REPORT OF THE EXTOMOLOGIST AXD BOTAXIST 185 



SESSIONAL PAPER No. 1G 



gone. I did not notice any of the moths last year, but now (June 15), the moths are 

 thick, and I send you a few to examine. I should like to know what these are, al- 

 though they did me no harm last year; in fact, they saved me a day or two's work 

 cutting weeds, hut I might not have a field of pigv\-eed ready for them when they conic 

 again.' 



The Sugar-beet Webworm can hardly be described as a green caterpillar, because it 

 is dark black, with greenish yellow stripes, but, strange to say, almost every corres- 

 pondent who mentioned it referred to it as a green caterpillar. As, however, in most 

 instances specimens of the caterpillars accompanied the inquiries, there was no doubt 

 a? to the identity of the species, which has been kindly supplied to me by Dr. Dyar, 

 cJ the Division of Entomology, at Washington. It would appear from the dates when 

 caterpillars are mentioned by observers in Manitoba, that there were two broods of 

 this insect last summer. The life history of the species has been carefully worked 

 cut by the Division of Entomology at Washington, and illustrated articles have ap- 

 peared upon it in ' Insect Life,' V. and VI., and in the recent Bulletin 43, by Mr. 

 E. H. Chittenden, on the ' Principal Insect Enemies of the Sugar-beet.' The excel- 

 lent illustrations given herewith have been kindly lent to me by Dr. Howard and were 

 used in the last named bulletin. 



The following letter gives some idea of the range of plants liable to be attacked 

 by these caterpillars. There is no doubt that the normal food plant is the Lamb's- 

 quarters or Wild Spinach (Chenopodliim album, L.), often called pigweed. 



' Deleau, Man., July 21. — We have had a visitation from a pest that I have never 

 seen before in my 21 years' residence here. About two weeks ago Vve noticed the pig- 

 weed on land left for summer-fallowing covered with a greenish worm, samples of 

 which I send yoii. In a day or two these swarmed into the garden in millions. They 

 scarcely touched potatoes, beans or corn, but devoured turnips, beets, cabbages, onions, 

 carrots, currant bushes, and even crap-apple leaves. We made a vigorous fight to snve 

 something, making narrow trenches for them to fall into, and tried various poisons, 

 but without avail; so, we stuck systematically to knocking them into tin pans and 

 emptying these into pails of water with coal oil in them. In this way we caught seve- 

 ral pailfuls in a day. They have now almost disappeared but have left the garden 

 in a very dilapidated condition. As soon as v\'e noticed them coming off summer- 

 fallow, we ploughed the land next to our garden, but they swarmed over on top of the 

 ploughing. They seem to be good travellers. I should like to know what they are.* 

 — J. E. Marples. 



Specimens of the caterpillars v«-ere sent, without any letter beiug received, from 

 Mr. TI. L. Patmore, of Brandon. 



Mr. Norman Cridrll?, of Aweme, sends the following notes : 



' Sept. 5. — Do you remember mentioning when here a small prairie moth, which 

 one of your correspondents was afraid of as a possible enemy of Vv-heat. I am sending 

 you now what I am pretty sure are the larvae of the moths you showed me. Ihese 

 caterpillars are here now simply in enormous numbers, more so than anything of t!ie 

 sort I have ever seen. They clear off all the food before them and then march on in 

 a regular sv.-arm, all going the same way. The food plant seems to be usually lamb's- 

 quarters, but this has been all eaten clean, and they are now turning their attention 

 to wild buckwheat, the native asters, the tumble-weed (Amarantus), sand cherry, red 

 cherry, rose, red-root pigweed, and even wheat and oats, as well as numerous other 

 plants. Fortunately, they are too late in the season to do much harm, and in any 

 case they seem to prefer weeds to grain. The moths were very abundant during June 

 and July.' 



'■ Sept. 27. — The larvae have now all disappeared beneath the ground, but whether 

 to hibernate or pupate, I am not quite sure. Several that I dug out had not yet under- 

 gone any change, but had merely made a straight burrow about two inches deep, which 



