— 147 — 



cies when a greater amount of material had been gathered. In such case 

 the later specimens were the safer guides for comparison. 



Mr. Smith instanced as illustrating this point the descriptions of 

 Arciia anna, Grote, and persephone, of the same author, the former 

 species proving to be simply an aberrant form o^ persephone. 



Herbert Osborn presented notes on the origin of the wing in Aicu- 

 rodes, and exhibited slides to illustrate the points observed. *' Slight 

 pressure upon fresh adults of Aleurodes causes the protrusion of pleural 

 folds upon the pruthorax and the abdominal segments. These pro- 

 trusions agree precisely in outline and position with the ex[)anded 

 pleural portions of the same parts as seen in prepupal and pupal stages. 

 Specimens in different stages of development show a modification of 

 this pleural portion in meso- and meta-thorax during prepupal and 

 pupal stages to form more contracted, denser and darker colored parts 

 from which the wings of imago are produced. The pleural expansions 

 of prothorax and abdomen are simply contracted to conform to the 

 outline of the body when the imago issues from the scal^, but are readi y 

 extended by pressure. No such protrusit)ns occurring on the meso- 

 and meta-thorax would seem to indicate that the portion thus extended 

 on the other segments has in these been transformed into the sack-like 

 expansion of wings. "' 



The time for the convening of section "F' having arrived it was 

 decided hj motion that the Club should meet again immediately after 

 adjournment of the section and also at nine o'clock in the morning and 

 after adjournment of section "F" in the afternoon of the followuig day. 



The Club reconvened at 3:30 and a paper by Clarence M. Weed 

 on the parasites of the honey-suckle Sphinx, Hemaris dijffinis, Boisd, , 

 was read by the Secretary. 



On the Parasites of the Honey-Suckle Sphinx, Hemaris diffinis, Boisd. 

 By Clarence M. Weed. 



Last August my attention was called to a parasitic attack upon the 

 lar\'3e of Hemaris diffinis which were then abundant upon the bush 

 honey-suckle ( Diervilla irifida ) on the grounds of the University of 

 Illinois; and a large number of the larvae were collected and the para- 

 sites bred. So far as I am able to learn from an examination of the 

 Uterature at hand no parasites of this Sphinx have as yet been recorded. 



The insects engaged in the attack belonged to three different spe- 

 cies — two being primary parasites and the third a secondary parasite. 

 The first two were Rhogas fiimipcnuis, Cresson, and an apparently un- 

 described variety o^ Apanteles limettilidis, Riley; while the third, which 

 attacks the Apanteles is a species of Hemiteles, probably undescribed. 



