18 THE EEPORT OF THE No. 36 



have been sown in wheat and which have been attacked by the Cecidomyicv the preceding 

 year, are much more infested with it than recently cleared land. (Moreover, an observer 

 has noticed prodigious numtoers of Cecidomyue on potato vines planted in a field which 

 had yielded wheat the preceding summer; these flies were henceforward harmless. Thus 

 the necessity of alternating the crops and keeping wheat as long as possible from the 

 lately infested spots is clearly indicated. 



" ' It has also ibeen demonstrated through observation,' says Mr. Dupont, ' that !by 

 modifying the time of earing cf the wheat so as to have it before the 16th of June or 

 after the 20th of July, that is, 'before or after the time of appearance of the Cecidomyice, 

 the damages caused by that insect are avoided.' 



" Let us then, with Mr. Dupont, say to the farmers: If you dread the wheat fly for 

 next year, do not sow your grain on the same field, nor in its neighbourhood; then, 

 sow, if possible, in April; if this is too early, then wait till the first days of June; lastly, 

 keep your fields clear from weeds which may offer secure shelter for the flies." 



That quotation far off echo of what has been done, at a pretty far distant 

 epoch, in Canada, by one of our entomologists, goes to show the spirit of co-opera- 

 tion in the study of the captivating science of entomology which leads the entomo- 

 logists all over the world, though strangers they may be to one another, to work 

 jointly for the elucidation of the numerous problems offered by that science.* 



*The above mentioned essay of Emilien Dupont has 'been published in French in 

 book form, as a pamphlet of 38 pages, Oif which the title page reads as follows: Essai 

 sur les insectes et les maladies qui affectent le ble, par Emilien Dupont, Ecr., de St. 

 Joachim, comte de Montmorency. L'auteur a regu le troisieme prix du Bureau d'Agri- 

 culture et des Statistiques. Montreal, des presses a vapeur du Canada Directory, rue 

 St-Nicolas, 1857. 



The name of Emilien Dupont is a pseudonym. The true name of the author is 

 L'Abbe Leon Provancher, of the Diocese of Quebec, the well-known French-Canadian 

 naturalist, who has written many works on natural history from 1857 to 1891. 



REPORT ON INSECTS FOR THE YEAR. 



Division No, 1, Ottawa Distkict — Arthur Gibsox, Entomological 



Branch, Ottawa. 



Attacking Field Crops. 



The Striped Cucumber Beetle, Diahrotica vittata Fab. In the early part of 

 the summer a good deal of injury was caused by this insect, particularly to cucum- 

 bers and Hubbard's squash. Many plants of the latter examined on June 21st were 

 seen to be seriously eaten. Experiments in controlling the beetle by spraying with 

 ordinary poisoned Bordeaux mixture were successful, the plants being thoroughly 

 drenched with the mixture. 



The Ash-gray Blister Beetle, Macrohasis nnicolor Kby., was again com- 

 plained of in the district as injuring potatoes in the first half of July. On July 

 7th from one hill 150 beetles were removed. 



The Imported Onion Maggot, Hylemyia antiqua Mg. In 1917 we continued 

 our experiments with a poisoned bait spray (sodium arsenite), to attract and kill 

 the flies, and as our results were of considerable value a separate statement on this 

 work appears on page 31. 



The Cabbage Root Maggot, Phorhia hrassiccB Bouche. While not specially 

 numerous, a good deal of injury was effected by the maggots. Complaints were 

 received chiefly from amateur gardeners who found that their cabbage, cauliflower 

 and turnip plants were being destroyed. One gardener brought to me, on July 



