An illustrated key to powder post beetles ( Coleoptera , Bostrichidae ) associated with rubberwood in Thailand , with new records and a checklist of species found in Southern Thailand

An illustrated key to seventeen species of Bostrichidae recorded in association with rubberwood in Th ailand is provided. A checklist is given of nine species infesting rubberwood sawn timber in sawmills in southern Th ailand, with information on distribution, host trees and biology. Th ree species are recorded for the fi rst time from Th ailand: Cephalotoma tonkinea Lesne, Lyctoxylon dentatum (Pascoe), and Minthea

An illustrated key to powder post beetles (Coleoptera, Bostrichidae) associated with rubberwood in Thailand, with new records and a checklist of species found in Southern Thailand Introduction Rubberwood (Hevea brasiliensis Muell.Arg.) is an environmentally friendly wood source, and is an important raw material for wood industries in South and Southeast Asian countries (Edwin and Pillai 2004, Hong 1996, Royal Forest Department of Th ailand 2005).It is a non-durable wood, extremely susceptible to staining fungi as well as insect attack due to its high starch content and low wood extractives (Akhter 2005, CIRAD 2003, Wong et al. 2005).Th e major insect pests of dried rubberwood sawn timber are powder post beetles belonging to the family Bostrichidae.Th ey are economically important beetles that can extensively damage dried and seasoned wood and wooden artifacts through the boring behavior of both adults and larvae (Akhter 2005, Creffi eld 1991, Gerberg 1957, Ivie 2002, Peters et al. 2002).In this paper we have followed the classifi cation of the most recently published catalogue of the Bostrichidae (Borowski and Węgrzynowicz 2007).Adults and larvae of most subfamilies of Bostrichidae both bore into and feed on the wood.One exception is the members of the subfamily Lyctinae in which only the larvae are wood feeders (Halperin andGeis 1999, Liu et al. 2008b).In Th ailand, Kamnerdratana et al. (1970) reported two powder post beetles, Sinoxylon anale Lesne and S. crassum Lesne, infesting rubber logs in southern Th ailand.Hutacharern and Tubtim (1995) in their checklist of forest insect pests of Th ailand, added 10 species associated with Hevea brasiliensis: Apoleon edax Gorham, Dinoderus spp., Heterobostrychus aequalis (Waterhouse), H. pileatus Lesne, H. unicornis (Waterhouse), Sinoxylon rufi corne Fåhraeus, Xylothrips fl avipes (Illiger), Lyctus africanus Lesne, Lyctus sp. and Minthea rugicollis (Walker).In this paper, we provide an illustrated key to all 17 species of Bostrichidae that have been recorded in association with rubberwood in Th ailand.We provide a checklist with notes on distribution and host plants of nine species of bostrichids that infested rubberwood sawn timber in sawmills in southern Th ailand, seven of which are newly reported from rubberwood, and three of which are newly recorded from Th ailand.

1.
Head directed to the front, fully visible from above .Body strongly shining.Punctures on pronotum and elytra less dense, separated by much more than their own diameter.Pronotum with oblique, elongate rugulosities at sides near posterior angles (Fig. 4a).Antenna (Fig. 12i Intercoxal process of fi rst abdominal ventrite forming a vertical lamina (Fig. 10b).Metepisternum narrowed posteriorly so that metepimeron nearly touches metasternum (Xyloperthini) .. Teeth on elytral declivity contiguous, inserted on sutural interstriae, laterally compressed, triangular, with pointed tips, a prominent costa present on the lateral margin of the declivity at the same level, and another weaker costa more apically and laterally (Fig. 9c).Larger species, 7-9 mm long .Elytral disc angularly separated from declivity; elytral margins carinate below, costate above, not rounded; submarginal carina along lateral margin of elytra curving dorsally at its posterior end to join carina forming lower margin of elytral declivity.Punctures of elytral disc increasing in size posteriorly, very coarse at upper margin of declivity.(Fig. 9a, d Posterior angles of pronotum lobed and projecting.Posterior part of pronotum with large, deep punctures.Male with two tubercles on elytral declivity, the outer forming an elongate costa, the inner forming a strong, pointed tooth directed inwardly and upwardly (Fig. 7c); frons without a nearly impunctate shining area in middle.Female without strong tubercles on elytral declivity, emargination between anterior angles of pronotum broad, extending about three quarters of distance between eyes; frons without a tuft of hairs.(Fig. 7

Checklist of species associated with rubberwood in southern Thailand
In the checklist, a dagger ( †) indicates a species newly recorded from Th ailand, an asterisk (*) indicates a dominant pest species of rubberwood sawn timber in southern Th ailand.Records of the Th ai provinces in which species have been collected include unpublished data from specimens in the collections of R. A. Beaver and W. Distribution.Very widely distributed in the Oriental region, from India and China to the Indonesian archipelago and New Guinea.Introduced into Africa (including Madagascar), Australia, Europe, Hawai'i, Mariana Is., New Caledonia, New Zealand, North America, South Africa and Venezuela, and established in some of these countries (Binda and Joly 1991, Borowski and Węgrzynowicz 2007, Chûjo 1958, Majka 2007, Starr and Starr 2003).Recorded in Th ailand from the provinces of Chantaburi, Chiangmai, Chonburi, Chumporn, Krabi, Nakhon Ratchasima, Phang Nga, Rayong, Samut Songkhram, Satun, Songkla and Trang.Host Plants.Polyphagous attacking almost any woody plant in suitable condition.Recorded in Th ailand from Bambusa arundinacea, Bombax anceps, Cassia fi stula, Cedrela angustifolia, C. odorata, Dendrocalamus strictus, Dipterocarpus tuberculatus, Koompassia malaccensis, Lagerstroemia calyculata, Parashorea stellata, Pterocarpus macrocarpus, Toona ciliata, T. sureni (Hutacharern and Tubtim 1995).Previously recorded from Hevea brasiliensis by Hussein (1981) in Malaysia, and Mathew (1982) in India.
Biology.Th e biology of the species is discussed by Beeson and Bhatia (1937), Ho (1995a) and Woodruff and Fasulo (2006).Th e species breeds not only in logs, but in planks, furniture and plywood.However, it is confi ned to wood containing starch, and the heartwood is not usually aff ected.In India it has an annual life cycle.Figures given by Ho (1995a) suggest that two generations a year may occur in Malaysia.(Hutacharern and Tubtim 1995).Previously recorded from Hevea brasiliensis in Th ailand by Kamnerdratana et al. (1970), and by Hussein (1981) in Malaysia.
Biology.Th e biology of the species is discussed by Beeson and Bhatia (1937) and Liu et al. (2008b).Th e life cycle may take only three months, but can extend over a period of years.Th e average life cycle in rubber wood is 84 days at room temperature (27.30 ± 0.67°C) (W.Sittichaya unpublished).Th e larval galleries do not normally penetrate the heartwood.Th e adults sometimes bore into living shoots to feed or hibernate, and may cause damage to young saplings.However, they do not breed there.
Sinoxylon unidentatum (F.) †* Fig. 9b, e Distribution.An Oriental species that has become almost cosmopolitan as a result of transport by man in infested timber.Th e species has usually been recorded under the name of its synonym, Sinoxylon conigerum Gerstaecker (Borowski and Węgrzynowicz 2007).Recorded in Th ailand from the provinces: Chiangmai, Chonburi, Chumporn, Rayong, Samut Songkram, Satun, Songkla, Phattalung, Nakorn Sri Th ammarat, Surat Th ani, Phang Nga, Krabi and Trang Hosts.Apparently polyphagous attacking almost any woody plant in suitable condition.No hosts appear to have been recorded in Th ailand.Previously recorded from Hevea brasiliensis in Malaysia by Tomimura (1993).Hevea brasiliensis is given as a major host by CAB International (2004).
Biology.Th e biology of the species appears not to have been studied in detail, but is likely to resemble that of other species of Sinoxylon (Beeson andBhatia 1937, Liu et al. 2008b).A summary of what is known is given in CAB International (2004 as S. conigerum).Tomimura (1993) showed that the adults and larvae reduced the starch content of rubber wood, but not the levels of holocellulose and lignin.

Tribe Xyloperthini
Xylopsocus capucinus (F.) Fig. 10 Distribution.throughout South and Southeast Asia from India to the Indonesian archipelago, New Guinea, New Caledonia, and the Melanesian islands; Introduced into Africa, South America, USA Recorded in Th ailand from the provinces Chaiyaphum, Chiangmai, Krabi, Nakorn Sri Th ammarat, Phattalung, Phang Nga, Satun, Songkla, Surat Th ani and Trang.
Hosts.Apparently polyphagous attacking almost any woody plant in suitable condition.Previously recorded from Hevea brasiliensis in Malaysia by Miller (1934) and Hussein (1981).No hosts appear to have been recorded previously in Th ailand.
Biology.Beeson and Bhatia (1937) note that in northern India, the adults emerge mainly between May and November, with a annual life cycle, that may be extended for a further one or occasionally two years.Woodruff et al. (2005) give further information from the published literature.Th e biology of the closely related species, Xylopsocus bicuspis Lesne is described by Liu et al. (2008a).Hosts.As with almost all bostrichids, this is a polyphagous species.Previously recorded from Hevea brasiliensis in Malaysia by Hussein (1981).In Th ailand recorded from Dipterocarpus sp., Hopea odorata, Mangifera indica (Kamnerdratana et al. 1970) and Choerospondias axillaris (Hutacharern and Tabtim 1995).
Biology.Beeson and Bhatia (1937) note that the species completes two generations a year in northern India, and occasionally a third generation.Th e minimum life cycle is about three months.Th ey found peak emergence occurred in April.Hosts.Th e species breeds primarily in bamboos (e.g.Bambusa, Dendrocalamus, Phyllostachys).It occasionally makes tunnels in the wood of trees, but rarely breeds there.In Th ailand, the species is recorded from Bambusa arundinacea, Dendrocalamus giganteus, D. hamiltonii, D. strictus, Gigantochloa nigrociliata, Th yrsostachys oliveri (Hutacharern and Tabtim 1995).All of these species are bamboos.Th ere appear to be no previous records from Hevea brasiliensis.
Biology.Observations made by the fi rst author show that the species was breeding in rubberwood (W.Sittichaya unpublished).Numerous young adults were obtained from rubberwood logs kept in breeding cages, and from dissected logs.Studies of the biology of this and related species of Dinoderus are described by Lesne (1924), Beeson and Bhatia (1937) and Liu et al. (2008b).Th e length of the life cycle depends on temperature.In the tropics, breeding continues throughout the year, and there can be six to seven generations in a year, but usually there are two to four.
Biology.Th e biology of the species does not seem to have been studied in detail, but is assumed to be similar to Minthea rugicollis (Walker) and other Lyctini (Beeson and Bhatia 1937, Lesne 1924, Liu et al. 2008b).Only the larvae are xylophagous.Th e life cycle takes 2-6 months depending on the starch and moisture content of the wood as well as temperature.Th e average life span of adults is 77 days (Ho 1995b).
Hosts.None recorded.Th e species was obtained from debarked logs of Hevea brasiliensis.
Biology.Adults were captured from logs infested by Heterobostrychus aequalis, Sinoxylon anale and S.unidentatum.Only 2 -3 specimens were obtained from each infested log.Observations by Lesne (1932) on species of the closely related genus Lyctoderma, indicate that the adult lives in the adult gallery of larger bostrichids, where its small size and strongly fl attened form enable it to slip beneath the larger beetle and avoid being crushed against the walls of the gallery.Th e adult feeds on small particles of wood in the gallery of the larger species.It can thus be classed as a commensal of other bostrichids.Th e larvae are presumed to be xylophagous.

Figure 1 .
Figure 1.Lyctus africanus Lesne, 1907.Dorsal view a lateral view of head b and frontal view of head c.