Crane flies and microlepidoptera also function as pollinators in Epidendrum (Orchidaceae: Laeliinae): the reproductive biology of E. avicula

Crane flies and microlepidoptera have been recorded as pollinators in unrelated orchid groups, but these insects have never been recorded in Epidendroideae, the most species‐rich orchid subfamily, which includes one of the most diverse genera among Orchidaceae, Epidendrum. Based on data on phenology, floral morpho‐anatomy, pollinators, pollination mechanisms and breeding system, the reproductive biology of E. avicula was studied in south‐eastern Brazil. Epidendrum avicula possess osmophores that produce a citric fragrance at night. The flowers attract Tipulidae flies and several families of microlepidoptera that drink the nectar produced in a tube formed by the adnation of the labellum and column. As is common in Epidendrum, after removing the pollinarium, both crane flies and micro‐moths get trapped by the proboscis, which frightens the insects and inhibits any possible intent to immediately visit another flower. The behavior of the pollinators on flowers, plus the retention of the anther cap by the pollinarium, results in a reduction in the occurrence of geitonogamy. Because E. avicula is self‐incompatible, the consequence of pollinator behavior and the floral mechanisms tend to reduce the pollen loss. As far as we know, this is the first study to report the reproductive biology of a species of Epidendroideae pollinated by crane flies and microlepidoptera. Based on more recent concepts of plant–pollinator interactions, although E. avicula is pollinated by several species belonging to two distinct orders, suggesting an unspecialized pollination system is involved, nectar‐seeking microlepidoptera and Tipulidae flies can be recognized as a single functional group.     

琼花生殖器官结构及传粉昆虫的观察

为了探讨影响琼花Viburnum macrocephalum f.keteleeri有性生殖的因素,对其生殖生物学和传粉生物学进行了研究。研究内容主要包括琼花花部特征、生殖器官解剖结构、花粉活力、花粉胚珠比(P/O)、繁育系统、传粉形式、传粉昆虫和花粉管生长路径等。结果表明:(1)琼花聚伞花序由大型不孕花和小型可孕花组成,可孕花雌雄蕊发育正常,雄蕊5枚,雌蕊1枚,干型柱头,单子房,倒生胚珠;不孕花的雌雄蕊在发育早期正常,而在花期时退化。雄蕊退化表现为雄蕊消失、花丝缩短或消失或花药大小不一;而雌蕊退化表现为雌蕊缩小或柱头开裂;有时雌雄蕊也存在瓣化现象。(2)自然条件下,单花花粉活性在散粉4–5d后明显下降,居群花粉活力在4月25日–28日开始显著下降。(3)花粉胚珠比P/O值为12800–18700,属专性异交型;繁育系统为异株异花授粉,属虫媒传粉植物。(4)可孕花大量散粉时间为9:00–16:00,昆虫访花高峰时段为11:00–15:00,访花昆虫中以蝶类和蜂类为主,蝶类访花频率最高。(5)落置柱头的花粉萌发率较高,花粉粒授粉后1h左右开始萌发,花粉管从柱头乳突细胞的间隙穿入花柱,沿花柱中央引导组织生长,18h左右进入子房,20h左右从珠孔进入胚囊。讨论了琼花的不孕花形成、花部结构适应、花型演化趋势、低结实率和花粉管生长特点。     

广东地区外来种五爪金龙的传粉生物学研究（英文）

五爪金龙(Ipomoea cairica)是一种匍匐或攀援生长的入侵杂草。2006-2007年作者在广东地区开展了对该入侵种的传粉生物学研究。五爪金龙在广东全年均可开花,花序为聚伞花序,花冠为紫色或蓝紫色喇叭状。开花时间在早晨4:30-5:20之间,下午17:40闭合,持续大约12h。每朵花平均分泌花蜜量为5.82±2.47μL(n=10),花蜜平均含糖量为41.03±6.52%,氨基酸含量为0.042mg/mL。开花过程中花粉活性和柱头可受性均保持较高水平(>90%)。花粉/胚珠比率(P/O)为4,778.18±264.58(n=10)。木蜂(Xylocopasp.)是其有效的传粉昆虫,蝇类和蝶类为随机访问者。开花过程中柱头与花药相接触,有利于自花授粉。然而,繁育系统的研究表明五爪金龙是自交不亲和植物,其种子仅能通过异花授粉获得。     

Caught in the act: pollination of sexually deceptive trap-flowers by fungus gnats in Pterostylis (Orchidaceae)

Background and Aims Pterostylis

is an Australasian terrestrial orchid genus of more than 400 species, most of which use a motile, touch-sensitive labellum to trap dipteran pollinators. Despite studies dating back to 1872, the mechanism of pollinator attraction has remained elusive. This study tested whether the fungus gnat-pollinated Pterostylis sanguinea secures pollination by sexual deception.

Methods

The literature was used to establish criteria for confirming sexual deception as a pollination strategy. Observations and video recordings allowed quantification of each step of the pollination process. Each floral visitor was sexed and DNA barcoding was used to evaluate the degree of pollinator specificity. Following observations that attraction to the flowers is by chemical cues, experimental dissection of flowers was used to determine the source of the sexual attractant and the effect of labellum orientation on sexual attraction. Fruit set was quantified for 19 populations to test for a relationship with plant density and population size.

Key Results

A single species of male gnat (Mycetophilidae) visited and pollinated the rewardless flowers. The gnats often showed probing copulatory behaviour on the labellum, leading to its triggering and the temporary entrapment of the gnat in the flower. Pollen deposition and removal occurred as the gnat escaped from the flower via the reproductive structures. The labellum was the sole source of the chemical attractant. Gnats always alighted on the labellum facing upwards, but when it was rotated 180 ° they attempted copulation less frequently. Pollination rate showed no relationship with orchid population size or plant density.

Conclusions

This study confirms for the first time that highly specific pollination by fungus gnats is achieved by sexual deception in Pterostylis. It is predicted that sexual deception will be widespread in the genus, although the diversity of floral forms suggests that other mechanisms may also operate.     

Pollination limitation,costs of capsule production and the capsule-to-flower ratio in Dendrobium monophyllum F. Muell. (Orchidaceae)

Abstract In perennial plants, life-history theory suggests that natural selection should result in the optimization of fruit-to-flower ratios within the limits imposed by the trade-offs between resource allocation for present reproduction and future growth and reproduction. The tropical orchid Dendrobium monophyllum F. Muell., an epiphyte or lithophyte, offers no nectar rewards, is self-incompatible and has a capsule-to-flower ratio of about 1:14. The influence of pollination limitation and the costs of capsule production on capsule-to-flower ratios were assessed using experimental and field studies in which individual plants were observed for 3 years. Pollinators visited about 80% of flowers, and capsule production was significantly related to inflorescence size and pollinaria removal. About nine pollinator visits occurred per capsule. Pollinator visitation and capsule production did not vary significantly between years. The inflorescence size classes most successful in capsule production were also the most frequent in natural populations. The experimental supplementation of outcross pollen to flowers increased capsule set over controls by 45% within a year, but was limited to about 53%. A capsule-to-flower ratio of 1:2 in experimental plants significantly decreased the subsequent growth and flowering of individuals relative to controls. A capsule-to-flower ratio above 1:10 in naturally pollinated plants decreased flowering in the subsequent year. Thus, it is suggested than an increase in capsule production above 10% would not necessarily correlate with greater reproductive fitness because of the increased cost of capsule production. The capsule-to-flower ratio recorded in this study could be evolutionarily stable because of trade-offs between selection for pollinator attraction and the cost of capsule production. The production of surplus flowers appears to function in pollinator attraction and increases fitness through male function.     

Distyly and sequential pollinators of Psychotria nuda (Rubiaceae) in the Atlantic rain forest, Brazil

Reciprocal herkogamy is known to promote intermorph-pollination in distylous species, which are generally self- and intramorph-incompatible. Legitimate crossing rates are also influenced by pollinator foraging strategy, which determines most of the pollen flow in natural populations. This study reports on the floral morphology, compatibility relations and pollination biology of Psychotria nuda (Cham. and Schltdl.) Wawra in the Atlantic rain forest, southeastern Brazil, based on floral measurements, hand-pollination experiments and focal observation of floral visitors. It was found that P. nuda does not present an exactly reciprocal herkogamy, however, this morphological trait in P. nuda is as good as in most of Rubiaceae. Reproductive experiments showed compatibility relations similar to those frequently observed in distylous species. The hummingbirds Ramphodon naevius and females of Thalurania glaucopis were the main pollinators of P. nuda, presenting the traplining foraging strategy, which seems to maximize intermorph crosses in P. nuda flowers. These hummingbirds pollinated P. nuda flowers sequentially throughout the flowering period.     

Pollination of Schisandra henryi (Schisandraceae) by female, pollen-eating Megommata species (Cecidomyiidae, Diptera) in south-central China

BACKGROUND AND AIMS: The mutualistic interaction between insects and flowers is considered to be a major factor in the early evolution of flowering plants. The Schisandraceae were, until now, the only family in the ANITA group lacking information on pollination biology in natural ecosystems. Thus, the objective of this research was to document the pollination biology and breeding system of Schisandra henryi. METHODS: Field observations were conducted in three populations of S. henryi and the floral phenology, floral characters and insect activities were recorded. Floral fragrances were sampled in the field and analysed using TCT-GC-MS. Floral thermogenesis was measured with a TR-71U Thermo Recorder. Pollen loads and location of pollen grains on insect bodies (including the gut) were checked with a scanning electron microscope and under a light microscope. KEY RESULTS: Schisandra henryi is strictly dioecious. Male flowers are similar to female flowers in colour, shape, and size, but more abundant than female flowers. The distance between tepals and the androecium or gynoecium is narrow. Neither male nor female flowers are fragrant or thermogenic. Schisandra henryi is pollinated only by adult female Megommata sp. (Cecidomyiidae, Diptera) that eat the pollen grains as extra nutrition for ovary maturation and ovipositing. Both male and female flowers attract the pollinators using similar visual cues and thus the female flowers use deceit as they offer no food. CONCLUSIONS: Schisandra henryi exhibits a specialized pollination system, which differs from the generalized pollination system documented in other ANITA members. Pollen is the sole food resource for Megommata sp. and the female flowers of S. henryi attract pollinators by deceit. This is the first report of predacious gall midges utilizing pollen grains as a food source. The lack of floral thermogenesis and floral odours further enforces the visual cues by reducing attractants for other potential pollinators.     

Effect of individual height and labellum colour on the pollination of Caladenia (syn. Arachnorchis) behrii (Orchidaceae) in the northern Adelaide region, South Australia

Caladenia behrii, a sexually deceptive orchid, is an endangered terrestrial orchid endemic to the Adelaide Hills, South Australia. We examined pollination success among individuals of different colours and heights in three populations of C. behrii in the northern Adelaide region. The labellum of C. behrii varies from cream to deep maroon. Over five years, the pollination success (pollinia deposited on stigma) of four colour groups (maroon, maroon and cream, hatched, and cream) was assessed for a total of 782 flowers. Labellum colour had no effect on the pollination success of individuals, indicating no frequency-dependent selection. It is likely that pollinators use the sexual pheromone mimic produced by the flowers as the main orientation cue. For three years the height of pollinated C. behrii individuals was recorded, along with the height of the nearest non-pollinated neighbour (distance of labellum from the ground, rather than stem length). Although a range of different heights was pollinated at population level, individual flowers that were taller than their closest neighbours were significantly more likely to be pollinated. Flower head height was not correlated with opening date and was greater for orchids growing among grass-tree leaves. Results imply that pollinators are more successful in finding tall flowers than short ones for visual and/or olfactory reasons; however, the effect of height preference is eliminated at population level.     

Comparative pollination biology in two sympatric varieties of Cypripedium macranthos (Orchidaceae) on Rebun Island,Hokkaido, Japan

Cypripedium macranthos sensu lato typically has purple‐pink flowers with no nectar and harvestable pollen. On Rebun Island, Hokkaido, Japan, purple‐pink‐flowered C. macranthos var. macranthos individuals rarely grow among numerous pale‐cream‐flowered C. macranthos var. rebunense plants. In both varieties, flower size is similar, their flowering periods completely overlap, and they share the same pollinator (Bombus pseudobaicalensis). However, in only one of 12 years from 2001 to 2012 did var. macranthos attain an annual fruit‐set ratio (an estimate of pollination success) higher than that of sympatric var. rebunense plants. These findings strongly suggest that in C. macranthos on Rebun Island, flower color results in the differential pollination success, because the pollinator prefers pale‐cream Cypripedium flowers and/or avoids purple‐pink ones, thereby producing pollinator‐mediated selection favoring pale‐cream flowers.     

云南省甲基苯丙胺等新型毒品滥用群体性特征分析及思考

部分甲基苯丙胺等新型毒品滥用群体的情况进行分析,就其群体性特征与传统毒品滥用群体特征作分析比较,提出新型毒品滥用的四个群体性特征:(1)年龄"低龄化";(2)滥用"群体化";(3)职业"多样化";(4)群体"转换化".该研究有助于新型毒品滥用的预防和控制工作,同时使我们的工作更具有针对性和实效性.     

Biodiversity of Bitahai Nature Reserve in Yunnan Province, China

Bitahai Nature Reserve is located in Northwest Yunnan and is the highest elevation and the highest latitude wetland nature reserve in Yunnan Province. Bitahai Nature Reserve is a typical wetland nature reserve in very low latitude and high elevation with large areas of coniferous forest around the alpine till lakes, wetland and water area ecosystem while compared with natural reserves distributed same latitude in the world. The area of the reserve distribution is the key area of Transverse Mountain Region. It was a refuge for plant and wildlife because Transverse Mountains were not covered by ice in the Tertiary. And the area is now regarded as a center of forming new species and preserving ancient species. Species biodiversity is high and the distribution of some endemic animals and plants are limited in Transverse Mountains area. In the nature reserve, there are many first and second grade protected plants and animals listed in Lists of China National Priority Protection Fauna and Flora. All of these are precious materials of genetic diversity. The diversities of the plant community and vegetation contribute to ecosystem diversity. Thus, Bitahai Nature Reserve holds with high conservation value. However, its biodiversity is threatened by different factors and its conservation should be paid great attention.     

珍稀濒危植物,中国山茶属(山茶科)一新变种

发表了山茶属（山茶科）西南山茶一新变种,即攀西黄花茶（Camellia pitardii Cohen Stuart panxiensis J. L. Liu）。     

Floral morphology and reproductive biology of Dendrobium jiajiangense (Orchidaceae) in Mt. Fotang,southwestern China

The relationships between floral morphology and the particular pollinator, flower shelter function and reproductive success as well as details of the breeding system of Dendrobium jiajiangense were investigated at Fotang Mountains in Jiajiang County, Sichuan Province, China. D. jiajiangense is pollinator-specific, being pollinated by Andrena parvula. There exists considerable mechanical fit between the floral morphology of D. jiajiangense and A. parvula. Importantly, A. parvula uses D. jiajiangense flowers as shelter both during rainy weather and at night during sunny weather. This significantly increase the pollination success of D. jiajiangens. D. jiajiangense is self-compatible but pollinator-dependent for fruit set. Fruit set of D. jiajiangens was 100% after hand-self-pollination, but seed viability was normally greatly reduced.     

Notes on the Nazeris fauna of Yunnan Province, China (Coleoptera, Staphylinidae, Paederinae)

Two new species of the genus Nazeris Fauvel collected from Nabanhe Nature Reserve, Yunnan Province, are described under the names of Nazeris nabanhensissp. n. and Nazeris caoisp. n. The male sexual characters are described and illustrated. A key to the Nazeris species of Yunnan is provided. A map of the collecting sites is given.     

Diverse visitors with various pollinator importance and temporal change in the important pollinators of <Emphasis Type="Italic">Geranium thunbergii</Emphasis> (Geraniaceae)

Assessing pollinator importance of each floral visitor to a plant species is a key to understanding plant–pollinator interaction. The present study examined visitation frequency, pollination efficiency, and pollinator importance of the full range of floral visitors to Geranium thunbergii natural population, by measuring seed-set. During 2 years of observations, the flowers were visited by at least 45 insect species belonging to four orders. Among the main 22 visitor species, 11 species belonging to three orders (Hymenoptera, Diptera, and Lepidoptera) acted as the efficient pollinators. In both years, Hymenoptera, especially bees, was the most important pollinator to G.thunbergii. Thus, the flowers could be considered as bee-pollinated. However, the most important species were not constant between years. The study also documented that the efficient pollinators have larger body sizes. The dish-shaped floral morphology, taxonomically diverse pollinators, and temporal change in the most important pollinators indicate that G.thunbergii–pollinator interaction is a rather generalized system. The results suggest that casual observations of visitation, or even precise measurement of pollinator importance in a single season is insufficient to identify important pollinators.     

A study of phlebotomine sandflies (Diptera: Psychodidae) in Yunnan Province, China. Sergentomyia (Sergentomyia) wangi n. sp

Among the phlebotomine sandflies collected in a lime-stone cave of 21 degrees 42' N, 10 degrees 23' E and 700 m above sea level on 14th August, Mengyuan, Mengla County, Xishuangbanna District, Yunnan Province, two males of the group fallax of subgenus Sergentomyia are quite different in morphology with those hitherto recorded in the literature. In the present paper its morphology is described with seven figures and the name Sergentomyia wangi is proposed in honor of professor Chao-Tsun Wang for his contribution in study and control of leishmaniasis in China.     

云南乍甸镇新植柑桔园农业生态经济系统功能分析

云南乍甸镇新植柑桔园农业生态经济系统功能分析李元,祖艳群（云南农业大学昆明６５０２０１）ＦｕｎｃｔｉｏｎａｌＡｎａｌｙｓｉｓｏｆＮｅｗｌｙ－ＢｕｉｌｔＯｒａｎｇｅＯｒｃｈａｒｄＡｇｒｏ－ＥｃｏｌｏｍｉｃＳｙｓｔｅｍｉｎＺｈａｄｉａｎＴｏｗｎ,Ｙｕｎｎ...