JOURNAL 



JOfto "^uvk €lntomoIogirfll KoriFJ^g. 



Vol. XXIX. SKPTK\mKH -December, 1921. Nos. 3 and 4. 



NOTES ON MILKWEED INSECTS IN NEW JERSEY. 



By Harry B. Weiss and Edgar L. Dickerson. 

 Xkw Brlxswick, X. J. 



In the following notes which are the results of nearly a year's 

 observations on the insects associated with Asclepias syriaca (A. 

 cormiti), the common species of the eastern states, and Asclepias 

 nilchra. which is considered a variety of Asclepias incarnata, special 

 attention is paid to those species about which little or nothing has 

 been recorded heretofore. However, in order to make the paper more 

 complete, it was thought desirable to treat other milkweed insects 

 briefly and to indicate where important papers relating to them could 

 be found. 



The milkweeds which are persistent perennials in many waste 

 places are widely distributed in North America and are best recog- 

 nized by their opposite or whorled leaves, flat-topped clusters of 

 showy flowers and their milky juice. In the flowers, the stamens 

 are united at least at the base and each of them bears a large dorsal 

 appendage. These appendages together form the corona. Especially 

 characteristic are the club-shaped pollen masses or pollinia. l-'or the 

 ;^(Urpose of pollination by insects, the pollinia are attached in pairs to 

 a corpusculum or glandular outgrowth of the stigma. 



.\ paper on milkweed insects would not be complete without ref- 

 erence to Robertson's writings on the '" Insect Relations of Certain 

 Asclepiads" (Bot. Gaz., Vol. 12. 1887, pp. 207-216; pp. 244-250; 

 Trans. St. Louis Acad. Set.. iSqf. pp. 569-577). In tiie first paper, 

 "ihe various species of Asclepias arc treated together with notes on 



