18 



efforts, but not sufficient, it appears, to secure their continuance, and we know of no one 

 now raising these larvae for the purpose of obtaining silk for commerce. The insect has 

 also been introduced into France with a similar object, but with what success we have 

 not learned. 



A NEW APPLE TEEE PEST. 



By Charles R. Dodge, Washington, D. C. 



As if the apple tree with its sixty or more insect enemies were not sufficiently 

 afflicted, a distant relative of the Canker-worm has been making itself so notorious in 

 Georgia, as to give apprehension of the total destruction of apple orchards in the locality 

 infested. The insect complained of is Eugonia subsignaria Pack., a measuring worm 

 which at times has been a veritable nuisance upon shade trees in New York and Phila- 

 delphia. 



In pursuance of my duties as a Special Agent of the Census Office (in the fruit in- 

 terest), and through subsequent correspondence, the following facts were obtained from 

 Mr. Adam Davenport, of Fannin County, in the state named. In his first communica- 

 tion, received some months since, it is stated that the worm made its appearance upon 

 Rich Mountain, a spur of the Blue Ridge, about four years ago, attacking forest and 

 fruit trees ; and that it had since spread over a large area, doing great damage. Apple 

 trees in June last were as destitute of leaves as in mid-winter, the fruit growing to the 

 size of marbles and falling off. 



A late communication — with the replies to a series of questions — shows the de- 

 struction to be even worse than at first reported. I give Mr. Davenport's own words : — 



"The insect made its appearance four years ago upon Rich Mountain, since which 

 time it has been spreading in a northern semi-circle, at the rate of about fifteen miles 

 a year. It is by far the most interesting insect that has plagued this country since the 

 first white settlement. So wonderfully prolific that in two years it literally covered 

 every tree, bush and shrub, and with the exception of a few varieties, stripped them of 

 their leaves. 



" The egg hatches about the first of May, and the caterpillar, which is dark brown, 

 lives about forty days, transforms to a chrysalis, lives in this state about ten days, and 

 emerges a milk-white miller. For two weeks before the first transformation the fall of 

 their excreta, in the woods, resembles a gentle shower of rain, and from its abundance 

 tinges the streams a dark green hue. I have seen trees that had been stripped of their 

 foliage, entirely wrapped up in their silken webs, resembling, when covered with dew, a 

 wrapping of canvas. They constitute a great feast for all insectivorous birds and ani- 

 mals ; it is said that even cattle and sheep eat them with great greed. They have an 

 instinctive way of protecting themselves by losing their hold upon the limb, at the 

 slightest touch, and swinging by their web in the air. For this reason they are easily 

 shaken off into sheets and destroyed. However, they are so numerous, this remedy is 

 worth nothing except in keeping them off very small trees. This instinct is not lost 

 after leaving the caterpillar state, for if a bird alights upon a tree above the millers, 

 they suddenly drop like a shower of snow to the ground for protection." 



In the Practical Entomologist, volume 1, page 57, an anonymous writer gives an 

 account of this insect's attacks on elms in Philadelphia. Dr. Packard, in his Mono- 

 graph of the Geometrid Moths, page 528, mentions only elm as a food plant ; but Prof. 

 Thomas, in his second Illinois Report, page 243, says : " I have not noticed them feed- 

 ing upon that tree, but have twice found them feeding upon apple, upon the leaves of 

 which I have reared them to the perfect insect. In neither case were they numerous." 

 Prof. Comstock makes brief mention of the insect in his recent report as United States 

 Entomologist, quoting Mr. Davenport, as above, to the effect that the worms were de- 

 stroying forests of hickory and chestnut, and were damaging fruit, trees. This state- 

 ment doubtless refers to the season of 1880. 



