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JOURNAL OF VARIATION. 



Vol. XXIII. No. 1. January 15th, 1911. 



Notes on Hellinsia osteodactyla, Z. {tn'th two plates). 



By Dk. T. a. CHAPxMAN, F.Z.S., and EDWARD GOODWIN. 



Mr. Edward Goodwin has supplied the following notes on this 

 species, and the editor asks me to add a few others on the structure, 

 and some other items about the species. 



Mr. Goodwin says, " In the autumn of 1908 I found about 50 

 larvfe of this species. They were spun up each in a seed-down (pappus) 

 in which they hybernate, and in some cases (probably nearly all) 

 pupate. These seeds are practically all blown off the dead stalks during 

 the winter, and H. osteodactt/la larvse with them, as I carefully examined 

 a lot of dead stalks in the following March. Very few seeds remained 

 on, and all I could find was one dead larva. 



Those I found in the autumn were put in a cage with plenty of 

 the foodplant, but at no time could I find any trace of feeding having 

 taken place. During the following April and May T searched the cage 

 for larvfB and had some difficuliy in finding about a dozen. Some of 

 these I placed in a chip box with some seed heads, which they spun 

 to the edge of the box, but all died before pupating. All my efltbrts to 

 find a pupa in the cage during June and July were futile, though four 

 perfect insects emerged early in August. 



The following autumn I again visited the locality, but to my 

 surprise the larvae were exceedingly scarce and I could find only half- 

 a-dozen. These I sleeved on the foodplant outdoors. On June 20th I 

 found that two of the larvae had spun together some seed heads to the 

 side of the sleeve. I transferred these to a large glass bottomed box 

 Avhich I inverted over some moss and placed it so that it would get a 

 little sunshine. This treatment was successful as both eventually 

 pupated about the third week of July, one in the pappus and one in the 

 moss and were then forw^arded to Dr. Chapman." 



The larva of H. osteodactyla presents the following characters, as 

 taken from the table in Tutt's British Lepidoptera, vol. v., p. 106. 

 The prothuracic plate has five hairs in the front row, three behind (on 

 each side), two small lenticles, a suture, no depression, and points as 

 minute plates as on the rest of the larva. The hairs i, ii, iii, iv, 

 and V are simple, no warts developed, vi has several small acces- 

 sory hairs, but there are no warts developed and no secondary skin 

 hairs. The most pronounced feature of the larva is that the skin 

 points are developed in small plates or scutcheons, largest and most 

 pronounced dorsally. 



