HALLE (SAALE ) 2012 MITT . DTSCH . GES . ALL G . AN G EW . ENT . 18 TIGER-wasps – A preliminary review of the apoid wasp diversity in Thailand (Hymenoptera: Apoidea) Volker Lohrmann, Lukas Kirschey, Stefanie Krause, Meike Schulze & Michael Ohl Museum für Naturkunde Berlin Abstract: Thailand is one of the countries in Southeast Asia with a remarkably rich but fragmentarily known insect diversity. Since its beginning in 2006, the Thailand Inventory Group for Entomological Research, known as the TIGER-group, has collected about 5,400 specimens of apoid wasps. Here we compare the preliminary results of our taxonomic analysis of this large sample with the published species/genus diversity of Thailand. Within the newly collected material, we recorded 57 genera of apoid wasps, with the following 22 genera listed for the first time for Thailand:Ampulicidae: Trirogma; Sphecidae sensu stricto: Chlorion; Crabronidae: Alyssontinae: Astata, Dryudella; Bembicinae: Alysson, Argogorytes, Brachystegus, Gorytes, Harpactus, Synnevrus; Crabroninae: Entomognathus, Lestica, Miscophus, Nitela, Paranysson, Prosopigastra, Solierella; Pemphredoninae: Ammoplanellus, Diodontus, Mimesa, Pemphredon and Psen. Key words: Aculeata, Sphecidae, Crabronidae, Ampulicidae, apoid wasp, digger wasp, Southeast Asia, Oriental region, Thailand, taxonomy, diversity, biogeography. Volker Lohrmann, Lukas Kirschey, Stefanie Krause, Meike Schulze & Michael Ohl, Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung an der Humboldt-Universität zu Berlin, Abteilung Forschung, Invalidenstr. 43, D-10115 Berlin; E-Mail: [email protected], [email protected], [email protected], [email protected], [email protected] Introduction Within aculeate Hymenoptera, the ‘apoid’ or ‘sphecid’ wasps (= Apoidea excluding bees) are one of the largest groups of solitary wasps currently comprising 9,666 species in 268 genera (PULAWSKI 2011). Apart from the Arctic and Antarctic regions, apoid wasps, which are remarkably diverse in terms of their morphology, ecology and life strategies, can be found throughout the world, with their highest diversity in the semiarid and arid regions. However, data enabling a substantial comparison of the apoid wasp diversity of the tropic and the semiarid/arid regions of the world are sparse. Although the aculeate wasp diversity of several parts of Southeast Asia has been intensively studied (e.g. by C. T. BIN G HA M [*1848 – †1908]: ‘British India’; K. V. KRO mb EIN [*1912 – †2005]: Ceylon; K. TSUNEKI [*1908 – †1994]: eastern Oriental and Palaearctic region), the larger part of the Oriental region has not been systematically investigated. From 2006 to 2009 the Thailand Inventory Group for Entomological Research (TIGER; http://sharkeylab.org/tiger/) has conducted a survey of the insects/ arthropods of Thailand with sampling points in 24 national parks all over the country. In terms of apoid wasps, the TIGER-project resulted in over 5,400 specimens which are the base of our study. Material and Methods Specimens have been pinned, labelled and subsequently identified to genus level. With respect to the Stigmina, which were identified using the key by FINNA M ORE (1995), genera have been identified with BOHART & MENKE ’s (1976) keys. Specimens will be deposited in the Queen Sirikit Botanic Garden, Chiang Mai (Thailand) and the Museum für Naturkunde, Berlin (Germany). In addition to our investigations on the newly collected specimens, an exhaustive literature search was done to estimate the number of genera and species recorded for this geographical region. The search 31 MITT . DTSCH . GES . ALL G . AN G EW . ENT . 18 HALLE (SAALE ) 2012 was done for a) Thailand and b) Greater Thailand (= Thailand including adjacent countries (Cambodia, Laos, Malaysia, Myanmar and Vietnam) as well as Brunei, Singapore and parts of Indonesia (Borneo and Sumatra)). Results As a result of our literature search, we have tracked 155 species which have been explicitly recorded from Thailand, representing 43 genera (see list of genera in Table 1), but more than 500 species in 55 genera from Greater Thailand. Of the 43 genera reported from Thailand, only 35 genera have been found in the TIGER-samples so far (Table 1 and Figure 1). However, additional 22 genera (Table 1; bold letters) found by us have not been reported from Thailand to date. This increases the total number of genera recorded from Thailand by 51%. Table 1: Checklist of apoid wasp genera reported from Thailand: based on literature (= Lit.) and the TIGER-samples (= Tiger); genera printed in bold are reported for the first time for Thailand; the classification followsP ULAWSKI (2011). Family/Subfamily/Genus Lit. Tiger Family/Subfamily/Genus Lit. Tiger Ampulicidae Crabroninae (cont.) Ampulicinae Eupliloides + - Ampulex + + Gastrosericus + + Trirogma - + Hingstoniola + - Dolichurinae Larra + + Dolichurus + + Lestica - + Sphecidae s. str. Liris + + Ammophilinae Lyroda + + Ammophila + + Miscophus - + Chloriontinae Nitela - + Chlorion - + Odontocrabro + - Sceliphrinae Oxybelus + + Chalybion + + Paranysson - + Sceliphron + + Pison + + Sphecinae Piyuma + + Isodontia + + Piyumoides + - Prionyx + - Prosopigastra - + Sphex + + Rhopalum + + Crabronidae Solierella - + Astatinae Tachysphex + + Astata - + Tachytes + + Dryudella - + Trypoxylon + + Bembicinae Vechtia + + Alysson - + Pemphredoninae Ammatomus + + Ammoplanellus - + Argogorytes - + Ammoplanus + + Bembecinus + + Carinostigmus + + Bembix + - Diodontus - + Brachystegus - + Mimesa - + Gorytes - + Pemphredon - + Harpactus - + Polemistus + + Hoplisoides + + Psen - + Lestiphorus + - Psenulus + + Nysson + + Spilomena + + Synnevrus - + Stigmus + + Crabroninae Tzustigmus + - Crossocerus + + Philanthinae Dasyproctus + + Cerceris + + Ectemnius + + Philanthus + + Encopognathus + + Entomognathus - + 32 HALLE (SAALE ) 2012 MITT . DTSCH . GES . ALL G . AN G EW . ENT . 18 Fig. 1: Generic diversity by subfamily with a comparison of congruency between literature- and TIGER-records (total numbers of genera are recorded above columns; numbers below columns indicate genera not recorded for the region before). Abbreviations correspond to subfamily names in Table 1. Checkered: records for Greater Thailand; Grey: TIGER-samples compared with the records of Greater Thailand; White: records for Thailand; Black: TIGER-samples compared with the records of Thailand. Fig. 2: Proportion of the four most abundant genera of the TIGER-samples (in terms of specimen numbers) with the number of species recorded from Greater Thailand in the past given in each slice. Grey: Trypoxylon; vertical stripes: Liris; horizontal stripes: Psenulus; white: Tachytes; black: remaining genera. Discussion and Outlook The Thai species diversity of apoid wasps is rather unevenly divided between the genera. Numerous genera are represented by a single species each, whereas a few markedly diverse genera comprise the majority of species (Figure 2). Highly diverse genera like Trypoxylon (about 99 species known from the greater area) and Psenulus (about 50 species known) are not only diverse in terms of species numbers, but are also markedly abundant in the TIGER-material (Figure 2). As an example, about 28% (more than 1,500 specimens; Figure 2) of the TIGER-specimens studied belong in Trypoxylon, representing a still unknown number of species. Not surprisingly, the portion of stem-nesting species among the TIGER- material is markedly large, as is well known from other tropical habitats. This bias towards stem-nesting is also reflected in the small average body size, although this might partially be the result of the collecting method, since smaller species are more likely collected by Malaise traps than large species. We also found a large number of hitherto undescribed species. Such new species are more common in genera with smaller species, which are more likely to be overlooked without the use of Malaise traps or other mass collecting methods (e.g. Alysson, Lyroda or Gorytes). However, even among the largest sphecids from Thailand, which are members of the genus Isodontia, we found undescribed species. As far as we can tell now, the total number of species and genera among the TIGER-material will approach the total number of apoid wasp species and genera already recorded from Thailand, although we predict significant differences in the specific species composition. Although there are still many taxonomic problems to be solved, particularly in the highly diverse genera like Trypoxylon or Psenulus, it already became clear that the TIGER-project significantly contributes to the knowledge of the wasp diversity in Thailand, with many implications for Southeast Asia. 33 MITT . DTSCH . GES . ALL G . AN G EW . ENT . 18 HALLE (SAALE ) 2012 Acknowledgements We thank Prof. Dr. Michael Sharkey (University of Kentucky) for providing the apoid wasps collected by the TIGER-team with financial support by the US-National Science Foundation (Grant Number: DEB- 0542864). Ronald Blanke, Vivien Firtzlaff and Philipp Vogt (all Berlin) kindly helped with mounting, labelling and pre-sorting the specimens. VL would like to thank the “Studienstiftung des deutschen Volkes” for financial support. Literature BOHART , R. M. & MENKE , A. S. (1976): Sphecid wasps of the world. A generic revision. – University of California Press; Berkeley, Los Angeles, London. ix + 695 pp. FINNA M ORE , A. T. (1995): Revision of the world genera of the subtribe Stigmina (Hymenoptera: Apoidea: Sphecidae: Pemphredoninae), Part 1. – Journal of Hymenoptera Research 4: 204-284. PULAWSKI , W. J. (2011): Catalog of Sphecidae sensu lato. (last access in April 2011). http://research.calacademy.org/ent/catalog_sphecidae/1623 34.