INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



411 



hatch in the spring and the caterpillars feed throughoul the summer 

 and adults appear in the fall. There is hut a single brood annually. 



Distribution. — The eggs of this species have been received from 

 Humboldt County. It does not appear to have been recorded from any 

 other section of the State. 



Food Plants.— In this State the apple is the only observed food 

 plant. It also attacks plum and rose, as well as forest and shade trees, 

 especially those belonging to the family 

 Rosacea. 



Control. — Control measures are the same as 

 for the California tussock moth. 



Natural Enemies. — This moth is also subject 

 to many of the same natural enemies attacking 

 the California tussock moth. 



THE FOREST TENT-CATERPILLAR 11 

 Malacosoma disstria Hiibner (Family Lasiocampidse) 



(Figs. 416-41S> 



Description. — The moths arc light brown 

 with a dark band across each of the fore 

 wings. The caterpillars are dark with bluish 

 head and a row of diamond-shaped white 

 spots along the middle of the back. They are 

 about 2 inches long. The pupae are reddish- 

 brown, 1 inch long and inclosed in a light 

 yellow cocoon. All stages of this species in 

 general resemble similar stages of the other 

 tent-caterpillars. 



Life History. — The life history is much like 

 that of other caterpillars. The larva? collect 

 in great colonies upon the trunks and larger 

 limbs of the trees, instead of resting in tents, as does its near relatives. 



Nature of Work. — The work of this species is the same as (hat of 

 the cankerworms. 



Fig-. 416. — Eggs of the 

 forest tent-caterpillar, 

 Malacosoma disstria Hiib- 

 ner, around a small apple 

 twig. Slightly enlarged. 

 (Author's illustration, Mo. 

 Bui. Cal. Tlort. Com. i 



29 "Four other tent-caterpillars, which have become of some importance in California 

 are as follows : 



1. The California tent-caterpillar, Malacosoma oalifornica Packard. The cater- 

 pillars are orange-colored and about 1 inch long. They feed normally upon the coasl 

 live oak and maul oak. but also attack apple and other fruit trees. 



2. Malacosoma constricta Stretch. The caterpillars are somewhat larger than 

 those of the preceding species and may be readily recognized by the distinct blue Hips 

 along the sides. They feed upon the black oak and valley oak and have not been 

 reported as pests of fruit trees. 



3. Malacosoma phivialis Dyer. The caterpillars are buff-colored ami usually feed 

 upon the alder, but occasionally become quite injurious to app 



4. The great basin tent-caterpillar, Malacosoma fragilis Stretch (Figs. 419, 420). 

 The caterpillars are pale blue on the sides and the median dorsal line is composi 

 blue spots instead of white spots or a white line as is usually the case in other species. 

 This insect was specially abundant and destructive in the north-central pari ol the 

 State during the summer of 1914. The caterpillars feed upon Ceanothus spp., wild or 

 bitter cherry, wild gooseberry, manzanita, sierra plum, wild rose and willow. (Van 

 Dvke, E. C". Mo. Bui. Cal. Hort. Com.. III. pp. 351 355, 1914.) 



The apple-tree tent-caterpillar. Malacosoma americana (Fa ' reported 



from this State, does not seem to have become established and is therefore omitted 

 in this edition. 



