木蜂與公主蘭：探討泰國Sirindhornia monophylla的自然授粉

Carpenter Bees and the Orchid of a Princess: Natural Pollination of Sirindhornia monophylla in Thailand

本文研究了泰國西部Sirindhornia monophylla的授粉生物學。此種蘭花為可分泌花蜜、非自花授但自交親合的陸生蘭。在經過了120個工時的實驗觀察後，有三個花蘆蜂屬的物種被視為主要的授粉者，分別是Ceratinidia lieftincki、C. collusor和綠蘆蜂，雄性與雌性都有授粉的行為；何威布朗蜂則為次要的授粉者。花蘆蜂會將花粉置於前額，並在拜訪下一朵公主蘭時將花粉塊沾黏於其柱頭上。另外有三種花蘆蜂屬的授粉者雖然也會拜訪花朵，但由於這些被拜訪的花朵其花粉都被上一個授粉者給帶走，因此並沒有觀察到這三種花蘆蜂屬的授粉者帶走花粉塊的行為，這額外的三個物種分別是：C. accusator、C. chiangmaiensis和C. bryanti。本研究是首次對Sirindhornia屬物種的授粉研究，此屬下的三個物種都在泰國紅皮書名單中。

Research on the pollination of Sirindhornia monophylla (Collett & Hemsl.) H. A. Pedersen & Suksathan was carried out in W Thailand, 2010‒2012. The orchid is a nectariferous, non-autogamous and self-compatible terrestrial. During 120 man-hours of flower watching, three species of Ceratina were found to be the main pollinators, viz. C. (Ceratinidia) lieftincki van der Vecht, C. (C.) collusor Cockerell, C. (Pithitis) smaragdula (Fabricius), males and/or females. Braunsapis hewitti (Cameron) was a minor pollinator. Ceratina acquired pollinia on their forehead and in some cases they subsequently deposited massulae on the stigma of other S. monophylla flowers. Three further species, viz. Ceratina (Ceratinidia) accusator Cockerell, C. (C.) chiangmaiensis W., M. & L. and C. (C.) bryanti Cockerell, did not acquire pollinia; but in these cases all pollen in the visited flowers had already been removed by previous pollinators. Ceratina belongs to family Apidae, subfamily Xylocopinae, tribe Ceratinini, whereas Braunsapis belongs to tribe Allodapini. Fruit set was nearly 50%. This is the first detailed account on the pollination of a Sirindhornia species, a recently described genus with three species, all included in the Thai redlist.