F. R Petiierbkidue and M. A. Husain 199 



Instar I. Smoky shade on dorsal surface of head, thorax and first 

 abdominal segment, interrupted in the region of the thorax by a mid- 

 dorsal pale line which continues on the head and bifurcates at the level 

 of the eyes (see PL IX, fig. 5). 



Longitudinal groove present on the head. 



Terminal joint of antenna the longest. 



Instar 11^ (Fig. 6). No smoky shade. 



Terminal joint of antenna slightly longer than the second. 



No wing pads. 



Instar III (PI. X, fig. 7). Small but distinct wing pads. 



Second joint of antenna the longest. 



Instar IV (Fig. 8). AVing pads reach second abdominal segment. 



Second antennal joint relatively longer. 



Instar V (Fig. 9). Wing pads reach fourth abdominal segment. 



Second antennal joint still longer. 



All these instars have 2-jointed tarsi. 



6. 0RTH0TYLTJ8 MARG1NALI8 REUT. {NASSATUS FALL. ET AUCT.). 



This species hatches about a fortnight later than P. rugicollis and 

 Psallus amhiguus. The adult resembles P. rugicollis in its green colour 

 but can be readily distinguished from it by the absence of a collar and 

 the two callosities on the pronotum; it is moreover covered with fine 

 white hairs. The eyes nearly touch the pronotum. 



The antennae are slender, medium sized, with the basal joint some- 

 what pale in both sexes, and the terminal joint with no pink colour. 



A very distinct orange spot is present between the last two pairs of 

 coxae. 



Male with asymmetrical genital forceps, that of the left side having 

 two conspicuous prongs. 



It is mentioned by Theobald (24, 28) and Schoyen(2i) as a pest of apples 

 but we find no evidence for this. We have found it in considerable 

 numbers in uninjured orchards. 



The egg of Orthotylus marginalis is smaller than that of P. rugicollis, 

 being only 0-95 mm. in length. It resembles the rubber part of a fountain 

 pen filler with the open end flattened laterally. 



It dift'ers from the egg of P. rugicollis in that the transverse section of 

 the cap is much longer than it is wide and the cap itself is convex. 



It is slightly curved in the region of the neck (cf. PI. IX, figs. 4 a and b). 



1 Crosby and Leonard's (7) third and fourth stage are alike and what they describe 

 as second stage is really the third. 



