460 



INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



appear in any numbers in the spring, to starve this first brood and thus 

 keep down the next generation. Other cuttings should be made when 



blooming begins. Successive irrigations 

 immediately after cutting to stimulate 

 vigorous growth is very important. 

 Disking the fields in the fall of the year 

 will kill many of the over-wintering 

 pupae. The food plants should not be 

 allowed to grow wild around the fields, 

 as they serve for excellent breeding 

 places. Pasturing the land also helps to 

 keep dowm the pest. 



Natural Enemies. — Mr. Wildermuth 

 records the following natural enemies : 

 the tachina flies. Phorocera claripennis 

 Macq. and Frontina archippivora Will.: 

 the phorid, Apkiochceta perdita Malloch ; 

 the hymenopterous egg parasites, Ap<ni- 

 teles flaviconche Riley, Chalcis ovata 

 Say. Pteromalus eurymi Gahan and 

 Trickogramma minutum Riley. The 

 author has collected quite a number of 

 the pupal cases of a Campoplex sp. 

 (Fig. 471) which is evidentlv parasitic 



s P Fi o^ aiklfeTe°a°f n The^arv^of u P on tne larvas - A bacterial disease also 

 this parasite attack the larvre of kills large numbers of the larvaa and 



the alfalfa caterpillar. Enlarged . . , ., 



four times. (Original) pup83 111 damp Weather. 



THE MOURNING CLOAK BUTTERFLY 



Euvancssa <mti<>p<i (Linnaeus) (Family Nymphalidse) 



[Vanessa antiopa (Linnaeus)] 



I Papilio iiiitiojxi Lmmmis) 



(Fig. 472) 



Description. — The butterflies are purplish-black with noticeable 

 yellow wing borders or margins, in which is a row of pale blue spots. 

 The wings are also noticeably notched or toothed along the margins. 

 The bodies are about 1 inch long, the w r ing expanse from 3 to 3-J- inches. 

 The caterpillars are black, besprinkled with minute white specks and 

 a row of eight brick-red spots along the back. The surface is rough, 

 each segment bearing from six to seven branched spines, giving the 

 whole caterpillar a decidedly spiny appearance. When full-grown 

 they are from 1% to 2 inches long. The chrysalids are dark brown with 

 light yellow spots upon the back and from f to 1 inch long. 



Life History. — The adults hibernate and are sometimes seen on 

 bright days in midwinter. They begin egg-laying about the first of 

 March. The eggs are laid upon the leaves ami around the twigs of the 

 host plants and the caterpillars move from plant to plant as the food 

 becomes scarce. They are social in habits and often appear in such large 

 numbers as to completely defoliate quite large areas. There are two 

 broods a year. 



