178 Journal of Agricultural Research voi. xviii. no. 3 



The following tables give the distinguishing structural characters sepa- 

 rating the three species: 



ADULTS 

 MALE GENITALIA CHARACTERS 



1. Anellus consisting of basal plate (juxta) with single, stout, ventrally 



projecting spur (calcar) P. penitalis. 



Anellus consisting of basal plate (juxta) with two long, slender, dor- 

 sally projecting arms (anellus lobes) siurounding aedoeagus 2. 



2. Extremity of tegumen rounded P. ainsliei. 



Extremity of tegumen trifurcate P. nuhilalis. 



FEMALE GENITALIA CHARACTERS 



1. Genital opening strongly chitinized anteriorly P. ainsliei. 



Genital opening not strongly chitinized anteriorly 2. 



2. Chitinized plates posterior to genital opening decidedly pear-shaped 



viewed from below P. penitalis. 



Chitinized plates posterior to genital opening nearly square viewed 

 from below P. nubilalis. 



WVJE 



1. Front evenly rounded or with only slight hump a. 



Front forming prominent projecting knob P. ainsliei. 



2. Cremaster broader than long P. penitalis. 



Cremaster longer than broad P. nubilalis. 



LARV^ 



1. Epicranial setse and puncture A}, A?, and A* lying in a straight line 



or with A* somewhat postero-laterad of A^, not postero-dorsad 2. 



Epicranial setae and puncture A^ A^, and A* forming an obtuse 

 angle with A* postero-dorsad of A- P. ainsliei. 



2. Epicranial punctvire O^ lying postero-dorsad of ocellus VI; mandible 



longer than broad; distal tooth concaved P. penitalis. 



Epicranial pimcture C lying directly posterior to ocellus VI; 

 mandible square; distal tooth pointed P. nubilalis. 



