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jab pokd (Aphis brassicae) of the mustard crop. Aphides are 

 also known to attack potatoes, cabbages, cauliflowers to- 

 bacco, arahar, turnip, radish, &c. An aphide which produced 

 curling and twisting of leaves of the tobacco plants grown at 

 the Sibpur farm in 189293, was identified as Siphonophora 

 scabiosa. The coccinelidae beetles (lady-birds) that preyed 

 upon these were identified as Chilomenes sex-rnaculata. 

 Another aphide which causes injury to the mustard and rape 

 crops, was identified by the authorities of the Indian Museum 

 as Rhopalosiphum dianthi. The females which are generally 

 wingless are viviparous, their abdomen being transparent, the 

 yellow young embryos may be seen through the green skin 

 of the abdomen. The colour of the insect, however, is not 

 always green, but it is sometimes ocherous red, or brown, or 

 yellow, or black. The pupae and the larvae can hardly be 

 distinguished. The wing-cases of the pupae are tipped with 

 brown and the points of antennae are also brown. The 

 larvae are the most voracious. Males are very rare, and for a 

 number of generations their help is not required for fertiliza- 

 tion. The asexual larvae usually develop into wingless 

 females. The fully mature sexual forms have prominent wings 

 but they also are propagated asexually. The blackish tea- 

 aphis has been already spoken of. 



1,272. The belief that blights, that is the appearance of 

 aphides and coccidae insects, are due to fog or east-wind, is 

 common not only in this country but also in England, but it 

 is a mere superstitious belief. The extraordinary multiplica- 

 tion of the aphides gives one the idea that they appear all of 

 a sudden, and their apparent sudden appearance is accounted 

 for in some fanciful way. Suppose one little aphis produced 

 from an egg deposited last autumn should appear in spring 

 on a bean creeper when it is just budding. She gives birth 

 say to 10 young aphides each of which is a female. In a few 

 days these ten females without any connection with a male 

 will each produce another 10 agamogenetic females. If the 



