Annales de la Société Entomologique de France (1998) 34, 259-283

François Rivière, Jean-Marie Klein, Jacques Duval, Yves Sechan, Remi Thirel, Marc Faaruia and Léon Colombani (1998)
Écologie d´Aedes polynesiensis Marks, 1951 (Diptera : Culicidae) vecteur de la filariose de Bancroft. Il - Les terriers du crabe terrestre Cardisoma carnifex comme gites larvaires
[Ecology of Aedes (Stegomyia) polynesiensis Marks, 1951 (Diptera : Culicidae), mosquito vector of Bancroft filariasis. II. - Studies in land crab holes of Cardisoma carnifex Herbst]
Annales de la Société Entomologique de France 34 (3), 259-283
Abstract: In the Indo-Pacific region, holes of the land crab of the genus Cardisoma are very commun in coastal areas of main land, islands and atolls of the tropical countries. Relationships between ecology of the mosquito Aedes polynesiensis Marks, vector of human diseases, and the holes of Cardisoma carnifex (Herbst) have been investigated between 1980 and 1986 in Polynesia. The authors first studied egg laying behaviour of A. polynesiensis according to diameter and length of galleries. Then they describe population dynamics and life tables of larvae and pupae of mosquitoes in regards to various physico-chemical factors as hole morphology, water level and analysis, and associated fauna. Data on relationships between pupal production, local abundance of crab holes and life cycles, densities of adult populations of A. polynesiensis and Brancroft filariasis transmission, are collected throughout the different archipelagoes of Polynesia. The authors conclude that holes of C. carnifex constitute the more productive breeding site for A. polynesiensis in Polynesia. They contain always large volumes of water and physico-chemical conditions are generally optimal for good and fast larval development: a) crabs dig holes permanently, b) Aedes eggs hatch by overflowing throughout the whole year with phreatic sheet movements up and down according to rainfall and also with variations of level of coastal sea waters due to tides, winds, storm swells, c) temperature range, pH and dissolved oxygen contents, alimentary ressources with best values for immature development of mosquitoes, d) crab holes being everywhere numerous in depressions of soft soils of coasts where phreatic water lays less than 1,30 meters deep, e) crab holes galleries being good resting places for adults ecophases of mosquitoes. The only ecological limiting factors for A. polynesiensis biology in crab holes is water salinity if holes have beeen digged near the sea level and predation by the cyclopoid copepod Mesocyclops aspericornis Daday.
In Polynesia, control of filariasis is limited because of difficulties to control mosquitoes living in crab holes. Methods using very toxic products to kill crabs, have to be avoided : phreatic sheets form main fresh water reserves of coastal regions of higher islands and on atolls, larvae of land crabs are essential for tropical coastal sea-water food chains; adults of land crabs aerate and recycle organic materials in salinated terrestrial soils. The authors conclude that only two methods can be used to control bancroftian filariasis vectors : local destruction of suitable place for crab holes by filling in and raising up depressionnal areas and the introduction of predatory copepods like M. aspericornis in land crab water.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: French)

Research topic(s) for pests/diseases/weeds:
environment - cropping system/rotation
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Aedes polynesiensis		French Polynesia
Mesocyclops aspericornis (predator)	Aedes polynesiensis		French Polynesia