178 EXPERIMENTAL FARMS 



5-6 EDWARD VII., A. 1906 



The Diamond-Back Moth (Plutella maculipennis, Curtis). — Tlie small active 

 caterpillars of this moth were abundant and destructive in many places during 1905. 

 They did considerable harm in rape fields and on Swede turnips and cabbag-es, and 

 occurred at various places from Nova Scotia to British Columbia. I have no record 

 of widespread or very serious damage in the East, but there is every indication that, 

 if the summer had been a hot and dry one, the loss would have been very great. As 

 it was, the frequent and copious rains in those places where the outbrealcs occurred, 

 enabled the plants to make such vigorous growth that the attacks of the caterpillars 

 were of smaU moment. It is well known that moisture and continued damp weather 

 are detrimental to this insect. Dr. C. -A. Hamilton found the species very abundant 

 for several miles round Mahone Bay, N.S. It also occurred in Prince Edward Island. 

 at Youghall, near Bathurst, N.B., at Ottawa, and at several places in Manitoba, the 

 North-west Territories and British Columbia. 



The remedies for this insect are dusting the plants infested with a dry Paris green 

 mixture consisting of one pound of Paris green in twenty-five of lime or wood ashes, 

 or spraying them with kerosene emulsion or a whale-oil soap solution. To allow 

 of the mixture being thrown well up under the leaves such a convenient implement 

 as has been given to me by Mr. Geo, E. Eisher, of Freeman, Ont., should be used. 

 This consists simply of a short length of metal pipe bent in the middle to the required 

 angle and having the nozzle attached to one end. As a supplementary treatment 

 inducing a vigorous growth, light dressings of some quick acting fertilizer such as 

 nitrate of soda, hoed in round the roots of the plant, are of great advantage. 



The Cucumber and Potato Flea-Beetle (Epitrix cucumeris, Harr.). — A serious 

 enemy to potatoes, but one which is frequently overlooked, is the so-called Cucumber 

 Flea-beetle. This minute dusky-black hopping beetle, about one-twelfth of an inch in 

 length, appears early in spring and again about the beginning of August, and some- 

 times in such numbers that it becomes a serious check to potatoes, tomatoes and all 

 kinds of cucurbits or members of the Gourd family. A remarkable outbreak of this 

 beetle occurred in Nova Scotia last August. 



' Mahone Bay, N.S., August 14. — We have the Cucumber Flea-beetle here on pota 

 toes more or less plentifully every year especially in June; this spring, however, I 

 thought they were not as abundant as usual. On August 3 1 looked over my potatoes 

 for the Colorado Potato Beetle and do /not remember seeing $ny flea-beetles at all. On 

 August 5 one side of the patch was simply alive with them, and by the next day they 

 had spread over the whole patch. I partly counted and partly calculated the number 

 and found them to average about 800 to each plant. By the 9th they had destroyed 

 between a quarter and a half of the leaf surface of the side of the patch first attacked. 

 That afternoon I gave them a dose of poisoned Bordeaux mixture. On the 11th they 

 had practically disappeared. A neighbour's potatoes about 150 yards away were nearly 

 as badly infested as my own. I have an idea that the poisoned Bordeaux mixture may 

 act rather by driving the beetles to adjacent vegetation than by killing them. After 

 they left the potatoes they turned their attention to cucumbers, beans, pumpkins, 

 squashes and tomatoes which were badly eaten. On account of this troublesome pest 

 it is almost impossible, without the most careful attention, to raise tomatoes here from 

 seed sown in the open, because they sweep away the young plants as soon as they appear 

 above the ground.' — C. A. Hamilton. 



The efficacy of the poisoned Bordeaux mixture for this insect was discovered by 

 Prof. L. R. Jones, of Vermont, in his very thorough experiments with Bordeaux mix- 

 ture against the Potato Rot. It is probable that the copper sulphate in this composi- 

 tion does have much effect in rendering the foliage distasteful to the beetles ; but there 

 is also little doubt that great numbers of the beetles eat the foliage and are poisoned. 

 This useful remedy is suitable for application to all of the plants mentioned above and 

 is also useful upon them in preventing fungous diseases which regularly attack them. 



