50 THE REPOET OF THE Xo. 36 



NOTE ON PHYSONOTA UNIPUNCTA (COLEOPTEEA). 



Albert F. Winn", Westmount, Que. 



In several parts of Mt. Eoyal Park, Monti'eal, there flourish large patches 

 of a wild sunflower, Helianthus decapetalns, notably around the edges of the open 

 area south and west of the toboggan slide, known as the "riding ring." This 

 plant has long been known to local entomologists as the food of a species of Tortoise- 

 beetle, and the early volumes of the Canadian Entomolo.jisP' contain several 

 articles by Caulfield and others relative to its habits and life-history. 



Like most other insects, Physonota unipuncta has its years of abundance, and 

 years when it seems to be wholly absent; but when common it is a most attractive 

 beetle, resting quietly on the upper side of the leaves on a hot July day, its brilli.mt 

 green and gold hues looking as if they belonged to a tropical insect. The ugly, 

 soft, spiny larvae with their forked tails recurved over the body and covered with 

 remnants of cast off skins and excrement as is usual among the Cassidhii; and the 

 yellow and black pupge — vaguely recalling in shape the horse-shoe crabs of the 

 Atlantic coast — are also common on the plant. 



By the end of August and early September, beetles again are seen on the 

 leaves, but very different from the midsummer ones. There is not a trace of 

 metallic green, but a sombre black and white, some examples mostly white, others 

 with the black preponderating. Mr. Caulfield, AV'ho spent a good deal of time 

 studying the beetle ahvays iised to refer to the summer and the autumn hroods in 

 just the same way that Lepidopterists speak of seasonally dimorphic butterflies 

 and moths. On many occasions I have observed the beetles at rest and the larvie 

 at work, but as the adults, both green and black and white, have a most un- 

 fortunate habit of losing all their beauty and markings, becoming a uniform 

 sickly yellow in cabinet specimens I have not paid much attention to the insect 

 further than occasionally collecting a few laxvse along with other live stock to 

 rear at home. 



A few years ago, however, I was hunting aroimd-in the late fall for evidences 

 of Lepidopterous boring larvae in various plants, and this Helianthus came in for 

 a little digging up Sy the roots, but very little injury was found. ~ During the 

 operations, among the. earth upturned, a Physonota was noticed, and to my great 

 surprise it was in its glorious green dress. No others were found, and although 

 the matter seemed puzzling and contrary to what might be expected, a possible 

 explanation M^as that occasional specimens of the early or summer brood went into 

 hibernation. 



Recently I had occasion to ask our good friend Mr. Morris, of Peterborough, 

 whose papers on the relation of beetles to certain plants have been so interesting, 

 whether Physonota was among his acquaintances. He replied that he had not 

 found it, but would like to get some, so a look-out was kept for larvae, and in July 

 a box of larva3 and some leaves was sent. They reached him just before he v/as 

 leaving for a vacation and he had a considerable amount of difficulty in finding an 

 acceptable substitute for Helianthus decapetalus, and then had to find some one 

 willing to look after the welfare of the repulsive looking grubs. He succeeded in 

 doing both and reared some of the beetles. 



Early in September I found that the sunflower had spread very much at the 

 back of the western part of our Mountain, where ir used to be rarely met with, and 



*Caulfield, Can. Ent, xvi, 227 (1884); xviii, 41 (1886.) 

 Hamilton, Can. Ent. xvi, 134 (1884); xviii, 113 (1886.) 



