212 THE AGRICULTURAL PESTS OF INDIA. 



They feed on the castor-oil plants, the leaves and flowers 

 of which they eat ; on two or three acres of land, in one 

 night, they will leave nothing but bare branches. The 

 plants seldom survive their attack, and at best yield only 

 one-fourth of the produce. The cultivators drive them 

 from the plants by smoking ; but this is impossible of 

 application when seeds are sown on an extensive area, in 

 which case the husbandmen give up all hopes of the 

 crop. The adult larva has sixteen legs, the first pair of 

 middle legs aborted; two dorsal red tubercles on twelfth 

 segment ; colour bluish-grey, numerously speckled with 

 bluish-black; a lateral and sub-lateral yellowish band, 

 with an intervening bluish-grey line ; spiracles and fore- 

 legs red ; a dorsal black stripe, bordered by reddish-white 

 spots, between fifth and sixth segments ; head black 

 striped. Pupa formed within a leaf. W.-M. 



Acheta. A large species of Acheta attacks the cas- 

 uarina trees. It lodges at the foot of the tree, and at 

 nightfall ascends the tree and cuts off the young top 

 shoots. See Gryllidse. 



Actinias and Medusas have more or less urticating 

 properties. The latter are of the class radiata, and 

 are commonly known by the name of sea-nettle and 

 jelly - fish. The Acting are polyps. A cyanea of 

 Pondicherry secretes an extremely acrid and irritating 

 fluid. The Physalia, or Portuguese man-of-war, also 

 causes a considerable amount of irritation, the stinging 

 sensation continuing for hours. Physalia is a colony, the 

 individuals of which are called zooids. Some are for 

 locomotion, others are feeders, and have other purposes, 

 but they all look alike, the appearance presented being a 

 blue, entangled, jelly-like mass of threads, coiling, con- 

 tracting, extendiog, floated and suspended from a rich 



