Bat visits to Marcgravia pittieri and notes on the inflorescence diversity within the genus Marcgravia (Marcgraviaceae)

We report bat visits to the inflorescences of Marcgravia pittieri. The animals were videotaped visiting the nectaries of the inflorescences in short hovering flight. Nectarivorous bats caught in front of the inflorescences were Anoura cultrata and Hylonycteris underwoodi (both Phyllostomidae: Glossophaginae). Furthermore, we provide a short overview on inflorescence architecture within the genus Marcgravia with a special focus on functional morphology in chiropterophilous species.     

东亚水鼠耳蝠形态描述与分类

水鼠耳蝠 Myotis daubentonii(Chiroptera,Vespertilionidae),广泛分布于欧洲和亚洲,亚种分化众多,在亚洲已报道有 M.d.ussuriensis,M.d.loukashkini,M.d.petax和M.d.laniger但其分类地位一直受到国内外学者的关注.中国的水鼠耳蝠长期以来被认为属于水鼠耳蝠M daubentonii亚种.最近有研究认为中国的水鼠耳蝠与欧洲的水鼠耳蝠M.daubentonii不同,并把"petax"提升为种.在中国境内相继采到17只鼠耳蝠标本,根据外形、头骨、牙齿、阴茎骨、线粒体DNA细胞色素b等特征,鉴定为东亚水鼠耳蝠Myotis petax,对中国水鼠耳蝠的种和亚种分类做一讨论.     

Winter mortality rates of bats inhabiting man-made shelters (northern Poland)

Non-predator and non-accidental mortality rates of bats inside the city of Toruń's fortification system (northern Poland) were studied over winter periods from 1995 to 2000. The bats were counted and dead bats collected at 1-month intervals from October to April. In total, thirty four dead bats were found. The percentage of dead individuals of the surveyed bats was low:Myotis daubentonii (0.6%),M. nattereri (0.4%),Plecotus auritus (0.4%),M. myotis (0.1%), and zero forBarbastella barbastellus. There was no clear difference in the species ratio of the observed and dead bats. The percentage of the dead to surveyed bats was lower in November (0.07%) and December (0.07%), and higher in September (3.3%) and April (1.3%). Temperature explained 84% of variation of the differences in mortality rates. Observations suggest that non-predator and non-accidental mortality inside the fortifications was extremely low and non-linearly correlated with the ambient temperature measured outside the fortifications.     

MORPHOLOGY AND DISTRIBUTION OF PETIOLAR NECTARIES IN IPOMOEA (CONVOLVULACEAE)

The distribution of petiolar nectaries in 24 species of Ipomoea was investigated. Petiolar nectaries were found on 12 species (8 new reports, 4 confirmations of previous reports) and quoted from the literature as being found on 3 other species; they were absent from 9 species investigated. The structure of petiolar nectaries in the genus ranges from simple beds of superficial nectar-secreting trichomes (1 species), to slightly recessed “basin nectaries” (8 species), to “crypt nectaries,” which are structurally the most complex extrafloral nectaries known (3 species). (Structures were not determined for 3 species.) Petiolar nectaries are present in all subgenera, but all crypt nectaries occur in the same section (Eriospermum). Species with extrafloral nectaries tend to be perennial; species lacking extrafloral nectaries tend to be annual. There is no relationship between temperate or tropical habitat and presence of nectaries.     

The influence of extrafloral nectaries on parasitism of an insect herbivore

The extrafloral nectaries of many plants promote ant defense against insect herbivores. We examined the influence of extrafloral nectaries on the levels of parasitism of a generalist insect herbivore, the gypsy moth (Lymantria dispar L.). Larvae and pupae of the moth were collected from trees with and without extrafloral nectaries growing in the same forests in South Korea and reared to evaluate parasitism. More parasitism occurred on plants with extrafloral nectaries in seven of the nine season-long collections at the six sites and in four out of five collecting periods. Parasitism was higher on the four main genera of plants with extrafloral nectaries than on any of five main genera of plants without extrafloral nectaries. There was no difference in parasitoid richness; nine species occurred in each group, eight of which were the same. There was a positive and almost significant correlation between the abundance of plants with extrafloral nectaries and the parasitism of gypsy moth at the sites. Extrafloral nectaries may reduce herbivory by inducing more parasitism of the insect herbivores that attack plants bearing the glands.     

Targeted predation of extrafloral nectaries by insects despite localized chemical defences

Extrafloral (EF) nectaries recruit carnivorous arthropods that protect plants from herbivory, but they can also be exploited by nectar thieves. We studied the opportunistic, targeted predation (and destruction) of EF nectaries by insects, and the localized chemical defences that plants presumably use to minimize this effect. In field and laboratory experiments, we identified insects that were possibly responsible for EF nectary predation in Vicia faba (fava bean) and determined the extent and accuracy of the feeding damage done to the EF nectaries by these insects. We also performed biochemical analyses of plant tissue samples in order to detect microscale distribution patterns of chemical defences in the area of the EF nectary. We observed selective, targeted feeding on EF nectaries by several insect species, including some that are otherwise not primarily herbivorous. Biochemical analyses revealed high concentrations of l-3,4-dihydroxyphenylalanine, a non-protein amino acid that is toxic to insects, near and within the EF nectaries. These results suggest that plants allocate defences to the protection of EF nectaries from predation, consistent with expectations of optimal defence theory, and that this may not be entirely effective, as insects limit their exposure to these defences by consuming only the secreting tissue of the nectary.     

Ecological and anthropogenic drivers of rabies exposure in vampire bats: implications for transmission and control

Despite extensive culling of common vampire bats in Latin America, lethal human rabies outbreaks transmitted by this species are increasingly recognized, and livestock rabies occurs with striking frequency. To identify the individual and population-level factors driving rabies virus (RV) transmission in vampire bats, we conducted a longitudinal capture-recapture study in 20 vampire bat colonies spanning four regions of Peru. Serology demonstrated the circulation of RV in vampire bats from all regions in all years. Seroprevalence ranged from 3 to 28 per cent and was highest in juvenile and sub-adult bats. RV exposure was independent of bat colony size, consistent with an absence of population density thresholds for viral invasion and extinction. Culling campaigns implemented during our study failed to reduce seroprevalence and were perhaps counterproductive for disease control owing to the targeted removal of adults, but potentially greater importance of juvenile and sub-adult bats for transmission. These findings provide new insights into the mechanisms of RV maintenance in vampire bats and highlight the need for ecologically informed approaches to rabies prevention in Latin America.     

Influence of elevated CO2 and ultraviolet-B radiation levels on floral nectar production: a nectary-morphological perspective

 Investigations of the effects of two global events – elevated CO₂ levels and enhanced ultraviolet-B (UV-B) radiation – on floral nectar production are reviewed from twelve dicotyledonous families. Furthermore, to allow comparisons between nectary morphology and nectar production in treated plants of these fifteen species, new data on floral nectary structure are provided for Malcolmia maritima (L.) R. Br. (Brassicaceae) and Scabiosa columbaria L. (Dipsacaceae). All but the last taxon possessed mesenchymatic floral nectaries with surface stomata. Few clear relationships existed between nectary morphology and various physiological responses to CO₂ or UV-B enrichment, indicating that species responded notwithstanding nectary structure itself. Overall, nectar-solute concentration was least affected by elevated CO₂ or UV-B radiation; consequently, changes in nectar volume were responsible for differences in nectar-sugar production per flower. Three species of Fabaceae experienced no change in floral nectar production upon exposure to elevated CO₂. To date, no study of enhanced UV-B radiation reported a consistent reduction in floral nectar production; three species of Brassicaceae responded differently, but various levels of ozone depletion were simulated. Experimentation with more taxa – including those possessing nectary types such as septal (gynopleural) nectaries (e.g. many monocotyledons) or aggregations of glandular trichomes – and expanding such physiological studies to species possessing extrafloral nectaries, are recommended. Received August 8, 2002; accepted November 23, 2002 Published online: June 2, 2003     

广东省发现长指鼠耳蝠及其回声定位声波特征

2013年7月在广东南岭国家级自然保护区阳山县境内(24°48′39.5′′N,112°51′01.3′′E,海拔155 m)捕捉到4只雄性蝙蝠,体型小,前臂长34.1~34.7 mm,颅全长14.3~14.7 mm;体毛浓密,背毛毛基黑色,毛尖灰色,腹毛黑或棕色,毛尖奶油白,靠近肛门处腹毛浅灰色,些许白色;翼膜附着于跖部末端;后足特别延展,长度超过胫骨长之半;鉴定为长指鼠耳蝠[Myotis longipes(Dobson1873)]。同时,基于Cyt b基因序列(1 140 bp)构建的部分鼠耳蝠物种系统进化关系,进一步确认上述标本为长指鼠耳蝠,为广东省翼手目新纪录。该种蝙蝠在我国贵州、广西、重庆有分布记载,但标本和相关资料很少。本文给出了长指鼠耳蝠的外形和头骨特征测量数据,并与印度的标本进行了对比。长指鼠耳蝠的回声定位声波为调频型(FM),主频率为68.2 k Hz;此外,对其分类地位和分布状况进行了讨论。标本保存于广东省生物资源应用研究所。     

DISTRIBUTION OF DEFENSE NECTARIES IN IPOMOEA (CONVOLVULACEAE)

The structure and distribution of defense nectaries in the genus Ipomoea (Convolvulaceae) were investigated. These nectaries do not reward pollinators and probably contribute to antiherbivore defense. Of 22 species sectioned, 15 had defense nectaries on the sepals. Of 12 other species observed, ten had sepal nectaries and two did not. Structurally, 14 of the species sectioned had crypt sepal nectaries and one had a basin nectary. Of the 14 species with crypt nectaries, two had invaginated spaces adding greatly to the internal area of these nectaries, and forming the most complex nectaries that have been reported. We term these labyrinthine crypt nectaries. All three types of nectaries are lined with secretory trichomes along the proximal surfaces of the crypts. Species with defense nectaries on the sepals tend to have petiolar defense nectaries as well, but the two locations may have different nectary types; e.g., basins on the petiole and crypts on the sepals. Since most reports of the function of these nectaries have shown antiherbivore defense by nectar feeders, the distributions of defense nectaries with respect to region and life history of the species were sought. Plants without sepal nectaries were found to have significantly smaller seeds than plants with sepal nectaries; they were also more frequently annuals. No significant relationship was found between region or breeding system and defense nectaries.     

Colleters in Turnera and Piriqueta (Turneraceae)

The anatomy of colleters was examined by light and scanning electron microscopy in 25 species of Turnera and nine species of Piriqueta. Based on morphology, four categories of colleters were recognized: standard, sessile, lachrymiform and trochleariform, all of which differ in shape and length/width ratio. They all have a similar anatomy: they consist of an axis of parenchymatous cells, sheathed by a palisade epidermis. The standard type is the most widespread in the studied taxa; the lachrymiform example was found in those species of Piriqueta with setiform glandular hairs; only one trochleariform example appeared in T: diffusa. The sessile type is considered to be a morphological transitional form between extrafloral nectaries and colleters. This is the first record of sessile, lachrymiform and trochleariform colleters. The anatomy of colleters is compared with other secretory structures such as glandular trichomes and extrafloral nectaries.     

Nectar biodiversity: a short review

 Nectaries differ in many aspects but a common feature is some kind of advantage for the plant conferred by foraging of consumers which may defend the plant from predators in the case of extrafloral nectaries, or be agents of pollination in the case of floral nectaries. This minireview is concerned mainly with floral nectaries and examines the following characteristics: position in flower; nectary structure; origin of carbohydrates, aminoacids and proteins; manner of exposure of nectar; site of nectar presentation; volume and production of nectar in time; sexual expression of flower and nectary morphology; nectar composition and floral sexual expression; variability of nectar composition; fate of nectar; energy cost of nectar production. The species of certain large families, such as Brassicaceae, Lamiaceae and Asteraceae, resemble each other in nectary organisation; other families, such as Cucurbitaceae and Ranunculaceae, have various types of organisation. A scheme is presented to illustrate factors influencing nectary and nectar biodiversity. Received July 23, 2002; accepted September 18, 2002 Published online: June 2, 2003     

Should aphids attract or repel ants? Effect of rival aphids and extrafloral nectaries on ant–aphid interactions

Among plants and herbivores, two types of conflicts occur in relation to mutualism with ants: one is competition for ant mutualism among myrmecophilous herbivores and plants, and the other is the conflict whether to attract or repel ants between myrmecophiles and nonmyrmecophiles that are damaged by ants. We investigated the extent to which two species of aphids (Megoura crassicauda and Aphis craccivora) and extrafloral nectaries on their host plant (Vicia faba var. minor) interact with one another for their relationships with ants. We designed an experiment where ants can choose to visit seedlings colonized by (1) M. crassicauda, (2) A. cracivora, (3) both aphid species, or (4) neither aphid species. Ants preferred A. craccivora to extrafloral nectaries and avoided tending M. crassicauda. We also analyzed the population growth of each aphid when it coexists with (1) ants, (2) the other aphid species, (3) ants and the other aphid species, or (4) neither of them. Under ant-free conditions, we detected an exploitative competition between the two aphid species. The ants had no significant effect on the population of A. craccivora, whereas they had negative effects on the population growth of M. crassicauda by attacking some individuals. When both aphids coexisted, M. crassicauda suffered ant attack more intensely because A. craccivora attracted more ants than extrafloral nectaries despite ant-repelling by M. crassicauda. On the other hand, the ants benefited A. craccivora by eliminating its competitor. To avoid ant attack, aphids may have been selected either to be more attractive to ants than other sympatric sugar sources or to repel the ants attracted to them. We hypothesize that competition among sympatric sugar sources including rival aphids and extrafloral nectaries is a factor restricting aphids to be myrmecophilous. Received: January 17, 2000 / Accepted: July 4, 2000     

Seed Dispersal by Bats and Birds in Forest and Disturbed Habitats of Chiapas,Mexico1

We examined seed dispersal by bats and birds in four habitats of the Selva Lacandona tropical rain forest region, Chiapas, Mexico. The four habitats represented a disturbance gradient: active cornfield, ten-year-old abandoned cornfield, cacao plantation, and forest. Using seed traps examined before sunrise (0400 h) and before sunset (1800 h), we compared volant vertebrate seed dispersal, assuming that seeds found at the end of the night were dispersed by bats and those found at the end of the day were dispersed by birds. We did not find seeds from other frugivores such as monkeys or opossums. In all habitats bats dispersed more seeds than birds. In most months bats also dispersed more seeds than birds, except in December when no seeds were found in the traps. Bats also consistently dispersed more species of seeds than birds, although a x2 comparison showed differences not to be significant. Fifty percent of the species represented in the dispersed seeds in all habitats were pioneer species. Cecropia seeds represented a high percentage (up to 87% of those dispersed by bats and up to 83% by birds) of dispersed seeds that fell in our traps. The influence of bats and birds on secondary successional processes is likely to be fundamental for the establishment of vegetation. Since bats dispersed more seeds than birds (primarily to disturbed areas and consisting primarily of pioneer species), they are likely to play an important role in successional and restoration processes among habitats as structurally and vegetationally different as cornfields, old fields, cacao plantations, and forest.     

The comparative phylogeography of neotropical mammals: patterns of intraspecific mitochondrial DNA variation among bats contrasted to nonvolant small mammals

The major aim of this study was to compare the phylogeographic patterns of codistributed bats and small nonvolant Neotropical mammals. Cytochrome b sequences (mitochondrial DNA) were obtained for a total of 275 bats representing 17 species. The tissue samples were collected in coastal Brazil, and were available from Mexico and the Guyana. The study concentrates on four species (Artibeus lituratus, Carollia perspicillata, Sturnira lilium and Glossophaga soricina) which were well represented. The other 13 species were sequenced to test the generality of the patterns observed. In general, sequence divergence values within species were low, with most bat species presenting less than 4% average sequence divergence, and usually between 1 and 2.5%. Clades of highly similar haplotypes enjoyed broad distribution on a continental scale. These clades were not usually geographically structured, and at a given locality the number of haplotypes was high (8-10). As distance increased, some moderately divergent clades were found, although the levels of divergence were low. This suggests a geographical effect that varied depending on species and scale. Small nonvolant mammals almost invariably have high levels of sequence divergence (> 10%) for cytochrome b over much shorter distances (< 1000 km). The grain of intraspecific variation found in small nonvolant mammals is much finer than in bats. Low levels of geographical structuring cannot be attributed to a slower evolutionary rate of bat DNA in relation to other mammalian taxa. The phylogeographic pattern of bats contrasts sharply with the pattern found for Neotropical rodents and marsupials.     

Morphological study of the heart innervation of bats Myotis daubentoni and Eptesicus serotinus (Microchiroptera: Vespertilionidae) during hibernation

The capability of bats to have heart rates fewer than 10 beats/min during hibernation and greater than 700 beats/min during flight surprises biologists and cardiologists. Cardioacceleration of hibernating bats is considered to be a function of their intracardiac nervous system. In the present study we investigated the morphology of the heart innervation of ten M. daubentoni and four E. serotinus bats during their natural hibernation in order to determine which intracardiac structures may be involved in cardioacceleration during their short-term (in av. 15-30 min) arousal from hibernation. The primary conclusions were as follows: (1) The innervation pattern of bats differs from many mammals in that bats have: (a) a subepicardiac nerve plexus which is vastly developed and contains a large number of intrinsic ganglia on both atria and ventricles, and (b) very small diameter axons within the unmyelinated nerve fibres, from 0.15 to 0.7 microm. (2) During hibernation an intercellular space of the sinoatrial node of M. daubentoni bats was in part filled with a cottony substance which can presumably be considered to be a temporary barrier between the conductive cardiomyocytes and nerve fibres. (3) In the hibernating bats, the acetylcholine vesicles were aggregated in the synaptic bulbs away from the presynaptic membrane. Possibly, the aggregation of the acetylcholine vesicles is capable of modifying cholinergic influences on the heart activity of hibernating bats. (4) The dense cores of catecholamine synaptic vesicles within, adrenergic axon terminals were seldomly observed in hibernating bats. Therefore, catecholamines probably do not play a crucial role in the cardioacceleration of hibernating bats.     

Floral rewards and pollination in Cytiseae (Fabaceae)

 Cytiseae have been reported to be mostly nectar-lacking, yet some taxa secrete nectar from extrastaminal nectaries. We studied the pollination biology of four shrubby species of Cytiseae (Cytisophyllum sessilifolium (L.) Lang, Spartium junceum L., Genista radiata (L.) Scop., Genista cilentina Valsecchi) which differ for ecology, distribution and population size. All species resulted obliged xenogamous, insect visits being necessary for successful pollination. Bumblebees and solitary bees are the principal pollinators, but also many beetles, some hover-flies, and few bugs visit flowers. Pollinator specificity is low, and this may be the reason of the scarce seed set compared to the number of ovules. Pollen is the main reward, but traces of glucose were detected in all species, at the base of vexillum or on the reproductive column. Nectar production is irregular in time, and apparently unpredictable. We suppose that nectar may play a role in attracting pollinators determining their right position for a successful pollination. Received August 12, 2002; accepted November 25, 2002 Published online: June 2, 2003     

Nectar-carbohydrate production and composition vary in relation to nectary anatomy and location within individual flowers of several species of Brassicaceae

Nectar-carbohydrate production and composition were investigated by high-performance liquid chromatography and enzymology in nine species from five tribes of the Brassicaceae. In six species (Arabidopsis thaliana (L.) Heynh., Brassica napus L., B. rapa L., Lobularia maritima (L.) Desv., Raphanus sativus L., Sinapis arvensis L.) that produced nectar from both lateral nectaries (associated with the short stamens) and median nectaries (outside the long stamens), on average 95% of the total nectar carbohydrate was collected from the lateral ones. Nectar from these glands possessed a higher glucose/fructose ratio (usually 1.0–1.2) than that from the median nectaries (0.2–0.9) within the same flower. Comparatively little sucrose was detected in any nectar samples except from Matthiola bicornus (Sibth. et Sm.) DC., which possessed lateral nectaries only and produced a sucrose-dominant exudate. The anatomy of the nectarial tissue in nectar-secreting flowers of six species, Hesperis matronalis L., L. maritima, M. bicornus, R. sativus, S. arvensis, and Sisymbrium loeselii L., was studied by light and scanning-electron microscopy. Phloem alone supplied the nectaries. However, in accordance with their overall nectar-carbohydrate production, the lateral glands received relatively rich quantities of phloem that penetrated far into the glandular tissue, whereas median glands were supplied with phloem that often barely innervated them. All nectarial tissue possessed modified stomata (with the exception of the median glands of S. loeselii, which did not produce nectar); further evidence was gathered to indicate that these structures do not regulate nectar flow by guard-cell movements. The numbers of modified stomata per gland showed no relation to nectar-carbohydrate production. Taken together, the data on nectar biochemistry and nectary anatomy indicate the existence of two distinct nectary types in those Brassicacean species that possess both lateral and median nectaries, regardless of whether nectarial tissue is united around the entire receptacle or not. It is proposed that the term “nectarium” be used to represent collectively the multiple nectaries that can be found in individual flowers. Received: 21 July 1997 / Accepted: 19 September 1997     

Activity Pattern of the Trawling Phyllostomid Bat,Macrophyllum macrophyllum,in Panamá1

We studied activity patterns of long‐legged bats, Macrophyllum macrophyllum (Phyllostomidae), in the Barro Colorado Nature Monument, Panamá, using radio‐telemetry. Activity of four males and five females equipped with radio‐transmitters were monitored for 4–7 entire nights each between April and July 2002. Bats exhibited maximum activity around dusk and high activity during the night. Males and females foraged for equal amounts of time in continuous flight (mean: 7 min, maximum 1 h) with interspersed resting phases (mean: 15 min, maximum 3 h). Activity of M. macrophyllum was sensitive to several factors. Time of emergence and return to day roost were correlated with time of sunset and sunrise, respectively. Maximum bat activity coincided with high abundance of aerial insects. Finally, heavy rain caused bats to reduce or cease flight activity. Direct observations and field video recordings support the assumption that M. macrophyllum employs two distinct foraging modes: trawling of insects from and capture of aerial insects at low heights above water. Combination of foraging modes gives M. macrophyllum high flexibility and efficiency in prey search. Activity, foraging mode, and morphology, which are similar to trawling bats from other families, distinguish M. macrophyllum from all other phyllostomid species and grant it access to open habitat above water, a habitat no other phyllostomid bat has conquered.     

Changes in abundance of hibernating bats in central Slovakia (1992–2009)

An analysis of long-term changes in abundance of hibernating bats as revealed from the annual monitoring programme conducted in four mountain regions of the Western Carpathians (Muránska planina Mts, Revúcka vrchovina Mts, Slovensky kras Mts, Štiavnické vrchy Mts) during the period 1992–2009 is providing in the paper. Data from 52 hibernacula were analysed. Among 18 bat species recorded, an apparent population increase of three most abundant thermophilous and originally cave dwelling species of bats, Rhinolophus hipposideros, R. ferrumequinum, Myotis myotis, was observed. In other bat species (e.g., R. euryale, M. emarginatus, M. mystacinus, M. dasycneme, Barbastella barbastellus), population trends could not be detected and because of data scarcity, they should be evaluated from more extensive datasets obtained from a wide range of hibernacula or from a completely different type of evidence.