ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1992.tb00026.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.The New World screwworm fly,Cochliomyia hominivorax(Coquerel) (Diptera: Calliphoridae), became established in the Old World for the first time during 1988, in the Socialist People's Libyan Arab Jamahiriya. An obligate parasite of mammals in its larval stages, causing wound myiasis, it is one of the most serious insect pests of livestock in the Americas. To avert a major disaster for the livestock industry and wildlife of Africa and southern Europe, the Libyan Government and the Food and Agriculture Organization of the United Nations launched a massive screwworm eradication programme, based on the sterile insect technique, SIT. An initial containment operation involved veterinary teams working in the infested area (25,000km2around Tripoli), regularly inspecting livestock and, if necessary, treating them with insecticide. Quarantine stations were also set up, to prevent the movement of infested livestock out of the area. Sterile flies from the Mexican‐American Commission for Eradication of Screwworms were first released in December 1990 at the rate of 3.5 million per week. This built up to 40 million per week by May 1991. The release of sterile flies was terminated on 17 October 1991, 6 months after the last detected case of screwworm myiasis in Libya. Intensive surveillance and quarantine activities will, however, continue through 1992. During 1992 the Libyan Government should be able to officially declare the New World screwworm eradicated from Libya, making it one of the most important success stories of pest contro

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1992.tb00027.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.The copepodMesocyclops aspericornisDaday and the larvivorous fishesGambusia affinis(B.&G.) andPoecilia reticulataR.&B., were released into mosquito breeding sites in Tuherahera village, Tikehau atoll, French Polynesia, to control larvae ofAedes aegypti(L.),Ae.polynesiensisMarks,Culex annulirostrisSkuse andCx quinquefasciatusSay. Treatments were completed within a week, in January 1990.Fish quickly eliminated mosquito larvae from the open breeding sites (ponds, wells). The impact of copepods in water tanks, drums and covered wells was inconsistent, apparently depending on the availability of microfaunal diet for growth of copepod nauplii. As the biting rate of adultAe.aegyptiseemed to be unaffected by the biological control of larvae, this village‐scale experiment was judged to be unsuccessful as a means of vector contro

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1992.tb00028.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.Irregular peaks ofP.falciparummalaria incidence were monitored in Suriname during 1982‐86. An attempt is made to correlate these fluctuations of malaria rates with rainfall and river level in relation to the periodic availability of breeding habitats for the malaria vectorAnopheles darlingiRoot.Densities of adult femaleAn. darlingiwere recorded in the Upper‐Marowijne region of Suriname, in a focus of malaria along the Marowijne River. Peaks in biting densities correlated well with periods of (i) high water level in the long rainy season, (ii) low water level in the long dry season, and (iii) abundant rainfall in the short rainy season. Critical levels of river‐height and rainfall were defined which could explain most of the monthly fluctuations in malaria parasite incidence observed in this

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1992.tb00029.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.Larval collections ofSimulium ochraceumWalker (Diptera: Simuliidae) were made in a variety of streams in the three onchocerciasis foci in Mexico and identified by cytotaxonomic criteria, based on the banding pattern of polytene chromosomes in larval salivary gland nucleii.S.ochracrumcytotype A was found in the Soconusco focus, cytotype B in the Oaxaca focus and cytotype C (not previously recorded in Mexico) in the Chamula focus. Attempts to analyse chromosomes of adult specimens were unsuccessful. A preliminary study of the cuticular hydrocarbons of adult specimens by gas liquid chromatography provided evidence that this technique may be suitable for separating the cytotypes.

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1992.tb00030.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.Mixtures of chromosomal forms A, B, C and D in natural populations ofAnopheles dirusPeyton&Harrisonsensu latoin Thailand show significant positive values of Wright's fixation index for six enzyme‐electromorph loci. The mean value ofFISover all loci was found to be +0.28 (SD 0.02), with a range of +0.57 (Odh) to +0.10 (Idh‐2). Partitioning electromorph data for the chromosomal forms reduces the meanFISto 0.03 (SD 0.01), which suggests that positive assortative mating is a characteristic of each form. This supports the hypothesis that the chromosomal/electrophoretic forms A, B, C and D represent four distinct biological species within theAn.diruscomplex.An example is given of the use of enzyme electromorphs as a means of vector identification during a malaria entomological field study involving a mixture ofAn.dirusspecies A and D. Electromorph identifications of 323 sp. A and 161 sp. D were more than 98% correct when cross‐referenced to specific DNA p

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1992.tb00031.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.Enzyme polymorphism in triatomine bugs of the genusRhodnius(Hemiptera: Reduviidae), vectors of Chagas disease, is analysed using both starch and polyacrylamide gel electrophoresis. Out of forty‐five enzymes assayed, the electromorphs of seventeen of them: AO, CA, DIA, ES, ES‐A, FH, GPD, G6PD, GPI, MDH, ME, 6PGD, PGM, ACON, ACPH, LAP and SOD, involving twenty‐two putative structural loci, were scorable. These gene‐enzyme systems were therefore selected for routine characterization ofR.prolixusStal adults from different strains. The first thirteen enzymes, involving sixteen structural loci, were also analysed in first instar nymphs of the three species,R.prolixus, R.robustusLarrousse andR.pictipesStal. Allelic frequencies were calculated for threeR.prolixusstrains: three to five loci appeared to be polymorphic. The proportion of polymorphic loci (22%) and the average hetero‐zygosity (0.06) indicated low genetic variability, with significant differences between the strains at individual loci.Rhodnius prolixusandR.robustuswere found to have identical isozymic patterns.R.pictipeswas genetically well differentiated, with twelve diagno

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1992.tb00032.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.Field trials with mosquito coils containing 0.15% Esbiothrin at Usa River settlement, northern Tanzania, during 1986 achieved a 52% reduction in biting rates ofAnopheles arabiensisPatton and a 73% reduction ofCulex quinquefusciatusSay mosquitoes. No mosquito biting activity occurred during the coil burning period which started at 20.00 hours daily and lasted for an average of 8.6 h. A sociological survey indicated that the coils were favourably accepted and produced no serious side‐effect

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1992.tb00033.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.The residual repellent activity of N, N‐diethylphenyl‐acetamide (DEPA), N, N‐diethyl‐3–methyl benzamide (DEET) and dimethylphthalate (DMP) against the hard tickRhipicephalus sanguineus(Latreille) and the soft tickArgus persicus(Oken) from topical application on rabbits and hens respectively in the laboratory have been studied. It was found that a 25% concentration of DEET gave strong repellency (>90%) against larvae and nymphs ofR. sanguineusfor 15 and 7 days respectively and againstA.persicuslarvae and nymphs>90% for 11 and 5 days respectively. Strong repellency (>90%) against adults of the hard and soft ticks was observed for 9 and 7 days respectively with 40% DEET. DEPA at 25% concentration showed strong repellency (>90%) against larvae and nymphs ofR.sanguineusandA.persicusfor 11 and 5 days respectively. Adults of hard and soft ticks were strongly repelled (>90%) for 9 and 5 days respectively by 40% DEPA. DMP was found to be the least effective against all stages of both specie

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1992.tb00034.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.Male and femaleT. infestanswere released on two consecutive nights in the salinas of Cordoba Province, Argentina, when air temperatures during the flying period averaged 28.5°C. 136 males (43% of the total released) and 170 females (57%) flew on the first night, and 6 males (18%) and 7 females (27%) on the second. Of these, we recovered 23 males and 14 females within loom, and a further female within 200 m, all from the first night's release. The remainder appear to have flown more than 100 m and possibly more than 200 m. In support of this conclusion 4 male and 5 female bugs were recovered in an abandoned brick house 550 m from the release point. Since the proportion of bugs apparently flying more than 200 m is considerably greater than that deduced from previous experiments at lower temperatures (Lehane&Schofield, 1981) it is possible that temperature influences not only the proportion of bugs flying but also the distance flown. Flight appears to be affected by wind speed. On the first night, when there was negligible wind, 43% of male and 57% of female bugs flew. On the second night, with winds gusting at 4–5 m/s, only 18% of the male and 27% of the female bugs fl

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1992.tb00035.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY