170 



None of tliem are kuowu to spin cocoous, but so tar as studied they 

 form cells of earth in which to pass the winter or undergo transforma- 

 ti(Mi. 



The larvte of JJolerus spp., found on (jruinineiie 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 I), col- 

 laHn Say, have been bred. 



The following general description will apply to all the forms studied : 



Head large aud i»i(iraiuent, almost as wide as lirst segmeut, more or less flattened 

 iu front, yellowish or greenish and variously marked with white or brown ; eyes 

 inclosed with a narrow dark brown or black ring. 



Body elongate, tapering nniformly 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, 

 (hirker or slate color on dorsum and sides; a light band covering stigmatal area. 



Thoracic feet light brownish at tip, and with light colored hairs, Avhich are longer 

 and more numerous than on bodj. 



The larva studied may be distinguished as follows : 



(1) Length of largest specimen, 24 mm. Head, viewed from the front, hexago- 

 nal, with the angles roimd; face, including antennie and mouth-parts and long^ 

 oval spot on cheek, whitish; a brown band starting near the base of the mandibles 

 and including the eyes, passes over the head in front; back of this l>and on the 

 vertex the color is light yellowish brown, in some specimens scarcely darker than the 

 oval spots on the cheeks ; the geual 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 20 mm. General shape of the 

 head as in (1), except that it is less flattened or is fuller in front, especially iu 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 riuff 

 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 baud; 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 Avith 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 Avhite 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 

 abdomiual legs. 



(5) Length, 18-20 mm. Shape of head and body as in (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 baud. 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 be a safe indication of a distinct 

 species, in view of the fact that it shows no teiulency to vary, and that in the case 

 of all the other forms studied there is no indication whatever of this mark. 



