10 OUR SHADE TREES AND THEIR INSECT DEFOLIATORS. 



together in each group (Fig. 1 e, magnified), aud so firmly fastened to 

 the leaf that they can only be detached with great care without break- 

 ing the thin and brittle shell. The number of eggs in each group 

 varies from four or five to twenty or more. Very rarely only three eggs 

 are seen iu one group, but we never found less than that number. The 

 egg itself is obloDg, oval, obtusely, but not abruptly, pointed at tip, 

 of straw-yellow color, its surface being opake and beautifully and 

 evenly reticulated, each mesh forming a regular hexagon, as shown y 

 highly magnified, in Fig. If. The form of the eggs is not quite con- 

 stant, some of them, especially those in the middle of a large group, 

 being much narrower than others. The duration of the egg-state is 

 about one week. 



The general shape of the larva is very elongate, almost cylindrical, and distinctly 

 tapering posteriorly in the early stages, hut less convex, and of nearly equal width 

 ■when mature. The general color of the young larva is yellowish-black, with the black 

 markiugs comparatively larger and more conspicuous, and with the hairs arisiug from 

 these markings much longer and stiffer than in the full-grown larva. With each 

 consecutive molt the yellow color becomes more marked, the black markings of less 

 extent and of less intense color, and the hairs much shorter, sparser, and lighter 

 in color. A nearly full-grown larva is represented in Fig. 1 g, aud in this the yellow 

 color occupies a wide dorsal stripe and a lateral stripe each side. The head (except- 

 ing the month parts and auterior margin of the front), the legs (excepting a ring 

 around the trochanters), and the posterior portion of the anal segment, are always 

 black. The first thoracic segment has two large black spots on the disk, of varying 

 extent, and often confluent. The following segments (excepting the anal segment) 

 are dorsall y divided by a shallow transverse impression into two halves, and the black 

 markings on these halves are arranged as follows: Two transversal dorsal markings,, 

 usually confluent, as shown in our figure; two round and sublateral spots; the tips of 

 the lateral tubercles are also black. The abdominal joints of the ventral surface have 

 each a transverse medial mark, and two round sublateral spots of black color. Stig- 

 mata visible as small umbilicate spots between outer sublateral series of dorsal mark- 

 ings aud lateral tubercles. The yellow parts of the upper side are opake, but those 

 of the under side shining. The black markings are polished, piliferous, and raised 

 above the remaining portions of the body. 



The larvre are destructive to the foliage from the month of May untiL 

 August. They have about two weeks of active life between the egg 

 and pupa states. During this time they prey upon the leaves, which 

 become skeletonized, leaving the venatiou, and commonly a certain 

 portion of the flesh of the leaf, which becomes rust-brown. They undergo 

 four molts, respectively observed at Washington on July 15 (at hatch- 

 ing) 20, 23, and 29 (pupation). When full grown they descend to the 

 ground and change to pupa under whatever shelter is near to the base 

 of the tree. 



The pupa (Fig. 1 j) is of a brighter color than the larva, oval in shape, 

 and strongly convex dorsally. It is sparsely covered with moderately 

 long but very conspicuous black bristles, irregularly arranged on head 

 and thorax, but in a transverse row on each following segment. The 

 pupa state lasts about from 6-10 days. 



The perfect beetle (Fig. 1 c, natural size ; k magnified) resembles somewhat in ap- 

 pearance the well known striped cucumber-beetle (Diabrotica vittata), but is at once 



