Hans Bänziger

Bees (Hymenoptera: Apidae) That Drink Human Tears

Abstract Lisotrigona cacciae, L. furva and Pariotrigona klossi (Meliponini, Apidae) workers drank lachrymation (tears) from human eyes in more than 262 naturally-occurred cases at 10 sites in N and S Thailand during all months of the year. A few visits were also seen to eyes of zebu and dog, indicating a probable broad mammalian host range. On man the bees were relatively gentle visitors, mostly landing on the lower eyelashes from where they imbibed tears for 0.5–2.5 min, often singly but occasionally in congregations of 5–7 specimens per eye. Less typically, they also took sweat, a behavior found in 11 other species of anthropophilous meliponines which are not lachryphagous. Nine further meliponine species were not anthropophilous. Lachryphagy in bees is compared to lepidopterous tear drinking and related feeding strategies such as puddling by various insects, mostly for salt requirements but in other cases proteins are sought. We propose that L. cacciae, L. furva and P. klossi drink tears for their high content in proteins in addition to, or in lieu of pollen, rather than only for salts and water. Few reports of flower visitation, rare presence of only minor amounts of pollen on legs, reduced pilosity, absence of resin on body and legs, presence of a strongly extensible metasoma for fluid transport, are all interpreted as possible indications of an adaptation to lachryphagy for proteins. The potential hazard of pathogen transmission by eye-visiting bees is discussed.

Three new species of Sarcophaga Meigen found during ecological studies on flesh flies (Diptera: Sarcophagidae) in Thailand

Three new species of Sarcophaga Meigen, 1826 are described from Thailand: Sarcophaga (Sarcosolomonia) circa sp. nov., S. (Mehria) lanna sp. nov. and S. (Rosellea) suthep sp. nov.

The Remarkable Nest Entrance of Tear Drinking Pariotrigona klossi and Other Stingless Bees Nesting in Limestone Cavities (Hymenoptera: Apidae)

Abstract Nest entrance complexes of the meliponine Pariotrigona klossi Schwarz were studied on a limestone rock face in S Thailand. Unique in several aspects, a complex consisted of several coral-like clumps, all interconnected by roofed conduits. Inside these conduits, which were firmly attached to the substrate, the bees crawled on bare rock. The clumps were composed of dozens of entrance tubelets of up to 10 cm long, 2.5–6 mm wide, ornamented with radially arranged, 1–7 mm long, often branched, strings of crystal-clear beads of resin. Connection to the nest was through a fissure in the rock via a hard resin tube connected to the roofed conduits. Generally only one worker bee occupied an entrance (opening gap 2–3 mm). Such architecture gives protection against ant and bee raiders, and at the same time allows simultaneous multiple landings for bees of populous nests. Pariotrigona klossi was innocuous even when a tubelet was destroyed, but breaking into the roofed conduits near the rock fissure caused a small group of workers to attack the intruder by pinching bites and unpleasant odor. At least 13 species of stingless bees were found to be calcicolous 0.5–20 m above the ground in S, W and N Thailand, limestone hollows being a new nesting location additional to the 10 types already known. Compared to arboricolous nesting, calcicolous habits allow larger and more permanent dwellings safer from falling debris, inclement weather, fire, and bears. Most species were facultative calcicoles already known as arboricoles. Whether in limestone or trees, the nest entrance architecture characteristic for each of the facultative calcicole species was essentially the same. Yet P. klossi and four Lepidotrigona taxa appear to be either obligate calcicoles or, if also arboricoles, to construct different entrances on limestone than on trees. The unusually complex nest entrance elaboration in P. klossi and the extreme length – up to 158 cm – of the alpenhorn-like, pendulous entrance tube of four taxa of Lepidotrigona appear ill-fitted for trees.

A new species of Lepidotrigona (Hymenoptera: Apidae) from Thailand with the description of males of L. flavibasis and L. doipaensis and comments on asymmetrical genitalia in bees

We describe Lepidotrigona satun Attasopa and Bänziger new species from southern Thailand based upon associated males and females (workers). The new species is a member of the L. ventralis species group, which is otherwise represented in Thailand only by L. flavibasis and L. doipaensis. We also describe the males of the latter two species, associated with nests from close to their type localities in northern Thailand. Lepidotrigona doipaensis Schwarz and L. flavibasis (Cockerell) had previously often been misidentified as L. ventralis (Smith), a species confirmed only from Borneo. Based upon differences in male morphology, especially of the metasomal sterna, we conclude that the male described from Vietnam by Sakagami (1975) as belonging to L. flavibasis represents an undescribed species. Our findings support previous taxonomic studies that highlight the importance of including males in the differentiation of closely related species of meliponines and their association with workers. The three species whose males we describe have asymmetric penis valves with the asymmetry differentially developed among the three. We compare this genitalic asymmetry with that known from a different apid genus, Tarsalia.

Pollination-system diversity in Epipactis (Orchidaceae): new insights from studies of E. flava in Thailand

The rewarding orchid Epipactis flava was studied in NW Thailand. Its flowers were visited by a wide range of insects, most of which served as pollinators. The most frequent pollen bearers were (in decreasing order): the cricket Homoeoxipha lycoides, stingless bees of the Tetragonula testaceitarsis/hirashimai complex, hoverflies of subfam. Syrphinae, the wasp Polybioides gracilis and sweat bees of subfam. Halictinae. We found no evidence of a link between the rheophytic habit of E. flava and its pollinator fauna. Whereas most pollinators visited the flowers to feed on nectar, females of Episyrphus alternans (Syrphidae: Syrphinae) were observed to oviposit despite the absence of prey for their young. Hence, we suggest that dual pollination systems contribute to the opportunist strategy of E. flava, and we discuss, in a phylogenetic framework, how the strategy fits in with those previously reported for Epipactis sect. Arthrochilium. The elastic attachment of the epichile (a universal trait in sect. Arthrochilium) was found to promote outcrossing, and we hypothesize that loss of the elastic hinge has provided a key innovation facilitating recurrent evolution of obligate autogamy in sect. Epipactis (which is nested in sect. Arthrochilium).

Reflectance and colour loci

Reflectance and colour loci (bee vision) of flowers of each species and paper discs used in this study