Annotated list of insects and mites collected on brambles in the Lower Fraser Valley

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A method for rearing the predaceous mite, Phytoseilus persimilis (Acarina: Phytoseiidae)

The predaceous mite, <i>Phytoseiulus persimilis</i> Athias-Henriot, was reared successfully in a darkened growth chamber on blotting paper on a freezer carton lid floated on water in a plastic saucer. Predators were fed with two-spotted spider mites collected from infested bean leaves with a mite brushing machine

Control of three species of leafhoppers, on Rubus in British Columbia

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Phytoseiulus persimilis (Acarina: Phytoseiidae) for control of two-spotted mites in a commercial greenhouse

Natural infestations of the two-spotted spider mite were controlled on green house cucumber by early releases of the predatory mite, Phytoseiulus persimilis Athias-Henriot. Later sporadic mite outbreaks severely damaged some plants and required frequent surveys and repeated predator releases in the greenhouse. However, no mite sprays were required and crop yield was satisfactory

A method for rearing the predaceous mite, Phytoseilus persimilis (Acarina: Phytoseiidae)

The predaceous mite, Phytoseiulus persimilis Athias-Henriot, was reared successfully in a darkened growth chamber on blotting paper on a freezer carton lid floated on water in a plastic saucer. Predators were fed with two-spotted spider mites collected from infested bean leaves with a mite brushing machine

Effect of a commercial insecticidal soap on greenhouse whitefly (Hom: Aleyrod.) and its parasitoid, Encarsia formosa (Hym: Euloph.)

Safer’s Insecticidal Soap (IS) was topically applied at six concentrations to all growth stages of greenhouse whitefly as well as larvae and adults of the whitefly parasitoid, the eulophid wasp Encarsia formosa. IS at 0.5% ai caused more than 94% mortality of all whitefly larval stages and adults, and more than 82.5% mortalitv of whitefly pupae. Adults hatched from treated pupae occasionally showed altered development. E. formosa adults were more tolerant to IS than whitefly and 81.5% survived a 0.5% IS treatment. It was concluded that IS is an effective pesticide for greenhouse whitefly and should be integrated with E. formosa in greenhouse trials

Formation of singularities on the surface of a liquid metal in a strong electric field

The nonlinear dynamics of the free surface of an ideal conducting liquid in a strong external electric field is studied. It is establish that the equations of motion for such a liquid can be solved in the approximation in which the surface deviates from a plane by small angles. This makes it possible to show that on an initially smooth surface for almost any initial conditions points with an infinite curvature corresponding to branch points of the root type can form in a finite time.Comment: 14 page

Dynamics of the Free Surface of a Conducting Liquid in a Near-Critical Electric Field

Near-critical behavior of the free surface of an ideally conducting liquid in an external electric field is considered. Based on an analysis of three-wave processes using the method of integral estimations, sufficient criteria for hard instability of a planar surface are formulated. It is shown that the higher-order nonlinearities do not saturate the instability, for which reason the growth of disturbances has an explosive character.Comment: 19 page

Efficacy of insecticides against geometrid larvae, Operophtera spp., on southern Vancouver Island, British Columbia

Permethrin, acephate, diazinon, malathion, endosulfan , methoxychlor , Imidan, naled and a spray containing surfactant only were the most effective treatments for control of winter moth, Operophtera brumata (L. ), and Bruce spanworm, O. bruceata (Hulst), on apple in the tight cluster bud stage. Resmethrin, trichlorfon, and Dipel and Thuricide formulations of Bacillus thuringiensis were less effective. The growth disruptor, Dimilin, provided good control at the pink bud stage. At this same stage, sprays with surfactant only were no better than untreated controls

Viruses to control winter moth, Operophtera brumata (Lepidoptera: Geometridae)

An abandoned apple orchard in Victoria, British Columbia, was used to test winter moth nuclear polyhedrosis virus (NPV) in 1979. Concentrations of 10", 107 and 10· polyhedral inclusion bodies (PIB)/ml were applied at the rate of 1 l/tree using a backpack mistblower, soon after the larvae hatched when buds were pre-pink and 8 days later when the buds were full pink. Each treatment was replicated on 6 trees; 6 trees were untreated checks. Best results were with 10" PIB/ml on pre-pink buds which caused 46% population reduction, a statistically significant saving of foliage and high levels of larval infection with both NPV and cytoplasmic polyhedrosis virus (CPV). Both viruses were found in larvae on the check trees and this was attributed to spray drift. The source of the CPV was investiga ted and found to be a contaminant of the NPV suspension in which the ratio of NPV: CPV PIB was 161 : 1. Despite the low level of CPV applied, up to 65% of the larvae were infected. In 1980, a survey to determine levels of infection in winter moth larvae showed no viruses in 5 untreated sites and only 1% NPV and 5% CPV in the treated orchard. The virus treatment did not initiate a continuing epizootic and the effective concentration of lOS PIB/ml was too costly to produce as a biocontrol agent having an impact only in the season of application