Some Studies of the Development of Lixus concavus, Say, 
and L. macer, Leconz/e. 
By F. M. Wesster. 
Concerning the habits and transformations of the twenty-five species 
of the genus Zzvus, inhabiting North America, North of Mexico, very 
little appears to have been learned ; the limited information we possess 
relating exclusively to but three species. 
From the fact that adults of Zevus rudel/us, Rand, have, on two oc- 
casions, been observed in considerable numbers clinging to the blossoms 
and leaves of an aquatic plant, Polygonum amphibium, this insect is sus- 
pected of infesting that plant, the theory being strengthened somewhat by 
the fact that Z. paraplecticus, an European species. breeds in the stems of 
Sium, or Water Parsnip. (Rep’t Com. Agr., 1870, p. 71.) The larve 
of another European species, Z. angustfatus, is said to mine in the stalks 
of beans. 
Lixus parcus, a native of California, is said by Prof. Riley to form 
galls in the stems of Amelanchier. (Proc. Ent. Soc, Wash., Vol. I, p. 33.) 
A single short notice, printed in 1866, by Mr. Townend Glover, 
contains all the published information we have respecting the life-history 
of concavus. Mr. Glover states that he observed the female beetle ‘‘bur- 
rowing into the foot-stalks of rhubarb, or pie-plant, and there depositing 
a single egg in each hole.” The observer failed to rear the young, how- 
ever, as the litter died in a few davs, as soon as the stalks became with- 
ered. (Rep’t Com. Agr., 1865, p. go.) 
Of the early stages of macer, we likewise have but little published 
information. Prof. Riley reared it in 1872 from Chenopodium hybridum, 
but the girdling habit of the larvae was not observed by him. (Loc. Cit.) 
Mr. D. W. Coquillett, in a short article published in 1883, (Can. Ent., 
Vol. XV, p. 113), states that on July 13th, 1881, near Woodstock, Mc- 
Henry County, Illinois, he observed a female of this species busily engag- 
el in gnawing holes in the stems ofa green Helanthus grosseserratus, or 
Wild Sun-flower. There were several holes in the stem, and in each he 
found one or two ezgs, of an elliptic ovoid form, polished, pale yellow, 
an 1 measuring about two and one-fourth mm. in length. In the stems 
of other similar weeds growing near by, he found several recently hatched 
larve. Stems of the same species of weed were examined during the 
Summer, and larve in different stages of their growth were observed: 
Sometimes two or three in the same plant. Late in October, pieces of 
these stems, from one and a half to three feet long, were found lying about 
on the ground, evidently having been gnawed off from within, excepting 
