AET. 23 REVISION OF MACROCENTEUS MUESEBECK 39 



26. MACROCENTRUS AEGERIAE Rohwer 



Macrocentrus aegeriae Ron wee, Proc. Ent. Soc. Wasliington, vol. 17, p. 56, 1915. 



Type. — In the United States National Museum. 



Rather easily distinguished from other Nearctic species by the 

 characters ascribed to it in the key. Apparently it is most similar 

 to meUifes but differs especially in the black posterior tibiae. It is 

 exceedingly close to the European mar^ginator (Nees), and may, in 

 fact, be identical with that species, which is also a parasite of 

 Aegeriidae, but I should like to see additional material of marginator 

 before s^monymizing aegeriae with it. 



In length aegeriae ranges from 6 mm. to nearly 10 mm. The head 

 is only very little wider than thorax ; face broad, punctate ; clypeus 

 large; eyes not large; malar space usually longer than basal width 

 of mandible ; antennae 41 to 49 segmented ; longest segment of max- 

 illary palpus slightly longer than second segment of antennal fla- 

 gellum; mesopleura closely punctate below; metapleura punctate; 

 apical teeth of middle and posterior trochanters well developed ; first 

 cubital cell very large, at least as long as first discoidal ; second ab- 

 scissa of cubitus much more than half as long as recurrent vein; 

 radius arising from far beyond middle of stigma; submedian cell 

 sparsely hairy; nervulus usually postf ureal by less than half its 

 length ; mediella usually a little more than twice as long as the lower 

 abscissa of basella, the latter about as long as nervellus; abdomen 

 with first two tergites, and usually more or less of third, aciculate; 

 first tergite strongly impressed at base; ovipositor sheaths fully as 

 long as the body. Black; antennae black; lower part of meso- 

 pleura and the mesosternum often ferruginous; legs testaceous, the 

 posterior femora at apex, posterior tibiae except at base, and the pos- 

 terior tarsi, black; wings subhyaline; stigma entirely brown; veins 

 brown. 



The material examined consists of the type and about 30 addi- 

 tional specimens in the national collection from localities in New 

 York. Pennsylvania, Connecticut, Virginia, West Virginia, Michi- 

 gan, North Carolina, Mississippi, Louisiana, Kansas, Idaho, Cali- 

 fornia, and Washington; and two specimens in the collection of the 

 Boston Society of Natural History, from New Hampshire and 

 Maine, respectively. Hosts recorded in the case of the material in 

 the National Museum include Synanthedo7i castaneae Busck, S. ex- 

 itiosa Say, S. pictipes Grote and Robinson, S. tipuliformis Linneaus, 

 S. ainerlcana Beuteimiuller, Proteopteryx holUaiia Slingerland (?), 

 Laspeyresia cupressana Kearfott, an undetermined aegeriid larva 

 in flowering dogwood, and an undetermined larva in rhododendron. 



