Notes and Glea7iings. 171 



Insects ivjurious to the Aster : Blistering Beetles, Plant-Lice. 

 — I have sometimes been informed by gardeners and otliers that they had aban- 

 doned attempts to cultivate the aster, on account of two troublesome insects 

 which destroyed the plant or the flower. 



These troublesome insects are the Caniharls, or blistering beetle, and the 

 Aphis radicans, or the root plant-louse ; the first destroying the flower, the 

 other a little white aphis, which attacks the root of the plant, sucking all the sap 

 from it, and causing it to wither and die before it comes to the flowering state. 



Of the Cantharis there are at least four species ; viz., C. vittata, C. airata, C. 

 cinerea, and C. marginata. All these species are injurious to vegetation ; but 

 C. airata, a black cantharis, is the rogue with which I am most familiar. I have 

 not been troubled with these plagues for many years. In a dryer soil than that 

 which I now cultivate, I had to contend with them, and made my fingers sore 

 by pinching their heads ; the only method I could devise then to get rid of 

 them. I was ignorant of their medicinal properties ; but the smarting of my 

 fingers induced me to consult Harris, as I always do when I come across an 

 insect which I do not understand. He thus describes them : " The following 

 are the most striking peculiarities of the family to which the blistering-beetles 

 belong. The head is broad and nearly heart-shaped, and it is joined to the tho- 

 rax by a narrow neck. The antennx are rather long and tapering, sometimes 

 knotted in the middle, particularly in the males. The thorax varies in form, but 

 is generally much narrower than the wing-covers. The latter are soft and flexi- 

 ble, more or less bent down at the sides of the body ; usually long and narrow, 

 sometimes short, and over-lapping on their inner edges. The legs are long and 

 slender; the soles of the feet are not broad, and are not cushioned beneath; and 

 the claws are split to the bottom, or double : so that there appear to be four claws 

 to each foot. The body is quite soft, and, when handled, a yellowish fluid, of a 

 disagreeable smell, comes out of the joints. These beetles are timid insects, 

 and, when alarmed, they draw up their legs, and feign themselves dead. Nearly 

 all of them have the power of raising blisters when applied to the skin ; and 

 they retain it when dead and even dry. It is chiefly this property that renders 

 them valuable to physicians. Four of our native cantharides have been success- 

 fully employed, and are found to be as powerful in their effects as the imported 

 species. Occasionally, potato-vines are very much infested by two or three 

 kinds of cantharides, swarms of which attack and destroy the leaves during mid- 

 summer." One of the species attacks the virgin's-bower (C/^;^^//^ Virginiana). 

 Cantharis cinerea begins to appear in gardens about the 20th of June, and at- 

 tacks and almost destroys the English bean. C. atrata, or black cantharis, may 

 be found in great abundance about the middle of August, or before, on potato- 

 vines, tall golden-rod {Solidago altissima), and on the wild indigo-plant ; and 

 this is the species which is a pest to asters in some places, eating oflF the whole 

 of the petals as they are appearing. The moment the plant is touched, they fall 

 to the ground, and make believe dead. They are in such numbers, sometimes, 

 that the disagreeable pinching process will not do much towards their destruc- 

 tion ; and I do not know how they can be got rid of, unless air-slacked lime is 

 strewed over the opening heads of the flowers, and over the ground. 



