Nikolay A. Vislobokov

Pollination of Vietnamese Aspidistra xuansonensis (Asparagaceae) by female Cecidomyiidi flies: Larvae of pollinator feed on fertile pollen in anthers of anthetic bisexual flowers

UNLABELLED • PREMISE OF THE STUDY Aspidistra is a species-rich, herbaceous monocot genus of tropical Southeast Asia. Most species are recently discovered and apparently endangered, though virtually nothing is known about their biology. Species of the genus are primarily distinguished using flower morphology, which is enormously diverse. However, the pollination process has not been directly observed in the center of diversity of the genus (N Vietnam and S China). Indirect and partly direct data on the only widely cultivated species of the genus (A. elatior) placed it among angiosperms with the most unusual pollination biology, though these data are highly controversial, suggesting pollen transfer by mollusks, crustaceans, flies, or possibly tiny soil invertebrates such as collembolans.• METHODS Pollination of Aspidistra xuansonensis in the center of diversity of the genus was studied using visual observations and videos and light and scanning electron microscopy investigation of flowers and their pollinators. Pollinators and their larvae were molecularly barcoded.• KEY RESULTS Aspidistra xuansonensis is pollinated by female cecidomyiid flies (gall midges). They oviposit on anthers, and larvae develop among the pollen mass. Molecular barcoding proved taxonomic identity of the larvae and the flies. The larvae neither damage floral parts nor cause gall formation, but feed on pollen grains by sucking out their content. The larvae move out of the flowers before decomposition starts. Carebara ants steal developing larvae from flowers but do not contribute to pollination.• CONCLUSIONS More than one kind of myiophily is present in Aspidistra. Brood site pollination was documented for the first time in Aspidistra. The pollination system of A. xuansonensis differs from other kinds of brood site pollination in the exit of the larvae prior to the decomposition of floral parts.

Aspidistra cylindrica (Asparagaceae), a New Species from Southern Vietnam

Abstract Aspidistra cylindrica, a new species from southern Vietnam (Kon Tum province), is described and illustrated. The new species possesses a unique combination of cylindrical shape of pistil and shoot system with foliage leaves crowded in groups and not divided into petiole and lamina. Aspidistra cylindrica resembles A. muricata but differs in longer leaves, shorter and wider perigone, shorter pistil, shape and colour of perigone lobes, anther position, and stigma shape. The conservation status of A. cylindrica is assessed. A key for species of Aspidistra in southern Vietnam is provided.

Tupistra siphonantha (Asparagaceae), a new species from Lao P.D.R. with a simple pistil

SummaryTupistra siphonantha N. Tanaka, Vislobokov & D. P. Hannon, a new species from central Laos is described and illustrated. It is distinguishable from all other members of Tupistra mainly by the synchronously blooming flowers, clavate-tubular, cream-white or fulvous perianth with strongly incurved segments, latrorse anthers with thecae separated by a round (papillary) projection from the perianth, and very small, simple pistil bearing a single ovule in the locule. It is also unique in having ellipsoid, smooth, orange fruits that are similar to those of Rohdea. The taxonomic position and features of the flowers and fruits of this species are briefly discussed. A key to the species of Tupistra reported from Laos is also provided.

Pollination Ecology of Two Co-occurring Species of Balanophora: Differences in Range of Visitors and Pollinators

Premise of research. Inflorescences of Balanophora species emit a sweet smell, produce nectar, and are visited by many different insects. All previous studies of the pollination biology of Balanophora included observation of one species of the holoparasite in one location. In the present study, we investigated and compared pollination systems of two co-occurring and coflowering Balanophora species: B. harlandii and B. fungosa ssp. indica. Methodology. The floral biology of Balanophora was studied using day and night visual observations as well as video and photo monitoring. Pollen grains, flowers, and captured pollinators were investigated using light microscopy and scanning electron microscopy. Pivotal results. It was found that flies (Drosophilidae, Syrphidae), wasps, and harvestmen (Phalangidae) pollinate B. harlandii, while B. fungosa is pollinated by flies (Calliphoridae, Drosophilidae, Limoniidae, Syrphidae) and harvestmen (Phalangidae). It was determined here for the first time that harvestmen are facultative pollinators of Balanophora. Conclusions. Both Balanophora species possess a generalist pollination strategy. However, B. harlandii is adapted mostly to day pollination, whereas B. fungosa is more likely adapted to day and night pollination. In the present study, wasps are the main pollinators of B. harlandii, whereas drosophilid flies are the main pollinators of B. fungosa. The small range of visitors for B. harlandii may be caused by the territorial behavior of wasps.

Flowering biology of Aspidistra (Asparagaceae): new data on pollination by dipteran insects

The genus Aspidistra comprises about 160 species of herbaceous plants. In previous investigations, different authors suggested that Aspidistra is pollinated by flies, fungus gnats, slugs, amphipods and even collembolans. The vast majority of data was based on only one species, A. elatior, and was not confirmed by direct observations. Recent field observations of anthetic plants confirm the idea of pollination by flies for two other species of the genus. The present study summarizes direct observations of flowering phenology and pollination of five previously unstudied species of Aspidistra. Flowering biology was studied using visual observations as well as video and photo monitoring. Flowers and captured pollinators were investigated using scanning electron microscopy. As a result, knowledge of the flowering biology of Aspidistra has been increased. The absence of heat production and an ultraviolet pattern were verified. The present data show that flowers of Aspidistra can serve as a food resource for animals. The investigated species of Aspidistra are pollinated by dipteran insects: A. formosa, A. marasmioides and A. subrotata are pollinated by fungus gnats; A. multiflora and A. oviflora are pollinated by flies. The occurrence of fungus-gnat pollination was directly demonstrated for the first time in the genus Aspidistra. The present study confirmed the idea of myiophily in the genus Aspidistra. Apparently, myiophily is common and diverse in Aspidistra. More likely, pollinators are attracted by scent, which is undetectable by humans, but the attraction mechanism is still not completely clear.

Pollination Ecology of Lowiaceae (Zingiberales): Nocturnal Carrion-Beetle Pollination of Orchidantha virosa

Premise of research. Previous investigations showed the occurrence of diurnal dung-beetle pollination in Orchidantha (Lowiaceae). Though many dung, carrion, and scavenger beetles are exclusively nocturnal, comprehensive night observations were never performed for this genus. In addition, some small mammals were occasionally observed feeding on flowers of Orchidantha during the night. Thus, the present study of pollination biology with observations throughout night fills a significant gap in our knowledge of the ecology of these plants. Methodology. Pollination of O. virosa was studied using day and night visual observations as well as video and photo monitoring. Pollen grains, flowers, and captured pollinators were investigated using LM and SEM. Pivotal results. The flowers of O. virosa are visited by diurnal flies, ants, and nocturnal carrion beetles, together with many other occasional visitors. Among them, only the carrion beetles from the genus Phaeochrous were shown to carry pollen of O. virosa. Nocturnal pollination was documented for the genus Orchidantha for the first time. Conclusions. Our study confirms the occurrence of coprocantharophily in Orchidantha. Taking all the features together, we can assume the described type of pollination (nocturnal deceptive carrion-beetle pollination without floral traps) to be rare within beetle pollination. We briefly review the knowledge of reproductive ecology in the genus Orchidantha and propose diversity of pollination modes (nocturnal and diurnal) within the family.