摘要:

Abstract.Animal‐baited traps, using fox, mink, rabbits and ducks, were used in host preference experiments in two habitats (Beach and Woods). A generalized linear model of blood‐feeding host preference is presented to test for significant differences between the isomorphic speciesSimulium venustumandSimulium truncatum.TheS.truncatumpopulation peaked before that ofS.venustum.On any given day the two species divided their blood‐feeding efforts among the different hosts in the same proportions. On the Beach, fox was the preferred host at the beginning of the season, but by the end of the season flies fed with equal frequency on the fox and the mink. In the Woods fox remained the preferred host throughout the season (late May to early July). Possible reasons for these feeding trends are disc

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1993.tb00661.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract.Stable flies (Stomoxys calcitransL.) deprived of a bloodmeal until 3 days post‐emergence had higher mortality rates than control flies fed from the day of emergence. Fat bodies of deprived females required one more bloodmeal to reach maximum size, and maximum size was smaller, than fat bodies of control females. Ovarian development did not commence prior to feeding in deprived flies, and proceeded more slowly thereafter, resulting in a one bloodmeal delay in egg maturation in deprived flies. Deprived females produced fewer (54.7, SD 2.8) eggs than controls (75.9, SD 3.7) and eggs from deprived females were smaller (mean length 684.0 μrn) than control females' eggs (mean length 1165.7

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1993.tb00662.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract.Use. of the organophosphorus insecticide malathion for mosquito control in Cuba, for 7 years up to 1986, selected elevated non‐specific esterase and altered acetylcholinesterase (AChE) resistance mechanisms inCulex quinquefasciatus.In central Havana space‐spraying of malathion was replaced by the pyrethroid cypermethrin in 1987: alternate cycles of malathion and cypermethrin were applied in some of the more rural areas of Havana district during 1987‐91. Consequently, populations ofCx quinquefasciatusin the central area of Havana developed resistance to cypermethrin, but there is no evidence of pyrethroid resistance in the outlying areas.Malathion resistance levels declined significantly after 1986, measured both by bioassay and the frequency of the elevated esterase resistance mechanism, and then stabilized with no measurable decline during 1990 in any of the populations tested. These populations had less than 10% frequency of susceptible homozygotes for both the esterase and AChE resistance mechanisms, indicating that organophosphate resistance is still prevalent in CubanCx quinquefasciatus.These two mechanisms appear to be in linkage equilibrium, suggesting that current selection for double resistance is not strong.In the central Havana region, pirimiphos‐methyl, an organophosphorus insecticide unaffected by the two common malathion resistance mechanisms, is now being used in a resistance management strategy designed to avoid pyrethroid resistance sp

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1993.tb00663.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract.A laboratory colony of the mosquitoAnopheles quadriannulatuswas established from a wild population occurring sympatrically withAn.arabiensisin Zimbabwe. These sibling species are members of theAn.gambiaeGiles complex and were distinguished primarily by means of their specific polytene chromosome banding patterns. By using an ox‐baited trap, we sampled selectively for the more zoophilicAn.quadriannulatus.It was confirmed thatAn.quadriannulatushas the diagnostic slow allozyme of aspartate aminotransferase (AAT95/95). In a mixed population under laboratory conditions,An.arabiensisdisplacedAn.quadriannulatuswithin eight generations, without introgression. Colonization ofAn.quadriannulatuswas facilitated by pooling the progeny from wild‐caught mothers of confirmed identity and by using a specially adapted cage to promote mat

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1993.tb00664.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract.Mosquitoes were collected on human bait over a 16‐month period (September 1988 to December 1989) in an urban and a rural area of Kinshasa, Zaïre.P.falciparummalaria sporozoite rates were determined by ELISA.In the urban areaCulex quinquefasciatusaccounts for 96% of the 121 bites/ person/night (b/p/n). The only anopheline isAnopheles gambiae, sensu stricto, with an average of 5.1 b/p/n and a sporozoite rate of 1.86%. The entomological inoculation rate (EIR) averages 0.08 infective b/p/n. Malaria transmission is almost interrupted at the end of the dry season.In the rural area mosquito nuisance is small (20b/p/n), almost entirely due to six species ofAnophelesincluding four vectors of malaria:An.gambiae(13.3 b/p/n),An.funestus(2.4b/p/n),An.nili(0.4b/p/n) andAn.brunnipes(0.7b/p/n) with mean sporozoite rates of 7.85%, 6.60%, 6.63% and 0.53% respectively.An.paludis(0.4b/p/n) andAn.hancocki(0.2b/p/n) were not found infective. Malaria transmission is intense and perennial: the overall EIR varies monthly between 0.60 and 3.29 infective b/p/n. The specific contributions ofAn.gambiae, An.funestusandAn.niliaverage 1.07, 0.14 and 0.03 infective b/p/n respectively.Malaria transmission peaks during the rainy season in both study areas. The daily mean survival rates forAn.gambiaewere 0.91 and 0.78 in the rural and urban area, respectively. AllAn.gambiaeexamined belonged to the forest cytotype (Coluzziet al., 1979). Through its effect on the sporozoite rate, the higher vector survival rate in the rural environment appears to be the major determinant of the greater malaria transmission rate in the rural area as compared to urban Kinsha

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1993.tb00665.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract.This first report on the lice of farm animals in Libya lists a total of fifteen species, as follows:Haematopinus quadripertususandLinognathus vitulifrom cattle,Bovicola ovis, Linognathus pedalis, L.afrlcanusandL.ovillusfrom sheep,L.stenopsis, L.africanusandBovicola capraefrom goats. Poultry harbouredLipeurus caponis, L.heterographus, Menacanthus stramineus, Menopon gallinae, Goniocotes gallinae, Goniodes gigasandG.dissimilis.

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1993.tb00666.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract.The mosquitoHaemagogus equinusis a known vector of yellow fever (YF) in central America. Seasonal abundance, daily biting activity and the age composition of adultHg. equinusfemale populations were monitored weekly during 1981–82 by human collectors on the ground at Point Gourde Forest, Chaguaramas, 16 km west of Port of Spain, Trinidad.2. Landing collections ofHg.equinusshowed diurnal activity from 06.00 to 20.00 hours (suntime), with a single peak between 08.00 and 14.00 hours.3. Overall, 5.6% ofHg.equinuswere collected during the dry season (December‐April) and 94.4% during the wet season (May‐November).4. Mean density ofHg.equinusin relation to man ranged from 0.35/man‐day in February to 133/man‐day in July, with averages of 2.8 in the wet season, 36.9 in the dry season and 22/man‐day for the whole year.5. Monthly parous rates averaged 62.1% (range 0‐88%); 2.8% of females were 2‐pars, another 2.8% were 3‐pars, but no older females ofHg.equinuswere found (sample size 467).6. These age‐grading data indicate thatHg.equinusfemales have relatively short life expectancy and hence low vector potential, which may help to explain why YF virus has seldom been isolated from

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1993.tb00667.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract.The reproductive status of native (wild) screwworm fly,Chrysomya bezziana, caught on swormlure‐baited sticky traps in Papua New Guinea is described. A total of 1122 females and 25 males were trapped. Of these females 595 were scored for insemination status and stage of ovarian development (on a scale of 2–10) of which 20% were in suitable condition for assignment to first, second and third ovarian cycles. Of the nulliparous females, only 17% were inseminated at stage 3 of ovarian development, 70% at stage 4, 93‐97% at stages 5 and 6, and all of stages 7–10 (gravids). All parous females were inseminated. More than half of the captured females were parous (58%) and only 7% of the total were gravid. Proportions of females in ovarian cycles 1, 2 and 3 were 41%, 50% and 9% respectively.Survival of femaleCh. bezzianain the laboratory was adequately described by lognormal and Gompertz survival functions, for both of which the mortality rate is an increasing function of reproductive age. Analysis of the reproductive age distribution of native females estimated their mean life‐expectancy at 9 days under the prevailing mean field temperature of 26.5oC. This equates to completion of 1.7 ovarian cycles and an estimated mean lifetime fecundity of 146 female progeny. The survival models, which also allowed responsiveness of females to swormlure‐baited traps (female trappability) to vary according to their stage of ovarian development, indicated significant age‐dependent trapping bias. These findings are compared with similar data for the New World screwworm fly,Cochliomyi

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1993.tb00668.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract.In urban Auckland, from September 1991 to May 1992, only six specimens of the Australian sheep blowfly,Lucilia cuprina, were collected in farmed parkland and in garden habitats. The common green blowfly,Lucilia sericata, was the most common calliphorid trapped in these habitats. Neither of the twoLuciliaspecies were found in native bush remnants in urban or rural areas whereCalliphora hilliwas dominant. Similarly very fewL.cuprina(0.3% of the total) were trapped in rural rubbish tips in January and February where the majority of blowflies were againL.sericata.These results are compared with data collected from pastoral habitats, whereL.cuprinais the major cause of flystrike.Lucilia cuprinawas reared from five out of ninety‐nine carcases found in rural areas.Calliphora stygiaandL.sericatawere the most common blowflies colonizing carrion and were reared from 59% and 51% of the carcases respectivel

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1993.tb00669.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract.A large‐scale trial investigated the possibility of eradicatingG.m.centralisfrom a traditional cattle rearing area using odour‐baited targets at a reduced overall target density from 4 to 0.5‐2.3 per km2, thus cutting down initial material costs by about 50%. Only the periphery of what was thought to be prime tsetse habitat (dense woodland) was treated with targets. These were all black or blue/black cloth (1.8 × 1m), sprayed with deltamethrin suspension concentrate and baited with butanone and/or acetone (40‐130mg/h) and l‐octen‐3‐ol (0.5mg/h). Although fly catches from traps and flyrounds initially dropped by approximately 3% per day and trypanosomiasis cases declined by 99% within a year, eradication was not achieved, so that more targets were deployed at a later stage. Although initially cheaper, the option of using reduced target densities proved financially unattractive because of prolonged periods of target maintenance prior to eradication. Revised strategies for tsetse control with odour‐baited, insecticide‐impregnated targets in west Za

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1993.tb00670.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY