So far, the thrips (Thysanoptera) fauna of Guadeloupe and Martinique is known to comprise 64 species in 45 genera (Bournier 1993, 1995; Mound & Marullo 1996; Michel et al. 2008; Michel & Ryckewaert 2014). Most of these species are found on spontaneous vegetation and are not of economic importance. But a limited number of thysanopteran species have been or still are crop pests. On banana Frankliniella parvula Hood causes occasionally damage of economic importance. Hercinothrips femoralis (Reuter) was an important pest but since the late 1990s its populations decreased and its importance has been substantially reduced. On the contrary, Elixothrips brevisetis (Bagnall), recorded for the first time in 1996, is now found regularly in the banana plantations and is considered to be a major pest. In recent years, the economic incidence of Chaetanaphothrips orchidii (Moulton) decreased considerably. This species is always present on the plants but very rarely observed. The importance of 2 other species of the same genus, C. leeuweni (Karny) and C. signipennis (Bagnall), cited as banana pests in the literature (Bournier 1984; Delattre & Torregrossa 1978; Simon 1990) is now negligible. With respect to vegetable and floral crops, Thrips palmi Karny, introduced to Guadeloupe and Martinique in 1985, was a very important pest of several crops (melon, cucumber, chili pepper and eggplant) (Denoyes et al. 1986; Etienne & Waetermeulen 1989; Etienne et al. 1990; Guyot 1988), but its populations decreased considerably during the past 15 years and its economic importance is now limited. Thrips tabaci Lindeman regularly causes damage to cultivated Alliaceae (onion, garlic and leek) particularly during periods without rain. Frankliniella occidentalis (Pergande) damaged Chrysanthemum and rose production in greenhouses over the years. It presence was linked to the importations of Chrysanthemum plants from Europe. Production of this floral crop has ceased and F. occidentalis, which did not acclimatize has virtually disappeared from the French West Indies. Since 2007 Holopothrips tabebuia Cabrera & Segarra has been a serious pest of ornamental trees of the genus Tabebuia, particularly T. heterophylla (Michel et al. 2008).

Regarding the parasitoids and predators of thrips, 2 species of Hymenoptera Trichogrammatidae (Delvare 1993), 6 species of Acari Phytoseiidae (Kreiter & Moraes 1997) and 1 species of Hemiptera Anthocoridae (Pluot-Sigwalt et al. 2009) were known from Guadeloupe.

This publication deals with the species of thrips, their ecology and their natural enemies in Guadeloupe and Martinique.

Materials and Methods

The list of thrips presented below includes all the species already mentioned from Guadeloupe and Martinique by several authors (Bournier 1993, 1995; Mound & Marullo 1996; Michel et al. 2008; Michel & Ryckewaert 2014) and the new records resulting from a survey carried out during more than 20 years. Thrips collecting was performed by visual observation or using a mouth-pooter (aspirator), sweep net or beating sheet. A Berlese funnel was used to collect thrips living in mosses. The parasitoids were obtained from rearing the host species. Predatory behavior was observed in natura. The natural enemies were identified by specialists cited in the text. The nomenclature adopted is available on the website ThripsWiki (2014).

During this survey, thrips were collected on numerous plant species. But, considering the definition of host plants given by Mound (2013) as well as the available information, we mention here only the plants on which thrips populations have been noticed — in some cases — with the presence of immature stages or thrips damage. The threshold we set to consider the thrips population as significant was 5 individuals collected on the same date on the same plant species in the same locality. The plants were identified using the Flora of Guadeloupe and Martinique (Fournet 2002).

Each specimen was mounted between a slide and cover slip, and all are kept in the CIRAD-CBGP collection, Montferrier-sur-Lez, France.

Results

Discussion

Most thysanopteran species reported from Guadeloupe and Martinique were already known from the Neotropical region and/or the U.S.A. However, 3 species have a different origin. Ceratothripoides brunneus was known from West Africa. Nesothrips minor is widely recorded from Mauritius and Reunion to India, Peninsular Malaysia, Thailand, Fiji and Hawaii (ThripsWiki 2014). Asprothrips bimaculatus most probably has been introduced from Asia but its origin remains unknown; Mirab-Balou collected it in China (pers. comm.).

Including the 28 species of Thysanoptera mentioned for the first time from Guadeloupe and Martinique, the thrips fauna of these French Over seas Departments now comprises 91 species in 59 genera. Among these species 57 are recorded only from Guadeloupe, 15 are recorded only from Martinique and 19 are recorded from both islands. Such a difference between the faunal compositions is probably a direct result of the more intensive surveys performed during a longer period in Guadeloupe than in Martinique.

Table 1.

Plants from which thrips have been collected (* = predators; D = feeding damage; L = larva; Pp = propupa; P = pupa; ♂/♂♂, ♀,♀ = low/high (at least 5 individuals) population of males and females.

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Until now only 9 species of natural enemies of thrips were known from Guadeloupe and no species was known from Martinique (Delvare 1993; Kreiter & Moraes 1997; Pluot-Sigwalt et al. 2009). The inventory presented above comprises 6 species of parasitoids and 17 species of predators of thrips including insects, mites and spiders, recorded for the first time from Guadeloupe and Martinique. Most of the observations related to thrips predation in Guadeloupe and Martinique concern Thrips palmi whose populations are often efficiently controlled by the joint actions of several beneficial species. Likewise the outbreaks of Gynaikothrips uzeli are also frequently limited by Thripastichus gentilei together with Montandoniola confusa.

The plants listed in Table 1 are plants from which thrips have been collected. They are not necessarily host-plants as defined by Mound (2013) because in most cases it is not known if thrips species reproduce on them. However, this list includes plant species on which thrips populations have been noticed with—in some cases—the presence of both sexes and/or immature stages and observation of feeding damage. Most of the plants in Table 1 are of economic importance, cover plants or weeds and the presence of thrips populations can be of significant interest, for instance in the framework of integrated pest management programs.

Generally speaking, the economic importance of thrips has changed considerably since the early 2000's. Some species previously considered as major pests are now of low economic importance. This change in status is probably a consequence, at least partly, of significant reduction of the use of pesticides, which has favored beneficials and field biodiversity in general. Competition or displacement between species is also another possibility, as H. femoralis and E. brevisetis for example. But, at the same time, the incidence of other species that damage crops and ornamental plants has persisted or increased. It follows from this that improving the knowledge of the thrips species associated with natural or anthropized ecosystems is of significant interest in implementing alternative cropping systems.