OF WASHINGTON. 33 



NOTES ON COCCID^. 

 By T. D. A. COCKERELL. 



Pseudococcus pandani (CklL). 



This species was described some ten years ago, from speci 

 mens found in the Marquesas Islands, and has not been received 

 from elsewhere. The following measurements, from the type, 

 are in /*, and are necessary additions to the original rather too 

 brief account. They are from a J containing many embryos. 



Antennal joints, (i) about 50, (2) 50, (3) 45, (4) 25, (5) 32, (6) 

 3 2 > (7) 35> (8) 80. Anterior leg; coxa, 140; femur with trochanter, 

 270 ; tibia, 142 ; tarsus, 80. Hairs of anal ring, 125 ; longest hair of 

 lateral caudal patches, about 140. The sides have small patches of 

 spines. 



Three distinct groups of Pseudococcus have quite similar 

 types of antennae ; these are the groups of P. citri, of P. neo- 

 mexicanus, and of P. longispinus. P. pandani is a member of 

 the citri group, and is, perhaps, a race of citri. It is at present an 

 open question what should be considered the limits of P. citri; 

 certainly various forms, ostensibly belonging there, present 

 important differences, but these may be due to individual or 

 racial variation. It will be necessary to measure carefully 

 numerous examples from each of several different localities 

 and food-plants, and also to find out experimentally whether 

 all forms can live equally well on all the plants cited for the 

 species. 



Pseudococcus armatus (Hempel), var. a. 



?. Ovisac pure white, long-oval, closely felted, about 3 mm. long; 

 females greyish-black, enclosed in the ovisac and having a bunch of 

 short cottony tassels (much like those of P. citri) at the caudal end; 

 these may be seen in the opening in the posterior part of the ovisac. 

 Boiled in caustic potash, the females are seen to be full of a blue-green 

 pigment; a female full of eggs, mounted on slide, is 1650 /* long, 930 

 broad, while the eggs are long-oval, 300/4 long. 



Skin with many round gland-orifices, not uniform in size; also some 

 spearhead-like spines, 12 & long, set in broad sockets ; and a few small 

 bristles. Anal ring ordinary, with six bristles. Caudal lobes quite 

 prominent, mammaeform ; labium dimerous, short, about 100 /" long and 

 87 broad at base, regularly tapering to apex; legs and antennae yellow 

 ish. 



Measurements in /* : anterior leg ; femur plus trochanter about 137, 

 tibia 55, tarsus (exclusive of claw) 50; claw about 20, stout, nearly 10 



