214 EXPERIMENTAL FARMS: 



64 VICTORIA, A. 1901 



THE PEA MOTH 

 {Semasia nigricana, Steph.). 



This insect was unusually abundant in the provinces of Ontario and Quebec 

 during the season of 1900. Prof. Lochhead reports it as troublesome this season in 

 the northern counties of Ontario : Grey, Bruce, Huron, Perth, Dufferin and Welling- 

 ton, but it does not appear to have been 

 quite so destructive as usual in the 

 Maritime Provinces, although inquiries 

 have been received from all three provinces. 

 Some experiments as yet incomplete may 

 be reported upon provisionally, as they 

 appear to be promising. Mr. J. E. Wetmore, 

 of Clifton, King's county, N.B., was good 

 M enough, at my request, to try spraying the 

 peas at the time the pods were forming, 

 with the same spray of Paris green and 



Tm„ Q -D ,. .. . .,, , ,^ water as is used for the Codling Moth. 



Fig. 8.— Pea Moth : caterpillar and moth. „, . . , i i . v 



2 and 4, enlarged. J- his experiment was suggested by tna 



similarity of the habits of the Pea Moth 



and those of the Codling Moth, and although only two sprayings were given, the results 



were so promising as to show the importance of careful experiments being carried out 



in spraying peas to prevent loss from the Pea Moth. There should be at least three 



sprayings, the first applied when the blossoms begin to fall, the second one a week 



later, and the third ten days later again. As liquids will not adhere easily to s-uch 



plants as the pea, owing to their waxy covering, it is necessary, after mixing the Paris 



green and water, 1 pound to 100 gallons, to add whale-oil soap, or some other soap, in 



the proportion of 1 pound to every 25 gallons of the mixture. Mr. Wetmore's report 



on the result of two sprayings, is as follows : — 



' Clifton, IST.B., October 4. — ^I think that the injury to pease in this section was 

 less this year than for a long time previously, and, therefore, it was not a very 

 favourable year for the experiment. Early peas never suffer much from the Pea 

 Moth, therefore I did not spray them, and they were not injured by the moth, except 

 a few at the latter end of the pick. I mixed the spray as you directed and applied it 

 with an Electric Sprayer, which only worked tolerably woU. The first application 

 was made on July 21, when the blossoms were beginning to fall from the pease, the 

 second one on July 28. I did not spray again, as the pease were about ready for use, 

 and I did not care to have the mixture on them. I gave the vines about the blossoms 

 a good soaking. I picked the first pease for the table on August 1, half sprayed and 

 half unsprayed, and. found one oatei-pi'llar in each. August 11, tested pease again, but 

 I could not detect any difference in sprayed and unsprayed pease. Very few pods 

 were affected in either, not more than one in fifty. I examined them for moth several 

 times after this, and found the number of affected pods increasing steadily in both 

 sprayed and unsprayed towards the end of the season. There was, however, a notice- 

 able difference between the sprayed and unsprayed at the end of the season, about 9 

 or 10 per cent of the sprayed pods were affected, while 20 to 25 per cent of the 

 ■unsprayed were attacked. I also examined pease on my neighbours' plots and found 

 about 25 x>er cent infested. This result was not entirely satisfactory to me, because 

 the mixture failed to keep the moth off entirely, though the vines were well drenched. 



'I do not think, however, that the moth always lays its eggs in the very early 

 stages. I have found a number of very young grubs on i>ease ready for the table, 

 though the majority were much older. In fact. T found all stages of growth at that 

 period, from very young to big fat grubs.' — J. E. Wetmore. 



