Observations on Mosquito Behaviour in Native Huts

1950 ◽  
Vol 41 (1) ◽  
pp. 63-78 ◽  
Author(s):  
A. B. Hadaway

Mosquitos continue to enter occupied, untreated native huts throughout the night, with peak periods of entry at dusk and dawn. Early morning mosquito catches do not give a true picture of the numbers entering and leaving huts during the night.In a series of catches 63 per cent. of 5,576 mosquitos and 79 per cent. of 506 Anopheles gambiae were caught resting on the underside of the thatch roof.By using five traps inserted in apertures one foot below the top of the wall, the numbers of mosquitos attempting to leave a hut were determined. Of 1,014 mosquitos entering huts before 10 p.m., 63 per cent. remained inside until 6.30 a.m., that is for 8½ hours. Catches to estimate numbers entering and leaving at different times during the night were also made.Treatment of huts with DDT wettable powder and DDT-kerosene solution did not interfere with the normal behaviour of mosquitos as far as entry was concerned. Biting occurred in the treated huts.The DDT wettable powder appeared to be more effective than the DDT-kerosene solution.Some mosquitos entered the treated huts, fed and then left before acquiring a lethal dose. After making contact with treated surfaces mosquitos became restless but, under the conditions existing in the huts during the experiments, activation did not result in more leaving the treated huts than the untreated one. Unfortunately there were few A. gambiae and the predominant species entering the huts was Taeniorhynchus fuscopennatus.Some of the female A. gambiae released into unoccupied DDT-treated huts escaped into the traps before acquiring a lethal dose. Although there was a tendency for more to enter the traps of a DDT-treated hut than those of an untreated hut, the data are insufficient to show a significant difference.The majority of mosquitos entering the traps did so within one hour of their release.No mosquitos were still alive 12 hours after their release in huts treated 17 weeks previously with DDT wettable powder or DDT-kerosene solution, or in the hut treated 12 weeks previously with "“Gammexane” wettable powder.

1964 ◽  
Vol 55 (1) ◽  
pp. 29-34 ◽  
Author(s):  
M. W. Service

Pyrethrum spray-sheet collections in a small village in Northern Nigeria showed that there was no significant difference in the numbers of Anopheles gambiae Giles and A. funestus Giles caught at different times in the early morning. In this village, huts at the edge nearest to the only breeding site attracted considerably more adults than those further away from the edge, and some huts were consistently more attractive to mosquitos than others. There was a positive correlation between the numbers of A. gambiae and A. funestus in the huts. Although significant differences were found between numbers of mosquitos caught in the huts occupied by different numbers of people, no simple relationship could be discovered between the combined densities of the two species and the number of hut occupants. It is concluded that there is need for further investigations into the factors influencing densities of the Anophelines in village huts.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Armel Djènontin ◽  
Aziz Bouraima ◽  
Christophe Soares ◽  
Seun Egbinola ◽  
Gilles Cottrell

Abstract Objective In the framework of EVALMOUS study aiming to assess the use and effectiveness of mosquito nets by pregnant women and other members of their household in a lagoon area in southern Benin, the behaviour of pregnant women relative to the time they go to bed using the net were recorded. Malaria vectors biting rhythm, Plasmodium falciparum infection and insecticide resistance genes in malaria vectors were also determined. Results Overall, 3848 females of Anopheles gambiae s. l were collected and 280 pregnant women responded to the survey. Almost all Anopheles gambiae s. l. tested were Anopheles coluzzi Coetzee and Wilkerson 2013 (Diptera: Culicidae). The CSP index in malaria vector was 1.85% and the allelic frequency of kdr gene was 74.4%. Around 90% of bites and Plasmodium falciparum Welch, 1897 (Haemosporida: Plasmodiidae) transmission occurred between 10 p.m. and 6 a.m., which coincides with the period when more than 80% of pregnant women were under bednet. Despite a slight early evening and early morning biting activity of malaria vectors in the study area, the good use of nets might remain a useful protection tool against mosquito biting and malaria transmission.


2015 ◽  
Vol 43 (1) ◽  
pp. 159-164 ◽  
Author(s):  
Hua CHENG ◽  
Linling LI ◽  
Juan HUA ◽  
Honghui YUAN ◽  
Shuiyuan CHENG

Recently, there has been an increasing interest among researchers in using combinations of biological control agents to exploit potential synergistic effects among them. In the present study, there were investigated commercially acceptable formulations of Bacillus cereus CE3 wetting powder with long storage life and retained efficacy to control chestnut and other fruit rot caused by Endothia parasitica (Murr) and Fusarium solani. The study sought to develop a new B. cereus formulation that would be more effective and better suited to the conditions of field application. By a series of experiments, the formulation was confirmed as follows: 60% B. cereus freeze-dried powder, 28.9% diatomite as carrier, 4% sodium lignin sulfonate as disperser, 6% alkyl naphthalene sulfonate as wetting agent, 1% K2HPO4 as stabilizer, 0.1% β-cyclodextrin as ultraviolet protectant. The controlling experiments showed that the diluted 100 times of 60% B. cereus wetting powder had 79.47% corrosion rate to chestnut pathogens; and this result is comparable to the diluted 1,000 times of 70% thiophanate-methyl. Safety evaluation results showed that rats acute oral lethal dose 50% was 5,000.35, therefore application of B. cereus wettable powder could not cause a person or animal poisoning. This work illustrated that 60% B. cereus wetting powder had commercial potential; however, to apply this formulation as a biological pesticide in the field, masses production processes need to be further studied.


1953 ◽  
Vol 44 (2) ◽  
pp. 231-254 ◽  
Author(s):  
G. Davidson

Experimental huts similar in construction to the dwellings commonly used in East Africa, but with exit window traps, were sprayed with various formulations of the three residual insecticides, DDT, BHC, and dieldrin, and the effect on the A. gambiae and A. funestus entering them was observed.The almost complete absence of kill recorded by Muirhead Thomson (1950) in experiments in similar huts in Tanganyika treated with DDT Ditreen was not confirmed by these experiments.A significant proportion of the A. gambiae and A. funestus entering huts treated with DDT did, however, escape unharmed, even immediately after treatment, whereas with the other insecticides, BHC and dieldrin, none of these mosquitos escaped the effect at least in the first month after treatment.In preliminary experiments in which observations were carried on for nine months after treatments, BHC P.530 still showed some effect after seven months. This was almost certainly due to the fumigant effect of the small amount of insecticide still remaining below the wall surface. The irritant properties of the two DDT formulations, Ditreen and the oil-bound suspension “Supona” D, still existed after nine months.In a second group of experiments, dosages of less than 80 mg. DDT and less than 60 mg. BHC (8 mg. of the gamma isomer) per sq. ft. gave over 50 per cent. kills of A. gambiae and A. funestus for only one month.In a third group of experiments, using two formulations of BHC, five of DDT, one of a mixture of DDT and BHC and one of dieldrin:—(a) Dieldrin was by far the most efficient insecticide and gave very high kills for over seven months.(b) The DDT formulations, Murphy paste, Murphy wettable powder, suspensions of DDT crystals <30 μ and 30–70 μ in diameter, when applied to the whole internal surface of the huts, produced fairly high kills over the period of the observations (six to seven months), but significant proportions of the mosquitos escaped their action even immediately after treatment.(c) The BHC formulations, P.520 and the oil-bound suspension “Supona” B, gave high kills for three to four months only.(d) The mixture of BHC and DDT in oil-bound suspension “Supona” DB gave the high initial kill of BHC and the long-lasting moderately high kill of DDT.(e) Against C. fatigans all the DDT formulations used in the third group of experiments gave very low kills, the BHC formulations high initial kills and dieldrin high long-lasting kills.BHC has marked fumigant and particulate properties lasting for three to four months. Dieldrin has a remarkable particulate action, which produces for the whole six-month period of the experiment, very high kills among mosquitos suspended without actual contact with the insecticidal surfaces; DDT only shows this particulate effect to a slight extent.It is probable that the differences in the toxicities to mosquitos of the insecticides used in these experiments is due partly to differences in the irritant properties of the insecticides. In the case of DDT many of the mosquitos having contact with this insecticide are irritated and escape from the treated surface before acquiring a lethal dose.


1970 ◽  
Vol 28 ◽  
pp. 11-14 ◽  
Author(s):  
MR Amin ◽  
MFA Mollah ◽  
MR Ali ◽  
M Nahiduzzaman

The study was conducted to determine a suitable feed for the desirable growth ofriverine catfish Rita rita (Hamilton) from January 2006 to December 2006. The experiment hadthree treatments with three replicates. Nine chambers of the raceway each of size 1.83 × 1.12 sqmeter were used. Local prawn, chicken viscera and commercially available formulated feed (CP)were supplied in treatment T1, T2 and T3, respectively at the rate of 7% body weight. Feed wassupplied twice in a day in the early morning and in the evening as the fish is nocturnal. The initialaverage weight of fish was 24.93±0.05g, 24.99±0.04g and 24.95±0.04g in T1, T2 and T3,respectively. The final weight of the fish under three treatments was 425.05±1.04g, 425.68±1.05gand 177.61±1.45g respectively. The initial length was 8.48±0.02, 8.49±0.02 and 8.50±0.01 in T1, T2and T3, respectively. The final length was 25.22±0.06 cm, 25.21±0.14 cm and 14.87±0.13 cm in T1,T2 and T3, respectively. The mean final weight and length was significantly (p<0.05) higher in T1and T2 compared with T3. However, there was no significant difference (p>0.05) between T1 and T2in terms of final weight and length was concerned. Better growth performances, however, wereobserved in T2 and T1, where prawn and chicken viscera were supplied as feed respectively.Lowest growth performance was observed in T3 where formulated feed (CP feed) was supplied.Key Words: Riverine Catfish; Feed; Growth; SGR; Survival.DOI: 10.3329/ujzru.v28i0.5279Univ. j. zool. Rajshahi Univ. Vol. 28, 2010 pp. 11-14


1957 ◽  
Vol 48 (3) ◽  
pp. 631-668 ◽  
Author(s):  
G. F. Burnett

Since November 1951, trials of residual insecticides have been carried out at Taveta, Kenya, against Anopheles gambiae Giles and A. funestus Giles in native-type huts fitted with exit traps.DDT wettable powder at over 2·5 g. DDT per sq. metre in a hut with plaster of absorbent mud gave, for eight months, kills of over 50 per cent. of the female Anophelines that entered.BHC wettable powder in huts with absorbent walls at 0·24 g. γ isomer per sq. metre gave kills of over 50 per cent. for nine months or more. On non-absorbent walls the kill fell rapidly during the third month and was negligible by the fifth. Insecticide persisted in walls of active material after the roof of inactive materials had become relatively innocuous.Wettable powders combining DDT and BHC were not effective unless the deposit of DDT was at least 2·1 g./m.2. For an equivalent cost, BHC alone was more effective on active walls and dieldrin on inactive ones.BHC in urea-formaldehyde resin at 2·5 g. γ BHC per sq. metre was persistent but the persistence was not commensurate with the cost of the material and difficulty of application. The insecticide persists longest on mud surfaces, presumably because it is absorbed from the skin of resin and later released as vapour. Absorption would render permanently innocuous a nonvolatile insecticide.Aldrin wettable powder was found considerably less persistent than BHC on absorbent walls.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Wenbe Hwang ◽  
Hsiu-Mei Lin

Our study investigated the fungistatic effects of the anal secretions ofNicrophorus nepalensisHope on mouse carcasses. The diversity of fungi on carcasses was investigated in five different experimental conditions that corresponded to stages of the burial process. The inhibition of fungal growth on carcasses that were treated by mature beetles before burial was lost when identically treated carcasses were washed with distilled water. Compared with control carcasses, carcasses that were prepared, buried, and subsequently guarded by mature breeding pairs of beetles exhibited the greatest inhibition of fungal growth. No significant difference in fungistasis was observed between the 3.5 g and the 18 to 22 g guarded carcasses. We used the growth of the predominant species of fungi on the control carcasses,Trichodermasp., as a biological indicator to examine differences in the fungistatic efficiency of anal secretions between sexually mature and immature adults and between genders. The anal secretions of sexually mature beetles inhibited the growth ofTrichodermasp., whereas the secretions of immature beetles did not. The secretions of sexually mature females displayed significantly greater inhibition of the growth ofTrichodermasp. than those of sexually mature males, possibly reflecting a division of labor in burying beetle reproduction.


Author(s):  
M. Kherroubi ◽  
F. Mouhouche ◽  
Z. Zerrouk Izzeddine ◽  
M. Chahbar

Biocontrol of the pine processionary moth Thaumetopoea pityocampa (Denis and Schiffermuller, 1775) with plant extracts Kherroubi, M. Mouhouche, F. Zerrouk Izzeddine, Z. Chahbar, M. Key words Thaumetopoea pityocampa, LD50, Populus nigra, Taxus baccata Reception date: 15/03/2019 | Acceptation date: 06/06/2019 | Publication date: 04/0/2019 © Copyright belongs to the authors, who license the journal Arxius de Miscel·lània Zoològica to publish the paper under a Creative Commons Attribution 4.0 License, which permits its distribution and reproduction in any medium, provided the original authors and source, the journal Arxius de Miscel·lània Zoològica, are cited. Download: PDF | Cite Share on: | Biocontrol of the pine processionary moth Thaumetopoea pityocampa (Denis and Schiffermuller, 1775) with plant extracts Kherroubi, M. Mouhouche, F. Zerrouk Izzeddine, Z. Chahbar, M. Abstract Biocontrol of the pine processionary moth Thaumetopoea pityocampa (Denis and Schiffermuller, 1775) with plant extracts The purpose of this study was to propose alternative solutions based on the use of natural, bio-insecticidal products to fight against the processionary moth, Thaumetopoea pityocampa (T. pityocampa), considered a defoliator because of the damage it causes to silvicultural. This insect also causes health problems in forests or wooded areas open to the public. To meet this objective, we evaluated the toxicity of six extracts from two plants: Taxus baccata and Populus nigra, collected from the regions of Blida, against first instar larvae of T. pityocampa. The results from these biological tests showed a significant difference between the six extracts. The LD50 (lethal dose) values were calculated by probit analysis using Finney’s table. The LD50 was also low for the two extracts Populus Methanol and Populus Methanol Chloroform (1.4 mg/ml and 3.3 mg/ml, respectively). However, the LD50 was relatively high for the rest of the extracts. In conclusion, the Bio-insecticides of Populus Methanol (PMP) and Populus Methanol Chloroform (PMC) showed to be active and could be integrated into the biological control of the egg parasitoids of T. pityocampa.


Author(s):  
J. I. Chikwendu ◽  
A. Onekutu ◽  
I. O. Ogbonna

Aim: The effect of Host blood on the fecundity of female Anopheles gambiae sensu lato mosquitoes was studied under normal conditions of 64±2% Relative Humidity and 27±2ºC Temperature. Methods: Three-five day old (F1) female Anopheles mosquitoes were transferred into wooden cages (40x40x40 cm) and fed blood from the following sources: man, cattle, chicken, goat, pig and sheep through an artificial feeding membrane. Engorged females were observed and fecundity recorded. The entire experiment was replicated five (5) times. Results: From the 1st to 4th gonotropic cycle, mosquitoes fed human blood produced significantly greater (p<0.05) number of eggs (Mean=121.90±1.18, 101.36±1.56, 64.12±1.54 and 29.66±1.69 respectively) than mosquitoes fed other blood meal sources. Across the six (6) blood meal trials (excluding that of sheep), there was a significant reduction (p<0.05) in fecundity from the 1st to 4th gonotropic cycles (1st>2nd>3rd>4th). There was no significant difference (p>0.05) in fecundity between pigs, chicken and sheep. Total mean longevity and total mean fecundity was significantly greater (p<0.05) in mosquitoes fed human and cattle blood than in mosquitoes fed the other blood sources. Conclusion: The results showed that blood meal source affects fecundity and longevity of female Anopheles gambiae s. l mosquitoes reared under laboratory conditions and that blood from humans as well as from other domestic animals is suitable for sustaining vectorial capacity in Anopheles gambiae s. l mosquitoes.


2019 ◽  
pp. 1-3
Author(s):  
B.V. Ramana* ◽  
A. Srikar ◽  
P. Prakash ◽  
Abhijit Chaudhury

Introduction: Tuberculosis is one of the oldest diseases with high morbidity and mortality. India accounts for one- fourth of the global TB burden (2.7million cases). Material and methods: A total 1056 patients were included in this study. All patients were requested to give two sputum samples, spot sputum sample (at the time of visit) and early morning sputum for mycobacterial testing. All spot samples tested with smear microscopy and Xpert MTB/Rif assay. Rifampicin resistant samples compared with conventional method. Results: Out of 1056 sputum samples GeneXpert MTB Rif assay detected positive 204 (19.3%), not detected 827 (78.31%). There is significant difference founded for positivity in spot samples and early morning sputum samples (P =0.0026). Rifampicins resistant were 8 (3.9%) andshown 100% sensitivity, specificity with Conventional method. Conclusion: For diagnosing tuberculosis and detecting Rifampicin resistance GeneXpert MTB/RIF has been especially recommended.


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