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Biomedical subjects

M S Mulla

Publications and source records attributed to M S Mulla.

At least 73 records · Page 4Linked to original sources
PubMed1988

Efficacy of Bacillus sphaericus 2362 formulations against floodwater mosquitoes.

Four new formulations of Bacillus sphaericus 2362 yielded excellent control of floodwater mosquitoes Psorophora columbiae and Aedes nigromaculis in irrigated fields in Kings and Riverside counties of California. A primary powder formulation (ABG-6184) was the most active, producing excellent control of Ps. columbiae and Ae. nigromaculis at the rates of 0.05 to 0.5 lb/acre (0.055-0.56 kg/ha). A liquid formulation (BSP-2) was slightly less active, but was effective against the same species in the range of 1.0-1.5 lb/acre (1.12-1.68 kg/ha). Activity of the two corn cob granular formulations was largely dependent on potency (spores/gram). The high spore count granules (1.5 x 10(9) spores/gram) yielded 91 and 98% reduction of Ae. nigromaculis at the rates of 2.5 and 5.0 lb/acre (2.8 and 5.6 kg/ha), respectively. Against the same population, the lower spore count formulation (7.6 x 10(8) spores/gram) produced complete control at the rate of 10 lb/acre (11.2 kg/ha), but poor results were obtained at the rate of 5 lb/acre (5.6 kg/ha).

Aedes↗
PubMed1988

Dispersal of Culex quinquefasciatus from a dairy in southern California.

The dispersal of Culex quinquefasciatus was studied near Norco, California in a periurban situation of southern California. Concurrent studies indicated that host-seeking females were most active up to one hour after sunset. A mark-release-recapture technique was used to document a mean distance traveled of 0.91 km in 12 hr (the first flight period) and a cumulative distance of 1.27 km after 36 hr (following the second flight period). Nearly 0.32% of 47,750 marked females were recaptured. A majority of the population moved with the prevailing wind. Unmarked females were captured at all trapping locations in the study.

Animals↗
PubMed1988

Efficacy of new insect growth regulators against mosquito larvae in dairy wastewater lagoons.

Four new insect growth regulators (IGRs) and a slow-release formulation of a currently-used IGR were evaluated for the control of Culex peus and Cx. quinquefasciatus in dairy wastewater lagoons. The IGR AC-291898 (CME 13406) proved highly efficacious, producing 100% control for one week and about 98% control for two weeks at the rate of 0.05 lb AI/acre (0.056 kg/ha). The IGR XRD-473 produced similar results at this rate. The effective rate of these two compounds seems to be in the range of 0.05 to 0.1 lb AI/acre (0.056-0.11 kg/ha). A granular formulation of S-31183 (0.5 G) applied at 0.05 lb AI/acre (0.056 kg/ha) yielded mediocre reduction whereas fenoxycarb EC 1 at up to 0.25 lb AI/acre (0.28 kg/ha) and methoprene 4% slow release pellets at up to 1.0 lb AI/acre (1.12 kg/ha) produced little or no control of Culex in the dairy wastewater lagoons. These compounds need to be applied at higher rates or suitable formulations will have to be developed to achieve satisfactory control.

Animals↗
PubMed1987

Floating bait formulations increase effectiveness of Bacillus thuringiensis var. israelensis against Anopheles larvae.

The development and screening of floating-type bait formulations designed to improve the activity of bacterial toxins against larval Anopheles is described. Floating and spreading abilities of carrier particles (wheat flour) were compared using corn oil, lecithin, and two products yielding surface films on water (Arosurf and Liparol). Mixtures containing 1 or 5% Arosurf showed the best spreading abilities on a water surface, but strongly inhibited the ingestion of wheat flour by Anopheles albimanus larvae. Corn oil and lecithin improved spreading satisfactorily at a concentration of 5% and inhibited larval feeding by only 6-25%. To select a suitable concentration of active ingredient in formulations, Bacillus thuringiensis var. israelensis (B.t.i.) primary powder in concentrations ranging from 0.01 to 0.5% was mixed with wheat flour/corn oil mixtures and tested in quantities exceeding the gut volumes of treated larvae. Complete mortality was obtained with concentrations of 0.1% (Anopheles stephensi), 0.2% (An. albimanus), or 0.3% (An. quadrimaculatus) B.t.i. When in 175-liter containers the activity of formulations (5% corn oil, 0.2% B.t.i.) and of toxin suspensions was compared by conventional dosage-mortality regression, formulations were more active by a factor of 68 against An. stephensi, 39 against An. albimanus and 67 against An. quadrimaculatus.

Animals↗
PubMed1986

Evaluation of two new insect growth regulators against mosquitoes in the laboratory.

Biological activity of two new IGRs was studied under laboratory conditions against 2nd- and 4th-instar larvae and pupae of Anopheles quadrimaculatus, Aedes aegypti and Culex tarsalis. The IGR S-21149, an oxime [0-(2-(4'-Phenoxyphenoxy)ethyl propionaldoxime], produced an overall mortality or inhibition of emergence of 95% (when 4th instar treated) at 0.0047, 0.0013 and 0.00041 mg/liter in the three species, respectively. The EI95 values for the second IGR S-31183, a pyridine compound, [1-(4'-Phenoxyphenoxy)-2-(2'pyridyloxy) propane] were 0.017, 0.0026 and 0.00032 mg/liter for the three species, respectively. Both materials in general were less active against 2nd than 4th-instar larvae, except that the 2nd- and 4th instars of An. quadrimaculatus were equally susceptible. Pupae treated at up to 0.1 mg/liter showed no mortality in the pupal or the ensuing adult stages.

Aedes↗
PubMed1986

Evaluation of new insect growth regulators against mosquitoes with notes on nontarget organisms.

Three new insect growth regulators (IGRs) were tested against Culex, Aedes and Psorophora mosquitoes. In the laboratory the 3 IGRs were active in the range of 0.3 to 1.5 ppb against Cx. quinquefasciatus. In field tests, the IGRs fenoxycarb and S-31183 formulations yielded complete control of floodwater mosquitoes at the rates of 0.005 to 0.01 lb AI/acre. In field tests against Cx. tarsalis, S-31183 formulations produced complete inhibition of emergence at the rates of 0.005 to 0.025 lb AI/acre. Fenoxycarb formulation produced similar results at the rate of 0.1 lb AI/acre. It is possible that initial and residual field activity of both IGRs can be increased by employing suitable formulations.

Animals↗
PubMed1986

Studies on potential biological control agents of immature mosquitoes in sewage wastewater in southern California.

Three biological control agents, a copepod, Mesocyclops leuckarti pilosa, and two fish, Cyprinodon macularius and Poecilia reticulata, were evaluated for their survival in secondary sewage effluent (SSE) and predation potential on mosquito larvae. Results showed that the survival of M. l. pilosa was not significantly affected in SSE or SSE diluted (50%) with water. In predation tests, the copepod consumed from 50 to 90% of the 1st-instar larvae of Culex quinquefasciatus in 24 to 72 hr and P. reticulata fed on almost all stages (egg to pupa) of the test mosquitoes. Survivorship of P. reticulata and C. macularius in SSE was not significantly affected by SSE under both greenhouse and sewage aquaculture conditions. Poecilia reticulata was distributed towards the influent end and C. macularius towards the effluent end of the aquaculture ponds, indicating the former species can tolerate higher levels of pollution which exists at the influent end of the pond. However, low water temperature and dissolved oxygen may be detrimental to these fish species in sewage aquacultural systems.

Animals↗
PubMed1985

Efficacy and field evaluation of Bacillus thuringiensis (H-14) and B. sphaericus against floodwater mosquitoes in California.

The microbial control agents Bacillus thuringiensis (H-14) and B. sphaericus were evaluated in laboratory and field against Psorophora columbiae. Bacillus sphaericus strain 2362 was also tested in the field against Aedes melanimon. Psorophora columbiae was slightly more susceptible than Culex quinquefasciatus to active strains of B. sphaericus. The LC90 for active strains ranged from 0.013 to 0.069 mg/liter. In field trials, aqueous suspensions of primary powder of B. sphaericus 2362 and 1593 yielded 98-99% reduction in larvae at the rates of 0.1 to 0.25 lb/acre of the primary powder. Granular formulations of Bt (H-14) were evaluated against Ps. columbiae, yielding 96-99% control of larvae at rates ranging from 1 to 10 lb/acre of the granules, depending on the potency and type of the formulations. Aedes melanimon was slightly less susceptible than Ps. columbiae to B. sphaericus 2362. In warmer water a rate of 0.25 lb/acre of the primary powder yielded 88% control, while this same rate in cool weather yielded only 4% reduction. A rate of 0.5 lb/acre of the primary powder was needed to obtain 94% control of larvae in cool weather.

Animals↗
PubMed1985

Laboratory and field evaluation of the IGR fenoxycarb against mosquitoes.

A new juvenile hormone mimic [fenoxycarb or RO13-5223 ethyl-(p-phenoxyphenoxy) ethylcarbamate] was evaluated in the field against Culex tarsalis in stagnant water ponds, Psorophora columbiae and Aedes melanimon in irrigated pastures. This material, showing high level of activity against Cx. quinquefasciatus in laboratory, was found to be highly effective against field populations of the 3 former species. A 5% attaclay granular formation yielded 100% inhibition of emergence in Cx. tarsalis at the rate of 0.1 lb/acre ai, 2 days after treatment. The extent of control declined markedly 7 days after treatment. An EC and 1% sand coated granular formulation yielded poor control providing 91 and 69% inhibition of emergence 2 days posttreatment at the high rate of 0.25 lb/acre ai. The 2 flood water mosquitoes were about 10 X more susceptible than Cx. tarsalis. The EC and 1% attaclay granular formulations produced 100% inhibition of emergence of the floodwater mosquitoes Ps. columbiae and Ae. melanimon in irrigated pastures at the rate of 0.01 lb/acre ai, while Cx. tarsalis required 0.1 lb/acre ai for this level of EI. Most of the mortality in treatments with this insect growth regulator was noted in the pupal stage, very few dying in the larval stage or as adults upon emergence. From extensive field studies, it can be concluded that fenoxycarb has excellent potential in operational mosquito control programs.

Animals↗
PubMed1984

Fate of Bacillus sphaericus 1593 and 2362 spores used as larvicides in the aquatic environment.

Dry powders produced from insecticidal Bacillus sphaericus strains 1593 and 2362 were applied against Culex tarsalis and Anopheles franciscanus mosquito larvae in small-plot field trials. Good control of C. tarsalis, but not of A. franciscanus, was produced at 0.1 and 0.2 lb/acre [ca. 0.122 and 0.244 kg/ha]. B. sphaericus spores settled rapidly from upper water layers and accumulated in bottom muds. Control of third/fourth-instar C. tarsalis larvae was maintained through day 4 after testing and was related to the presence of at least 100 spores per ml in the upper water layer 2 days earlier. B. sphaericus was shown to recycle in dead larvae both in the laboratory and in the field, producing an increase of 100- to 1,000-fold in spore numbers. There was no evidence of recycling in treated water nor of significant spore persistence upon reflooding of ponds after a very hot, dry period.

Animals↗
PubMed1982

Field evaluation of the microbial insecticide Bacillus thuringiensis serotype H-14 against floodwater mosquitoes.

Four experimental formulations of the microbial insecticide Bacillus thuringiensis var. israelensis (serotype H-14) were evaluated in the field against larvae of the floodwater mosquitoes Aedes nigromaculis and Psorophora columbiae with ground and aerial application methods. The formulations included ABG-6108D (Abbott Laboratories, North Chicago, Ill.), a wettable powder containing about 400 IU/mg, Sandoz 402-WDC (Sadoz, Inc., Homestead, Fla.), a flowable concentrate containing 600 IU/mg, and two wettable powder formulations of Bactimos (Biochem Products, Montchanin, Del.), one with 3,000 IU/mg and the other with 6,000 IU/mg. Trials against both species indicated they were similar in susceptibility to B. thuringiensis var. israelensis (serotype H-14), and that by using ground application methods, populations of second and third instars could be reduced by 83 to 100% with ABG-6108 and Sandoz 402-WDC at 0.56 to 1.12 kg/ha and with Bactimos (6,000 IU/mg) at 0.44 kg/ha. When applied aerially, approximately two to three times the ground rates had to be used to obtain similar population reductions. Fourth instars were difficult to control, requiring approximately 1.5 to 2 times the rates required for the earlier instars to obtain 80 to 100% reductions. However, these rates were not sufficient to obtain adequate control if larvae were late fourth instars.

Aedes↗