ISSN:0006-3592    

DOI:10.1002/bit.260220702

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractBiological insecticide formulations based on the entomogenous bacterium.Bacillus thuringiensis, have begun to be used widely in agriculture. This spore‐forming bacillus can be grown in submerged culture and formulated to provide stable agricultural formulations compatible with aerial and ground application systems. The safety of these products to nontarget organisms and man is responsible for the growing interest in their use on a variety of crops including pastures and forests. No longer a laboratory curiosity,B. thuringiensisis an economic alternative to chemical insecticide

ISSN:0006-3592    

DOI:10.1002/bit.260220703

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThe structural chemistry of theBacillus thuringiensisparasporal protein crystal is discussed in terms of purification techniques, removal of contaminating proteases, crystal subunit size, crystal shape, interchain crosslinks, the ultimate toxin, and lysinoalanine. The alkaline pH cleavage of disulfide bonds is stressed in relationship to this role in crystal solubilization and toxin formation. The future implication s of plasmid‐coded crystal formation andB. thuringiensis var. israelensis(effective against mosquitoes and black flies) are also discusse

ISSN:0006-3592    

DOI:10.1002/bit.260220704

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractFrom 1972 to 1977 a large laboratory effort was devoted to determining data on efficacy, safety, environmental impact (on nontarget organisms), and some preliminary field work using several isolates ofBacillus sphaericus. TheB. sphaericusstrains were found to be specific in their mosquito larvicidal activity, not causing mammalian toxicity nor apparent perturbation of the environment. During this period several fermentation and industrialization problems were investigated so that by 1978, using new strains and cultures, it was possible to have prepared kilogram amounts of an active dry stable powder, of strain 1593, for field evaluation. These field evolution. These field evaluations are presently still in progress. Control has been seen particularly againstCulex,Anopheles, andPsorophoraspecies, with some what less control aganstAedesspecies. Unlike the agriculturally orientedBacillus thuringiensiscandidates,B. sphaericusbacterial cell, which is digested in the larval midgut (within a peritrophic membrane), releasing a toxin as early as 15 min after ingestion. Subsequent death of the larva ensues. Recent evidence suggests that appliedB. sphaericuspowder will survive in aquatic situations (ditches, ponds, and tree holes) for at least nine month. Comparisons of theB. sphaeicusstrains with recently isolated strains ofB. thuringiensis (var. israelensis), the latter being particularly active againstAedes species, indicates that they may be useful complements of each other in overall mosquito control strategies. The recent isolation of several new strains ofB. thuringiensis, from WHO‐CCBC accessions from Roumania, indicate that although theB. thuringiensisisolate is a rare event when compared to the occurrence ofB. sphaericusisolates (they usually occur together in accessions from whichB. thuringiensisis isolated), several new useful strains ofB. thuringiensisshould be anticipated. The longevity of theB. thuringiensisstrains in the wild has not yet been investigate

ISSN:0006-3592    

DOI:10.1002/bit.260220705

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractSeveral baculvirusus of nuclear polyhedrosis virus (NPV) have been produced and tested for microbial control of variousLepidoptera spp.To date, there are three registered preparations of NPV that are exempt from the requirement of tolerance by the Environmental Protection Agency (EPA) in the United States (US). The first and only commercially available viral preparation used in agriculture was developed by Sandoz, Inc. under the name of Elcar® for control ofHeliothisspp. on cotton. The other two baculovirus preparations were developed and registered by the US Department of Agriculture (USDA) for control of Douglas‐fir tussock moth and gypsy moth on forests. Several methods are being used for production of NPV viruses: (1) field collection of diseased larvae, (2) laboratory rearing of insects followed by infection with viral inoculum, (3) tissue culture. and (4) tissue culture and mass rearing larvae. Recent progress in mass production of insect virus points toward the adoption of tissue culture with the whole organism technology for production of a standardized viral product. The practical usefulness of various baculovirus preparations has been demonstrated for protection of forests from defoliation by various lepidopterous species. In agriculture, Elcar® has been successfully marketed and has been very well received for use in integrated pest management on cotton. Recent development also demonstrated that use of adjuvants further increase the efficacy of Elcar® againstHeliothisspp. on co

ISSN:0006-3592    

DOI:10.1002/bit.260220706

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThe genusBaculoviruscontains three subgroups of viral types: (1) nuclear polyhedrosis viruses (NPVs), (2) granulosis viruses (GVs), and (3) nonoccluded baculoviruses. While little information is available for viruses from the third subgroup, several aspects of the infectivity and mode of action of NPVs and GVs have been studied. The most common route of entry of a virus into an insect host isper os, and both virus types enter midgut cells (primary site of infection) by membrane fusion. However, two distinct mechanisms of virus uncoating occur among the baculoviruses: NPVs uncoat within the nucleus, whereas GVs uncoat at the nuclear pore complex. Baculoviruses of subgroup 3 appear to uncoat by either mechanism. In addition to replicating within the nucleus, NPV inoculum virus may pass through the intestinal epithelium immediately after ingestion, thereby establishing a systemic infection of the hemocoel prior to virus replication in midgut cells. The GVs do not appear to pass through midgut cells as rapidly as NPVs and in general, the developmental cycle of GVs is longer than that of NPVs. NPVs have been grown in cell culture while GVs have not.

ISSN:0006-3592    

DOI:10.1002/bit.260220707

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractAt least two experimental nematode biological insecticide formulations are currently being produced in small quantities around the world, These formulations are efficacious and people are willing to pay money for them. Advantages for the use of these parasites can be: nonpolluting, self‐perpetuating, safe, and not harmful to beneficial organisms. The disadvantages are: relatively short shelf‐life, acceptability, moisture, price, and dispersal techniques. One of the preparations is a nematode that vectors a bacterium. It can be produced at the rate of 100 × 106infective nematodes/2 liter container at a cost of 2 cents/106. It can kill over 1000 species of insects. The other product kills over 60 species of mosquitoes and has been sold as mermithid nematode eggs in moist sand. This mosquito parasite can be established in the new site and self‐perpetuate to suppress mosquito parasite can be established in the new site and self‐perpetuate to suppress mosquito populations. It kills the mosquito before pupating. Increased research activity, using these parasites in the last ten years, has stimulated interest in these organisms for pest insect

ISSN:0006-3592    

DOI:10.1002/bit.260220708

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractDespite the chronic and debilitative nature of the infection they cause, several species of microsporidia and neogregarines offer a good potential as microbial control agents, particularly against insect pests of high economic thresholds. Techniques for mass production of protozoa have usually involvedper os, inoculation or injection of the protozoa into their usual or alternate hosts. The spores are harvested subsequently from heavily infected host tissues by grinding, filtration, and differential centrifugation. Although fresh spores are used in most field tests, the spores of many species can be stored with high survival either frozen or in water at low temperatures (0–4°C) for up to several months. Sunlight or ultraviolet (UV) radiation is a serious factor limiting spore persistence. However, the protozoa do not appear to be significantly limiting spore persistence. However, the protozoa do not appears to be significantly more susceptible to UV radiation than other insect pathogens and persistence can be prolonged with UV protectants. Most field tests with protozoa have involved the application of spores in sprays and have usually resulted in a high degree of infection in the target host species. The potential for control of few species has been improved by formulation of spores in to baits, and the potential of other species will likely increase if suitable bait formulation can be devised in the future. One species,Nosema locustae, formulated as a bait, has been successfully used to control grasshoppers on rangelands. Limited laboratory and field studies have also suggested that increased short‐term control might be obtained if candidate protozoan species can be combined with certain insecticides. While recent and increased efforts have been devoted to assess the potential of protozoa as microbial control agents, potential hazards to nontarget organism have been investigated for only three species. Their close relation taxonomically to protozoa pathogenic for mammals will necessitate careful evaluation of the safety of candidate control species for nontarget organ

ISSN:0006-3592    

DOI:10.1002/bit.260220709

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

ISSN:0006-3592    

DOI:10.1002/bit.260220710

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractPartial acid hydrolysis was studied as a per treatment to enhance enzymatic hydrolysis, such a pretreatment was carried out in a continuous flow reactor on oak corn Stover, newsprint, and Solka Floc at temperatures ranging from 160 to 220°C, acid concentration ranging from 0 to 1.2%, and a fixed treatment time of 0.22 min. The resulting slurries and solids were than hydrolyzed withTrichoderma resseiQM 9414 cellulase at 50°C for 48 hr. For all substrates except Solka Floc, increased glucose yields were achieved during enzymatic hydrolysis of the pretreated materials as compared to hydrolysis of the original substrate. In several cases, after pretreatment, 100° of the potential glucose content of the substrate was converted to glucose after 24hr of enzymatic hydrolysis. It is felt that the increased glucose yields achieved after this pretreatment are due to acid's removal of hemicellulose, reduced degree of polymerization, and possibly due to a change in the crystal structure of the cellulo

ISSN:0006-3592    

DOI:10.1002/bit.260220711

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY