INSECT ENEMIES OF WESTERN FORESTS 



69 



The control of this defoliator can be accomplished by spraying in 

 March and April with lead arsenate spray when the worms are very 

 small and again during the last of July and first part of August. 







Figure 31. — The California oak worm (Phryganidia califoniica) : A, Adult motli, natural 

 size ; B, eggs, X 4 ; C, young larva, X 3 ; D, full-grown larvae, X % ; E, pupa, X 2. 

 (Drawings by Edmonston. ) 



TUSSOCK MOTHS 



{Hemerocampa spp.) 



The tussock moths represent a very destructive group of leaf- 

 feeding insects that attack coniferous species as well as broaclleaved 

 trees. The adults are dark-brown or dull colored, very fuzzy moths, 

 that are chiefly nocturnal in habit. The males fly, but the wrings of 

 the females are but short pads, of no use for flight. The abdomens of 

 the females are large and covered with a mat of dark-gray hair. 

 The full-grown caterpillars are strikingly marked and very hairy 

 with prominent pencils or small tufts of hairs on all the body seg- 

 ments, the whole giving much the appearance of a toothbrush. The 

 larval hairs are easily detached and in some species are somewhat 

 poisonous, causing a rash or eczema when they come in contact with 

 the skin. 



The female lays small white eggs in a mass on top of her own 

 cocoon and covers them with a frothy, gelatinous secretion in which 

 are embedded hairs from her body. The eggs hatch into tiny, very 

 hairy caterpillars. Since the females are unable to fly, the principal 

 time of dispersion is probably during this young caterpillar stage, 



