August, '17] ESSIG: TOMATO AND LAUREL PSYLLIDS 435 



deposited in sufficient numbers to serve as a ready means of locating 

 an infestation. A slight smutting also accompanies the attacks. 



Adults (Fig. 22 A). The mature insects are first pale green or light 

 amber but soon become darker, there being a considerable variation 

 in the degree of intensity of the colors. Normally the color is light 

 amber-brown with numerous very dark brown or black markings as 

 shown in the accompanying drawing. A very conspicuous white 

 powdery stripe extends across the dorsal base of the abdomen, and a 

 somewhat definite horse-shoe shaped and quite large area of the same 

 color and covered with fine white powder occurs on the dorsal pos- 

 terior two thirds of the abdomen. The legs are light amber and 

 sparsely hairy. At the tip of the hind tibiae there are two apical dark 

 spines on the inside and one on the outside (Fig. 22 C). The antennae 

 (Fig. 22 I, J) are ten-jointed and dusky, excepting the first three and 

 the basal half of the fourth joints. In many individuals the bases of 

 all the joints excepting the last two are yellow. On the fourth joint 

 near the tip is located a circular sensorium with a peculiar lid or 

 operculum, as shown in Figure 22 B, I, while on each of joints six, eight 

 and nine there is a single simple circular sensorium near the tip. The 

 writer is unable to locate the one on joint two as reported by Sulc. 

 The average length of the body is about 1.8 mm. 



Technical Description 



The original technical description as given in English by Dr. Karel 

 Sulc is as follows: 



Head. — Breadth of the vertex behind the eyes, 0.34 mm., with the eyes 0.52 mm., 

 the length along the middle-line 0.16 mm., posterior margin of the vertex regularly 

 and slightly excised, posterior angles slightly truncate, the anterior ones broadly 

 rounded; a median line divides the vertex in two halves, either showing a distinct 

 fovea in the middle. Antennae filiform 1 mm. long in all; the length of single joints 

 is: of the 1st, 2nd, 9th, and 10th 0.05 mm., of the 3rd 0.18 mm., 6th 0.13 mm., 7th 

 0.15 mm., and 8th 0.12 mm. ; siliell-organs [sensorial present on the joints 2, 4, 6, 8, 9; 

 that on the 4th joint is very peculiar being in the form of a hollow ball with a circular 

 opening covered with a spoonshaped movable operculum; the other smell-organs 

 show the form of simple pits. The 3 basal joints of the antennae are yellow, the 4th- 

 8th yellow, brown at their ends, the 2 last black. Frontal lobes very short, 0.06 

 mm. only long, rounded at the apex. Clypeus in the form of a pearhaK and not pro- 

 duced anteriorly. Colors of the head: the ground yellow-white, in the middle of the 

 vertex a horseshoe-shaped large brown spot, the middle hne of the vertex and the 

 frontal lobes dark brown, the apex of the latter being lighter, clj-peus yeUowish- 

 white. 



Thorax: the ground color white-yellowish with a large, well defined brown marking. 



Elytrse: length 2.60 mm., greatest breadth 1.00 mm.; apex in the cell. marg. I., 

 nearly at the end of M1+2 and forming an acute angle; the anterior part of its margin 

 being a httle shorter than the posterior one. C -|-Sc, R moderately arcuate, R sinuate^ 

 ending at the beginning of the second third of M1+2: M slowly arcuate with its apex 



