New Pest Response Guidelines - aphis - US Department of Agriculture

Identification
Pupae
The pupae of SSM are dark brown to almost black, between 33 and 39mm in
length and 10 to 11mm in width for females and between 28 and 34mm in
males (EPPO, 2005). Wing sheaths reach to the 4 th abdominal segment of the
pupae. The cocoon is gray or brownish, measuring 70mm in length and 12 and
15mm in width, appearing compact in shape, with a rough surface (Figure 3-12
on page 3-13). Blue thoracic hairs from the larva are sometime visible on the
cocoon (Rozhkov, 1970). An estimated 90% of the last instar larvae pupate
underneath branches on the tree crown, with a small percentage (8.3%) on the
tree trunk and very rarely (1%) in other places (Liu and Shih, 1957; Rozhkov,
1970). On average, the last instar larvae pupate in 3 days (Liu and Shih, 1957).
Figure 3-12 Siberian silk moth cocoons on Siberian larch, Larix sibirica (John
H. Ghent, USDA Forest Service, Bugwood.org).
12/2012-01 Dendrolimus Pine Moths 3-13