distribution from Massachusetts to California; in addition 

 to the type, two from Darby, Mont., are recorded as having been 

 reared from Gacoeda argyrospila Walker, and two from St. Annes, 

 Quebec, as having been obtained from Tmetocera ocellana Schiffer- 

 miiller. Much additional material in the collection of the gipsy- 

 moth laboratory has been examined. This includes series reared 

 from Gacoeda rosaceana Harris, C. rosana Linnaeus, Pyrausta per- 

 textalis Lederer, and Harpipteryx frustrella Walsingham, taken at 

 various New England localities. 



