SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 77 



The CaLterpillacr Placgvie. 



BY PROF. J. J. RIVERS 



The caterpillar that has caused so much damage to culti- 

 vated plants throughout Southern California is that of Vanessa 

 caryae (the West Coast Lady) a sister to the "Painted Lady." 

 The ordinary food plant of this insect is the common mallow 

 (Malva pariflora) which, having become exhausted, the cater- 

 pillars sought other foods, and failing to find plants of the 

 order Malvaceae they indulged in indiscriminate nibbling of 

 that which was unsuitable, and there followed in consequence 

 Bacterial diseases, which caused death to a large proportion 

 of the brood, through an attack of Flacherie. This is one way 

 of reducing the over balance of the species in the butterfly state. 

 Nearly all the species of the Vanessida are common this season, 

 and several in profusion. The abundance in some years, and 

 scarcity in others is readily accounted for by the working of 

 })arasitic influences. The butterfly can exist without the par- 

 asitic fly, but the parasite cannot live without the butterfly. 

 The scarcity of the butterfly is followed the next season by the 

 scarcity of the parasite, and when the parasite becomes more 

 numerous, then the following season the butterfly becomes 

 fewer in numbers until in a few seasons the parasite is also 

 reduced to the lowest number consonant with existence. This 

 state of things goes. 'on alternating indefinitely. 



Notes aLi\d New^s. 



In the Sacramento mountains of New Mexico, Stipa Vaseyi is locally 

 known as " sleppy grass" on account of its soporific effect on horses 

 and cattle grazing thereon. It has been known by this name for many 

 years. Vernon Bailey writes in ' ' Science, March, '03, of his experience 

 with a team which fed on this plant. All were affected with sleepiness, 

 and in one the stupor lasted three days. The native stock horses and 

 cattle, after one experience, will not again partake of it. When a full 

 meal is partaken of, the animals are reported to remain in a stupor for 

 a week or ten days. Mr. Bailey ate a handful of the rice-like seeds but 

 observed no effect. 



We beg to remind our readers that subscriptions for 1903 are 

 now due. 



From the Technological Museum, Sydney, N. S. W., there has just 

 been issued an exhaustive treatise on the chemical constituents of the 



