Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Pest Control”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,081 records · Page 60Linked to original sources
PubMed2003

Rapid evolution and the cost of resistance to Bacillus thuringiensis in greenhouse populations of cabbage loopers, Trichoplusia ni.

The microbial insecticide Bacillus thuringiensis (Bt) has become the mainstay of non-chemical control of Lepidopteran pests, either as sprays or through the incorporation of Bt toxins into transgenic crops. Given the wide use of Bt, it is striking that currently only one pest species, Plutella xylostella, has been reported to have developed significant resistance to Bt outside the laboratory. By contrast, we report here the frequent and rapid development of resistance to B. thuringiensis kurstaki (Dipel, Abbott) in populations of cabbage loopers, Trichoplusia ni, in commercial greenhouses. Resistance to Bt appears to be costly and there is a rapid decline of resistance in populations collected from greenhouses and maintained in the laboratory without selection. Management of pests resistant to Bt in vegetable greenhouses will require sporadic use of Bt-based sprays or alternatively use of sprays containing other Bt toxins.

Animals↗
PubMed2000

Biocontrol of ticks.

The increasing resistance of arthropodes to pesticides, their high price, and the growing public demand for safer food and a cleaner environment are obliging animal growers to minimize the use of pesticides by introducing alternative means for tick control. The development of a biological tick control method has been neglected as compared to the control of plant pests or dipterous insects harmful to men and animals. There are abundant observations, but only a few studies have as yet been conducted on pathogens, parasitoides, and predators of ticks. A first attempt at tick biocontrol was made with the introduction of tick-parasitic wasps from France to the USA and Russia. During the past decade, interest in developing antitick biocontrol agents such as birds (Brazil, Kenya, and Zimbabwe), parasitoides (Kenya and USA), entomopathogenic nematodes (Egypt, Israel, Guadeloupe, and USA), entomopathogenic fungi (Brazil, Cuba, Israel, Kenya, and USA), and bacteria (Brazil) has gained momentum. The reintroduction of oxpecker birds in some areas of Zimbabwe remains up to now the only known successful attempt at tick biocontrol.

Animals↗
PubMed2002

Endotoxin activity of Moraxella osloensis against the grey garden slug, Deroceras reticulatum.

Moraxella osloensis is a gram-negative bacterium associated with Phasmarhabditis hermaphrodita, a slug-parasitic nematode that has prospects for biological control of mollusk pests, especially the grey garden slug, Deroceras reticulatum. This bacterium-feeding nematode acts as a vector that transports M. osloensis into the shell cavity of the slug, and the bacterium is the killing agent in the nematode-bacterium complex. We discovered that M. osloensis produces an endotoxin(s), which is tolerant to heat and protease treatments and kills the slug after injection into the shell cavity. Washed or broken cells treated with penicillin and streptomycin from 3-day M. osloensis cultures were more pathogenic than similar cells from 2-day M. osloensis cultures. However, heat and protease treatments and 2 days of storage at 22 degrees C increased the endotoxin activity of the young broken cells but not the endotoxin activity of the young washed cells treated with the antibiotics. This suggests that there may be a proteinaceous substance(s) that is structurally associated with the endotoxin(s) and masks its toxicity in the young bacterial cells. Moreover, 2 days of storage of the young washed bacterial cells at 22 degrees C enhanced their endotoxin activity if they were not treated with the antibiotics. Furthermore, purified lipopolysaccharide (LPS) from the 3-day M. osloensis cultures was toxic to slugs, with an estimated 50% lethal dose of 48 microg per slug, thus demonstrating that the LPS of M. osloensis is an endotoxin that is active against D. reticulatum. This appears to be the first report of a biological toxin that is active against mollusks.

Animals↗
PubMedDate not supplied

Fungal keratitis caused by Metarhizium anisopliae var. anisopliae.

Metarhizium anisopliae var. anisopliae (Metschnikov) Sorokin 1883 to our knowledge has never been reported as an agent of human or animal mycosis. This fungus has great importance as an agent of biological control of different pests and mosquito larvae in Colombia. It has been isolated as the aetiological agent of keratomycosis for the first time from the eye of a Colombian male.

Adolescent↗
PubMed2004

Bactrocera tryoni and closely related pest tephritids--molecular analysis and prospects for transgenic control strategies.

Bactrocera tryoni is a serious pest of horticulture in eastern Australia. Here we review molecular data relevant to pest status and development of a transformation system for this species. The development of transformation vectors for non-drosophilid insects has opened the door to the possibility of improving the sterile insect technique (SIT), by genetically engineering factory strains of pest insects to produce male-only broods. Transposition assays indicate that all five of the vectors currently used for transformation in non-drosophilid species have the potential to be useful as transformation vectors in B. tryoni. Evidence of cross mobilization of hobo by an endogenous Homer element emphasises the necessity to understand the endogenous transposons within a species. The sex-specific doublesex and yolk protein genes have been characterized with a view to engineering a female-specific lethal gene or modifying gene expression through RNA interference (RNAi). Data are presented which indicate the potential of RNAi to modify the sex ratio of resultant broods. An understanding of how pest status is determined and maintained is being addressed through the characterization of genes of the circadian clock that enable the fly to adapt to environmental cues. Such an understanding will be useful in the future to the effective delivery of sophisticated pest control measures.

Animals↗
PubMed2002

Which predatory mite can control both a dominant mite pest, Tetranychus urticae, and a latent mite pest, Eotetranychus asiaticus, on strawberry?

After biological control of Tetranychus urticae using Phytoseiulus persimilis, a latent mite pest, Eotetranychus asiaticus, was found on strawberries growing in a plastic greenhouse in western Japan. To determine whether the release of P. persimilis, an exotic natural enemy of T. urticae, enhanced the occurrence of the latent pest, the efficiency of P. persimilis in controlling E. asiaticus was compared with the efficiency of two indigenous phytoseiid mites, Amblyseius californicus and A. womersleyi, under laboratory conditions. Phytoseiulus persimilis and A. californicus attacked not only T. urticae but also E. asiaticus. However, the predators produced very few eggs and their offspring rarely reached adulthood when fed on E. asiaticius, so their potential as control agents for the latent mite appears to be low. In contrast, A. womersleyi feeding on E. asiaticus reproduced as well as when fed on T. urticae, and exterminated both species of spider mite. This suggests that A. womersleyi has greater potential as a biological control agent in crops where both species may occur.

Animals↗
PubMed2006

Pest management through continuous and impulsive control strategies.

In this paper, we propose two mathematical models concerning continuous and, respectively, impulsive pest control strategies. In the case in which a continuous control is used, it is shown that the model admits a globally asymptotically stable positive equilibrium under appropriate conditions which involve parameter estimations. As a result, the global asymptotic stability of the unique positive equilibrium is used to establish a procedure to maintain the pests at an acceptably low level in the long term. In the case in which an impulsive control is used, it is observed that there exists a globally asymptotically stable susceptible pest-eradication periodic solution on condition that the amount of infective pests released periodically is larger than some critical value. When the amount of infective pests released is less than this critical value, the system is shown to be permanent, which implies that the trivial susceptible pest-eradication solution loses its stability. Further, the existence of a nontrivial periodic solution is also studied by means of numerical simulation. Finally, the efficiency of continuous and impulsive control policies is compared.

Algorithms↗
PubMed2004

The pathogenicity of Vairimorpha necatrix (Microspora: Microsporidia) against the tomato moth, Lacanobia oleracea (Lepidoptera: Noctuidae) and its potential use for the control of lepidopteran glasshouse pests.

A droplet feeding technique was used to feed known amounts of Vairimorpha necatrix (Kramer) spores to larvae of the tomato moth, Lacanobia oleracea (L) in order to assess the susceptibility of this lepidopteran pest to the pathogen. All first- to fourth-instar larvae died as a result of ingesting 1000 or more V necatrix spores. Two forms of death were observed, which were dependent on the dose and the age of the insect when treated. For first-instar larvae, rapid death (within 6days of dosing) occurred after ingestion of 2000 spores, whereas lower doses resulted in a proportion of larvae dying from chronic infection (microsporidiosis). For more advanced stages, increasing spore doses were required to give rapid death, such that a dose of 200,000 spores was needed to give 80% mortality within 6 days for third-instar larvae. Rapid death was not observed in fourth- to sixth-instar larvae. In all cases successful pupation and adult emergence were much reduced compared with non-infected larvae. Suspensions of V necatrix were sprayed on to tomato (Lycopersicon esculentum Mill) plants maintained in small glasshouses prior to infestation of the plants with L oleracea larvae. The numbers and biomass of pest larvae retrieved from the plants sprayed with V necatrix were significantly reduced by up to 40% and 70%, respectively, compared with plants sprayed with water (control). Similarly, plants sprayed with V necatrix showed a reduction in damage of up to 45% compared with the control plants.

Animals↗