Andricus mukaigawae ( Mukaigawa, 1913 )

Alazmah, Abdulfatah, 2022, First Record of the Oak Gall Wasp (Hymenoptera, Cynipidae) in Myanmar, Bulletin of the National Museum of Nature and Science. Series A, Zoology 48 (2), pp. 89-95 : 91-93

Andricus mukaigawae ( Mukaigawa, 1913)

Specimens examined. Myanmar (new record): 3 ˂˂, asexual generation, Tedim Township, Falam District , Chin State, gall collection and dissection: 21. XI. 2019, N. Tanaka et al. leg., host: Quercus griffithii .

Summary of taxonomic characteristics based only on a Myanmar specimen used for DNA extraction. Head brown, except for black areas around antennal rim, ventral margin of face, including clypeus, and occipital foramen; mandible brown, with black teeth; antenna dark brown, except for light brown scape, pedicel, and F1; palpi light brown. Mesosoma brown, except for black areas around anterolateral margin of mesoscutum, anteroadmedian and parapsidal signa, mesoscutal fovea, metascutellum, lateral propodeal carina, central propodeal area, subalar area, and carinae on metapleural area; legs brown, except for darker tarsal claws. Metasoma brown, except for darker dorsal surface, light brown hypopygium and black third valvula.

Head slightly narrower than mesosoma in dorsal view, rudely coriarious to finely colliculate, with dense setae. Ventral clypeal margin slightly incised medially. Facial strigae radiating from lateral clypeus obscure, reaching about half ways to eye margin. Subocular impression absent. Diameter of antennal rim 1.5 times as broad as distance between inner margins of rims, 1.3 times as broad as distance between lateral margin of antennal rim and inner margin of compound eye. Gena broadened behind eye. POL: OOL: LOL = 16: 11: 7. Antenna with 15 antennomeres; relative lengths of scape, pedicel, and F1–F13: 38, 20, 61, 50, 35, 32, 32, 25, 22, 22, 22, 20, 20, 20, 20; F12 and F13 fused, separated by obscure transverse furrow.

Mesosoma almost as long as high in lateral view, with dense setae, except for bared surface of anteroadmedian and parapsidal signa, scutellar fovea, subalar area, and central propodeal area. Pronotum rugose. Mesoscutum rudely coriarious to finely colliculate; base of each seta with or without small round depression; median mesoscutal line present only as slight impression at posterior margin of mesoscutum; notaulus percurrent. Scutellum rugose; bottom of scutellar fovea smooth. Mesopleuron coriarious; setae relatively sparse, except at mesopleural triangle. Propodeum with distinct lateral propodeal carina; central propodeal area smooth. Metatarsal claw strongly bent at apex; base expanded to pronounced and pointed tooth. Marginal cell of forewing open, 3.2 times as long as broad. R 1 not reaching wing margin. Length of forewing 5.2 mm, of hind tibia 1.7 mm.

Metasoma smooth; tergum II with dense setae anterolaterally. Projecting part of hypopygial spine 4.5 times as long as high in lateral view, 2.5 times as long as broad in ventral view; subapical setae long, reaching beyond apex of spine.

Variations within Myanmar material (n = 3). Length of forewing 5.1–5.3 mm. Length of hind tibia 1.6–1.7 mm. Marginal cell of forewing 3.2– 3.6 mm.

Remarks. In the present study, we recorded A. mukaigawae for the first time in Myanmar. Abe et al. (2012) recorded A. mukaigawae in northeastern India and regarded it as the first record of a gall wasp with a distribution from East Asia to the Indian subcontinent. Our finding of A. mukaigawae in Myanmar supports and expands on this contention. In both instances, A. mukaigawae was recorded from Q. griffithii , which is widely distributed in the Oriental region, including Myanmar, Thailand, Laos, and Vietnam ( Govaerts & Frodin 1998). This suggests that A. mukaigawae may have a wide distribution across East Asia, the Indian subcontinent, and the Indochinese Peninsula. Myanmar lies at the northwestern edge of the Indochinese Peninsula, most of which is in the Oriental region, but northern Myanmar is adjacent to the Palearctic region ( Udvardy, 1975; Morrone, 2015). Therefore, Myanmar is important in terms of the biogeographic connection between the Oriental and Palearctic regions inhabited by Asian Cynipidae .

Lithosaphonecrus mindatus , the only known cynipid species in Myanmar before this study, belongs to the tribe Synergini . Andricus mukaigawae belongs to the tribe Cynipini , which is known for inducing galls on oaks and their relatives, and is thus known as the oak gall wasp. Therefore, this is the first record of the oak gall wasp and the second record of the family Cynipidae in Myanmar. Both Cynipini and Synergini consist of herbivorous insects associated with oaks and their relatives of the family Fagaceae ( Ronquist et al., 2015; Buffington et al., 2020), and host plant diversity is important when estimating the species richness of herbivorous insects ( Lin et al., 2015). As approximately 80% of all known cynipid species belong to the two tribes ( Ronquist et al., 2015), the diversity of Fagaceae is important for cynipid diversity. Two species of Castanea , 15 of Castanopsis , 31 of Lithocarpus , and 33 of Quercus , which belong to Fagaceae , have been recorded in Myanmar ( Kress et al., 2003). In particular, the mountainous areas of the northern to northwestern ranges of Myanmar (Kachin, Sagaing, and Chin) are species-rich in oaks and their relatives; at least one species of Castanea , seven of Castanopsis , 17 of Lithocarpus , and 21 of Quercus have been recorded ( Kress et al., 2003). This suggests that further field surveys focusing on these areas will help uncover the species diversity of the Cynipidae in Myanmar.