- DISTINGUISHING CHARACTERS 3 



{Coccus viridis, Gr.)/ brown bug (Saissetia hemisphcer-icujti, 

 Targ.) and mealy bug (Fulvinaria psidii, Mask.) are often 

 found associated together in Mysore, and planters have 

 some difficulty in distinguishing one from another, more 

 especially in their younger stages.^ In the adult stage, 

 the green bug is of a pale lemon-green colour and has 

 almost invariably a dark loop on the back (see Plate I, 

 Fig. 1). The shape is a flat oval, but those along the sides 

 of veins show a slight twist to right or left and have the 

 front end more or less sharpened to a point. If an adult 

 bug is lifted from the leaf, a few young and their cast 

 skins are found beneath. The mealy bug, when full 

 grown, secretes a waxy material resembling cotton in 

 appearance which, like a cushion, lifts up the hind end of 

 the body and in which eggs are laid. It shows no black 

 loop on the body and no live young are to be found beneath 

 the mother (see Plate I, Fig. 2). The colour varies 

 considerably with the host plant but those on coffee are 

 usually more yellowish and less transparent than green 

 bug. There is no difficulty in recognising the brown bug 

 in its adult stage. It is of a snuff-brown colour and al- 

 most hemispherical in shape (see Plate I, Fig 3). The 

 difficulty in distinguishing one species from another arises 

 when the bugs are in the earlier stages of growth. The 

 young of green and mealy bugs are almost alike and it is 

 only after some experience that one is able to differentiate 

 the two species. The young of the mealy bug are usually 

 a shade deeper green than those of green bug and are 

 more opaque (see Plate I, Figs. 4 and 5). The young 

 brown bugs are either dark pink or completely yellow. 

 When of the former colour, they are easily recognised. 

 When yellow, the shape has to be examined, which is a 

 short instead of an elongated oval. Half-grown specimens 

 can be distinguished by the presence of a branched ridge 

 on the back somewhat resembling an " x " which has been 



* This insect was originally described by Green as Lecanium viride, 

 and by this name it is commonly known. Recent systematic w^ork, 

 however, has led to the splitting up of the genus Lecaniuvi. This gene- 

 ric name therefore ceases to exist and the older name Coccus takes 

 its place in the case of the green bug. Vide M. E. Fernald, Cata- 

 logue of the Coccidae of the World, Hatch Experiment Station 

 Bulletin No. 88. 



*In the frontispiece, Figs. 1-3 show the appearance of these 

 three pests on coffee leaves and twigs. Plate I, Figs. 1-6, show in 

 more detail the appearance of both young and adults of the three forms. 



b2 



