70 



It was readily identified by me, and the request for its identification 

 and a remedy for it was answered virtually as follows: 



The beetle is a member of the destructive family of leaf-eating beetles known as 

 Chrysomelicbe. It has received in the Western States the popular name of the cotton- 

 wood beetle from its special fondness shown for the foliage of the cottouwood tree 

 (I'opulus monihfera). In recent years it has become almost equally injurious to wil- 

 lows. It was first brought to public notice by Professor Snow in the year 1875 by 

 its widespread destruction of the cotton wood in Kansas, and a few years later (1878) 

 by Professor Eiley in his accounts of its more serious ravages in Nebraska and 

 Dakota, Avhere the rapidly growing cottouwoods had been extensively planted by 

 new settlers in the treeless plains of that region. Many thousands of trees were 

 killed through their defoliation for successive years, the remnants of the leaves turn- 

 ing black and shriveled, as if struck by " fire blight." 



The beetle has never before, so far as known to me, appeared in injurious numbers 

 in the State of New York. It has not been a common insect with vis. Indeed, it had 

 never come under my observation until in the year 1890, when, duriug the early part 

 of July (4th to 7th), both the larv;e and the beetles were found by me in Keene Val- 

 ley, in the Adirondack Mountains, feeding on willows growing along the banks of 

 the An Sable Eiver. Nearly a hundred were collected foi- the State collection. Not 

 a single example of the insect has since been seen by me in the five following years 

 of collecting in that locality. 



Both the larva and the beetle feed upon the willow. * * * xhe larva is at 

 first black; when full grown it is of au elongate form and measures nearly a half 

 inch iu length. It is then of a dingy yellowish color, with head and legs shining 

 black, tAvo rows of black spots on the back, and iu line with these a row of black 

 tubercles on each side. These tubercles, when the larva is disturbed, throw out 

 from each one (for its defense from its enemies through the pungency of the odor) a 

 globule of a milky fluid, which is drawn into them again when the alarm passes 

 away. 



The beetles are oval, more flattened than the chrysomelids usually, and A'ary in 

 length from two-tenths to three-tenths of an inch. The head is black. The thorax 

 is mainly black centrally, with its two outer sides bordered with red. The wing 

 covers are tlul> yellowish, with about seven black spots and lines, and the inner 

 margins joining over the back, also black. The legs are yellow and black, and the 

 body beneath blue-black. 



The injurious character of the beetle is intensified from there being two or three 

 or moie broods of it each year. The brood now present Avitli you is from eggs that 

 were laid on the willow early in the season. Under favoring conditions for multii)li- 

 cation the subsequent broods will be more numerous and of course more destructive. 



It is fortunate for your willow growers that we have a comparatively simple 

 remedy for this new willow T)est, otherwise the industry so important to your people 

 might be seriously impaired. A tliorough spraying of the willows with Paris green 

 in water should kill all the insects in their larval and perfect stages that feed upon 

 the leaves. 



Directions for preparing and using the spraying mixture and infor- 

 mation regarding pumps available for the purpose accompanied tlie 

 above. 



]n some correspondence following only a partial success was reported 

 to me as the result of the spraying recommended. The increase of the 

 insects could not be kept down, and consequently in several instances 

 entire fields of willow had been destroyed and plowed up. Some other 

 suggestions were made by me and were, I believe, faithfully tried. 



