The Ruby-throated Hummingbird and its major food plants: ranges, flowering phenology, and migration

1982 ◽  
Vol 60 (2) ◽  
pp. 210-219 ◽  
Author(s):  
Robert I. Bertin
Keyword(s):  
Seed Set ◽  
Flowering Phenology ◽  
Food Plants ◽  
Field Observations ◽  
Forest Types ◽  
Insect Pollination ◽  
Major Food ◽  
Insect Visitation ◽  
Herbarium Data ◽  
And Migration

The Ruby-throated Hummingbird (or rubythroat, Archilochus colubris) and several of its major food plants were examined to assess the importance of rubythroat versus insect pollination, the overlap of geographical ranges, and the synchrony between migration and flowering times. Seed set of Impatiens biflora was increased 8–17% by rubythroat and insect visitation over the level achieved by insects alone. The rubythroat's range is not contiguous with that of any of 22 putative food plants examined, but is nearly coincident with the range of certain forest types, perhaps reflecting the importance of sap for food. A new method was developed to estimate peak flowering times of plants from herbarium data. Based on these data and field observations, only one rubythroat food plant (Impatiens biflora) had peak flowering times close to peak rubythroat migration times throughout their shared range. Rubythroats and their North American food plants are facultative mutualists, with the plants apparently having been evolutionarily more labile.

A comparison of flower-visiting insects to rare Symphyotrichum sericeum and common Solidago nemoralis (Asteraceae)

Botany ◽  
2010 ◽  
Vol 88 (3) ◽  
pp. 241-249 ◽  
Author(s):  
Diana Bizecki Robson
Keyword(s):  
Seed Set ◽  
Visitation Rate ◽  
Hand Pollination ◽  
Insect Visitation ◽  
The Common ◽  
Insect Activity ◽  
Flower Visiting ◽  
Common Plant ◽  
Insect Visitors ◽  
Over Time

Flower-visiting insect activity to the rare Symphyotrichum sericeum (Vent.) G.L. Nesom and the common Solidago nemoralis Ait. var. longipetiolata (Mack. & Bush) Pal. & Steyerm. was examined to detect compositional and temporal similarities. A hand pollination experiment was conducted to determine whether pollen was limiting seed set. Of the 31 insect taxa that visited these plants, Bombus bifarius Cresson was the most common visitor to both species. More insect visitors of the Halictidae and Bombyliidae were received by S. sericeum than S. nemoralis, which received more visitors of the Syrphidae and Tachinidae. The insect visitation rate was not significantly different between the two plant species. Solidago nemoralis was visited by fewer insect taxa per day than S. sericeum, but the constancy of its visitors was higher. The insect visitor composition changed over time, with B. bifarius ignoring S. sericeum plants initially, then visiting them more frequently as the number of receptive S. nemoralis capitula declined. Hand pollination increased seed set in the earliest flowering capitula of S. sericeum, but not for those flowering during the peak. This research shows that the quantity of insect visits to the rare plant is comparable with that of the common plant but that pollination quality may be lower, particularly for early blooming capitula.

Latitudinal shift in the timing of flowering of tree species across tropical Africa: insights from field observations and herbarium collections

2020 ◽  
Vol 36 (4) ◽  
pp. 159-173
Author(s):  
Dakis-Yaoba Ouédraogo ◽  
Olivier J. Hardy ◽  
Jean-Louis Doucet ◽  
Steven B. Janssens ◽  
Jan J. Wieringa ◽  
...  
Keyword(s):  
Tree Species ◽  
Central Africa ◽  
Flowering Phenology ◽  
Graphical Analysis ◽  
Dry Season ◽  
Circular Statistics ◽  
Significant Shift ◽  
The North ◽  
Herbarium Data ◽  
Herbarium Collections

AbstractTemporal and spatial patterns in flowering phenology were assessed for eight tropical African tree species. Specifically, the frequency and seasonality of flowering at seven sites in central Africa were determined using field data, graphical analysis and circular statistics. Additionally, spatial variation in the timing of flowering across species range was investigated using herbarium data, analysing the relative influence of latitude, longitude and timing of the dry season with a Bayesian circular generalized linear model. Annual flowering was found for 20 out of the 25 populations studied. For 21 populations located at the north of the climatic hinge flowering was occurring during the dry season. The analysis of herbarium collections revealed a significant shift in the timing of flowering with latitude for E. suaveolens, and with the timing of the dry season for M. excelsa (and to a lesser extent L. alata), with the coexistence of two flowering peaks near the equator where the distribution of monthly rainfall is bimodal. For the other species, none of latitude, longitude or timing of the dry season had an effect on the timing of flowering. Our study highlights the need to identify the drivers of the flowering phenology of economically important African tree species.

Reproductive ecology of Dryas integrifolia in the high Arctic semi-desert

1996 ◽  
Vol 74 (9) ◽  
pp. 1451-1460 ◽  
Author(s):  
P. G. Krannitz
Keyword(s):  
Seed Dispersal ◽  
Seed Set ◽  
High Arctic ◽  
The Arctic ◽  
Bet Hedging ◽  
Crop Failure ◽  
Flower Stalk ◽  
Insect Visitation ◽  
Solar Noon ◽  
Seed Data

Flowering and fruiting of Dryas integrifolia were studied at Igloolik and Pangnirtung to analyse the importance of variation in heliotropy and flower size to seed set and weight. In addition, peduncle elongation and seed plume length were also studied to analyse variation in seed dispersal characters. At both Igloolik and Pangnirtung, most Dryas flowers were not heliotropic throughout the course of the day, but in general, pointed towards the solar noon sun. Benefits to orienting toward the sun were warmer gynoecial temperatures, heavier seeds, and more insect visitation (though not percent seed set). Flowers varied in size from 1.2 to 2.7 cm in diameter and differed in size between plants. Even though larger flowers did not point towards the solar noon sun more than smaller flowers, they had heavier and proportionally more seeds. Variation in peduncle elongation suggests the potential for conservative dispersion when a flower has produced only a few propagules: flowers with fewer or no seeds had shorter stalks. Similarly, with good seed production, a bet hedging strategy is apparent: seeds located at the centre of the receptacle had much longer plumes than those at the perimeter of the seed head. All seed data were from Pangnirtung; the cold summer in 1986 at Igloolik resulted in a complete seed crop failure. Despite the adversity of the arctic climate, there are moderate summers during the lifetime of perennial plants such as D. integrifolia in which adaptations like those described in this study benefit the production of sexual offspring. Keywords: heliotropism, flower stalk elongation, basking insects, seed dispersal, insolation, bet hedging.

scholarly journals Using Commercial Bumble Bee Colonies as Backup Pollinators for Honey Bees to Produce Cucumbers and Watermelons

1998 ◽  
Vol 8 (4) ◽  
pp. 590-594 ◽  
Author(s):  
M.S. Stanghellini ◽  
J.T. Ambrose ◽  
J.R. Schultheis
Keyword(s):  
Honey Bee ◽  
Honey Bees ◽  
Seed Set ◽  
Citrullus Lanatus ◽  
Bumble Bees ◽  
Bumble Bee ◽  
Insect Visitation ◽  
Parasitic Mite ◽  
Fruit Abortion ◽  
Bee Colonies

The effectiveness of bumble bees, Bombus impatiens Cresson, and honey bees, Apis mellifera L., on the pollination of cucumber, Cucumis sativus L., and watermelon, Citrullus lanatus (Thunb.) Matsum. & Nakai, was compared under field conditions. Comparisons were based on fruit abortion rates and seed set as influenced by bee type (honey bee or bumble bee) and the number of bee visits to treatment flowers (1, 6, 12, and 18 bee visits), plus two controls: a no-visit treatment and an open-pollinated (unrestricted visitation) treatment. For both crops, an increased number of bee visits had a strong positive effect on fruit and seed set. All cucumber and watermelon flowers bagged to prevent insect visitation aborted, demonstrating the need for active transfer of pollen between staminate and pistillate flowers. Bumble bee-visited flowers consistently had lower abortion rates and higher seed sets in the cucumber and watermelon studies than did honey bee-visited flowers when compared at the same bee visitation level. Only slight differences in fruit abortion rates were detected between bee types in the watermelon study. However, abortion rates for bumble bee-visited flowers were consistently less than those for honey bee-visited flowers when compared at equal bee visitation levels, with one exception at the 12 bee visit level. As the number of honey bee colonies continues to decline due to parasitic mite pests and based on the data obtained, we conclude that bumble bees have a great potential to serve as a supplemental pollinator for cucumbers, watermelons, and possibly other vine crops, when honey bees available for rental are in limited supply.

scholarly journals Comparative reproduction mechanisms of three species of Ocimum L. (Lamiaceae)

2016 ◽  
Vol 69 (1) ◽  
Author(s):  
Matthew Oziegbe ◽  
Temitope Olatayo Kehinde ◽  
Joshua Olumide Matthew
Keyword(s):  
Reproductive System ◽  
Seed Set ◽  
Ocimum Basilicum ◽  
The Self ◽  
Self Pollination ◽  
Insect Visitation ◽  
Open Treatment ◽  
Fruit And Seed Set

<em>Ocimum</em> species have a combination of reproductive system which varies with the locality and cultivar. We have studied here the reproductive mechanisms of five variants of three <em>Ocimum</em> species in Nigeria, namely: <em>Ocimum canum</em> Sims., <em>O. basilicum</em> L., and <em>O. americanum</em> L. Flowers from each variant were subjected to open and bagged pollination treatments of hand self-pollination, spontaneous self-pollination and emasculation. All open treatments of the five <em>Ocimum</em> variants produced more fruit and seed than the corresponding bagged treatments. The two <em>O. canum</em> variants and <em>O. basilicum</em> ‘b<span><sub>1</sub></span>’ produced high fruit and seed set in the open and bagged treatments of spontaneous self-pollination. <em>Ocimum basilicum</em> ‘b<span><sub>2</sub></span>’ and <em>O. americanum</em> produced higher fruit and seed set in the self-pollination open treatment but significantly lower fruit and seed set in the bagged treatment. Fewer fruit and seeds were produced in the emasculated open treatments but none in the emasculated bagged treatments of the five <em>Ocimum</em> variants. The floral foragers comprising of bees, wasps and butterflies visited the <em>Ocimum</em> species to collect pollen or nectar in the open treatments. The two <em>O. canum</em> variants and <em>O. basilicum</em> ‘b<span><sub>1</sub></span>’ variant reproduced mainly through autogamy but <em>O. basilicum</em> ‘b<span><sub>2</sub></span>’ and <em>O. americanum</em> showed mixed reproduction of autogamy and outcrosssing. Insect visitation to the flowers enhanced pollination resulting in higher fruit and seed set in all the <em>Ocimum</em> species studied.

scholarly journals Rotating Arrays of Orchid Flowers: A Simple and Effective Method for Studying Pollination in Food Deceptive Plants

Diversity ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 286 ◽  
Author(s):  
Daniela Scaccabarozzi ◽  
Andrea Galimberti ◽  
Kingsley W. Dixon ◽  
Salvatore Cozzolino
Keyword(s):  
Field Observations ◽  
Pollination Success ◽  
Visitation Rates ◽  
Visitation Frequency ◽  
Pollination Mechanisms ◽  
Behavioural Patterns ◽  
Insect Visitation ◽  
Southwest Australia ◽  
First Time ◽  
Effective Pollinators

Floral deception has been observed in several genera in angiosperms, but is most common in the Orchidaceae. Pollination mechanisms in food deceptive plants are often difficult to assess, as visitation frequency by insects requires numerous hours of field observations to ascertain. Here, for the first time, we describe in detail and validate a simple and effective method that extends previous approaches to increase the effectiveness of pollination studies of food deceptive orchids. We used an orchid of southwest Australia, Diuris brumalis (Orchidaceae), that visually mimics model plants belonging to the genus Daviesia (Faboideae). Arrays of orchid flowers were placed and moved systematically in proximity to model plants, resulting in rapid attraction of the pollinators of D. brumalis. We compared pollinaria removal (as an indicator of pollination success) in naturally growing orchids with pollinaria removal in arrays of orchid flowers in the same sites. We showed that the proposed method greatly enhances pollinator attractiveness in food deceptive systems with very low pollination rates, and we compared its efficiency with other similar methods. The approach can be used for observing pollinator behavioural patterns and confirming effective pollinators for food deceptive species with low insect visitation rates.

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