Author
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PANTOJA, ALBERTO |
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FRANQUI, R - UNIV. OF PUERTO RICO |
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SALAZAR, A - UNIV. OF PUERTO RICO |
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Submitted to: Journal of Agriculture of the University of Puerto Rico
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 3/20/2007 Publication Date: 10/20/2007 Citation: Pantoja, A., Franqui, R.A., Salazar, A. 2007. Recovery of Plaesius javanus Erichson from plantains in Puerto Rico. Journal of Agriculture of the University of Puerto Rico. 91(3-4):215-217. Interpretive Summary: Technical Abstract: Plantains and bananas (Musa spp.) are the primary source of dietary carbohydrates, vitamins, and minerals for more than 400 million people in tropical and subtropical regions worldwide (McNicoll 1989). During 2002-2003 Puerto Rico produced 388 million plantain fruits with an estimated value of $54.51 million (Ortiz, 2001). Worldwide, the banana root weevil (BRW), Cosmopolites sordidus (Germar), is the most important insect pest of banana and plantain (Gold et al., 1998; Ostmark, 1968). The weevil has been implicated in the decline and disappearance of highland banana in central Uganda (Gold et al., 1998) and western Tanzania (Bosch et al., 1995). In Puerto Rico, C. sordidus is considered the most important pest of plantains and bananas (Román et al., 1982; Inglés and Rodriguez, 1989), limiting the development of a large-scale, commercial Musaceae industry. Larval damage affects plant growth and development, reduces bunch weight and quality and, in heavy infestations may cause the corm to snap at ground level before the bunch is ripe (Ndiege, 1991). Marketable yields may be reduced 25-90% worldwide (Gorenz, 1963) and up to 90% in the Caribbean basin (Román et al., 1982; Arleu & Neto, 1984). Although several strategies have been employed with various degrees of success for management of C. sordidus, characteristically, weevil control depends heavily on insecticide use to reduce the adult (Inglés & Rodríguez, 1989; Román et. al., 1982). The development of Integrated Pest Management (IPM) programs is dependent on the understanding of the biology, behavior, population dynamics, and natural enemies of the pest. Mortality factors are important in the interpretation of the effects of control methods on pest populations and damage; therefore knowledge on the presence of natural enemies is of importance in developing IPM programs. In spite of the economic importance and lack of effective insecticides for it control (Román et al., 1982; Inglés and Rodriguez, 1989), little is known about the natural enemies of C. sordidus in Puerto Rico. According to Ostmark (1974) only fifteen predators of the BRW have been reported worldwide. The use of predatory beetles, especially Plaesius javanus (Coleoptera: Histeridae) and Dactylosternus hydrophiloides (Coleoptera: Hydrophilidae), has not yielded promising results in the Pacific region (Ostmark, 1974; Waterhouse and Norris, 1987; Weddell, 1932). However, the introduction of these two predators was successful in controlling C.sordidus larvae in Fiji and Tahiti (Smith, 1982). The predatory beetle, P. javanus was introduced to Fiji, Samoa, Jamaica, Australia, Uganda, Tahiti, and Puerto Rico during 1913 to 1964 (Cruz and Segarra, 1992; Hyasin and Gold, 1994; Wolcott, 1948). Wolcott, (1948) reported that in captivity the adult histerids fed on both larvae and pupae. A release of P. javanus was in the Adjuntas region was documented by Wolcott (1948). However, no recovery studies have been conducted to establish its presence in Puerto Rico after the initial release (Cruz and Segarra, 1992). From April 1997 to April 1998 fifty plantain corms were collected from untreated plantains fields in Corozal and dissected to collect C. sordidus larvae. Corms were heavily infested by C. sordidus larvae, pupae, and adults. During the inspection of the corms, three adult P. javanus were collected and preserved in 70% alcohol. Two of the specimens were in the same corm. Specimens were identified by S. Medina-Gaud, Curator of the Museo de Entomología y Biodiversidad Tropical (MEBT) at the |
