Vespa tropica ( Linnaeus, 1758 )

Lee, John X. Q., Soh, Zestin W. W., Chui, Shao Xiong, Leong, Andrea Q. E., Ong, Christabel N. Y. & Ascher, John S., 2023, Hornets (Vespidae: Vespinae) of Singapore: ecology, identification, and national conservation assessment, Raffles Bulletin of Zoology 71, pp. 457-477 : 469-472

Vespa tropica ( Linnaeus, 1758) Greater Banded Hornet

( Figs. 4B , 11 )

Sphex tropica Linnaeus, 1758 . Systema Naturae, Tenth Edition, 1:571 - “in Indiis” (holotype female Uppsala).

Vespa tropica leefmansi van der Vecht, 1957 , Zoologische Verhandelingen 34:19, female, male - [ Indonesia] “Solok, Padang, Sumatra ” (holotype female Leiden ); also from Vietnam; Thailand ; Malaysia; and other islands in Indonesia.

Global distribution. Afghanistan; Bangladesh; Bhutan; Cambodia; China (mainland, Hong Kong, Macao); India (including Andaman and Nicobar Islands); Indonesia (Greater and Lesser Sundas, Kalimantan, Wallacea); Laos; Malaysia (Peninsular Malaysia, Sabah, Sarawak); Myanmar; Nepal; Pakistan; Papa New Guinea (including New Britain); Philippines; Singapore; Sri Lanka; Thailand; Timor Leste; Vietnam. Also Guam (introduced).

Diagnosis. Usually larger in size than V. affinis . Workers average 23–30 mm, males average 26–28 mm and queens average 30–34 mm, though unusually large individuals may approach 40 mm in total body length. Very similar in overall colour to V. affinis but the orange banding on the metasoma is confined to only the second metasomal segment and is broadly black basally (with this black area often forming a shallow u-shaped indentation) ( Fig. 11A ). Vespa tropica has projecting paired lobes on the clypeus contrasting with the broad lobes of V. affinis . The forewings of V. tropica are dark but become lighter orangish apically (more strongly contrasting than in V. affinis ; this character requires experience to assess especially in light of differing appearance of folded and unfolded wings). Vespa tropica is the local hornet most likely to be confused with a local paper wasp, P. sagittarius , which is relatively large and has a very similar colour pattern, as both species are black with a yellow or orange second tergum and with similarly dark-based and apically orange wings. In addition to the structural characters and more slender and long-legged body form (with gradually tapering first tergum) of Polistinae , the band on the second tergum of P. sagittarius is lighter yellow as opposed to darker yellow or orange in V. tropica . In the Polistes the second tergum may be entirely yellow, and if there is a blackened area at the base it is not in the u-shaped form found in V. tropica .

Materials examined. Singapore: 1 female (ZRC), coll. unknown, no date ; 1 female (ZRC), coll. unknown, no date, ex. Pseuderanthemum sp. ; 1 female (ZRC), coll. K. M. Foong, 23 August 1968; 1 female (ZRC), coll. unknown, 18 November 1980, ex. Baphia sp. ; 1 female (ZRC), coll. unknown, 18 November 1980; 1 female (ZRC), coll. unknown, 2 January 1981, ex. Baphia nitida ; 1 female (ZRC), coll. P. Chen, 2 January 1981, ex. Codiaeum sp. ; 1 female (ZRC), coll. unknown, 16 February 1982, ex. Canna sp. ; 1 female (IDL), coll. unknown, 8 August 1998; 1 female (ZRC), coll. unknown, 18 July 2001; 1 female (ZRC), coll. unknown, 18 July 2012; 1 female (ZRC), Ang Mo Kio , coll. unknown, 13 January 2011 ; 1 queen (IDL), Ang Mo Kio Town Garden West, coll. Z. W. W. Soh, EJYS, JSA, 22 August 2014 ; Bedok : 1 female (ZRC), coll. unknown, no date; 1 female (IDL), coll. H. Zhang, 21 October 2016; 1 female (ZRC), Bukit Batok Nature Park , coll. D. Tan, 9 December 2013 ; Bukit Timah Nature Reserve : female (ZRC), coll. unknown, no date ; 1 female (ZRC), coll. unknown, 9 April 1989; 1 female (ZRC), coll. Mangrove Insect Project, 16 August 2016; 1 female (IDL), coll. N. Choudhary, 10 September 2018; 1 female (IDL), Bukit Timah Nature Reserve , PUB Turf Area, coll. A. Q. E. Leong, R. Y. Y. Lee, SXC, 21 December 2017 ; 1 female (IDL), Bukit Timah Nature Reserve , Taban Loop, coll. R. Y. Y. Lee, A. Q. E. Leong, 26 January 2017 ; 1 female (IDL), Buona Vista , coll. R. J. Y. Lim, 18 September 2016 ; 1 female (IDL), Cho Chu Kang , coll. S. R. Logaeswary, 23 October 2017 ; Clementi : 1 female (ZRC), coll. A. Foong, 12 August 2000; 1 female (ZRC), coll. K. Wong, 29 March 2012; 1 female (IDL), Coney Island , coll. unknown, 27 October 2016 ; 1 female (ZRC), Fort Canning Park , coll. unknown, no date; Holland Woods : 1 female (IDL), coll. S. Y. Kuah, 19 September 2017; 1 female (IDL), HortPark , coll. J. Clerbois, 8 November 2017 , ex. Cordyline sp. ; Kent Ridge Park: 2 females (ZRC), coll. unknown, 15 October 2014; 1 female (IDL), coll. W. X. Bok, 6 September 2017; 1 female (ZRC), Lentor Street , coll. K. Inoue, 21 September 2014 ; 1 female (ZRC), Lower Peirce , coll. S. K. Yeo, 13 May 1992 ; 1 female (ZRC), Mandai , coll. DHM, 20 November 1967 ; 1 female (ZRC), Nee Soon Swamp Forest , coll. Mangrove Insect Project, 3 December 2014 ; 1 queen (IDL), NUS, Eusoff Hall , coll. W. Hidayat, 14 October 2016 ; 1 female (IDL), NUS, Faculty of Science , coll. N. C. K. Hui, 13 October 2017 ; NUS, Lower Kent Ridge Road : 1 female (ZRC), coll. unknown, 15 September 1999; 1 female (IDL), coll. J. Y. Chan, 4 September 2015; 1 female (IDL), NUS, Raffles Hall , coll. B. Lum, 8 October 2015 ; NUS, Ridge View Residences: 1 female (IDL), coll. S. Ananthanarayanan, C. Nghai, 24 August 2016; 1 female (IDL), coll. Y. Jen, 13 September 2018; 1 female (IDL), coll. I. A. Bialy, 14 September 2018; 2 females (IDL), coll. Y. J. Tang, 14 to 15 September 2018; 1 female (IDL),

Fig. 12. Singaporean distribution of Vespa tropica .

NUS, Sheares Hall, coll. B. T. M. Lim, 22 October 2015; 1 female (ZRC), coll. B. M. J. Ho, 8 September 2014; 1 female (IDL), Pulau Ubin , coll. JSA, SXC, B. M. J. Ho, D. Zhang, 11 April 2018 ; 3 females (ZRC), Pulau Ubin , Chek Jawa Mangroves, coll. Mangrove Insect Project, 14 April to 24 August 2016 ; 1 female (ZRC), Queen Astrid Park , coll. Y. H. Koo, 29 August 1988 ; 1 queen, 1 worker (IDL), Sallim Road , coll. J. T. W. Tan, 4 April 2014 ; 1 female (ZRC), Seletar Hills Estate , coll. DHM, 23 March 1995 ; 1 female (IDL), Serangoon , coll. M. Goh, D. Fung, 6 November 2018 ; 1 female (IDL), Small Sisters’ Island, coll. unknown, 15 January 2017 , ex. Coccoloba uvifera ; Sungei Buloh Wetland Reserve : 1 female (ZRC), coll. K. L. Yeo, 26 July 2006; 1 female (ZRC), coll. Mangrove Insect Project, 17 July 2013; 1 female (IDL), Tampines Central Park , coll. Z. Y. Tan, 19 September 2015 ; 1 queen (IDL), Ulu Pandan Rd. , coll. S. Yau, 5 Feb 2019 .

Remarks. A common and widespread species in Singapore, thus justifying Least Concern status (see below). It is known to be a specialist predator on the brood of social wasps in the subfamily Polistinae ( Matsuura, 1991) ( Fig. 11B ), which in Singapore include species of Polistes , Parapolybia and Ropalidia , and also the Stenogastrinae ( Matsuura, 1991; Turillazzi, 1991; Landi et. al., 2002). However, in Thailand, it has been recorded to slaughter and occupy commercial honey bee ( Apis mellifera ) hives in the same way as the giant hornets Vespa mandarinia Smith, 1852 , and Vespa soror du Buysson, 1905 ( Burgett & Akratanakul, 1982; Ritter & Akratanakul, 2006). The first author has observed and photographed an individual removing and preying on a larva of a mud-dauber wasp ( Sceliphron javanum ) after scraping at the mud with its mandibles for nearly 10 minutes to break into the nest ( Fig. 11C ), and also observed individuals attempting to attack a nest of the dwarf honey bee Apis andreniformis .

This species usually builds nests in concealed spaces. The most common nesting site is an underground cavity; wasps excavate soil to enlarge the cavity as the nest grows and deposit the excavated soil as roughly spherical pellets outside the nest entrance ( Fig. 11D ). Other cavities such as tree hollows and crevices between rocks are also favoured. Occasionally, a nest may be built inside a building, usually in the shelter of a box or other object, and rarely exposed on the ceiling of a building or structure. A very small number of nests built in exposed locations in trees have been recorded in Singapore ( Chan, 1972; pers. obs. by the first author) and Tioman Island ( Martin, 1995). Unlike the nests of V. affinis and V. analis , V. tropica nests have an incomplete, often bowl-shaped envelope that covers only the sides of the combs and leaves the bottom exposed ( Fig. 11E ). Instead of an imbricate structure with scalloped markings, the envelope is thin and laminar in nature, comprising large broad sheets laid in a largely horizontal manner. Matsuura & Yamane (1990) noted that this species in Sumatra built nests of up to 5,000 to 6,000 cells and colonies produced 500 to 1,000 new queens. Polygyny has been recorded for this species ( Matsuura & Yamane, 1984; Banu & Huda, 1989; Matsuura, 1991; pers. obs.), with nests in Sumatra having between two and six queens ( Matsuura & Yamane, 1984). However, not enough colonies have been studied in tropical Southeast Asia to determine whether single or multiple-queen colonies are more prevalent regionally. A nest built in on a basket stored in a cardboard box which was still in the early stages of development collected by the first author in 2012 contained three queens and an estimated 50– 60 workers ( Fig. 11F ), while a smaller nest collected in 2009 had only one queen and fewer than ten workers.

Floral associations. Baphia nitida ; Baphia sp. ; Calliandra haematocephala ; Calliandra tergemina ; Callistemon citrinus ; Canna sp. ; Cocos nucifera ; Codiaeum sp. ; Cordyline sp. ; Malvaviscus arboreus ; Mangifera indica ; Melaleuca viminalis ; Musa sp. ; Nephelium lappaceum ; Pseuderanthemum sp. ; Roystonea regia ; Xanthostemon chrysanthus

Figures

Fig. 4. Comparison of the clypeus of Vespa affinis (A) and V. tropica (B). The white arrows point to the clypeal apices, bordering a medial emargination, which are semi-circular protuberances in V. affinis but more strongly produced as triangular projections in V. tropica. (Photographs: John Lee).

Fig. 11. Vespa tropica in Singapore. A, dorsal view of a worker; B, worker feeding on larvae from the nest of a paper wasp (Ropalidia jacobsoni); C, worker feeding on larvae from the nest of a mud-dauber wasp (Sceliphron javanum); D, nest in an underground cavity; E, lateral view of a nest showing the bowl-shaped envelope; E: nest constructed in baskets. (Photographs: John Lee and Jit-Leang Foo).