Reproductive Ecology of Ocimum americanum L. and O. basilicum L. (Lamiaceae) in India

Abstract Ocimum americanum and O. basilicum bloom once a year. They produce flowers over a long period, a few flowers being produced each day. The flowers of both are short-lived (3-4 hours), bisexual, zygomorphic, and chasmogamic with anthers dehiscing in the bud stage. The open flowers offer nectar and pollen as rewards and are visited and sternotribically pollinated by day-flying animals. The blossoms are flag-shaped, and the reproductive organs are close to the lower corolla lip. The stamens and stigma show movements immediately after anthesis and remain for 20–30 minutes and this may cause self-pollination. Both species reproduce primarily through autogamy. Flowers are open during 5:30–13:30 hr in O. americanum and during 7:00–13:00 hr in O. basilicum . Certain bee species like Apis florea, A. cerana indica, Amegilla sp., and Pseudapis oxybeloies , and the butterfly Surandra queretroum are the most frequent and consistent visitors and can be pollinators for both plant species.     

Flowering, pollination and seed production of Acacia nilotica

Acacia nilotica flowers during the rainy season in Kenya. The flowers shed their pollen between 07.30 and 12.00 hours. Average pollen production is 1.1 million grains per inflorescence. Pollination is by native solitary bees of the genera Creightonella, Chalicodoma, Megachile, Anthophora, Nomia and Xylocopa. Less than 1/3 of the flowers are hermaphroditic and the pod set per hermaphroditic flower is 0.3 percent. The ovary contains 16 ovules, and the average seed set per pod is 10.8. One tree can produce more than 30000 seeds in one fruiting season.     

Diversity in bee (Hymenoptera: Apoidea) and social wasp (Hymenoptera: Vespidae, Polistinae) community in "campos rupestres", Bahia, Brazil

Hymenoptera such as bees and social wasps are regular floral visitors in "campos rupestres" vegetation. A community of bees and social wasps was studied during floral visitation in an area of "campos rupestres", at Chapada Diamantina, BA, Brazil, from September 2001 to April 2002. The community was described in relation to diversity, evenness, and dominance rank, considering the individuals abundance (H' = 2.14/ J' = 0.55) and biomass (H' = 2.34/ J' = 0.60). Thirty nine bee (588 individuals/ 15.742 g) and 11 social wasp species (52 individuals/ 2.156 g) were collected, being the first report of social wasps for the Brazilian "campos rupestres". The main species regarding number of individuals were Trigona spinipes (Fabricius), Apis mellifera L., Frieseomelitta francoi (Moure), and Bombus brevivillus Franklin. About 48% of the species were represented by a single individual. There was an inversion in the dominance rank when the species biomass was considered. B. brevivillus, A. mellifera, T spinipes, and other species represented by 15 individuals or less, such as the social wasps Synoeca cyanea (Olivier), Polistes canadensis (L.) and Myschocyttarus drewseni (Saussure), and the bees Eufriesea nigrohirta (Friese), Xylocopa grisescens Lepeletier and Megachile (Pseudocentron) sp.l were the predominant species. The use of biomass in diversity analysis permitted to detect differences in the relative contribution of species in hierarchy dominance. The comparison between bee faunas from different areas indicates a large similarity of the sampled fauna in Palmeiras (Bahia State) with neighboring ecosystems, although with low values of similarity.     

中国切叶蜂属十四新种记述(蜜蜂总科,切叶蜂科)

记述切叶蜂科切叶蜂属Megachile Latreille 7亚属14新种:Megachile(Eutricharaea )laminopeds sp.nov.,Megachile ( Amegachile ) alboplumula sp. nov. , Megachile ( Xanthosaurus ) plumatus sp. nov., Megachile ( Xanthosaurus) hei sp. nov., Megachile (Xanthosaurus) silvapis sp. nov., Megachile (Pseudomegachile) eurycephala sp. nov.,Megachile ( Pseudomegachile ) nigropectoralis sp. nov.,Megachile (Pseudomegachile) sphenapis sp. nov., Megachile (Callomegachile) gigas sp. nov. , Megachile ( Callomegachile ) rhyssalus sp. nov. , Megachile ( Lagella ) hubeiensis sp. nov,Megachile ( Lagella ) trizonata sp. nov. , Megachile ( Chelostomoda ) nigroapicalis sp. nov. , Megachile ( Chelostomoda ) crabipedes sp.nov..采自云南、海南、湖北、四川、贵州等地. 模式标本均保存于中国科学院动物研究所.     

心叶凹唇姜的开花格局和雄性先熟机制

心叶凹唇姜 (Boesenbergia longiflora) 是分布于亚洲热带的一种姜科植物, 在我国滇南地区成片生长于石灰山贫瘠的岩石缝隙和路边林下的冲积土壤上。心叶凹唇姜的花寿命为两天, 第1天为严格的雄性阶段, 第2天为严格的雌性阶段, 是典型的花内雄性先熟, 一朵花的雌、雄性阶段没有重叠, 因而完全避免了自花授粉的发生。对这两种生境 (石灰山贫瘠的岩石缝隙和路边林下) 下的心叶凹唇姜的4个野外种群 (在云南省普洱市的翠云乡彩虹洞、南岛河、澜沧县惠民乡和西双版纳州绿石林森林公园) 和栽培植株的开花格局进行调查后发现, 大多数个体在同一时间内只有一个花序开花, 并且每隔一天才开一朵花, 只有10%左右的植株同时具有雄性阶段和雌性阶段的花, 这样的开花格局有效地降低了同株异花授粉发生的可能。心叶凹唇姜的平均花粉-胚珠比 (Pollen-ovuleratio) 为291, 应该是以异交为主的混合交配系统。其自然种群存在着花粉限制, 彩虹洞、南岛河和绿石林3个不同种群的平均结籽率都不到60%, 这可能与其较小的花展示有关。心叶凹唇姜为泛化传粉植物, 不同种群的有效传粉昆虫种类各不相同。在两种不同的生境条件下, 心叶凹唇姜花的大小和开花格局都没有显著的差异, 大多数个体同时只具有一种性阶段的花, 说明心叶凹唇姜这种独特的开花格局是长期进化的结果。心叶凹唇姜通过隔一天开一朵花的开花格局, 配合雄性先熟机制, 有效地降低了自交的发生。     

Pollination biology of Albizia lebbeck (L.) Benth. (Fabaceae: Mimosoideae) with reference to insect floral visitors

Indian siris, Albizia lebbeck (L.) Benth. (Fabaceae: Mimosoideae) has significant importance to human beings for its multipurpose use. Insects play a crucial role in the pollination biology of flowering plants. In the current study, we studied the pollination biology of A. lebbeck with special reference to insect floral visitors. The effectiveness of floral visitors was investigated in term of visitation frequency, visitation rate and pollen load during 2012 and 2013. In the second experiment, effect of pollinators on yield of A. lebbeck was studied in open and cage pollination experiments. Floral visitor fauna of A. lebbeck included eight-bees, two wasps, two flies, and two butterflies species. Among them, Apis dorsata, Apis florea, Amegilla cingulata, and Nomia oxybeloides had maximum abundance ranging from 349–492, 339–428, 291–342 and 235–255 numbers of individuals, respectively during two flowering seasons. A. dorsata had the highest visitation frequency (6.44 ± 0.49–8.78 ± 0.48 visits/flower/5min) followed by Amegilla cingulata (6.03 ± 0.43–7.99 ± 0.33 visits/flower/5min) and A. florea (3.61 ± 0.31–4.44 ± 0.18 visits/flower/5min). A. dorsata, N. oxybeloides, and Amegilla cingulata had the highest visitation rates (18.904 ± 1.53–11.43 ± 1.17 flower visited/min) and pollen load (15333 ± 336.22–19243 ± 648.45 pollen grains). The open pollinated flowers had significantly higher capsule weight (4.97 ± 0.21 g), seed weight (1.04 ± 0.05 g), seed numbers per pod (9.80 ± 0.34) and seed germination percentage (84.0 ± 1.78%) as compared to caged flowers. The results suggested bees especially A. dorsata, N. oxybeloides and Amegilla cingulata could be effective pollinators of A. lebbeck.     

Metabolism of 1-naphthyl-N-methyl carbamate (carbaryl) by bacterial isolates from honey bees and the effect of bacterial inoculations on carbaryl tolerance in bees

I.D. SHARMA AND A. NATH. 1996. The bacteria which inhabit the body of foragers of Apis cerana indica F. were evaluated for degradation of carbaryl (1-naphthyl- N -methyl carbamate). Citrobacter sp., Enterobacter aerogenes and an unidentified isolate could utilize carbaryl as sole carbon and energy source. The enrichment cultures of bacteria could degrade carbaryl 0.019–0.082 in nutrient broth and 0.111–7.895 mg μg^-1 bacterial dry wt in basal salts medium of 1 mmol 1^-1 carbaryl. 1-Naphthol was the major product of carbaryl degradation. The dip and injection inoculations of foragers ( Apis cerana indica F. and Apis mellifera L.) with these bacteria resulted in a significant increase in tolerance to carbaryl. The application of mixed culture to bees induced higher tolerance than the individual isolates. This is the first report of the use of bacteria to decontaminate a living system.     

Pollination and breeding system of Couepia uiti (Mart. and Zucc.) Benth (Chrysobalanaceae) in the Pantanal da Nhecolandia.

The pollination biology and breeding system of Couepia uiti was studied. In this species, flowers opened at 06:00 AM anthesis, and nectar production began at around 0800 h, reached a maximum volume from 09:30 AM to 10:30 AM, and decreased thereafter. The nectar sugar concentration increased continuously, but showed an abrupt increase from 10:00 AM to 12:00 AM. Pollen release occurred at about 09:30 AM and was quickly collected. The stigmas became receptive at around 12:00 AM. The pollinators of C. uiti included the bees Apis mellifera, Xylocopa sp. and Bombus sp., and three species of wasps. This conclusion was based on the observation that these hymenopterans had C. uiti pollen on their bodies, visited the receptive flowers, and touched the anthers and stigmas, thereby promoting pollination. Of these floral visitors, A. mellifera was considered to be the most efficient pollinator. However, mixed pollination also occurred. The number of C. uiti flowers visited in the morning (n = 52) was three times smaller than in the afternoon (n = 62), and the species richness of floral visitors was also bigger in the afternoon (eight in the afternoon versus five in the morning). This finding indicated that these floral visitors preferred to exploit nectar rather than pollen. Controlled pollination experiments showed that C. uiti was a self-incompatible species that produced fruits only by cross-pollination. Treatments such as agamospermy and spontaneous and self-pollinations did not produce fruits.     

PARASITES AND OTHER ORGANISMS ASSOCIATED WITH NESTS OF AMEGILLA FRIESE (HYMENOPTERA: ANTHOPHORINAE)

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Amegilla (Amegilla) pulchra (Smith) (Anthophorinae, Anthophorini) is parasitised by Thyreus caeruleopunctatus (Blanchard) (Anthophorinae, Melectini), Miltogramma sp. (Sarcophagidae), Zonitis sp. (Meloidae), and fungus, and information is given on the habits of the parasites and the number of cells parasitised. A specimen of Thyreus nitidulus (Fabricius) was seen working in a nest. Trogoderma apicenne Reitter (Dermestidae) and Lasioderma serricorne (Fabricius) (Anobiidae) were reared on debris in old cells.
Amegilla (Asarapoda) sp. is parasitised by Thyreus lugubris (Smith).
Pyemotes ventricosus (Newport) (Acarina, Pyemotidae) killed pupae of both species of Amegilla in open cells.
A. (A.) pulchra is the first hymenopterous host recorded for an Australian Meloid.     

Reproductive ecology of Rhodomyrtus tomentosa (Myrtaceae)

Rhodomyrtus tomentosa (Ait.) Hassk. is widely distributed in tropical Asia and is an invasive species in Florida, USA. The purpose of the present study was to investigate the reproductive ecology of the species in order to provide information that may be useful in elucidating factors contributing to its invasiveness. The research was carried out at Heshan Hilly Land Integrated Experimental Station, the Chinese Academy of Sciences, Guangdong Province, China in 2003 and 2004. Rhodomyrtus tomentosa flowers in March or April and the flowering period lasts for about 3 months. Flowers open early in the morning and last 2–3 days. The pollen remain viable for about 12  h and the stigma is only receptive on the blooming day. The breeding system is a mixed mating system (outcrossing and geitonogamy). The species is bee-pollinated with pollen as the floral reward. Almost all pollinators appeared before 12  am. Amegilla florea (Smith) Brooks and Xylocopa nasalis Westwood are the primary pollinators for the species. The results indicate that the reproductive features of R. tomentosa – with the mixed mating system and common generalist pollinators – are not limiting factors when colonization occurs in a new environment.     

Multifunctional bracts in the dove tree Davidia involucrata (Nyssaceae: Cornales): rain protection and pollinator attraction

Although there has been much experimental work on floral traits that are under selection from mutualists and antagonists, selection by abiotic environmental factors on flowers has been largely ignored. Here we test whether pollen susceptibility to rain damage could have played a role in the evolution of the reproductive architecture of Davidia involucrata, an endemic in the mountains of western China. Flowers in this tree species lack a perianth and are arranged in capitula surrounded by large (up to 10 cm x 5 cm) bracts that at anthesis turn from green to white, losing their photosynthetic capability. Flowers are nectarless, and pollen grains are presented on the recurved anther walls for 5-7 days. Flower visitors, and likely pollinators, were mainly pollen-collecting bees from the genera Apis, Xylocopa, Halictus, and Lasioglossum. Capitula with natural or white paper bracts attracted significantly more bees per hour than capitula that had their bracts removed or replaced by green paper. Experimental immersion of pollen grains in water resulted in rapid loss of viability, and capitula with bracts lost less pollen to rain than did capitula that had their bracts removed, suggesting that the bracts protect the pollen from rain damage as well as attracting pollinators.     

Nectar robbery by bees Xylocopa virginica and Apis mellifera contributes to the pollination of rabbiteye blueberry

Honey bees, Apis mellifera L., probe for nectar from robbery slits previously made by male carpenter bees, Xylocopa virginica (L.), at the flowers of rabbiteye blueberry, Vaccinium ashei Reade. This relationship between primary nectar robbers (carpenter bees) and secondary nectar thieves (honey bees) is poorly understood but seemingly unfavorable for V. ashei pollination. We designed two studies to measure the impact of nectar robbers on V. ashei pollination. First, counting the amount of pollen on stigmas (stigmatic pollen loading) showed that nectar robbers delivered fewer blueberry tetrads per stigma after single floral visits than did our benchmark pollinator, the southeastern blueberry bee, Habropoda laboriosa (F.), a recognized effective pollinator of blueberries. Increasing numbers of floral visits by carpenter bee and honey bee robbers yielded larger stigmatic loads. As few as three robbery visits were equivalent to one legitimate visit by a pollen-collecting H. laboriosa female. More than three robbery visits per flower slightly depressed stigmatic pollen loads. In our second study, a survey of 10 commercial blueberry farms demonstrated that corolla slitting by carpenter bees (i.e., robbery) has no appreciable affect on overall V. ashei fruit set. Our observations demonstrate male carpenter bees are benign or even potentially beneficial floral visitors of V ashei. Their robbery of blueberry flowers in the southeast may attract more honey bee pollinators to the crop.     

IMMATURE STAGES OF AUSTRALIAN ANTHOPHORINAE (HYMENOPTERA: APOIDEA)

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Immature stages of two species in each of the two tribes, Anthophorini and Melectini, of Anthophorinae found in Australia were studied for the first time. The larvae and pupa of Amegilla (Amegilla) pulchra (Smith), the mature larva and pupa of Amegilla (Asarapoda) sp., the mature larva of Thyreus lugubris (Smith) and the pupa of Thyreus caeruleopunctatus (Blanchard) are described and the larvae are figured, and information is given on their behaviour and development.     

Comparative effectiveness of wild bee pollination on the post-harvest characteristics of Grewia asiatica (Malvaceae)

Measuring the pollination potential of different native bees is helpful in identifying the most efficient species for their conservation and proper utilization. The current study was carried out at the Research Farm of The Islamia University of Bahawalpur to compare the pollination efficiency of four native bee species: Apis dorsata, Megachile bicolor, M. cephalotes and Megachile (Callomegachile) sp. Apis dorsata was the most abundant floral visitor of Grewia asiatica comprising 36.46% of floral visitors following by M. cephalotes and Megachile sp. The peak abundance of A. dorsata and M. bicolor was recorded at 12:00 and 08:00, respectively whereas for M. cephalotes and Megachile sp. at 16:00. Visitation frequency, stay time, body and proboscis length were significantly higher in A. dorsata whereas visitation rate, pollen load and pollen deposition were significantly higher in M. bicolor. The maximum fruit weight was recorded when M. bicolor and Megachile sp. had been the pollinators. The post-harvest fruit weight loss was lower in M. bicolor pollinated fruit -with more gradual wrinkling- than in fruit that had resulted from pollination by A. dorsata, M. cephalotes and Megachile sp. Our results suggest that M. bicolor was better pollinator of G. asiatica in terms of its reproductive success and post-harvest qualities. Further studies should focus on conservation of M. bicolor in the region.     

Comparison of pollen transfer dynamics by multiple floral visitors: experiments with pollen and fluorescent dye

BACKGROUND AND AIMS: Most plant species are visited by a diversity of floral visitors. Pollen transfer of the four most common pollinating bee species and one nectar-robbing bee of the distylous plant Gelsemium sempervirens were compared. METHODS: Naturally occurring pollen loads carried by the common floral visitor species of G. sempervirens were compared. In addition, dyed pollen donor flowers and sequences of four emasculated recipient flowers in field cages were used to estimate pollen transfer, and the utility of fluorescent dye powder as an analogue for pollen transfer was determined. KEY RESULTS: Xylocopa virginica, Osmia lignaria and Habropoda laboriosa carried the most G. sempervirens pollen on their bodies, followed by Bombus bimaculatus and Apis mellifera. However, B. bimaculatus, O. lignaria and H. laboriosa transferred significantly more pollen than A. mellifera. Nectar-robbing X. virginica transferred the least pollen, even when visiting legitimately. Dye particles were strongly correlated with pollen grains on a stigma, and therefore provide a good analogue for pollen in this system. The ratio of pollen : dye across stigmas was not affected by bee species or interactions between bee species and floral morphology. However, dye transfer was more sensitive than pollen transfer to differences in floral morphology. CONCLUSIONS: The results from this study add to a growing body of literature highlighting that floral visitors vary in pollination effectiveness, and that visitors carrying the most pollen on their bodies may not always be the most efficient at depositing pollen on stigmas. Understanding the magnitude of variability in pollinator quality is one important factor for predicting how different pollinator taxa may influence the evolution of floral traits.     

Airborne pollen survey of central calcutta,india, in relation to allergy

A continuous aeropalynological survey at Central Calcutta for two consecutive years (1985–1987) was done by using a Burkard Seven Day Recording Volumetric Spore Trap. A total of 65 pollen taxa was identified of which pollen of Trema orientalis showed a maximum frequency (about 68%) followed by Poaceae and Cyperaceae. A pollen calendar was prepared and seasonal periodicities were recorded. Some entomophilous pollen types (e.g., Delonix regia, Bougainvillea spectabilis) were also observed. The presence of pollen of Pinus, Podocarpus, and Alnus in the air of Calcutta is probably due to long distance transport from Eastern Himalayas where these plants grow. Routine skin tests were performed by using the antigenic extracts of 22 pollen types where grass, Catharanthus roseus, Cocos nucifera, Azadirachta indica, Carica papaya, Albizia lebbek, Shorea robusta, Eucalyptus sp., Terminalia sp., were proved to be allergenically potent.     

Bee diversity (Hymenoptera: Apoidea) visiting Broad Bean (Vicia faba L.) flowers in Egypt

Different bee flower visitors were observed during the flowering seasons of Broad Bean in Ismailia, eastern Egypt, the Nile Delta and Alexandria, western Egypt. Eight major bee visitors were observed: Andrena ovatula (Kirby, 1802), Andrena sp. (Andrenidae), Chalicodoma siculum (Rossi, 1792) (Megachilidae), Colletes lacunatus Dours, 1872 (Colletidae), Apis mellifera Linnaeus, 1758, Anthophora hispanica (Fabricius, 1787), A. aegyptiaca (Dalla Torre and Friese, 1895) and Xylocopa pubescens (Spinola, 1838) (Apidae). Anthophora hispanica and A. aegyptiaca as well as Chalicodoma siculum had their peak flying period in the middle of the flowering season of the Broad Bean, while Xylocopa pubescens and Andrena sp. had their peak period in the second half of the flowering period.     

草豆蔻传粉生物学的研究

比较研究了花柱卷曲性植物草豆蔻 Alpinia hainanensis两种表型(上举型和下垂型)的传粉生物学特性。结果表明:草豆蔻的花柱卷曲运动节律与其他已报道的山姜属Alpinia植物基本一致,而下垂型花的花柱卷曲运动明显滞后于上举型花约2 h。草豆蔻的花柱卷曲运动中存在一些不同步的现象,甚至在同一花序上的两朵花的花柱运动节律亦会表现出不一致的现象,但上举型花的花药开裂时间却严格同步,都发生在同类型个体的柱头全部位于花药上方之后进行。草豆蔻上举型花的花蜜分泌量、单花花粉量、花粉/胚珠比率(P/O)均明显比下垂型花多,而两种表型的胚珠数、花蜜糖含量、氨基酸含量无显著差异。在草豆蔻的单花期内不同时间段进行人工授粉,上举型花在其柱头位于花药下方时进行人工授粉,其结实率明显比柱头位于花药上方时人工授粉的处理高,下垂型花则没有显著差异。在自然居群中,草豆蔻的主要传粉者是无垫蜂Ameglla sp.和两种木蜂Xylocopa sp.,但存在传粉者不足而影响结实率的现象。完全套袋、去雄和去雌(去柱头)处理的均不结实,表明草豆蔻中不存在无融合生殖、主动自花授粉和滞后自交的生殖保障现象。而人工自交和异交均具有较高的结实率,表明草豆蔻为自交亲和植物。草豆蔻的繁育系统是具花柱卷曲性运动的异花授粉的交配系统。     

Modern pollen assemblages from Reasi (Jammu and Kashmir), India: a tool for interpreting fossil pollen records

Twenty five surface samples/moss cushions were collected for palynological analysis from open areas of Reasi District, Jammu and Kashmir (India). These samples were used to investigate the relationships between extant vegetation and modern pollen spectra, which serve as modern analogue for the reliable ecological interpretation of fossil pollen records. The present vegetation in the region comprises tropical dry deciduous forests and subtropical pine forests with scattered stands of oak. The pollen analysis reveals that Pinus sp. (average 69% in the pollen assemblages), amongst the conifers, dominates the pollen rain, which can be attributed to its high pollen productivity and exceptional pollen dispersal efficiency. Cedrus sp. and Podocarpus sp. pollen contribute with an average of 16 and 5% to the total pollen rain. Other conifers such as Picea sp., Abies sp., Juniperus sp. and Tsuga sp., as well as broad-leaved taxa such as Quercus sp., Alnus sp., Betula sp., Carpinus sp., Corylus sp., Juglans sp., Ulmus sp., Salix sp., Elaeocarpus sp., Mallotus sp. and Aesculus sp., have lower averages of 1 to 4.5% in the total pollen rain which could be either due to their poor pollen dispersal efficiency or to the poor preservation in the samples. Tubuliflorae (average 25%), Poaceae (average 6.26%), Cerealia and other crop plants (average 7.68%) are other prominent taxa in the pollen rain. The nearly complete absence of members of tropical dry deciduous forests in the pollen spectra likely is due to the fact that most species in this vegetation type are not wind pollinated.     

Analysis of Airborne Pollen Fall in Edirne,Turkey

In the atmosphere of Edirne 12 691 pollen grains belonging to 42 taxa were identified by using of Durham sampler in 2000 and 2001. A total of 6 189 pollen grains per cm2 were recorded in 2000 and a total of 6 502 pollen grains per cm2 in 2001. Total pollen grains consisted of 71.81% grains from arboreal plants, 25.88% grains from non-arboreal plants and 2.31% unidentified pollen grains. Pollen from the following taxa were also found to be prevalent in the atmosphere of Edirne: Gramineae, Pinus sp., Quercus sp.,Cupressaceae/Taxaceae, Platanus sp., Salix sp., Morus sp., Populus sp., Carpinus sp., Juglans sp.,Chenopodiaceae/Amaranthaceae, Fraxinus sp., Fagus sp., Ulmus sp., Ailanthus sp., Alnus sp., Ostrya sp.,Helianthus sp. The season of maximum pollen fall was from April to June, with a prevalence of arboreal pollen in the first month, and of pollen from non-arboreal plants in the last months of the year.