Susceptibility of the sod webworm \u3ci\u3ePediasia trisecta\u3c/i\u3e to biological control agents

Homeowners in Tennessee have observed complete destruction of their lawns by the sod webworm a few months after applying an insecticide to control sod webworms or white grubs. The reason for this increase rather than a decrease in the webworm population is not perfectly understood. We believe, however, that the natural enemies of the webworm may be reduced to such low population levels that they exert very little control on the webworm. Thus, once the natural enemies are destroyed in a lawn, it may require several months or even years for them to increase to a population level necessary to exert a satisfactory control on the webworms. In the absence of their natural enemies, which serve to control their population, the webworms, because of their high reproductive potential, increase rapidly and lawn destruction follows. Insecticides which cause an increase of webworm numbers are the chlorinated hydrocarbons such as dieldrin and chlordane. These are excellent insecticides for the control of soil insects such as white grubs which feed on grass roots but have not been satisfactory in webworm control in Tennessee. Insecticides that are recommended by the Institute of Agriculture for webworm control (Sevin and Diazinon) have not been implicated in causing webworm increases, but they probably do have an adverse effect on the natural enemy population. There is also a possibility that webworms may develop resistance to these chemieaIs. In addition, these chemicals have the disadvantage of having to be applied every 3 weeks during the summer because of their short activity period. Because of the above-mentioned disadvantages of chemicals, we are searching for new means of sod webworm control. Biological control, which involves the dissemination of large numbers of parasites, predators, and/or insect pathogens, may offer promise in sod webworm control. We have conducted preliminary studies utilizing biological control agents which are non-toxic to humans, birds, wildlife, and fish. Some of these agents are so specific as to insects attacked that certain ones can be selected that destroy the target insect pest but leave unharmed other insects and mites which are predators and parasites. Biological control agents cause no phytotoxicity at high rates as some insecticides do. Insect pathogens, which were the subject of this study, are manufactured in various formulations such as wettable powders, dusts, baits, and aqueous suspensions, and can be applied with the same equipment as insecticides. Costs for those whi

The response of Kentucky bluegrass turf to insecticidal treatments

The most common insect pests of Kentucky bluegrass (Poa pratensis L.) in Tennessee are sod webworms and white grubs. Attempts to control these insects with insecticides has, at times, resulted in the entire destruction of the lawn by sod webworms. Pass (1965) has shown that applications of aldrin, chlordane, and dieldrin increased the webworm population 2-3 fold. Streu and Vasvary (1966) found the same phenomenon in chinch bug control. Both Pass and Streu believed that this population increase of the target pest may have been related to an interference in some population-limiting mechanism, such as the natural enemies, but neither investigator definitely proved this. In view of the problem that home owners have had after applying insecticides for webworm and grub control, it was decided to conduct a study to determine the overall effects of insecticides on bluegrass. The research reported herein covers only a preliminary phase of that study: the effect of insecticides on botanical composition of a bluegrass turf

High-solids black liquor firing in pulp and paper industry kraft recovery boilers: Phase 1 -- Final report. Volume 2: Project technical results

This project is a multiple-phase effort to develop technologies to improve high-solids black liquor firing in pulp mill recovery boilers. The principal means to this end is to construct and operate a pilot-scale recovery furnace simulator (RFS) in which these technologies can be tested. The Phase 1 objectives are to prepare a preliminary design for the RFS, delineate a project concept for evaluating candidate technologies, establish industrial partners, and report the results. Phase 1 addressed the objectives with seven tasks: Develop a preliminary design of the RFS; estimate the detailed design and construction costs of the RFS and the balance of the project; identify interested parties in the paper industry and key suppliers; plan the Phase 2 and Phase 3 tests to characterize the RFS; evaluate the economic justification for high-solids firing deployment in the industry; evaluate high-solids black liquor property data to support the RFS design; manage the project and reporting results, which included planning the future program direction

Susceptibility of the sod webworm \u3ci\u3ePediasia trisecta\u3c/i\u3e to biological control agents

Homeowners in Tennessee have observed complete destruction of their lawns by the sod webworm a few months after applying an insecticide to control sod webworms or white grubs. The reason for this increase rather than a decrease in the webworm population is not perfectly understood. We believe, however, that the natural enemies of the webworm may be reduced to such low population levels that they exert very little control on the webworm. Thus, once the natural enemies are destroyed in a lawn, it may require several months or even years for them to increase to a population level necessary to exert a satisfactory control on the webworms. In the absence of their natural enemies, which serve to control their population, the webworms, because of their high reproductive potential, increase rapidly and lawn destruction follows. Insecticides which cause an increase of webworm numbers are the chlorinated hydrocarbons such as dieldrin and chlordane. These are excellent insecticides for the control of soil insects such as white grubs which feed on grass roots but have not been satisfactory in webworm control in Tennessee. Insecticides that are recommended by the Institute of Agriculture for webworm control (Sevin and Diazinon) have not been implicated in causing webworm increases, but they probably do have an adverse effect on the natural enemy population. There is also a possibility that webworms may develop resistance to these chemieaIs. In addition, these chemicals have the disadvantage of having to be applied every 3 weeks during the summer because of their short activity period. Because of the above-mentioned disadvantages of chemicals, we are searching for new means of sod webworm control. Biological control, which involves the dissemination of large numbers of parasites, predators, and/or insect pathogens, may offer promise in sod webworm control. We have conducted preliminary studies utilizing biological control agents which are non-toxic to humans, birds, wildlife, and fish. Some of these agents are so specific as to insects attacked that certain ones can be selected that destroy the target insect pest but leave unharmed other insects and mites which are predators and parasites. Biological control agents cause no phytotoxicity at high rates as some insecticides do. Insect pathogens, which were the subject of this study, are manufactured in various formulations such as wettable powders, dusts, baits, and aqueous suspensions, and can be applied with the same equipment as insecticides. Costs for those whi

The response of Kentucky bluegrass turf to insecticidal treatments

The most common insect pests of Kentucky bluegrass (Poa pratensis L.) in Tennessee are sod webworms and white grubs. Attempts to control these insects with insecticides has, at times, resulted in the entire destruction of the lawn by sod webworms. Pass (1965) has shown that applications of aldrin, chlordane, and dieldrin increased the webworm population 2-3 fold. Streu and Vasvary (1966) found the same phenomenon in chinch bug control. Both Pass and Streu believed that this population increase of the target pest may have been related to an interference in some population-limiting mechanism, such as the natural enemies, but neither investigator definitely proved this. In view of the problem that home owners have had after applying insecticides for webworm and grub control, it was decided to conduct a study to determine the overall effects of insecticides on bluegrass. The research reported herein covers only a preliminary phase of that study: the effect of insecticides on botanical composition of a bluegrass turf

High-solids black liquor firing in pulp and paper industry Kraft recovery boilers. Final report, Phase 1, Volume 1: Executive summary

This project is a multiple-phase effort to develop technologies to improve high-solids black liquor firing in pulp mill recovery boilers. The objectives are to develop a preliminary design of a recovery furnace simulator; evaluate the economics of high-solids; and delineate a project concept for evaluating candidate technologies to improve chemical recovery