Treesearch

In March and April 1983, 289 and 196 young grafted sugar maple trees were tapped and evaluated for sap-sugar content. In April, sap was collected from taps both above and below the graft union. Diameter of all tapped trees at 18 inches above the ground was measured. Analysis of the data revealed that: (1) trees selected for high sugar yield cannot be reproduced by grafting on rootstock of unknown but varying sugar content without encountering large fluctuations in sap sweetness of the trees produced; (2) diameter is not correlated with sap sweetness of young grafted trees; (3) numerous...

This panel of experts from Canada and the United States has been brought together to discuss control techniques and strategies employed against these important defoliators - the spruce budworm and the gypsy moth. In selecting the panel we have chosen people with experience ranging from research to control.

Sandoz is pleased to announce the acquisition of Zoecon Incorporated of the United States and Canada. Effective November 15, 1983, all Zoecon and Sandoz Crop Protection Division personnel, facilities and products will be combined under the Zoecon, Inc. name. Zoecon will be a wholly owned subsidiary of Sandoz Ltd. with major offices in Palo Alto, Calif. and Dallas, Texas.

Interest in and discussion of the relationship between droplet spectrum emitted and droplet spectrum deposited, spray cloud behaviour, the relationship between droplets deposited and efficacy, and optimum droplet size, has increased in recent years and has resulted in a number of collaborative studies addressing aspects of these questions. The questions are particularly pertinent to operational use of Bacillus thuringiensis (Bt) preparations because Bt must be ingested, probably repeatedly, (Fast and Reginiere, Can. Ent. 116: 123-130; 1984) before it can act. Therefore, numbers of droplets...

This research report is concerned with: 1). A field application program using encapsulated Bt. The objectives of that program involved spray physics and the delineation of the critical parameters inherent in the delivery of Bt sprays to the microhabitat of the spruce budworm. The field application work was carried out jointly with Dr. Alam Sundaram and the Forest Pest Management Institute (Canada). Most of the data from the field studies will be published in a separate paper with Dr. Sundaram. 2). A laboratory program concerned with stabilization studies on pure Bt and BtI crystals. The...

Each year in Northeastern United States over 500,000 acres of oak forests are aerially sprayed to prevent massive defoliation by the gypsy moth. In Pennsylvania alone 400,000 acres were proposed for treatment in 1983 with commercial preparation of Bacillus thuringiensis (Bt).

I think it is time to open the panel. On my left respectively are Bill Waters, Professor of Entomology and Forestry, University of California, Berkeley; Gerald S. Walton, Biometrician, Northeastern Forest Experiment Station, Hamden; and Leo Cadogan, Forest Pest Management Institute, Canadian Forestry Service, Sault Ste. Marie, Ontario. My name is Dan Schmitt, Program Manager, Northeastern Forest Experiment Station, U.S.F.S., Broomall, Pa. I am going to ask each of the panelists to discuss field test design and data analysis for pesticide applications in the context of three general areas:...

The gypsy moth Lymantria dispar (Linnaeus) has grown in economic importance as an insect pest over the past 75 years. From a localized infestation of a small geographical area of New England, the gypsy moth has spread to such an extent that is now found over much of the United States. Control measures are varied, but effective biological control is needed to control pest populations, especially in such sensitive areas as parks, residential areas, and municipal watersheds.

Gypsy moth nucleopolyhedrosis virus polyhedral inclusion bodies dissolve slowly in host digestive fluids, in vitro. Infectious viral material is in the hemocoel two hours after ingestion of inclusion bodies. Hemocytes produce and release nucleocapsids throughout the course of infection, but in the fat body, nearly all nucleocapsids are enveloped and occluded.

Enzyme-linked immunosorbent assays (ELISA) were developed for detecting gypsy moth (Lymantria dispar L.) nuclear polyhedrosis virus (NPV). They were used to detect the presence of NPV in hemoplymph samples collected from infected larvae. The incorporation of hybridoma antibodies with these procedures would make them even more specific for gypsy moth NPV detection. A pilot study of evaluating NPV spray with ELISA is also presented here. Potentially, these immunochemical methods have important applications in an IPM approach toward the control of gypsy moth.