SO OUR SHADE TREES AND THEIR INSECT DEFOLIATORS. 



ject and of striking appearance (Fig. 14). The head and two little ele- 

 vated spots situated on joints 9 and 10, are bright vermilion-red 5 the 

 l>ack is velvety black with two bright yellow subdorsal lines, and 

 another yellow line each side along the lower sides. The whole body is 

 thinly clothed with long pale yellow hairs, originating from small wart- 

 like elevations. Four cream-colored or white dense brushes of hair 

 :are in a row on the middle of the fourth, fifth, sixth, and seventh dor- 

 sal joints, while from each side of the head arises a long plume like tuft 

 of black hair projecting forward and outward. A similar plume pro- 

 jects upwards from the last dorsal joint. The hairs composing these 

 plumes are coarse, barbed, knobbed, and arranged in sets of unequal 

 length, thus giving the plumes a turbinate appearance. 



Habits of the Larva. — The young caterpillars scatter all over the tree 

 soon after hatching. When disturbed they make free use of a fine 

 silken thread which they spin, and by which they let themselves down. 

 The full grown larvae are often seen to change quarters and travel from 

 one branch to another, or from one tree to another. Their rather quiet 

 way of moving contrasts strongly with the nervous movements of the 

 Fall Web- worm. 



A new Form of Orgyia Attack. — In the first edition we omitted to make 

 mention of a most interesting account of a new form of Orgyia attack 

 which had just been published at that time by Mr. Liutner in his sec- 

 ond report as State entomologist of Kew York. We can not now do 

 bett r than to insert his account of this peculiar injury in his own 

 words. It is an interesting instance of a new habit having been locally 

 acquired, and, so far as we have been able to ascertain, it has been 

 observed nowhere else — 



u In the summer of 1883, contemporaneously with the first appearance 

 of the Orgyia attack upon the foliage, between the 10th and the 15th 

 •of Jane, the sidewalks, streets, and public parks in Albany, wherever 

 the white elm (Ulmus Americanus) was growing, were observed to be 

 sprinkled with newly-fallen leaves. They continued to drop in increas- 

 ing number until toward the close of the mouth, when, in many x>laces 

 where they had been permitted to lie undisturbed, they completely 

 covered the walks or ground. 



"Upon taking some of them up for examination, they were found to 

 be attached to the tips of the twigs and to comprise nearly all of the 

 new growth of the season. The pieces were from 2 to 3 inches in length, 

 each bearing from four to ten fresh uninjured leaves. It was evident 

 that they were not being broken off by unusually high winds, for even 

 in the absence of winds each day continued to add to their number 

 and to increase the abundance of the fall. 



"Making critical observation for the discovery, if possible, of the 

 cause of so unusual a phenomenon, it was noticed that from above the 

 point at which the tip had been broken the bark was entirely removed 

 for an extent averaging one-tenth of an inch. The manner of its re- 

 moval showed it to have been eaten by an insect. The suggestion was 

 made to me that it was the work of some small insect of similar habits 

 to those of the twig girdler, Oncideres cingulatus (Say), but the closest 

 examination failed to show either scar or egg within the tip. 



