The seed-corn maggot, Hylemya cilicrura (Rond.), infests a wide range of hosts in all provinces of Canada and is also a pest in the Yukon and the Northwest Territories. H. liturata (Meig.) frequently occurs in smaller numbers along with H. cilicrura. H. liturata has not ,been recorded from Alberta, Saskatchewan, and Manitoba (Brooks, 1951). Detailed accounts of the species have not been published by Canadian entomologists, though H. cilicrura has been known as a pest of cultivated crops in Canada for over 70 years. In southwestern Ontario the seed-corn maggot is one of the most serious soil pests of vegetables and field crops.

The formation of a yellow band inside the stalk of each ovariole was a good indicator that a female European corn borer had laid eggs. The absence of these bands was less reliable as an indicator that no eggs had been laid, probably due to the time taken for the bands to form. The numbers of moths accumulating in a light trap over a week at Harrow, Ontario, and the numbers of females estimated to have laid eggs correlated significantly with the numbers of larvae developing in nearby green pepper plots 3, 4, and 5 weeks later during second generation flights. This enabled linear equations for forecasting pepper damage to be developed, in which the dissection data was more useful than the total moth catch alone.

Can. Ent. 100: 549-556 (1968) Oviposition of the predacious mites Phytoseiulus persirnilis and Typhlodrornus fallacis began 2 days after mating, reached a peak in 1 week, and then declined irregularly. The rates of oviposition were higher, and the oviposition period shorter at 26" than at 20°C. P. persirnilis laid 47% more eggs than T. fallacis. The generation time for both species was very dependent on temperature. Minimum values of 112 hours for P. persirnilis and 127 hours for T. fallacis were obtained at 28".Calculations of potential predator populations from the generation time, agespecific fecundity, and proportion of females were made on a daily basis for successive generations. The potential number of living females derived from one mated pair increased logarithmically after a few cycles representing new generations. The rate of increase of P. persirnilis populations was 26% higher than that of T. fallacis, and in both species the rate at 26" was about double the rate at 20".

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4n attempt was made to suppress Rn incipient spruc-budworm outbreak in the Lower St. Lawrence region of Quebec througli rhe acrial application of DDT. Operations began in 1960 and continued in 1961 and 1961 when they finally mct with succcss. Failure to achierc success earlier was due parrly to the exceptionally favoural)le survival conditions for the insect in 1960, and partly to the inadvertent omission of a small infested area from the program in 1961. T h e operations grearlv reduccd spruce bud~cform populations each year in the outbreak area, whilc the action of natural control factors. including pnrasitcs and predators increased. The col!apsc of tllc outbrcak was the result of the combined effects of the chenlical treatments and of natural control factors.