摘要:

Abstract.The role of some adult flies (Diptera: Cyclorrhapha) as carriers of helminth parasites of man was studied at four sites in Malaysia: a refuse dump, where no helminth‐positive flies were detected, and in three peri‐domestic situations where four species of flies carried up to three types of nematodes.The dominant fly speciesChrysomya megacephala(Fabricius) carried eggs of the roundwormAscaris lumbricoidesL., the pinwormTrichuris trichiura(L.) and hookworm on the adult external body surface and in the gut lumen, in association with Bukit Lanjan aborigines.Chrysomya rufifacies(Macquart) andSarcophagaspp. also hadAscaris lumbricoidesandTrichurus trichiuraeggs in their gut contents. Human helminths were not recovered fromLispe leucospila(Wiedemann),Lucilia cuprina(Wiedemann) or the houseflyMusca domesticaL.In an urban slum area of Kuala Lumpur city, filariform larvae identified as the hookwormNecator americanus(Stiles) occurred in the intestines of the face‐flyMusca sorbensWiedemann (22 larvae per 100 flies) and ofChrysomya megacephala(4.5 larvae per 100 flies). This concentration of apparently infectiveN. americanusinM. sorbens, a fly which often breeds in faeces and browses on human skin, could have transmission pote

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1988.tb00043.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Abstract.Twoin vitrotests were used to investigate the effect ofOnchocerca lienalisStiles infection on the haemolymph ofSimulium ornatumMeigen. The first of these examined the effect of infected haemolymph on the motility of freshO. lienalisorBrugia pahangiBuckley&Edeson microfilariae. Incubation of haemolymph from individual flies with fresh microfilariae was performed in the wells of Terasaki micro‐tissue culture plates. Motility of both species of parasite was found to be significantly attenuated when compared to worms incubated in control haemolymph groups.The second assay was that of agglutination of cat erythrocytes in the presence of haemolymph from individual flies, also performed in Terasaki plates. This test demonstrated significant increases in the rates of haemagglutination in the haemolymph ofO. lienalisinfected blackflies. The titre appeared to increase during the initial 5 days of infection up to a level of 1/32+, but then fell between day 5 and 7 to a maximum level of 1/2. The proportion of flies exhibiting haemagglutination also rose following infection.Despite the apparent absence of melanization and encapsulation, simuliids may have at least two humoral haemolymph components available to them for parasite regulation; a fast‐acting factor responsible for rapid parasite death, and more specific agglutinins, possibly lectins. The role of the latter in defence is as yet uncl

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1988.tb00044.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Abstract.Studies on larval population densities and adult emergence rates of the Brugian filariasis vectorsMansonia bonneaeEdwards andMa.divesSchiner were conducted in freshwater swamp forest bordering the Sadong River, Serian District, Sarawak, East Malaysia, during 1984–85.Three species of aquatic host‐plants in the Family Araceae were identified as supporting immature stages of theMa. bonneae/divescomplex. Proportions of positive plants were 4.7%, 6.5% and 3.4% with 6.4±2.6, 7.3±2.8 and 10.1±1.1 larvae per positive plant, respectively, for the plant speciesHomalomena cordataSchott,H.rostrataGriffiths andHydrostemma motleyi(Hook. f.) Mabberley. These data indicate no significant preferences between the three types of host‐plant.Detailed monitoring of the host‐plantH.cordatarevealed no significant monthly fluctuations in larval density per plant nor the proportion of positive plants. 11.6% of larvae wereMa.divesand 88.4% wereMa.bonneae.Mean daily yields ofMa.bonneae/divesadults per square metre ofH.cordatavegetated water surface were 0.45 males plus 0.57 females during the wet season (December‐February) compared with 0.2 males plus 0.31 females during the dry season (June‐August). Thus output of adults per plant was approximately halved, and suitable breeding areas were further reduced, during the dry season. By extrapolation from these rates, a crude mean estimate for productivity ofMa.bonneae/divesfemales is 1.6 million per hectare per annum in swamp forest habitats vegetated with any of the host

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1988.tb00045.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Abstract.The development of puparia ofGlossina morsitans morsitansWestwood was disrupted by topical applications of the juvenile hormone mimics S‐methoprene (the resolved enantiomer of 11‐methoxy‐3, 7, 11‐trimethyl‐2, 4‐dodecadienoic acid 1‐methyl ester) (Zoecon), S21149 (propionaldoxime‐0–4‐phenoxyphenoxyethylether) (Sumitomo), or S31183 (2‐[1‐methyl‐2‐(4‐phenoxyphenoxy)ethoxy]pyridine) (Sumitomo) dissolved in acetone. Puparia so treated during the first 4 days of life suffered developmental abnormalities, the severity of which were dose‐dependent. Similarly, puparia produced by adult females treated with these compounds were abnormal. Dose–response data showed that effects were greatest with S31183 and least with S‐methoprene. Abnormalities in the form of abdominal lesions and wing crumpling were typical of flies emerging from puparia produced by S‐methoprene‐treated females. However, arrested development at the red eye and pigmented seta stage within the puparium were typical of offspring of females treated with S21149 and S31183. A dose of 2 μg per female of S31183 was sufficient to prevent emergence of offspring produced for the rest of the life of the fly. The same dose resulted in partial recovery of females treated with S21149 some 18 days following treatment. Treatment with 2 μg S‐methoprene did not suppress completely the production of normal offspring and recovery was complete some 27–35 days after treatment. Exposure of males to 20 μg S31183 did not impair their ability to inseminate females; transfer of material during copulation was sufficient to prevent the production of viable offspring by their mates.Although the doses involved in the present experiments were high, the low mammalian toxicity of S31183 makes it an attractive candidate for further evaluation as a safe chemosterilant for tsetse. Of particular interest is the lack of similarity between the molecular structures of juvenile hormones and this mimic which tends to arrest development at a precisely defin

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1988.tb00046.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Abstract.Permethrin selection of DDT resistantAnopheles stephensiListon mosquito larvae produced a reduction in susceptibility to knockdown (2 h exposure) of 17‐fold, but only 1.6‐fold to kill (24 h exposure). Genetic analysis, incorporating visible mutant markers, was interpreted as indicating that, through multigenic inheritance, several interacting genetic factors were collectively responsible for reduced larval susceptibility to knockdown. These were maintained together only under selection pressure, as the effect was lost quickly in the absence of selection or with outcrossing. The 30–40‐fold DDT‐resistance found in the parental strain was barely altered by permethrin selection, suggesting no relationship with the major source of DDT resistance. This was confirmed in single family studies. Some evidence for an additional tolerance to DDT was found to be associated with reduced larval susceptibility to p

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1988.tb00047.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Abstract.Phlebotomine sandflies were surveyed in two ecologically contrasted areas, the northern moist and southern wet tropical forests, of the Territorio Federal Amazonas, Venezuela.Three new taxa and twenty‐one new records were added to the previously known species list for Venezuelan sandflies, which now totals eighty species. Both sexes ofLutzomyia (Psychodopygus) killickisp.n.,L.(Trichophoryomyia) bettiniisp.n.,L.(Nyssomyia) olmeca reductasubsp.n.and and the females ofL.bernaleiOsornoet al., Brumptomyia pintoiCosta Lima andL.begonae(Ortiz&Torres) are described and illustrate

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1988.tb00048.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Abstract.Soil analysis was carried out on samples obtained from a breeding‐site of the sandfliesPhlebotomus perniciosusNewstead,P. perfiliewi perfiliewiParrot andSergentomyia minuta(Rondani) in Sardinia. Soil texture, pH, CaCo3, organic matter and water content showed no correlation with the number of sandflies that emerged from the places where soil samples were taken. It appears that pre‐imaginal stages of these phlebotomine sandflies are associated with a relatively stable, cool and humid environment protected from sunshine and rain, rich in clay and in organic nitro

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1988.tb00049.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Abstract.Five species of Calliphoridae, mostly females, were collected using fly‐traps baited with freshly killed rodent carcasses. Female blowflies were examined to determine the stages of ovarian development.The traps were selective for certain ovarian stages which varied according to the species.Phoenicia eximia(Wiedemann) was attracted to the traps mainly to oviposit, whereas females ofChrysornya albiceps(Wiedemann),C.putoria(Wiedemann) andC.megacephala(Fabricius) were captured in intermediate stages of oogenesis but seldom with eggs mature for oviposition.It is concluded that this kind of baited trap is unsuitable for the collection of male blowflies and that samples of female blowflies are specifically biased in favour of certain ovarian condition

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1988.tb00050.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Abstract.A method has been developed to distinguish between mated female individuals of the sibling speciesAnopheles gambiaeGilessensu strictoandAnopheles arabiensisPatton. The DNA probe pAnal, reported by Gale&Crampton (1987a) to be useful for the specific identification ofAn.arabiensismales, is here shown to be sufficiently sensitive to deduce the species identity of inseminated females from the identity of the sperm contained within the spermatheca.

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1988.tb00051.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Abstract.Starved houseflies were held over a suspension of Aujeszky's virus (PRV‐1) for 24–48 h. One group was rinsed in 70% ethanol to kill virus attached to the body surface. No virus was isolated from this group. For the other group the titre of virus decreased more rapidly on the body surface of flies than in the environment. Model experiments demonstrated that the Aujeszky's virus cannot survive in the body of the housefly but the body surface may be contaminated for a period of time depending on the initial viral titre. Experiments showed that susceptible pigs fed on flies contaminated with Aujeszky's virus may become infected. The quantity of virus (5 × 105pfu ml‐1) shed by a single housefly during biting and vomiting on the cornea or abraded skin proved to be sufficient to cause infection in susceptible pigs, rabbits and a lamb. It is possible that houseflies could play a role in transmission of infection within herds. Transmission between herds is much less

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1988.tb00052.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY