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At least 685 records · Page 38Linked to original sources
PubMed1980

The use of dragonfly nymphs in the control of Aedes aegypti.

The predatory rates of the dragonfly nymphs on Aedes aegypti were studied in the laboratory and under field conditons. Labellulid nymphs were found to predate on Ae. aegypti larvae and pupae readily. The rate of consumption was found to be 133 +/- 21 all stages of larvae per medium size nymph per 24 hours. In container habitats complete elimination of all larvae and pupae were achieved between day 4 and 9 depending on density of aquatic stages. The dragonfly nymphs as predators could be used in biological control of Aedes mosquitoes.

Aedes↗
PubMed1987

The biotechnology of Bacillus thuringiensis.

One of the challenges in the application of biotechnology to pest control is the identification of agents found in nature which can be used effectively. Biotechnology offers the potential of developing pesticides based on such agents which will provide environmentally sound and economically feasible insect control alternatives. Such an agent, the insect pathogen Bacillus thuringiensis, is the subject of intense investigations in several laboratories. Insecticides which use the entomocidal properties of B. thuringiensis are currently produced and sold worldwide; new products are currently in the development stage. Herein, the biology and genetics of B. thuringiensis and the problems associated with current products are critically reviewed with respect to biotechnology. Moreover, the economic and regulatory implications of technologically advanced products are evaluated.

Amino Acid Sequence↗
PubMed1991

Consumption of Biomphalaria glabrata egg masses and juveniles by the ampullariid snails Pila ovata, Lanistes carinatus and Marisa cornuarietis.

Lanistes carinatus and Pila ovata from Kenya and Marisa cornuarietis from the Dominican Republic were examined for their ability to consume egg masses and juveniles of Biomphalaria glabrata (M line strain) under laboratory conditions. Adults of all three ampullariid species consumed all egg masses presented to them over a five day period of observation. Juvenile P. ovata consumed significantly more egg masses than juveniles of M. cornuarietis or L. carinatus. Both adult and juvenile ampullariids generally ate more egg masses when maintained under a temperature regime (25-32 degrees C) approximating conditions in coastal Kenya than at 13-25 degrees C which approximates the temperature regime near Nairobi, Kenya. Egg masses attached to floating 'refugia' were not attacked, apparently reflecting the difficulty experienced by ampullariids in reaching free-floating objects. Adults of each ampullariid species ate approximately 25% of all lariids in reaching free-floating objects. Adults of each ampullariid species ate approximately 25% of all 1.5 +/- 0.5 mm B. glabrata juvenile snails presented to them. P. ovata adults consumed significantly more 3.0 +/- 0.5 mm juveniles than adults of the other two species. B. glabrata egg masses and juveniles were consumed even though lettuce was continually present in experimental aquaria. Implications of these results for biological control studies in East Africa are discussed.

Animals↗
PubMed1999

Biological control and invading freshwater snails. A case study.

Introductions of four species of freshwater snails occurred between 1972 and 1996 onto Guadeloupe Island. Two of them, Melanoides tuberculata and Marisa cornuarietis, were subsequently used as biological control agents against Biomphalaria glabrata, the snail intermediate host of intestinal schistosomiasis. In 1996, a general survey was carried out in 134 sites which had already been investigated in 1972. The total number of mollusc species had increased from 19 to 21. Site numbers housing B. glabrata and two other species had strongly declined. This decline may be mainly attributed to a competitive displacement by M. tuberculata and M. cornuarietis as illustrated by several biological control programmes. There were no changes in the remainder of the malacological fauna.

Animals↗
PubMed2000

Genetic diversity and biological control activity of novel species of closely related pseudomonads isolated from wheat field soils in South Australia.

Rhizobacteria closely related to two recently described species of pseudomonads, Pseudomonas brassicacearum and Pseudomonas thivervalensis, were isolated from two geographically distinct wheat field soils in South Australia. Isolation was undertaken by either selective plating or immunotrapping utilizing a polyclonal antibody raised against P. brassicacearum. A subset of 42 isolates were characterized by amplified 16S ribosomal DNA restriction analysis (ARDRA), BIOLOG analysis, and gas chromatography-fatty acid methyl ester (GC-FAME) analysis and separated into closely related phenetic groups. More than 75% of isolates tested by ARDRA were found to have >95% similarity to either Pseudomonas corrugata or P. brassicacearum-P. thivervalensis type strains, and all isolates had >90% similarity to either type strain. BIOLOG and GC-FAME clustering showed a >70% match to ARDRA profiles. Strains representing different ARDRA groups were tested in two soil types for biological control activity against the soilborne plant pathogen Gaeumannomyces graminis var. tritici, the causative agent of take-all of wheat and barley. Three isolates out of 11 significantly reduced take-all-induced root lesions on wheat plants grown in a red-brown earth soil. Only one strain, K208, was consistent in reducing disease symptoms in both the acidic red-brown earth and a calcareous sandy loam. Results from this study indicate that P. brassicacearum and P. thivervalensis are present in Australian soils and that a level of genetic diversity exists within these two novel species but that this diversity does not appear to be related to geographic distribution. The result of the glasshouse pot trial suggests that some isolates of these species may have potential as biological control agents for plant disease.

Bacterial Typing Techniques↗
PubMed1992

Promotion of apple tree growth and fruit production by the EBW-4 strain of Bacillus subtilis in apple replant disease soil.

A field trial was conducted near Kelowna, British Columbia, to determine the effect of biological treatments alone and in combination with formalin fumigation in apple replant disease soil. The response was measured by the increase in cross-sectional trunk area, total shoot growth, and fruit yield of McIntosh apple trees on M.26 rootstock. The postplanting drench application of strain EBW-4 of Bacillus subtilis alone was consistently effective in increasing cross-sectional trunk area for 5 years, total shoot growth for 4 years, and fruit yield for 3 years. The biological agent EBW-4 of B. subtilis in combination with formalin fumigation was also effective in promoting total shoot growth and cross-sectional trunk area. The application of formalin fumigation alone was effective in increasing shoot growth for 2 years and cross-sectional trunk area for 1 year only. This treatment did not increase fruit yield for 3 years. The consistent performance of strain EBW-4 of B. subtilis during 1986-1991 indicates that this bacterium has the potential for biological control of replant disease under orchard conditions in the Okanagan Valley of British Columbia.

Bacillus subtilis↗
PubMed2003

Record of Evlachovaea sp. (Hyphomycetes) on Triatoma sordida in the state of Goiás, Brazil, and its activity against Triatoma infestans (Reduviidae, Triatominae).

A fungal isolate was detected on a dead Triatoma sordida (Stål) collected in a peridomestic area in central Brazil. The fungus belongs to Evlachovaea Borisov and Tarasov, a new genus that was recently described in Russia. The isolate seems to be a third species and the second new and undescribed species from Brazil. The fungus was shown to be active against Triatoma infestans (Klug) third-instar nymphs at a humidity close to saturation. However, activity was reduced at a lower humidity (75%). Values of LC50 varied between 1.1 x 10(5) and 1.5 x 10(4) conidia/cm2 treated surface, 15 and 20 d after fungal application and incubation at humidity close to saturation. This new fungus may have a potential for biological control of peridomestic Chagas' disease vectors during the rainy season.

Animals↗
PubMed2004

Predatory potential of Nepa cinerea against mosquito larvae in laboratory conditions.

Biocontrol potential of nepidae bug, Nepa cinerea against immature stages of Anopheles stephensi, Anopheles culicifacies, Culex quinquefasciatus and Aedes aegypti was studied under laboratory conditions. It was found that N. cinerea had the highest predation against An. stephensi followed by An. culicifacies, Cmx quinquefasciatus and Ae. aegypti. From the analysis, it was found that N. cinerea has good predation efficacy. It can be used as a biological control agent to control of mosquito breeding in integrated disease vector control programme.

Aedes↗
PubMed1979

Study on the possibility of adopting a complex method in Blattella germanica (L.) control on board ships.

Campaings to control the German cockroach, Blattela germanica, were conducted at 14-day intervals over a period of 5.5 months on two merchant vessels of similar size and type. On one ship only the chemical "Gertoks", carbamate insecticide containing 1% propoxur was applied, and on the second ship two preparations simultaneously, a chemical and a biological--"Biotrol 25 W" containing Bacillus thuringiensis. - In order to assess the success of the control, the extent of infestation in the accomodation was determined immediately before and 24 h after the spraying. - The susceptibility of the cockroaches caught on the ships, to the two preparations applied, was also determined. It was found that "Gertoks" was an efficient preparation, the biopreparation "Biotrol 25 W" being less efficient. - A certain increase in resistance of the cockroaches to both preparations, was noted. - The above observations indicate that a considerable drop in numbers of population of cockroaches can be achieved if the ship's crew carry out systematic thorough spraying of ships quarters infested by cockroaches, with Gertoks". They also confirm previous suggestions that complex method in B. germanica control on board ships is possible, using chemical and biological preparations containing Bac. thuringiensis spores simultaneously.

Animals↗
PubMed1982

[Effect of parasitism on the resistance of Cionella lubrica Müller to temperature and desiccation].

In an experimental study carried out on a strain of Cionella lubrica, it was shown that this species could survive at high temperatures ranged from 37 degrees C to 40 degrees C and in drought situations for periods of 50 to 70 days. The young snails were more resistant than adults. The snails infected by D. lanceolatum survived less than uninfected snails. As a result, it is suggested that the optimal times for the application of biological control of C. lubrica would be May-June and September-October for the region of Limousin.

Animals↗