Persistence and recycling of Bacillus sphaericus 2362 spores in Culex quinquefasciatus breeding sites in West Africa

1987 ◽  
Vol 25 (4) ◽  
Author(s):  
Luc Nicolas ◽  
Jo�l Dossou-Yovo ◽  
Jean-Marc Hougard
Keyword(s):  
West Africa ◽  
Culex Quinquefasciatus ◽  
Bacillus Sphaericus ◽  
Breeding Sites

scholarly journals Analysis of toxicity on Bacillus sphaericus from amazonian soils to Anopheles darlingi and Culex quinquefasciatus larvae

2008 ◽  
Vol 38 (2) ◽  
pp. 255-262 ◽  
Author(s):  
Eleilza de Castro Litaiff ◽  
Wanderli Pedro Tadei ◽  
Jorge Ivan Rebelo Porto ◽  
Ila Maria de Aguiar Oliveira
Keyword(s):  
Larvicidal Activity ◽  
Culex Quinquefasciatus ◽  
Bacillus Sphaericus ◽  
Probit Analysis ◽  
Lethal Concentration ◽  
Anopheles Darlingi ◽  
Median Lethal Concentration ◽  
Standard Strain ◽  
Breeding Sites ◽  
High Effectiveness

Bioassays under laboratory conditions aiming to determine the larvicidal activity of Bacillus sphaericus were carried out on Anopheles darlingi and Culex quinquefasciatus. In order to estimate the toxicity through median lethal concentration (LC50) and the relative potency of the strains to B. sphaericus standard strain 2362, probit analysis was performed utilizing the POLO-PC program. The findings of LC50 pointed out high effectiveness on strains IB15 (0.040 ppm), IB19 and S1116 (0.048 ppm), IB16 (0.052 ppm) and S265 (0.057 ppm). Strain IB15 presented nearly 50% more potency than strain 2362 in bioassays conducted on A. darlingi. It was observed that IB16 and S1116 strains were the most powerful against C. quinquefasciatus, showing to be about 300-400% stronger than 2362 strain. The results show that laboratory conditioned evaluation can be an important way to select promising bacteria with entomopathogenic action on biolarvicides production for use on mosquitoes breeding sites.

Ultrastructural analysis of midgut cells from Culex quinquefasciatus (Diptera: Culicidae) larvae resistant to Bacillus sphaericus

Micron ◽  
2008 ◽  
Vol 39 (8) ◽  
pp. 1342-1350 ◽  
Author(s):  
Janaina Viana de Melo ◽  
Romero Henrique Teixeira Vasconcelos ◽  
André Freire Furtado ◽  
Christina Alves Peixoto ◽  
Maria Helena Neves Lobo Silva-Filha
Keyword(s):  
Culex Quinquefasciatus ◽  
Bacillus Sphaericus ◽  
Ultrastructural Analysis

scholarly journals Conjugal Transfer of a Toxin-Coding Megaplasmid from Bacillus thuringiensis subsp. israelensis to Mosquitocidal Strains of Bacillus sphaericus

2006 ◽  
Vol 72 (3) ◽  
pp. 1766-1770 ◽  
Author(s):  
Katherine Gammon ◽  
Gareth W. Jones ◽  
Steven J. Hope ◽  
Cláudia M. F. de Oliveira ◽  
Lêda Regis ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Aedes Aegypti ◽  
Culex Quinquefasciatus ◽  
Vegetative Growth ◽  
Bacillus Sphaericus ◽  
Conjugal Transfer ◽  
Large Plasmid ◽  
Erythromycin Resistance ◽  
Plasmid Loss ◽  
The Stability

ABSTRACT Both Bacillus sphaericus and Bacillus thuringiensis subsp. israelensis produce mosquitocidal toxins during sporulation and are extensively used in the field for control of mosquito populations. All the known toxins of the latter organism are known to be encoded on a large plasmid, pBtoxis. In an attempt to combine the best properties of the two bacteria, an erythromycin resistance-marked pBtoxis plasmid was transferred to B. sphaericus by a mating technique. The resulting transconjugant bacteria were significantly more toxic to Aedes aegypti mosquitoes and were able to overcome resistance to B. sphaericus in a resistant colony of Culex quinquefasciatus, apparently due to the production of Cry11A but not Cry4A or Cry4B. The stability of the plasmid in the B. sphaericus host was moderate during vegetative growth, but segregational instability was observed, which led to substantial rates of plasmid loss during sporulation.

A field trial of the synthetic oviposition pheromone with Culex quinquefasciatus say (Diptera: Culicidae) in Kenya

1988 ◽  
Vol 78 (3) ◽  
pp. 463-470 ◽  
Author(s):  
W. A. Otieno ◽  
T. O. Onyango ◽  
M. M. Pile ◽  
B. R. Laurence ◽  
G. W. Dawson ◽  
...  
Keyword(s):  
Growth Regulator ◽  
Culex Quinquefasciatus ◽  
Pupal Stage ◽  
Insect Growth Regulator ◽  
Breeding Sites ◽  
Insect Growth ◽  
Gravid Females ◽  
A Site ◽  
Effervescent Tablet ◽  
First Time

AbstractThe synthetic attractant pheromone 6-acetoxy-5-hexadecanolide in a formulation of 20 mg containing 5 mg of the active (−)-(5R,6S)-isomer in an effervescent tablet produced a high, positive overall response by gravid females of Culex quinquefasciatus Say when the mosquitoes were exposed to the pheromone in established breeding sites in western Kenya. Significantly more females (82%) oviposited around the pheromone source compared to a control. The activity of the pheromone persisted in the established breeding place for four days after application. The addition of the insect growth regulator S-31183 (2-[1-methyl-2-(4-phenoxyphenoxy)ethoxy]pyridine) to the formulation did not affect the activity of the pheromone. Newly-made breeding sites exposed domestically were not attractive initially for oviposition by gravid females but, after 18 days, they became more attractive. Trays treated with synthetic pheromone diverted females from similar unbaited trays exposed within 10 m. A sample of larvae taken from a site treated with pheromone and insect growth regulator showed 100% mortality by the pupal stage. Thus, the efficacy of the pheromone has been demonstrated for the first time in the field and the possibility of using this material in combination with a ‘safe’ insecticide confirmed.

Interaction of the Bacillus sphaericus mosquito larvicidal proteins

1990 ◽  
Vol 36 (12) ◽  
pp. 870-878 ◽  
Author(s):  
Elizabeth W. Davidson ◽  
Coreen Oei ◽  
Marian Meyer ◽  
Allan L. Bieber ◽  
John Hindley ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Sequence Analysis ◽  
Key Words ◽  
Culex Quinquefasciatus ◽  
Bacillus Sphaericus ◽  
Insecticidal Proteins ◽  
Posterior Midgut ◽  
Sds Page ◽  
Reduced Activity

Genes for 51.4- and 41.9-kDa insecticidal proteins of Bacillus sphaericus were separately cloned and expressed in Escherichia coli. Both proteins were required for toxicity. Approximately equal numbers of cells containing the 51.4- and 41.9-kDa proteins produced the greatest toxicity; excess 41.9-kDa protein did not affect toxicity, whereas excess 51.4-kDa protein reduced activity. Larvae were killed when 41.9-kDa protein was fed up to 24 h after the 51.4-kDa protein, but not when the order of feeding was reversed. Radiolabelled toxins bound in approximately equal amounts to the gastric caecum and posterior midgut of Culex quinquefasciatus larvae. Radiolabelled 51.4-kDa protein was rapidly degraded by ca. 12–13 kDa in the larval gut, while 41.9-kDa protein was degraded by 1–2 kDa. Nonreduced toxin extracted from B. sphaericus produced a band on SDS–PAGE of ca. 68–74 kDa that contained both 51.4- and 41.9-kDa proteins based on sequence analysis, and a band of ca. 51 kDa that contained primarily 41.9-kDa protein. Escherichia coli containing 51.4-kDa protein enhanced toxicity of the latter eluted SDS-PAGE band. These proteins may associate very strongly, and trace amounts of 51.4-kDa protein in preparations of 41.9-kDa protein from B. sphaericus may be responsible for the previously reported toxicity of the latter. Key words: Bacillus sphaericus, toxin, mosquito, cloning.

Production of Bacillus sphaericus strain 1593 primary powder on media made from locally obtainable Nigerian agricultural products

1983 ◽  
Vol 29 (6) ◽  
pp. 704-709 ◽  
Author(s):  
Jason A. N. Obeta ◽  
Nduka Okafor
Keyword(s):  
Aedes Aegypti ◽  
Anopheles Gambiae ◽  
Culex Quinquefasciatus ◽  
Bacillus Sphaericus ◽  
Agricultural Products ◽  
Good Growth ◽  
Mineral Salts ◽  
Arachis Hypogea ◽  
Viable Cells ◽  
The Media

Five media, formulated from dried cow blood, mineral salts, and seeds from four species of legumes, were assessed for growth, sporulation, and insecticidal properties of Bacillus sphaericus strain 1593. Bacterial powders, prepared from broth, were assayed against Culex quinquefasciatus, Anopheles gambiae, and Aedes aegypti. Good growth and sporulation were obtained with all the media. The highest number of viable cells and spores per millitre (8.6 × 108 and 8.1 × 108) were obtained in media containing ground seeds of Vignia unguiculata, Voandzeia subterranean, and Arachis hypogea. All powders were effective against C. quinquefasciatus and A. gambiae. Powders from media containing Arachis hypogea were the most effective with LC50's of 4.344 × 10−3 ± 1.650 × 10−4 and 0.193 ± 1.376 × 10−2 μg/mL for C. quinquefasciatus and A. gambiae, respectively. Aedes aegypti larvae were only slightly susceptible to the powders. This investigation shows that these media can be used for the production of B. sphaericus 1593 primary powder.

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