THE COTTONWOOD LEAF-BEETLE. 
427 
6. Dorytomus mucidus Say. 
This insect is found running on and flying about cotton wood trees 
early in April and again in August. In October it is found under 
dead bark of trees in winter quarters. Common. Illinois. (A. S. 
McBride. Can. Ent., xii, p. 106.) 
7. Eros coccinatus Say. 
Found in April in Illinois in the cottonwood, under logs in the woods. 
(McBride, loc. eit.) 
8. Wallastonia quercicola (Boheman). 
This was taken by Mr. W. Knaus from " cottonwood logs in a some- 
what advanced state of decay." 
The beetle appears in Kansas in June and July. " The present 
season I took about a dozen specimens from logs that had been used in 
a stable for the past seventeen years ; a number were taken from the 
larval burrows, and numbers of small white fleshy larvae were also 
observed in the same pieces of timber ; these larvae, I feel confident 
were those of W. quercicola, but as I found no pupae and did not con- 
tinue my observations on their transformation, I can not speak with 
absolute certainty." He was strengthened in the conviction that the 
arvae of this weevil are wood-eating by the fact that it has a close 
structural relation to the Scolytidae. (Bulletin Brooklyn Ent. Soc, vii, 
p. 150.) 
9. Mecas inornata (Say). 
3ffr. Walsh has described the excresence made by this borer in the 
saplings of the cottonwood and willow in Illinois. 
A rather sudden swelling on such of the main stems as are .50 to 1.25 inch in diame- 
ter, cracking open in two or three deep, irregular scabrous, brown, more or less trans- 
verse, gaping, thick-lipped fissures. This is the appearance presented as early as 
August and until the following spring; but July 19 nothing is seen but a smooth, 
elongate swelling of the stem, pithy inside, and without 
any cracks or roughness outside, and undistinguishable 
externally from the tenthredinidous gall, S. nodus n. sp., 
in the form in which it occurs on "the same willow later in 
the season. Very probably, however, as with many if not 
all Saperdo?, the larva is at least two seasons in arriving at 
maturity, and the normal appearance of the pseudo-gall is 
not assumed until the following season. The insect does 
not make its way out in spring through the deep cracks of 
this pseudo-gall, but each bores a hole for himself in the 
manner usual in this family. The gall on the cottonwood 
is absolutely identical with the willow-gall, and was recog- 
nized by myself as such at the first glance. It was found 
exclusively on young saplings. In both cases it was per- 
fectly healthy plants that were attacked. Although this 
pseudo-gall weakens mechanically the stem upon which it 
grows, and to such an extent that it occasionally causes 
the stem to break in two with the wind, yet otherwise the 
stem never perishes, but on the contrary the wound is gradually healed and over 
grown by fresh woody matter (Walsh). 
\W 
Fig. 156.— Hecas inorftata.— 
Smith del. 
