314 Kansas Academy of Science. 



HABITS OF PARASITIC HYMENOPTERA, II. 



By Charles H. Withington, University of Kansas, Lawrence. 



L YSIPHLEB US CER AS APHIS ( Fitch ) . Plate II. 



DESCRIPTION. 



npHIS parasite "is black with its palpi or feelers and legs pale 

 ^ yellowish brown; antennae almost as long as the body, 18- 

 jointed, the third and following joints equal, cylindric, thrice as 

 long as broad, the last elongated ovate; abdomen elliptic, rather 

 narrower and shorter than the thorax, scarcely pedicelled at its 

 base, shining, tinged with brownish; wings pellucid, stigma smoky 

 white. Length, 0.07." (Fitch's First Annual Report.) 



HABITS AND LIFE-HISTORY. 



Copulation occurs soon after emergence, and the method of ap- 

 proach and action is precisely that described in Lysiphlehus sp. 

 The female seeks her prey, Siphonophora rosm, and deposits her 

 eggs in much the same manner as Lysiphlebus sp. {tritici) , QxcQ-pi 

 that in seven instances out of ten she was seen to bring the tip of her 

 abdomen under her body before she was within half an inch of the 

 aphid. If for some reason the aphid becomes aware of the para- 

 site's presence and begins to move, the parasite will stop and ap- 

 parently watch the aphid, and just as soon as it becomes quiet the 

 Lysiphlehus will thrust her ovipositor into the body of the aphid 

 and then go on in search of another. In one instance a large aphid, 

 upon being disturbed by the parasite, kept jerking her body from 

 side to side for eleven minutes, and during all this time ihe para- 

 site waited. While the parasite is watching an aphid the antennae 

 are not touching the leaf but pointing toward the louse and held 

 perfectly rigid. (Plate II.) 



About three days after the aphid is parasitized it stops repro- 

 ducing, and if examined closely the abdomen is seen to be slightly 

 enlarged, and in two more days a brownish object inside is percep- 

 tible. This at the end of the eighth day resembles a crescent in 

 shape and shows very plainly through the wall of tlie now swollen 

 abdomen. Soon the abdomen begins to turn brown, and two 

 days later the louse becomes attached firmly to the leaf or stem. 

 By this time the body of the parasitized aphid is swollen until it 

 is almost round, light brown in color, and the skin hard and horny 

 in appearance. In five or six days more the parasite is ready to 



