170 
None of them are known to spin cocoons, but so far as studied they 
form cells of earth in which to pass the winter or undergo transforma- 
tion. eee 
The larvee of Dolerus spp., found on Graminee in this country, repre- 
sent at least five well-marked forms and may belong to as many dis- 
tinct species. The adults of but two species, D. arvensis Say and D. col- 
laris Say, have been bred. , ; 
The following general description will apply to all the forms studied : 
Head large and prominent, almost as wide as first segment, more or less flattened 
in front, yellowish or greenish and variously marked with white or brown; eyes 
inclosed with a narrow dark brown or black ring. 
Body elongate, tapering uniformly and gradually towards the tip, with numerous 
transverse wrinkles, and finely rugose or punctured; head and sides of body espe- 
cially near lower edge and at tip, armed with minute whitish hairs. Color, greenish, 
darker or slate color on dorsum and sides; a light band covering stigmatal area. 
Thoracic feet light brownish at tip, and with light colored hairs, which are longer 
and more numerous than on body. 
The larva studied may be distinguished as follows: 
(1) Length of largest specimen, 24mm. Head, viewed from the front, hexago- 
nal, with the angles round; face, including antenne and mouth-parts and long 
oval spot on cheek, whitish; a brown band starting near the base of the mandibles 
and ineluding the eyes, passes over the head in front; back of this band on the 
vertex the color is light yellowish brown, in some specimens scarcely darker than the 
oval spots on the cheeks; the genal suture separating the cheek from the vertex is 
usually stained with brown. Punctation of head and body rather coarse and notice- 
able. 
(2) (D. arvensis?) Length of largest specimen about 20mm. General shape of the 
head as in (1), except that it is less flattened or is fuller in front, especially in partly- 
grown specimens. The pattern of the markings is similar to (1), but the dark brown 
is replaced by a light yellowish brown throughout. The eyes with encircling ring 
are, on account of the surrounding light color, especially prominent. The head, 
particularly, and the body are smoother and the punctation is finer. 
(3) Size of larva and shape of head as in (2); frontal brown band as in (1), except 
that it rarely includes the eyes; the dorsal area of the head is as in (1), or some 
specimens dark brown and unicolorous with frontal band; the genal suture is more 
distinctly marked with brown. This form is particularly distinguished by the well- 
defined subdorsal brownish band, which is rather sharply limited below by the light 
stigmatal area, and passes into the general slate color of the dorsum above. 
(4) Shorter and more robust than (1). Head as wide or wider than first segment, 
and with very faint markings, which are somewhat irregular, but similar in gen- 
eral pattern to foregoing. This form is easily separated from the others by the pre- — 
sence on the lateral white stripe of a row of black spots, one on each segment, just 
above the stigmata; a similar spot occurs at the base of each of the thoracic and 
abdominal legs. 
(5) Length, 18-20 mm. Shape of head and body asin (1). Markings of head sim- 
ilar to (1), except that the whitish area on the cheek, including the genal suture, is 
entirely covered by a branch of the brown frontal band. The dorsal area is as with 
(1), light yellowish brown. The occurrence of this distinct and prominent pos- 
terior branch of the frontal brown band seems to bea safe indication of a distinct 
species, in view of the fact that it shows no tendency to vary, and that in the case 
of all the other forms studied there is no indication whatever of this mark. 
