An examination of nectar production in 34 species of Dendrobium indicates that deceptive pollination in the orchids is not popular

Abstract:Nectarivorous flower mites can reduce the volume of nectar available to pollinators. The effects of the flower mite Proctolaelaps sp. on nectar availability in flowers of a melittophilous bromeliad Neoregelia johannis (Bromeliaceae) was evaluated in a coastal rain forest in south-eastern Brazil. In a randomized block experiment utilizing 18 flower pairs, one per bromeliad ramet, pollinators (Bombus morio) and mites were excluded, and then nectar volume, sugar concentration and sugar mass were quantified over the anthesis period. Mites significantly reduced nectar volume early in the morning (6h00–8h00), but not later (10h00–12h00). Mites decreased total volume of nectar available up to 22%. Sugar concentration in nectar was higher earlier in the morning, and decreased between 10h00–12h00. The pronounced consumption of nectar by mites during the period of higher sugar concentration reduced the total amount of sugar available to pollinators by 31%. This is the first study showing that flower mites decrease nectar rewards in a melittophilous plant. Because nectar volume by itself incompletely describes nectar production rates and the effects of nectar removal by flower mites on the availability of sugar, our study highlights the inclusion of sugar content in future studies assessing the effects of thieves on nectar production rates.

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Calculating nectar production rates: residual nectar and optimal foraging

Oecologia ◽

10.1007/bf00399227 ◽

1983 ◽

Vol 58 (2) ◽

pp. 258-259 ◽

Cited By ~ 9

Author(s):

Michael Zimmerman

Keyword(s):

Optimal Foraging ◽

Production Rates ◽

Nectar Production

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Quantity over quality: light intensity, but not red/far‐red ratio, affects extrafloral nectar production in Senna mexicana var. chapmanii

Ecology and Evolution ◽

10.1002/ece3.1644 ◽

2015 ◽

Vol 5 (18) ◽

pp. 4108-4114 ◽

Cited By ~ 7

Author(s):

Ian M. Jones ◽

Suzanne Koptur

Keyword(s):

Light Intensity ◽

Extrafloral Nectar ◽

Nectar Production

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Differential nectar production between male and female flowers in a wild cucurbit: Cucurbita maxima ssp. andreana (Cucurbitaceae)

Canadian Journal of Botany ◽

10.1139/b02-110 ◽

2002 ◽

Vol 80 (11) ◽

pp. 1203-1208 ◽

Cited By ~ 16

Author(s):

Lorena Ashworth ◽

Leonardo Galetto

Keyword(s):

Reproductive Output ◽

Male Flower ◽

Female Flower ◽

Cucurbita Maxima ◽

Nectar Production ◽

Male And Female ◽

Nectar Sugar Composition ◽

Nectar Sugar ◽

Male Flowers ◽

Female Flowers

In dioecious and monoecious plants that depend on animal vectors for reproduction, pollinators have to be attracted to male and female flowers for pollination to be effective. In the monoecious Cucurbita maxima ssp. andreana, male flowers are produced in greater quantity, are spatially more exposed to pollinators and offer pollen in addition to nectar as floral rewards. Nectar traits were compared between male and female flowers to determine any differences in the characteristics of the main reward offered to pollinators. Nectar chemical composition and sugar proportions were similar between flower types. Total nectar sugar production per female flower was threefold higher than per male flower, and nectar removal did not have any effect on total nectar production in both flower morphs. Pollinators reduced nectar standing crops to similar and very scarce amounts in both flower types. Results indicate indirectly that pollinators are consuming more nectar from female flowers, suggesting that the higher nectar production in female flowers may be a reward-based strategy to achieve the high female reproductive output observed in this species.Key words: Cucurbitaceae, Cucurbita maxima ssp. andreana, nectar production, nectar sugar composition, removal effects, standing crop.

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Thinking honeyeater: nectar maps for the Northern Territory, Australia

Pacific Conservation Biology ◽

10.1071/pc000061 ◽

2000 ◽

Vol 6 (1) ◽

pp. 61 ◽

Cited By ~ 35

Author(s):

John C. Z. Woinarski ◽

Greg Connors ◽

Don C. Franklin

Keyword(s):

Northern Territory ◽

Dry Season ◽

Spatial And Temporal Variation ◽

Wet Season ◽

Nectar Production ◽

The World ◽

Eucalypt Forests ◽

The Times ◽

Species Specific ◽

Nectar Availability

We create monthly maps of nectar availability for the 1.4 x 106 km2 jurisdiction of the Northern Territory, Australia. These are based on a combination of vegetation mapping and a series of indices of plant species specific nectar scoring. The maps reveal complex spatial and temporal variation in nectar availability, but most notably a greater nectar resource in the monsoon-influenced north than in the arid south, and a peak in nectar availability in the dry season. The latter is associated with the extensive tropical eucalypt forests (especially those co-dominated by Eucalyptus miniata and E. tetrodonta). In contrast, wet season nectar availability in these forests is limited, but riparian and swampland forests, typically dominated by Melaleuca species, provide rich but spatially restricted nectar resources. The extensive and rich nectar resources available in eucalypt forests in the dry season supplement the diets of many species which are not primarily nectarivorous. This resource helps shape the singularity of northern Australian eucalypt forests relative to other extensive forests elsewhere in the world. Nectarivores remain in the system through a combination of movements across a number of scales, habitat shifting, and diet shifting. The latter is aided by the peaking of invertebrate and fruit resources at the times of minimum nectar production; a shuffling in resource availability brought about by the extreme climatic seasonality.

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