34 THE BUTTERFLIES OF THE WEST COAST 



§ 33. Food-Plants. 



To many species of butterflies mentioned in this book, "The 

 Food-Plants" are noted down in the body of the work, as ascer- 

 tained by myself and also by many other observers, since the study 

 of butterflies began; but the student must not think that these 

 lists of names of plants are complete, and that there are no other 

 plants used as larval food-plants besides these as noted ; on the 

 other hand there are many caterpillars that are well-nigh omniv- 

 orous, and will eat almost any green thing rather than starve. 

 Yet it is true that a majority of caterpillars will only eat the leaves 

 of one particular plant, or at best, only the leaves of one group of 

 plants, as the Pentstemons. Other larvze feed on the immature 

 seeds of leguminous plants ; and still others feed on the pith of 

 some flower-stem ; and one kind live in the interior of a succulent, 

 juicy leaf. 



Probably a majority of the species of larvae are unknown as to 

 their food-plants. To discover these plants, and to get eggs, and 

 rear the larvje through to pupation and to emergence, will furnish 

 employment for the working butterfly man of coming generations, 

 for many years. And the doing of these things will settle many 

 things, and many a disputed point, as nothing else will, as for in- 

 stance, the status or value of many so-called varieties and sub- 

 species. 



§ 34. The Army Worm. 



The so-called "army worm" is composed chiefly of the larvje of 

 moths, and not of those of butterflies. But when the army 

 worm appears the season is certain to be a favorable one for but- 

 terflies, as well as for moths: and if a drag-net be drawn it will 

 be sure to catch numbers of the larvae of butterflies, along with 

 those of moths. For many of the butterfly larva are largely omniv- 

 orous, and will eat the leaves of most cultivated plants and 

 grasses. Pyrameis Cardui, P. Caryc and Colias Eurythcme are 

 the chief sinners, being everywhere abundant, and the larvae are 

 practically omnivorous, so that the larvae of those species are 

 oftenest caught in the company of the army worm proper, and so 

 receive undue blame. 



Moths are almost always nocturnal, they fly by night, and the 

 caterpillars feed mostly by night and are, therefore, but seldom 

 seen, so that they escape notice, ordinarily, and the blame falls 



