106 THE OLIVE 



borina' in the forks of the vouiio; wood. If discovered in time it 

 can, to a great extent, be gotten rid of by shaking the trees both 

 night and morning. The Polycaon is not a very dangerons pest, 

 altliouoli it causes more or less iniurv to the tree, which mav resuh 

 in the loss of several of the minor branches. 



PSYLLA OLE.E. 



{See Plate AT.) 



The egg of the i)sylla is spheroidal in shape, and of a diaphan- 

 ous Avhite color, a little over a hundredth of an inch in diameter. 

 (Fig. 2.) 



The larva (Fig. 3) is a de])ressed ovoid, oblong, the head bi-fes- 

 tooned in front, the last abdominal ring is very much larger than 

 the others. It is rather soft and of a greenish white color, the eyes 

 red, the extremities of the antenna? and tarsi, black. It is com- 

 l)letely covered with a cottony substance Avhich is thick and long 

 on the abdomen, and falls behind in a fringe. 



The chrysalis (Fig. 4) resembles the larva in its general appear- 

 ance, differino' from it in the shield wino;, which is oval and rido'ed, 

 covering the sides of the abdomen, gi'eenish in color, with last ab- 

 dominal ring brown or nearly black, the shield wing of a yellow 

 brown color. The insect (Fig. 5, 6) has a wide head, triangular in 

 sha])e, the upper part curved in, and square at the corners, with a 

 deep scallop nearly bi-secting the lower part, the eyes oval, placed 

 at upper corners of the head, the antennae (Fig. 8) six jointed ; the 

 last one terminating in two short bristles, the upper thorax very 

 short, the lower thorax large, convex, twice as long as it is wide, 

 and nearly hexagonal. Upi^er wings or shield wing, oval, rhom- 

 boidal, much longer than the abdomen and meeting in a sort of 

 i-oof at the upper margin of the skull ; a sinew, starting from 

 the point of the shoulder, is visible, which bi-sects it. The lower 

 wings are shorter than the ui)per ones. Abdomen small terminat- 

 ing in a blunt point,.and in the female provided with a distinct 



