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 1,405 records · Page 78Linked to original sources
PubMedDate not supplied

[Infectivity of the entomopathogenic fungus Verticillium lecanii in mice and guinea pigs].

The resistance of plague insects to chemical insecticides as well as the importance of a healthy environment demands an alternative for agricultural plagues. Among others, biological control seems an alternate strategy with fungal entomopathogens playing a relevant role. The hyphomycete Verticillium lecanii is a natural bioregulator of aphids, scales and white-flies that attack different agricultural plantations. Its use in biological control programs must be assessed previously by safety procedures such as its innocuity in mammals and useful animals and plants. The aim of this study was pointed at demonstrating the innocuity of V. lecanii in mice and guinea pigs. Two strains of the fungus were injected intraperitoneally (10(8) conidia/kg of animal weight) to 130 mice and 66 guinea pigs. Two control groups were included, one injected with heat-killed fungi and the other with sterile physiological saline. The animals were killed at 8, 30 and 70 days after infection, and mycological and histopathological studies performed in their organs. Negative results obtained with the live fungus in the same manner as the two control groups, suggest the innocuity of V. lecanii in mice and guinea pigs.

Animals↗
PubMed1996

[Studies of the usefulness of Beauveria bassiana for eradication of cockroaches (Blattella germanica L.)].

The ability of killing cockroaches (Blattella germanica L.) by various strains of the mushroom Beauveria bassiana was studied, including also strains obtained by passaging. The study was conducted using adult insects, of varying age and sex, derived from laboratory cultures or caught in hospital rooms. The obtained results pointed out differences in the pathogenicity of B. bassiana strains for the studied populations of insects. The per cent of mortality among the insects depended on the pathogenic properties of B. bassiana strains, the density of mushroom spores in the food and on the sex of the insects. Passaging was found to be useful in case of strains with low pathogenicity for the insects since the passaged strains were more effective in their action on the insects than before passaging. Out of the studied strains the 23rd strain was most effective in reducing the number of the insects.

Animals↗
PubMed1999

Assessment of the application of baculoviruses for control of Lepidoptera.

Baculoviruses, among other insect viruses, are regarded as safe and selective bioinsecticides, restricted to invertebrates. They have been used worldwide against many insect pests, mainly Lepidoptera. Their application as microbial pesticides, however, has not met their potential to control pests in crops, forests, and pastures, with the exception of the nuclear polyhedrosis virus of the soybean caterpillar (Anticarsia gemmatalis), which is used on approximately 1 million ha annually in Brazil. Problems that have limited expansion of baculovirus use include narrow host range, slow killing speed, technical and economical difficulties for in vitro commercial production, timing of application based on frequent host population monitoring, variability of field efficacy due to climatic conditions, and farmers' attitudes toward pest control, which have been based on application of fast-killing chemical insecticides. Farmer education regarding use of biological insecticides and their characteristics is considered one of the major actions necessary for increased use of baculoviruses. Strategies to counteract some of the limitations of baculoviruses, especially their slow killing activity, have been investigated and are promising. These include the use of chemical or biological substances added to virus formulations and genetic engineering of the viruses themselves to express insect toxins or hormones. Such strategies can enhance viral activity and increase speed of kill as well as reduce larval feeding activity. The use of baculoviruses against Lepidoptera is reviewed, with the utilization of the nuclear polyhedrosis virus of A. gemmatalis in Brazil serving as a case-study.

Journal Article↗
PubMed2005

Conservation of natural enemies in cotton: comparative selectivity of acetamiprid in the management of Bemisia tabaci.

The integrated control concept emphasizes the importance of both chemical and biological control for pest suppression in agricultural systems. A two-year field study was conducted to evaluate the selectivity of acetamiprid for the control of Bemisia tabaci (Gennadius) in cotton compared with a proven selective regime based on the insect growth regulators (IGRs) pyriproxyfen and buprofezin. Acetamiprid was highly effective in controlling all stages of B tabaci compared with an untreated control, and generally produced lower pest densities than the IGR regime. Univariate analyses indicated that nine of 17 taxa of arthropod predators were significantly depressed with the use of acetamiprid compared with an untreated control, including common species such as Geocoris punctipes (Say), Orius tristicolor (White), Chrysoperla carnea Stephens sensu lato, Collops vittatus (Say), Hippodamia convergens Guérin-Méneville, and Drapetis nr divergens. Compared with results from independent, concurrent studies using mixtures of broad-spectrum insecticides at the same research site, acetamiprid depressed populations of fewer predator taxa; but, for eight predator taxa significantly affected by both regimes, the average population reduction was roughly equal. In contrast, only four taxa were significantly reduced in the IGR regime compared with the untreated control and three of these were omnivores that function primarily as plant pests. Principal response curves analyses (a time-dependent, multivariate ordination method) confirmed these patterns of population change for the entire predator community. Predator:prey ratios generally increased with the use of both IGRs and acetamiprid compared with an untreated control, but ratios were consistently higher with IGRs. Parasitism by aphelinid parasitoids was unaffected or depressed slightly in all insecticide regimes compared with the control. Because of its high efficacy, acetamiprid may play an important role in later stages of B tabaci control where less emphasis is placed on selectivity. However, our results suggest that acetamiprid would be a poor substitute for the currently used IGRs in the initial stage of control where insecticide selectivity is crucial to a functional integrated control program for B tabaci in cotton.

Animals↗
PubMed2004

Toxicity of chemicals commonly used in Indonesian vegetable crops to Liriomyza huidobrensis populations and the Indonesian parasitoids Hemiptarsenus varicornis, Opius sp., and Gronotoma micromorpha, as well as the Australian parasitoids Hemiptarsenus varicornis and Diglyphus isaea.

Liriomyza huidobrensis (Blanchard) and Liriomyza sativae (Blanchard) are important pests of vegetable crops in Indonesia and are likely to spread to neighboring countries. Three pesticides (dimehypo, abamectin, and cyromazine) are currently used to control these pests, but there is little information on their effectiveness against field populations and on their impact on parasitoids controlling Liriomyza species. The toxicity of these chemicals to L. huidobrensis and three common parasitoids (Hemiptarsenus varicornis Gerault, Opius sp., and Gronotoma micromorpha Perkins) was therefore evaluated in Indonesia with mortality laboratory assays. All three chemicals were effective against larvae of three populations of L. huidobrensis with different histories of chemical exposure. Dimehypo caused mortality in adult Opius sp., G. micromorpha, and H. varicornis, whereas abamectin was toxic only at concentrations substantially higher than the field rate. Cyromazine did not influence survival of the parasitoids. A commonly used fungicide, mancozeb, had no impact on parasitoid mortality. Trials were repeated with a strain of H. varicornis from Australia and a different parasitoid (Diglyphus isaea) recently found in Australia. Neither parasitoid was influenced by mancozeb or cyromazine. Abamectin applied at field rates caused some mortality among the adults of both species, but was less toxic than chlorpyrifos. Abamectin produced lower LC50s against Australian H. varicornis than against Indonesian H. varicornis. These results suggest that cyromazine can be incorporated into Liriomyza control programs in Indonesia that conserve parasitoids, whereas dimehypo and abamectin need to be used cautiously. Local Australian parasitoids should help control L. huidobrensis as long as only cyromazine and nontoxic fungicides are applied.

Agriculture↗
PubMed1997

Assessment of environmental pollution by PCBs, DDT and its metabolites using human milk of mothers in Zimbabwe.

The milk samples were collected from mothers who had lived in the area for at least 5 years, healthy and breast feeding their first, second or third child. Of the 175 mothers' milk samples analysed, the organochlorine pesticide residues were detected in the following order of frequency: pp-DDE, 100%, pp-DDT 98%; and sum PCB, 53%. Of all the seven areas analysed the Kariba area and the highest mean level of sum DDT--25,259 ng/g milk fat and the lowest mean level of sum DDT of 1607 ng/G milk fat was found in Esigodini which is a rural area. The major DDT metabolite was pp-DDE. The ratio of pp-DDT/pp-DDE was highest in Kariba (0.6) suggesting recent pollution by DDT in that area. The results show that the vector control programmes (extensive pesticide spraying of disease-carrying pests, such as mosquitoes and tsetse flies), agricultural activities and dietary habits were the main contributing factors towards the high levels of pesticides in most of the areas. Kadoma area had the highest mean level of sum-PCB (60 ng/g milk fat).

Adolescent↗
PubMed2004

[Host transfer of Beauveria bassiana population in pine stand ecosystem and impact of its genetic diversity on sustainable control of Masson's pine caterpillars].

In an anniversary investigation post inoculative release of Beauveria bassiana against Masson's pine caterpillars in a Masson's pine plantation, 119 strains were isolated from 30 host insects, soil, litter and air. Based on an esterase isozyme analysis, all these strains were assigned to 32 esterase types, suggesting abundant genetic diversity. The esterase type 2 was assigned including 18 other strains from 11 different host insects, indicating that the released strain had successfully survived in different insect populations and persisted in enzootic condition in 12 insect populations including pine caterpillars and grey pine weevils. Other host insects could maintain the food chain when the target insect population was low. The other esterase types included 1-23 strains. The anniversary host transfer dynamics further revealed that B. bassiana could transfer among different host insects in the pine ecosystem. The virulence of the strains of each esterase differed substantially, which suggested that B. bassiana persisted and dispersed along more than one route, and each esterase stood for at least one branch in the food web. Some hosts connected different esterase types at nodal points, making the food web very complicated. In addition, the strains isolated from soil, litter, forest crown and air belonged to different esterase types, suggesting that a complex of saprophytic food chains existed in the plantation, which made the food web more complicated, and benefited the sustainable control of the Masson's pine caterpillar and other pest insects in the ecosystem.

Animals↗
PubMed1997

Insect-pathogen dynamics: stage-specific susceptibility and insect density dependence.

The control of insect pests by using insect pathogens as dynamic biological control agents is a recent effort. Model studies on insect-pathogen relations can help in the development of biocontrol programs. Except for the work of Briggs and Godfray [1], insect-pathogen models ignore the stage-specific susceptibility of insects. Moreover most models do not incorporate insect self-regulation. We develop stage-structured models of insect-pathogen relations incorporating insect-density dependence and disease transmitted through direct contact between susceptible and infective individuals. The models are analyzed by using steady-state and stability analysis. Numerical solutions are used as sources of further insight into the dynamics of the insect-pathogen systems. It is shown that there are major differences in the dynamics of adult- and juvenile-infecting diseases. Moreover, the interplay between insect-density dependence and stage-specific susceptibility has important consequences for the dynamics of insect-pathogen systems.

Agriculture↗
PubMed2026

Characterization and genomic analysis of Bacillus halotolerans G3-2: a potential biocontrol agent against apple Alternaria leaf blotch disease.

BACKGROUND: Apple Alternaria leaf blotch (ALB) is a devastating disease threatening the apple industry worldwide. Biocontrol offers an effective and environmentally friendly alternative for disease management. RESULTS: Bacillus strain G3-2 exhibits strong antagonistic activity against Alternaria alternata (a major causal pathogen of ALB). In dual-culture assays, G3-2 inhibited A. alternata by 88.39%; in detached-leaf inoculation assays, it reduced the lesion area by >88%. 16S rRNA sequencing and phylogenetic analysis identified this strain as Bacillus halotolerans. Oxford Nanopore Technology (ONT) sequencing generated a 4.18-Mb complete genome (43.8% G + C) containing 4149 protein-coding genes, 30 rRNAs and 86 tRNAs. CAZy annotation identified 182 genes encoding carbohydrate-active enzymes (CAZymes), including glycoside hydrolases, glycosyltransferase, and carbohydrate esterases, suggesting potential for glycosylated secondary metabolite production. AntiSMASH analysis detected nine biosynthetic gene clusters, including those for surfactin, fengycin, bacillaene and laterocidine. Plate assays confirmed that G3-2 has the ability to produce protease, cellulase and siderophore. Moreover, it exhibits ~70% inhibition against several other phytopathogenic fungi. CONCLUSIONS: These findings demonstrate that G3-2 suppresses A. alternata through antibiosis (lipopeptides and polyketides), nutrient competition (siderophores) and cell-wall degradation (proteases and cellulases). Moreover, our study revealed that it has great potential to be used as a broad-spectrum, environmentally friendly biocontrol agent. © 2026 Society of Chemical Industry.

Alternaria↗