320 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 



eggs as the trees drop their seeds, and they commence to fall and perish with the 

 leaves, the later ones persisting, like the last leaves, till frost cuts them off. 



As will have been already noticed, Mr. Snow has found from his own observations 

 that the insects were injuriously abundant every other year, and I have bean inter- 

 ested in endeavoring to find an explanation of this fact. The increase of the insect's 

 natural enemies whenever they became excessively abundant, and the consequent 

 decrease of the plant feeder the following year, undoubtedly have something to do 

 with it; but there is also good evidence that a great many of the eggs remain on the 

 ground for two consecutive winters before hatching. Messrs. T. W. Bringham and 

 L. Trouvelot have both found from experience that the eggs of this insect for the 

 most part batch only after the interval of two years,* and an examination made of 

 a large number, which I have myself kept the present winter, shows that while some 

 have proceeded far in embryonic development, others show no development what- 

 ever, thus corroborating the experience of these gentlemen. 



We may very justly conclude, therefore, that the species will only be injurious 

 every alternate year. 



Among the natural enemies of this Walking-stick, Mr. Snow has observed that 

 the crows were very abundant about them, as well as some other smaller birds. 

 Turkeys, as well as chickens, also feed upon them, and may be made good use of 

 while the insects are young and remain near the surface of the ground. 



Of the insects that prey upon them, I noticed, both in the immature and perfect 

 states, three species of half- wing bugs (Heteroptera), namely, Arma spinosa, Podisus 

 cynicus Say, both in the typical form, and in the variety obaouripes as determined by 

 Professor Uhler ; also Acholla muUispinosa (De Geer.) 



Egg. — Bean-shaped, hard, and highly polished ; obliquely truncate at the anterior 

 end, which consists of a dark oval raised rim, inclos''ng a slightly elevated, convex, 

 densely and deeply punctate brown lid, which is replaced after the young has 

 hatched by the white sunken amnion, which is shed within the egg. Color black, 

 with frequently a faint olivaceous hue, the ventral side in strong contrast, whitish 

 inclining to pale fulvous, and with anelliptical scar recalling the hilum of a seed, 

 the interior slightly depressed, the borders slightly raised. This scar reaches to 

 near the lid anteriorly, and ends in a cord posteriorly, to which cord the black color 

 of the posterior extends in a broad point. There is usually more or less black 

 within the posterior portion of the scar. Average length 2. G'"™; thickness from side 

 to side, 1.2™™. 



Larva. — When newly hatched 11.5™™ long, exclusive of antennae. Color, uniform 

 pale yellowish-green, the front pair of legs speckled with brown. Antennae with 

 rather prominent bristles. Sex undistiuguishable. Femora subequal in size. No 

 femoral spines. 



The adult. — The colors of the adult are quite variable, and are generally obliterated 

 in cabinet specimens. Shades of gray, brown, and greenish-brown predominate, the 

 head of the male being paler and having three longitudinal fuscous stripes, and the 

 middle thighs having annulate shades of the same color. The front legs of the male 

 and the shanks of the others are almost always green. The colors of the female are 

 more uniform, generally grayish, with paler specks and mottlings on the head and 

 along the back ; but occasionally pale green predominates. Structurally the male is 

 at once distinguished by his shorter, more slender body; his longer legs and feelers; 

 his narrower and less dilated front thighs; his swollen middle thighs, and by the 

 greater stoutness of the spines near the ends of the middle and hind thighs, these and 

 the other distinguishing sexual characters beiug less obvious in the earlier stages of 

 growth. 



Remedies. — While the insects are young, they may be destroyed by sprinkling the 

 underbrush in the timber with Paris green water, wherever the timber is inclosed so 

 that domestic animals can be kept away from the poisoned vegetation. 



Proc. Bost. Soc. Nat. Hist., Vol. XI, pp. 88 and 89. 



