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Memórias do Instituto Oswaldo Cruz

Print version ISSN 0074-0276On-line version ISSN 1678-8060

Mem. Inst. Oswaldo Cruz vol.100 no.1 Rio de Janeiro Feb. 2005

https://doi.org/10.1590/S0074-02762005000100007 

GENERAL BIOLOGY
SHORT COMMUNICATION

 

Moonlight and blood-feeding behaviour of Lutzomyia intermedia and Lutzomyia whitmani (Diptera:Psychodidae:Phlebotominae), vectors of American cutaneous leishmaniasis in Brazil

 

 

Nataly A SouzaI,1; Cláudia A Andrade-CoelhoI; Vanderlei C SilvaI; Alexandre A PeixotoII; Elizabeth F RangelI

IDepartamento de Entomologia
IIDepartamento de Bioquímica e Biologia Molecular, Instituto Oswaldo Cruz-Fiocruz, Av. Brasil 4365, 21045-900 Rio de Janeiro, RJ, Brasil

 

 


ABSTRACT

Lutzomyia intermedia (Lutz & Neiva, 1912) and L. whitmani (Antunes & Coutinho, 1939) (Diptera: Psychodidae: Phlebotominae), two important vectors of American cutaneous leishmaniasis in Brazil, occur in sympatry in the locality of Posse county, Petrópolis municipality, state of Rio de Janeiro, Brazil. We investigated the influence of the lunar cycle on the frequency of specimens of the two species caught while attempting to bite the collectors and in CDC light traps. Analysis of the numbers of sand flies captured in different lunar phases for two consecutive years in the peridomestic site and forest shows that there is a significant positive correlation between moonlight intensity and the numbers of L. intermedia and L. whitmani females collected while blood-feeding, whereas the opposite was observed for the CDC traps.

Key words: Lutzomyia intermedia - Lutzomyia whitmani - lunar cycle influence


 

 

Phlebotomine sand flies belong to a medically important group of insects, some of which are the vectors of Leishmania (Forattini 1973). They are mostly nocturnal and in the light of existing knowledge one might expect these vectors to be affected by the lunar cycle (Chaniotis et al. 1971, Mellor & Hamilton 2003).

A two-year study of the seasonal variation of Lut-zomyia intermedia and Lutzomyia whitmani, two important vectors of American cutaneous leishmaniasis in Brazil, was carried out in the locality of Posse, Petrópolis municipality, state of Rio de Janeiro (112 km from the city of Rio de Janeiro) (Souza et al. 2002).

During that period we frequently noticed that larger numbers of females were caught attempting to bite the collectors on Full Moon nights than at other times. However, this trend was not observed for sand flies collected in CDC light traps. Therefore, to investigate this further, we analysed two years data comparing the numbers of the two species collected in CDC light traps or biting man at different phases of the moon.

Sand flies were captured in 72 collections at "Sítio Catavento", Posse, in the peridomestic sites and in the nearby forest carried out between July 1996 and June 1998. Details of the methodology used and the study area can be found in Souza et al. (2002).

Figs 1 and 2 show the mean numbers, respectively after logarithmic transformation, of L. intermedia and L. whitmani females collected on human bait (top) or in CDC traps (bottom) at peridomestic sites by moonlight intensity (1 = New Moon, 2 = First and Last Quarters, 3 = Full Moon). Many more females of the two species were captured on human bait at Full Moon than at New Moon with intermediate numbers in the First and Last Quarters when the light intensity was also intermediate. This positive trend is highly significant as is shown in the Table, which presents the results of the Spearman's correlation coefficient between moonlight intensity and the number of females of the two species collected in the two areas on human bait. An exactly opposite pattern is observed for the total number of sand flies collected with CDC light traps. Again the negative trend correlation between moonlight intensity and number of sand flies captured is highly significant, as it is also indicated in the Table. Figs 3 and 4 show that the same patterns are observed in the forest and, once again, the correlations are highly significant (Table).

 

 

 

 

 

 

 

 

Other studies have demonstrated some influence of the lunar phases on phlebotomine behaviour (Aguiar & Soucasaux, 1984, Aguiar et al. 1985, Morrison et al. 1995, Sherlock et al. 1996, Carvalho et al. 2000, Santos-De Marco et al. 2002), although the methods used were sometimes different from those used by the present authors hence the results are not always comparable. For example, Santos-De-Marco et al. (2002) in Viçosa, state of Minas Gerais, using illuminated Shannon and Falcão light traps, showed that females of L. intermedia initiated activity earlier during the First Quarter and Full Moon phases than during the Last Quarter and New phases. Aguiar et al. (1985), studying the ecology of sand flies in a national park with a mountainous region covered by Atlantic tropical rainforest (Parque Nacional da Serra dos Órgãos, state of Rio de Janeiro), reported that CDC light traps captured higher numbers of specimens of different species during the New Moon, as here observed. However, Aguiar and Soucasaux (1984), working in the same area, did not detect enhanced blood feeding frequency during Full Moon as reported here. Morrison et al. (1995), working in a small rural community in Colombia where American visceral leishmaniasis is endemic, observed that L. longipalpis was significantly more abundant in active collections in a pigpen and in a cattle corral on nights when the moon was visible than during dark nights.

A number of studies have also demonstrated the effect of moonlight on mosquito behaviour (reviewed in Clements 1999). For example, Bidlingmayer (1974) suggested that moonlight reduces the effectiveness of CDC traps and Janouseck and Olson (1994), studying the activity of mosquitoes by using different trapping methods, observed that it was possible to collect larger numbers of specimens by using CDC light traps in the absence of moonlight than on moonlit nights.

In the present study it was observed that the total number of L. intermedia and L. whitmani captured with CDC light traps is inversely correlated with the intensity of the moonlight and that the opposite is observed for females captured on human bait. It is possible that on the darker nights (New Moon) the light of the CDC light trap is more effective in attracting sand flies. However, the effect of the darkness on the blood feeding frequency is more difficult to explain. The most likely explanation is that the moonlight helps sand flies to navigate and to find its host (Mellor & Hamilton 2003). Further studies under more controlled conditions are needed to understand the effects of moonlight intensity observed in this and other studies. Nevertheless, it would seem that the lunar phase is a factor that should be taken into consideration when planning or analysing data on sand fly captures.

 

ACKNOWLEDGMENTS

To Ms Deise Aparecida Barrichelo, owner of the Sítio Catavento farm where the study was conducted, for her constant support and encouragement, to Mr Luís Henrique Costa for his technical support in the field and laboratory, as well as to Professor Richard Ward, Keele University, UK, for his critical revision.

 

REFERENCES

Aguiar GM, Soucasaux T 1984. Aspectos da ecologia dos flebótomos do Parque Nacional da Serra dos Órgãos, Rio de Janeiro. I — Freqüência mensal em isca humana (Diptera, Psychodidae: Phlebotominae). Mem Inst Oswaldo Cruz 79: 197-209.         [ Links ]

Aguiar GM, Vilela ML, Schuback PD, Soucasaux T, Azevedo ACR 1985. Aspectos da ecologia dos flebótomos do Parque Nacional da Serra dos Órgãos, Rio de Janeiro. IV — Freqüência mensal em armadilhas luminosas (Diptera, Psychodidae: Phlebotominae). Mem Inst Oswaldo Cruz 80: 465-482.         [ Links ]

Bidlingmayer WI 1974. The influence of environmental factors and physiological stage on flight patterns of mosquitoes taken in the vehicle aspirator and truck, suction, bait and New Jersey light traps. J Med Ent 15: 119-146.         [ Links ]

Carvalho RW, Souza MB, Serra-Freire NM, Pontes CS, Conceição NF, Almeida AB, Campos VS 2000. Flebotomíneos (Diptera, Psychodidae) da Ilha do Araújo, município de Paraty, estado do Rio de Janeiro, Brasil. 2 — Comportamento da fauna frente à variação horária e ao ciclo lunar. Entomol Vect 7: 143-153.         [ Links ]

Chaniotis BN, Correa MA, Tesh RB, Johnson KM 1971. Daily and season man-biting activity of phlebotominae sand flies in Panama. J Med Ent 4: 415-420.         [ Links ]

Clements AN 1999. The Biology of the Mosquitoes. Vol. 2 Sensory Reception and Behaviour, CABI Publishing, Oxon, 740 pp.         [ Links ]

Forattini OP 1973. Entomologia Médica, Vol. 4, Blücher Ltda., São Paulo, 658 pp.         [ Links ]

Mellor HE, Hamilton JGC 2003. Navigation of Lutzomyia longipalpis (Diptera: Psychodidae) under dusk or starlight conditions. Bull Ent Res 93: 315-322.         [ Links ]

Morrison AMY, Ferro C, Pardo R, Torres M, Wilson ML, Testh RB 1995. Nocturnal activity patterns of Lutzomyia longipalpis (Diptera: Psychodidae) at an endemic focus of visceral leishmaniasis in Colombia. J Med Ent 32: 605-617.         [ Links ]

Santos-De-Marco T, Gaia MCM, Brazil RP 2002. Influence of the lunar cycle on the activity of phlebotomine sand flies (Diptera, Psychodidae). J Am Mosq Control Ass 18: 114-118.         [ Links ]

Sherlock IA, Maia H, Dias-Lima AG 1996. Resultados preliminares de um projeto sobre a ecologia dos fleboto-míneos vetores de leishmaniose tegumentar no estado da Bahia. Rev Soc Bras Med Trop 29: 207-214.         [ Links ]

Souza NA, Andrade-Coelho CA, Vilela ML, Peixoto AA, Rangel EF 2002. Seasonality of Lutzomyia intermedia and Lutzomyia whitmani (Diptera: Psychodidae: Phlebotominae), occurring sympatrically in area of cutaneous leishmaniasis in the state of Rio de Janeiro, Brazil. Mem Inst Oswaldo Cruz 97: 759-765.         [ Links ]

 

 

Received 10 August 2004
Accepted 24 November 2004
Financial support: UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases, Howard Hughes Medical Institute, The Wellcome Trust, Fiocruz, CNPq

 

 

1 Corresponding author. E-mail: souzana@ioc.fiocruz.br

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