INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



453 



THE CYPRESS MOTH 

 Argyresthia cupressella Walsingham (Family Hyponomeutidae) 



(Fig. 4 04) 



Description. — The moths are very small, bright, iridescent golden 

 or yellow, with three light brown bands across the front wings, the tips 

 of which are also brown, as shown in Fig. 464. The hind wings are 

 light yellow. Both pairs of wings are fringed with long light yellow 

 hairs, which are dark at the tip of the front wings. The length of the 

 moths is about y'V inch, the wing expanse nearly 4 inch. The eggs are 

 yellowish-green when first laid, turning reddish or pink with age. They 

 are strongly convex and slightly elongated. The surface is finely sculp- 

 tured. The length is ^ 

 inch. The larva* or eater- 

 pillars are light green or 

 whitish with a reddish 

 dorsal spot on the eighth 

 segment of the older ones. 

 The prothoracic shield, 

 head and mandibles are 

 brownish. W h e n dis- 

 turbed they hang by a 

 silken thread. Thfi pupa 1 

 are light brown, about ] 

 inch long and are inclosed 

 in white cocoons attached 

 to the twigs. 



Life History. — The 

 eggs are laid singly upon 

 flic small terminal twigs, 

 usually near the base, in 



the axil of 

 As soon as 

 larvae enter 



the leaflets, 

 hatched the 

 the twigs and 



Fig. 464. — The cypi-ess moth, Argyresthia cupres- 

 sella Walsingham. Larva, pupa, larval cell in tip of 

 twig and adults. All slightly enlarged. Specimens 

 collected in Golden Gate Park. San Francisco, by 

 Harold Compere. (Original) 



burrow downwards for about an inch. 

 Several twigs may be attacked by a single caterpillar. When fully 

 matured the larva? leave the burrows and spin small white cocoons on 

 the twigs in which to pupate. According to D. W. Coquillett. the 

 larvae appear in February and April and the adults in April and early 

 May. Eggs remain over winter and hatch in the spring. 319 From the 

 observations of the writer in the Golden Gate Park, San Francisco, 

 where this moth is a serious pest, at least some of the eggs hatch in 

 the fall and the larvai spend the winter within the burrows. Adults 

 appear in April and are still plentiful in June and the first of July, 

 when the eggs are being laid. Mr. Harold Compere has observed larvas 

 in their burrows the last of December, pupae in May and adults and eggs 

 during the last of May and sometimes afterwards. By the middle of 

 May all larvae have pupated and adults are plentiful until fall. There 

 are apparently two broods a year. 



Nature of Work.— The larvte burrowing in1<> tie- lips cause them to 

 enlarge and finally to die. The exit hole is always plainly visible. In 



•""Insect Life, III, p. 116-118, 1890. 



