First report of Heterorhabditis bacteriophora (Poinar, 1975) (Nematoda: Heterorhabditidae) isolated from the red palm weevil, Rhynchophorus ferrugineus (Oliver, 1790) (Coleoptera: Curculionidae) in Turkey E. Atakan 1 , I. H. Elekc ¸iog ˘ lu 1 , U. Go ¨zel 2 ,C ¸ . Gu ¨nes ¸ 2 and O. Yu ¨ ksel 3 1 C ¸ ukurova ¨ Universitesi Ziraat Faku¨ltesi Bitki Koruma Bo¨l¨ um¨ u, Adana (Turkey); e-mail: eatakan@mail.cu.edu.tr 2 C ¸ anakkale Onsekiz Mart ¨ Universitesi Ziraat Fak¨ ultesi Bitki Koruma Bo¨l¨ um¨ u, C ¸ anakkale (Turkey) 3 Adana B¨ uy¨ uks ¸ehir Belediyesi Park ve Bahc ¸eler M¨ ud¨ url¨ u˘ g¨ u, Adana (Turkey) Infestation levels of the red palm weevil, Rhynchophorus ferrugineus (Oliver, 1790) and its natural enemies on palm trees in recreation areas were investigated in the Adana province of Turkey in 2008. The trunks of dead palms were sampled for R. ferrugineus and for the presence of entomo- pathogenic nematodes. While 20% of Phoenix canariensis Hort. were found to be killed by R. ferrugineus, only 2 trees from other species, 1 Washingtonia filifera (L. Linden) and 1 Phoenix dactlylifera L., were killed. Only one species of entomopathogenic nematode, Heterorhabditis bacteriophora (Poinar, 1975) (Nematoda: Heterorhabditidae), was isolated from the R. ferrugineus specimens. Seasonal mortality rate in the total larval population (total 565 larval specimens) of R. ferrugineus was 69%. H. bacteriophora resulted in a significant mortality rate (80%) in the pupae population (total 314 pupal specimens). Overall, 70% of the total of 879 pre-adult specimens were found to be fatally infested by the attacks of this nematode. Heterorhabditis bacteriophora killed few adults, corresponding to 2% of the overall mortality rate. It is concluded that H. bacteriophora could be evaluated as a potential candidate for biological control of R. ferrugineus in the Mediterra- nean region. Introduction Red palm weevil, Rhynchophorus ferrugineus (Oliver, 1790) is a very harmful weevil species causing serious damage, particularly on date palm trees in the Gulf region (Cox, 1993; Abraham et al. , 1998) and the Middle-East (Cox, 1993; Kehat, 1999). The injury to palms is due to larval stages tunneling in the trunks which is clearly visible only after severe infection occurred. This creates serious problems in controlling the pest in date palms due to late detection of infestations of R. ferrugineus. Economic loss in the infested date palm plantations in Saudi Arabia have been esti- mated to be 200 million US dollars a year (Gardner, 1998). Yield loss in date palm crop by infestations of R. ferrugineus is very serious. Gush (1997) estimated infestations to cause a decrease in yield from 10 tonnes to 0.7 tonnes per ha. Rhynchophorus ferrugineus was reported for the first time on ornamental date palm trees, Phoenix dactylifera L. in Mersin prov- ince, Turkey in 2005 (Karut & Kazak, 2005). In 2007, destructive infestations of R. ferrugineus on the Canary Island date palm trees, P. canariensis Hort, also grown as an ornamental plants, occurred in Adana province, Turkey (Atakan & Yu ¨ksel, 2008). Recently, this insect pest has become widely distributed in date palms grown in parks and gardens over most parts of the Mediterranean and Aegean regions of Turkey within just 2 years of its first report. Information about the biology, ecology and impact of this pest species as well as its control by the various management tactics including biological control agents are reviewed in detail by Murphy & Briscoe (1999) and Ferry & Gomez (2002). Most laboratory and field studies deal with the use of chemical insec- ticides in pest management of the red palm weevil. Problems due to the widespread use of chemical insecticides encourage the development of alternative pest management tactics includ- ing use of biological control elements such as entomopathogenic nematodes. Entomopathogenic nematodes belonging to the genera, Steinernema and Heterorhabditis (Nematoda: Steinerne- matidae, Heterorhabditidae) are well known as promising bio-control agents of R. ferrugineus. Knowledge about infesta- tions of entomopathogenic nematodes on R. ferrugineus is well documented with some good results achieved in preventing pop- ulation increases of R. ferrugineus (Abbas & Hanonik, 1999; Abbas et al. , 2000; Hanonik et al. , 2000; Shamseldean, 2004). In Turkey, Heterorhabditis bacteriophora (Poinar, 1975) has been isolated from various insect species such as, larvae of black vine weevil, Otiorhynchus sulcatus (F.) and sugarcane weevil, Bothynoderes punctiventis Germ (Kepenekc ¸i et al. , 1999; Susurluk, 2008; Susurluk & Ehlers, 2008), and also from soil (Gu ¨nes¸, 2008). In Turkey, information about bio-ecology, natural enemies and pest management of this extremely harmful insect species is very limited. This study aimed to determine the pest status and natural enemies of R. ferrugineus after its introduction to Adana prov- ince in Turkey. ª 2009 The Authors. Journal compilation ª 2009 OEPP/EPPO, Bulletin OEPP/EPPO Bulletin 39, 189–193 189