Skip to main content
×
×
Home

The life-cycle of Philornis downsi (Diptera: Muscidae) parasitizing Darwin's finches and its impacts on nestling survival

  • B. FESSL (a1), B. J. SINCLAIR (a2) and S. KLEINDORFER (a3)
Abstract

The fly, Philornis downsi Dodge & Aitken, was first collected in 1964 on the Galápagos Islands and is now widespread across the archipelago. Virtually nothing is known about the behaviour and ecology of the fly as well as for the genus in general. Here, we describe all larval instars for the first time, and discuss infection intensity and impacts of parasitism on nestling survival of Darwin's finches. Adult P. downsi are non-parasitic free-living flies, whereas the larvae are obligate blood-feeding parasites on nestling birds. The larvae show a marked shift in their host site specificity – a novel finding for the genus Philornis: the first and early second larval instars live as agents of myiasis in finch nostrils and other tissues, while the older second and third instar larvae reside in the nest material and feed externally on the blood of nestlings, leading to blood losses in nestlings of 18–55%. Pupation occurs in the bottom layer of the nest. The combined effects of tissue damage by the endoparasitic instar larvae and anaemia by nest-dwelling haematophagous instar larvae account for the high nestling mortality (76%) due to Philornis parasitism. This represents the highest mortality by Philornis reported in the literature and emphasizes the extremely serious threat this parasite poses for the endemic passerine fauna of the Galápagos Islands.

Copyright
Corresponding author
Le Grand Mas d'Avignon, Le Sambuc, 13200 Arles, France. E-mail: marisk@wanadoo.fr
References
Hide All

REFERENCES

Arendt, W. J. ( 1983). The effects of dipterean ectoparasitism on the growth and development of nestlings of the Pearly-eyed Trasher (Margarops fuscatus) in the Luquillo Mountains, Puerto Rico. M.A. thesis, University of Missouri, Columbia, MO, USA.
Arendt, W. J. ( 1985 a). Philornis ectoparasitism of pearly-eyed trashers. I. Impact on growth and development of nestlings. Auk 102, 270280.
Arendt, W. J. ( 1985 b). Philornis ectoparasitism of pearly-eyed trashers. II. Effects on adults and reproduction. Auk 102, 281292.
Arendt, W. J. ( 2000). Impact of nest predators, competitors, and ecotparasites on pearly-eyed trashers, with comments on the potential implications for Puerto Rican parrot recovery. Ornitología Neotropical 11, 1363.
Causton, C. E., Peck, S. B., Sinclair, B. J., Roque-Albedo, L., Hodgson, C. J. and Landry, B. ( 2006). Alien insects: threats and implications for the conservation of the Galápagos Islands. Annals of the Entomological Society of America 99, 121143.
Couri, M. S. ( 1985). Considerações sobre as relações ecológicas das larvas de Philornis Meinert, 1890 (Diptera, Muscidae) com aves. Revista Brasileira de Entomologia 29, 1720.
Couri, M. S. ( 1999). Myasis caused by obligatory parasites. 1a. Philornis Meinert (Muscidae). In Myasis in Man and Animals in the Neotropical Region ( ed. Guimarães, J. H. and Papavero, N.), pp. 5170. Bibliographic Data Base, FAPESP, Sao Paulo, Brazil.
Courtney, G. W., Sinclair, B. J. and Meier, R. ( 2000). Morphology and terminology of Diptera larvae. In Contributions to a Manual of Palaearctic Diptera. General and Apllied Dipterology ( ed. Papp, L. and Darvas, B.), pp. 85161. Science Herald, Budapest.
De Carvalho, C. J. B., Couri, M. S., Pont, A. C., Pamplona, D. and Lopes, S. M. ( 2005). A catalogue of the Muscidae (Diptera) of the Neotropical region. Zootaxa 16, 3253.
Delannoy, C. A. and Cruz, A. ( 1991). Philornis parasitism and nestling survival of the Puerto Rican sharp-shinned hawk. In Bird-Parasite Interactions. Ecology, Evolution and Behaviour ( ed. Loye, J. E. and Zuk, M.), pp. 93103. Oxford University Press, Oxford.
Dodge, H. R. and Aitken, T. H. G. ( 1968). Philornis flies from Trinidad (Diptera, Muscidae). Journal of the Kansas Entomological Society 41, 134154.
Dudaniec, R., Kleindorfer, S. and Fessl, B. ( 2006). Haemoglobin level and survival in Darwin's small ground finch (Geospiza fuliginosa): effects of the parasite Philornis downsi. Austral Ecology 31, 8894.
Dudaniec, R. Y. and Kleindorfer, S. ( 2006). The effects of the parasitic flies Philornis (Diptera, Muscidae) on birds. Emu 106.
Dvorak, M., Vargas, H., Fessl, B. and Tebbich, B. ( 2004). On the verge of extinction: a survey of the mangrove finch Cactospiza heliobates and its habitat on the Galápagos islands. Oryx 38, 19.
Ferrar, P. ( 1987). A Guide to the Breeding Habits and Immature Stages of Diptera Cyclorrhapha. Scandinavian Science Press, Leiden, The Netherlands.
Fessl, B., Couri, M. S. and Tebbich, S. ( 2001). Philornis downsi Dodge & Aitken, new to the Galápagos Islands (Diptera, Muscidae). Studia Dipterologica 8, 317322.
Fessl, B., Kleindorfer, S. and Tebbich, S. ( 2006). An experimental study on the effects of an introduced parasite in Darwin's finches. Biological Conservation 127, 5561.
Fessl, B. and Tebbich, S. ( 2002). Philornis downsi – a recently discovered parasite on the Galápagos archipelago – a threat for Darwin's finches? Ibis 144, 445451.
Gold, C. S. and Dahlsten, D. L. ( 1983). Effects of parasitic flies (Protocalliphora) on nestlings of mountain and chestnut-backed chickadees. Wilson Bulletin 95, 560572.
Grant, P. R. ( 1999). Ecology and Evolution of Darwin's Finches. 2nd Edn. Princeton University Press, Princeton, New Jersey.
Hector, D. P. ( 1984). Botfly (Diptera, Muscidae) parasitism of nestling aplomado falcons. Condor 84, 443444.
Kovach, A. G. B., Szasz, E. and Pilmayer, N. ( 1969). The mortality of various avian and mammalian species following blood loss. Acta Physiologica Academiae Scientarum Hungaricae 35, 109126.
Nores, A. I. ( 1995). Botfly ectoparasitism of the brown cacholote and the firewood gatherer. Wilson Bulletin 107, 734738.
Oniki, Y. ( 1983). Notes on fly (Muscidae) parasitism of nestlings of South American bids. Le Gerfaut 73, 281286.
Sabrosky, C. W., Bennett, G. F. and Withworth, T. L. ( 1989). Bird Blowflies (Protocalliphora) in North America (Diptera: Calliphoridae), with Notes on the Palaeartic Species. Smithonian Institution Press, Washington, D.C.
Skidmore, P. ( 1985). The Biology of the Muscidae of the World. Dr W. Junk Publishers, Dordrecht.
Snyder, N. F. R., Wiley, J. W. and Kepler, C. B. ( 1987). The Parrots of Luquillo: Natural History and Conservation of the Puerto Rican Parrot. Western Foundation of Vertebrate Zoology, Los Angeles, USA.
Sturkie, P. D. ( 1986). Body fluids: blood. In Avian Physiology ( ed. Sturkie, P. D.), pp. 102129. Springer Verlag, New York.
Teixeira, D. M. ( 1999). Myiasis caused by obligatory parasites Ib. General observations on the biology of species of the genus Philornis Meinert, 1890 (Diptera, Muscidae). In Myiasis in Man and Animals in the Neotropical Region ( ed. Guimarães, J. H. and Papavero, N.), pp. 7196. Editora Plêiade, São Paulo, Brasil.
Wiedenfeld, D. A., Jimenez, U. G., Fessl, B., Kleindorfer, S. and Valarezo, J. C. ( 2006). Distribution of the introduced parasitic fly Philornis downsi (Diptera, Muscidae) in the Galápagos Islands. Pacific Conservation Biology (in the Press).
Young, B. E. ( 1993). Effects of the parasitic botfly Philornis carinatus on nestling house wrens, Troglodytes aedon, in Costa Rica. Oecologia 93, 256262.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Parasitology
  • ISSN: 0031-1820
  • EISSN: 1469-8161
  • URL: /core/journals/parasitology
Please enter your name
Please enter a valid email address
Who would you like to send this to? *
×

Keywords

Metrics

Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed