No. 2. ] Notes. 99 



From the fact that young caterpillars first appear upon the lower 

 leaves, Scott thinks that the eggs are probably deposited upon the 

 ground. In America, however, the eggs have been found deposited all 

 over the cotton plant ; the probabilities are, therefore, that this will also 

 be found to be the case upon the opium poppy in India. 



Besides the opium poppy, which it attacks in Upper Bengal, the 

 North- Western Provinces, and the Punjab, Heliothis armigera feeds 

 upon various pulses, both those that grow in the cold weather and also 

 those that grow in the rainy season. The caterpillar feeds upon the 

 seeds and seed-pods of the pulse, but never gets entrapped in them, as 

 in the opium capsule. From his observations Scott concludes that there 

 must be at least two generations in the year, while from the life his- 

 tory of the insect in America there would seem to be every reason to 

 expect that there are considerably more than this number in India. 

 Attacking, as it does, chiefly the lower surface of the leaves and the 

 interior of the capsules, Scott thinks that hand-picking is the only mode 

 of keeping the insect in check. In this opinion he is supported by Mr. 

 F. Moore, the well-known entomologist, to whom in 1878 specimens of 

 the insect were submitted by Dr. Anderson for examination. 



In his report, dated 3rd July 1878, to the 

 Dr. Anderson's notes. Board of Revenue, on Heliothis armigera, Dr. 

 Anderson writes — 

 " I consider that the facts which have been adduced by Mr. Scott regarding the 

 habits of tbe caterpillars of this moth are strong evidence in support of his opinion 

 that the opium poppy is not the natural food of the larvae of Heliothis armigera, and 

 Mr. Moore's statement that this is the first time he has heard of the insect's attacking 

 the opium poppy is confirmatory of Mr. Scott's opinion. Mr. Scott remarks, 'I can 

 speak from careful, and now indeed extensive, observation that neither this caterpillar 

 nor anv other which I. have made experiments with, will attack the parts of the opium 

 poppy-when in any way replete with a normally concentrated milk sap.' He limits 

 the attacks of caterpillars to two critical stages in the life of the plant : first, the ger- 

 mination of the seed and early growth of the young plant ; and, secondly, the mature 

 stage, when the juices are exhausted. The larvae, however, of certain species of moths 

 have a perfect immunity from the poisonous principles of some of the most deadly 

 plants. The caterpillar of Deiopeia pulchella feeds on the kernel of the seed of Phy- 

 sostigmavenenosum, which contains the virulent poisonous principle eserine, and the 

 pupaa have been found in the centre of this hard bean apparently entrapped, much in 

 the same way that the pupaa of H. armigera are in the capsules of the poppy. The 

 insect is widely distributed, even perhaps more so than H. armigera, occurring, like it> 

 in India ; so that Tliy so stigma venenosum is not the exclusive food of its larvae any 

 more than the opium poppy is the exclusive food of the larva of H. armigera. 



"It has been proved by experiment that the excrement of the larva of D. pulchella 

 contains the poisonous principle of the bean unaltered, and to that strength that when 

 half a grain of the excrement had been administered to a linnet the bird died in several 

 minutes." 



Dr. Anderson observes that though apparently insensible to the active 

 principle of the Calabar bean the caterpillar is easily poisoned by hydro- 

 cyanic acid, and be goes on to notice— 



