The Walking Sticks 



slightly compressed at the sides, and of a polished black color 

 with a whitish stripe on one side. They resemble the small plump 

 seeds of some leguminous plant. They are not laid in clusters or 

 fastened to the plant but are dropped loosely on the ground 

 where they remain through the winter and hatch the following 

 May. Some of them are retarded in their hatching and young 

 walking sticks may be found throughout the summer. In hatch- 

 ing the top of the egg lifts up like the lid of a vessel. The young 

 when first hatched are 4. 5 mm. long, and of a uniform pale yellow- 

 ish-green color. They live, as a rule, near the ground and drop 

 readily when disturbed. They molt but twice, retaining the same 

 color until maturity, and develop rapidly, averaging, under favor- 

 able circumstances, about six weeks from birth to maturity. 

 When adult the green color becomes gray and brown. This 

 change in color is protective since in the early summer while 

 vegetation is green, the insects are also green ; when the foliage 

 turns in the autumn they change color to correspond to a certain 

 extent, and when the foliage is stripped they closely resemble the 

 twigs upon which they rest. The front legs of the insect are 

 stretched out straight in front so as to increase the twig-like 

 appearance. The males are smaller than the females and 

 frequently retain the green color in the mature condition, follow- 

 ing the rule which holds more or less throughout nature, that the 

 male sex is not so well protected as the female, since upon the 

 latter depends the all-important function of reproduction. There 

 is but one generation annually and, as before stated, the insect 

 hibernates in the egg state on the surface of the ground. In 

 spite of the protection afforded by form and color the insect 

 seldom becomes sufficiently abundant as to be ranked as injurious 

 although it feeds voraciously upon the leaves of plants during all 

 stages of growth after hatching. In the few instances where it 

 has become sufficiently abundant to do noticeable damage it has 

 been easy to reduce its numbers to a minimum by burning over 

 the leaves on the ground during the winter time, thus destroying 

 the hibernating eggs. In 1898 this insect appeared in extraor- 

 dinary numbers in a black-walnut forest in western New York, 

 so that in the autumn the dropping of the eggs on the leaf-covered 

 earth sounded like a heavy shower of rain. 



325 



