550 PROCEEDINGS Of THE THIRD ENTOMOLOGICAL MEETING 



with these both on Morus spp. and cotton and can readily be distin- 

 guished from P. coryynhatus and Phenacoccus hirsutus in being 

 pale- white. All the three mealy-bugs appear together on the cotton 

 top-shoots. They can be differentiated easily thus : — 



Pseu dococcus corym ba tus. 



Phenacoccus hirsutus. 



JS'j/c/s.— Round, cylindrical, 

 flattened at both ends, 

 dark castaneous, fully 

 covered over with fine 

 cretaceous white floc- 

 culent material forming 

 the female ovisac. 



Nymphs. — Deep chocolate, 

 dorsum covered thinly 

 with a whitish meal. 



Females. — Dark castane- 

 ous. completely covered 

 with sticky cretaceous 

 white ovisac also con- 

 taining chocolate brown 

 eggs. The female if 



removed from the ovisac 

 is covered thinly with 

 whitish meal. 



Pseudococcus virgatus. 



Eggs. — Round, cylindrical, 

 flattened at both ends, 

 bright jjink lying close 

 to each other witliin the 

 female ovisac made up 

 of thin, cretaceous white 

 cottony threads. The 

 flocculent material is 

 not so sticky as that of 

 P. corymbatus and the 

 eggs could be seen dis- 

 tinctly within the ovi- 

 sac with a hand lens 

 magnifying 10 diameters. 



Nymph. — Bright pink, dor- 

 sum covered with a thin 

 whitish meal. 



Females. — Bright pink, to 

 darkpink, cretaceous 



white cottony ovisac 

 completely covering the 

 female with eggs which 

 too are bright pink. The 

 flocculent whitish mate- 

 rial of the ovisac con- 

 sists of cottony threads 

 which are not so sticky 

 as in P. corymbatus. 



Eggs. — Round, cylindrical, 

 flattened at both ends, 

 few, bigger than those of 

 P. corymbatus or P. hirsu- 

 tus. Pale yellow. Very 

 thinly covered with a 

 few white cottony 

 threads. 



Nymph. — Pale j-ellow, with 

 two stout, cretaceous 

 threads at pygidial end. 



Females.— Vale yellow to 

 dusky yellow at period of 

 gestation, eggs are also 

 pale yellow, fewer in 

 number than those of P. 

 corymbatus of P. hirsu- 

 tus. Ovisac does not 

 cover up the female as 

 well as tlie eggs. The 

 gravid female has two 

 stout caudal threads at 

 anal lobes. The whitish 

 cottony threads forming 

 the ovisac are few and 

 lie loosely below and 

 laterally of the female 

 while laying eggs. 



The above description is from specimens not treated with KOH. 

 If these are, however, treated in KOH 10 jper cent, over a spirit lamp 

 or a laboratory gas-burner, the reactions are very prominent and 

 characteristic. 



Pseudococcus corymbatus. Turns deep blackish green or practically 

 black, then deep green, light green, finally clears up after a brisk boil 

 of 7 to 10 minutes. Even then in some cases the visceral contents are 

 not easily ejected. These take a much longer time to clear up. 



