90 THE COCCIDAE 



normally consist of six segments, but there are only three present 

 in the species named. The antennae of this stage of this species 

 are peculiar in form for coecids. The proximal and the distal 

 segments are, so far as shown, greatly swollen, much larger tlian 

 the intermediate segments, and the distal segment is distinctly 

 truncate. The greatly swollen prothoracic legs, which are fitted 

 for digging, are characteristic not only of the first nymphal stage 

 but of all the stages wliere the legs are present. The comparative 

 size and length of eacli profemur are always much greater than the 

 combined tibia and tarsus and claw. The nymph attaches itself 

 to the root of a plant by its rostralis and feeds upon the sap. It is 

 quite likely that the sexes are, as among other coecids, indis- 

 tinguishable in the first nymphal stage. 



Green states that the nymphs apparently undergo several 

 stages. Since he describes the individuals of the first nymphal 

 stage as larvae, this would be in addition to these. The insects,, 

 while growing, according to Mayet, excrete the envelope or cyst 

 that subsequently encloses the nymph. It is this so called cyst,, 

 because of its iridescence and wonderful pearly lustre, that has 

 attracted the attention of observers and that has received the 

 common name of Ground Pearl. Writers frequently speak of this 

 stage of the insect as an encysted one, but this is not a true charac- 

 terization as this term is ordinarily used in zoology. The insect 

 is simply enclosed in a compact thin-walled case or scale wliieh 

 bears the same relation to the nymph as the cocoon to the pupa or 

 as the wax or scale of other coecids does to the insect. This ease 

 is formed either entirely from wax excreted by the insect, entirely 

 from the cuticle molted by the insect, or from a combination of tlie 

 wax excreted by the insect and its molted cuticle. The cysts, 

 when fully developed, are more or less irregular in form and 

 composed of closely applied small overlapping flakes or plates. 

 The overlapping of the plates gives the cyst the appearance of a 

 minute pine-cone or swollen bud. The form and structure of the 

 cyst would suggest that it is formed entirely of wax. The cj'sts 

 vary considerable in color. What are apparently the young cysts 

 are pale yellow, becoming darker with age until they are deep 

 bronze brown in the oldest individuals. The amount of lustre 

 also varies with the age of the cyst and as to whether the outer 

 plates, which are usually dull, are wanting or not. 



The various accounts would seem to carry the idea that the 

 cyst was begun during the first nymphal stage. The female nymph 

 at the first molt loses its legs and eyes. The antennae are repre- 



