pair of long slender brownish filaments on each side of the second 
and third segments; a pair of small, rusty red tubercles on the 
eighth segment; and a broad stripe on the dorsum from the pro- 
thorax to the first pair of filaments. Larvae are active from May 
to July; adults, from late June to August. 
The elm spanworm, E'nnomos subsignarius (Hbn.) (fig. 131), 
occurs occasionally in southern Ontario and throughout eastern 
United States, west to Michigan, Colorado, and Texas. Its pre- 
ferred hosts are recorded as hickory, oak, and ash, but it also 
attacks a large number of other hardwoods (140). About 100 
years ago, it was best known as a shade tree pest in the larger 
cities of eastern United States (343). In recent years it has been 
predominantly a forest pest, with widespread severe outbreaks 
occurring in the southern Appalachians (238). 
The adult is a powdery white moth with a wingspread of 30 
to 87 mm. Full-grown larvae are usually dull, slate black in color 
except for rusty head capsules; they are slightly more than 50 
mm. long. 
Winter is spent in the egg stage. Hatching begins in late April 
in the South. Farther north, it may not start until late May or 
early June. Young larvae feed on the lower surfaces of leaves, 
producing shot-hole effects. Older ones eat the entire leaf with 
the exception of the midrib and petiole. To pupate, mature larvae 
spin coarse, net-like cocoons of silken threads, often on partly 
bs 
y 
iu 3 
C D 
F-500617, 500618, 500615, 500619 
FIGURE 131.—Elm spanworm, Ennomos subsignarius: 
A, adults; B, eggs; C, larvae; D, pupae. 
343 
