Search results for "Pollinator"

Low fruit set in a dioecious tree: pollination ecology of Commiphora harveyi in South Africa

2005

Dioecious plant species differ in floral morphology and rewards between females and males. Pistillate flowers on female plants often lack pollen and can be less attractive to pollinators, which can have consequences for the visitation rates of the sexes. We studied the pollination ecology of the dioecious tree Commiphora harveyi in a coastal scarp forest in eastern South Africa. Floral display, visiting insect species, visitation rate and natural fruit set were recorded. Additionally, we pollinated flowers by hand to determine experimental fruit set. We found that male trees had more and larger flowers per inflorescence than female trees. Both sexes produced nectar in low amounts. During 20…

Pollination syndromes in African Marantaceae

2009

† Background and Aims The Marantaceae (550 spp.) is the most derived family in the order Zingiberales and exhibits a complex explosive pollination mechanism. To understand the evolutionary significance of this unique process of pollen transfer, comparative morphological and ecological studies were conducted in Gabon. † Methods During a total stay of 11 months, 31 species of Marantaceae were investigated at different sites in Gabon. The study included analyses of floral diversity, observations on the pollinator spectrum as well as ecological measurements (e.g. nectar sugar concentration and volume). † Key Results Analyses reveal five flower types based on flower size and pigmentation, spatia…

FLIES AS POLLINATORS OF MELITTOPHILOUS SALVIA SPECIES (LAMIACEAE)

2014

UNLABELLED • PREMISE OF THE STUDY Floral adaptation to a functional pollinator group does not necessarily mean close specialization to a few pollinator species. For the more than 950 species of Salvia, only bee and bird pollinations are known. Restriction to these pollinators is mainly due to the specific flower construction (lever mechanism). Nevertheless, it has been repeatedly suggested that Salvia flowers might also be pollinated by flies. Are flies able to handle the lever mechanism? Are they functionally equivalent pollinators? In this study, we compared and quantified pollen transfer by bees and flies to test whether flies are true pollinators in Salvia.• METHODS We identified pollin…

Bee reverse-learning behavior and intra-colony differences: Simulations based on behavioral experiments reveal benefits of diversity

2014

Abstract Foraging bees use color cues to help identify rewarding from unrewarding flowers. As environmental conditions change, bees may require behavioral flexibility to reverse their learnt preferences. Learning to discriminate perceptually similar colors takes bees a long time, and thus potentially poses a difficult task to reverse-learn. We trained free-flying honeybees to learn a fine color discrimination task that could only be resolved (with about 70% accuracy) following extended differential conditioning. The bees were then tested for their ability to reverse-learn this visual problem. Subsequent analyses potentially identified individual behavioral differences that could be broadly …

Essential oils of Chiliadenus lopadusanus (Asteraceae).

2013

The essential oils from the leaves and flowers of Chiliadenus lopadusanus growing on Lampedusa Island were obtained by hydrodistillation and analyzed by GC-MS. The major component was camphor (39.4% in the leaves and 24.0% in the flowers), followed in the leaves by torreyol (6.7%), t-cadinol (5.2%) and 1,8-cineole (3.8%), while in the flowers by t-cadinol (15.2%), t-muurolol (5.1%) and torreyol (4.5%). Among the compounds identified, several seem to play a role in antibacterial, antifungal, allelopathic and spasmolytic activity. In addition, several compounds identified in this study seem to influence the attraction of Megachile (Eutricharaea) apicalis (Megachilidae) and Halictus (Seladonia…

Influence of different pollinators on Winter melon grown under polyethyle tunnels

2002

Pollination ecology of the dioecious tree Commiphora guillauminii in Madagascar

2004

In dioecious plant species differences in morphology and resources between female and male flowers can have consequences for flower visitation rates. Female flowers sometimes lack pollen and can be less attractive to pollinators than male flowers. We studied the pollination ecology of the dioecious tree Commiphora guillauminii in a dry deciduous forest in western Madagascar. We recorded floral display, visiting insect species and visitation rates for female and male trees. The results showed that female trees produce significantly larger but fewer flowers per inflorescence than male ones. Number of flowers per tree did not differ between the sexes. During 270 observation-hours we observed 1…

Electrophysiological and behavioural responses of the housefly to “sweet” volatiles of the flowers of Caralluma europaea (Guss.) N.E. Br.

2013

In sapromyiophilous plants, up to date, long range attraction of fly pollinators has been thoroughly investigated and attributed to ‘‘fetid’’ floral compounds, while the ‘‘sweet’’ floral scent fraction has not been spe- cifically investigated and its role has received little atten- tion. The aim of the present study was to verify if terpenoids, which are the main compounds of the floral bouquet of Caralluma europaea, play a role in the attrac- tion of its pollinator Musca domestica. Terpinolene, a- terpinene and linalool, described as the three main volatiles of the flowers of C. europaea, were evaluated in electro- physiological investigations and blends of these com- pounds as well as the…

Milichiella lacteipennis: new record for Lampedusa Island (Italy).

2009

The authors report the first record of Milichiella lacteipennis (Loew) (Diptera Milichiidae) in Lampedusa Island (Italy), and give information on its distribution and biology.

Periploca laevigata Aiton subsp. angustifolia (Labill.) Markgraf on Lampedusa Island

2012

Periploca laevigata Aiton subsp. angustifolia (Labill.) Markgraf [synonym: Periploca laevigata Labill.] (Apocynaceae – Periplocoideae sensu Endress & Bruyns 2000) is a Mediterranean-Saharan element growing wild in the low and middle Mediterranean basin and descending southwards to the northern and central Sahara. It is found in North Africa (from Morocco to Egypt), southern Spain, Sicily, Malta, Crete, Lebanon and Syria (Ghrabi 2005). In Sicily it is reported only from some Sicilian Islands: Egadi, Pantelleria, Lampedusa and Linosa (Pignatti 1982). In this paper we report some unpublished data and a summary of information of recent publications on P. laevigata subsp. angustifolia made durin…