188 EXPERIMENTAL FARMS. 



immunity of certain districts in Canada from the attacks of the Pea Weevil, Bruchus 

 pisi, L., large quantities of seed pease have of late years been grown in these districts 

 for European and American seed houses. Late last season and during the present sum- 

 mer, complaints have come in of the ravages of the Pea Moth, the caterpillar of which 

 is generally spoken of in the trade as the " grub. " Mr. N. H. Cowdry, an extensive 

 grain merchant, of Lindsay, Ont., writes : — 



" We have no 'pea bugs' in this section; but the ' grubs ' seem to be nearly as 

 bad a pest ; our farmers know no way to prevent the attack. " 



Messrs. N. B. Keeney and Son, of LeRoy, N. Y., wrote to me as follows : — 



"November, 18, 1893. — We are growing pease for the seed trade in the counties 

 east of Toronto, Ont., and also in .Northern Michigan. The principal obstacle we 

 encounter in our Canadian field, is the injury by a worm which works inside the pea pod 

 and eats the outside of the green pea when it is in suitable condition for cooking. The 

 injury done by this worm frequently results in destroying the usefulness of from 10 to 

 20 per cent of the crop, and we would like to know if there is any possible means of pre- 

 venting the work of this worm. " 



"June 29, 1894. — We shall be glad to have instructions from you and will follow 

 same to our best ability, and we hope a remedy may be discovered for this very serious 

 hindrance to the prosperity of Canadian pea growers. This insect has never worked, to 

 any extent, on this side of the line, so far as we have been able to learn ; nor have we 

 ever seen it in Northern Michigan, notwithstanding we have shipped Canadian grown 

 ppase to Michigan for seed. " 



Several specimens of the larvae were from time to time forwarded to me by Mr. N. 

 H. Cowdry and Messrs. Keeney and Son's agents, and these are now passing the winter 

 as larvae inside their cocoons. Next spring I hope to obtain the perfect insect, which 

 is undoubtedly a small moth and may possibly prove to be the European Pea Moth, 

 Semasia nebritana, Treits. (Grapholitha pisana, Gn.j. The preparatory stages and the 

 habits of the insect, as far as worked out, all agree closely with those of the European 

 species, as figured and described in Curtis's Farm Insects, page 348, and Miss Ormerod's 

 valuable Manual of Injurious Insects, page 163. Miss Ormerod's description of the 

 English species is as follows : — 



" These caterpillars or maggots are fleshy and slightly hairx', about or somewhat more 

 than a quarter of an inch in length, and are generally yellowish in colour, with a black 

 head, a brown band on the ring next to the head, and eight brown dots on most of the 

 following rings. They sometimes, however, vary in colour ; in some specimens the head 

 and the next ring are brown, and in some they are intensely black. The legs on the 

 three rings next to the head are black. 



" The caterpillars go down into the earth to change, where they spin a cocoon (that 

 is, a kind of egg-shaped covering formed of silken threads drawn from the mouth) in 

 which they remain till spring, when they turn to chrysalids, out of which the moths ap- 

 pear in June. 



"The moths are rather more than half an inch in the spread of the wings, satiny, 

 and mouse-coloured. The upper wings have a row of very short white streaks directed 

 backwards from the front edge, and a silvery oval ring with five short black lines inside 

 it placed near the hinder margin." 



The following account of the habits of this insect is from the Agricultural Zoology 

 of Dr. J. Ritzema Bos (London, 1894) : — 



" The moths fly about in large numbers round the pea blossoms, always a short 

 time after sunset. The females lay one, two, or at most three eggs on a very young 

 pod, or an ovary. In fourteen days the caterpillar is hatched, bores into the pod, and 

 attacks the pease. The opening made in the margin of the pod closes up again. The 

 pod generally ripens early. When it opens, the full-grown caterpillars creep out, and 

 become pupa? in the soil, within a web, where the pupa lives through the winter. The 

 pease attacked are always covered, while in the pod, with the coarse-grained excre- 

 ment of the caterpillars, and are often united two or three together by web fibres." 



Commenting on the above, Mr. Cowdry writes : — " The pods here seldom open na- 

 turally, and I think do not ripen early. The quantity of excrement and web fibres is 



