scholarly journals Characterization of Salix nigra floral insect community and activity of three native Andrena bees

2020 ◽  
Author(s):  
Sandra J. Simon ◽  
Ken Keefover-Ring ◽  
Yong-Lak Park ◽  
Gina Wimp ◽  
Julianne Grady ◽  
...  
Keyword(s):  
Visual Cues ◽  
Floral Scent ◽  
Visual Observation ◽  
Community Diversity ◽  
Insect Community ◽  
Salix Nigra ◽  
Native Bee ◽  
Single Host ◽  
Male Flowers ◽  
Threaten Species

AbstractSalix nigra (black willow) is a widespread tree that hosts many species of polylectic hymenopterans and oligolectic bees of the genus Andrena. The early flowering time of S. nigra makes it an important nutritive resource for arthropods emerging from hibernation. However, since S. nigra is dioecious, not all insect visits will lead to successful pollination. Using both visual observation and pan-trapping we characterized the community of arthropods that visited S. nigra flowers and assessed the differences among male and female trees as well as the chemical and visual drivers that influenced community composition across three years. We found that male trees consistently supported higher diversity of insects than female trees and only three insect species, all Andrena spp., consistently visited both sexes. Additionally, A. nigrae, which was the only insect that occurred more on female than male flowers, correlated strongly to volatile cues. This suggests that cross-pollinators cue into specific aspects of floral scent, but diversity of floral visitors is driven strongly by visual cues. Through time the floral activity of two Andrena species remained stable, but A. nigrae visited less in 2017 when flowers bloomed earlier than other years. When native bee emergence does not synchronize with bloom, activity appears to be greatly diminished which could threaten species that only subsist on a single host. Despite the community diversity of S. nigra flowers, its productivity depends on a small fraction of species that are not threatened by competition, but rather rapidly changing conditions that lead to host-insect asynchrony.

scholarly journals Neural and behavioural responses of the pollen-specialist bee Andrena vaga to Salix odours

2021 ◽  
Author(s):  
Hannah Burger ◽  
Melanie Marquardt ◽  
Katharina Babucke ◽  
Kim C. Heuel ◽  
Manfred Ayasse ◽  
...  
Keyword(s):  
Visual Cues ◽  
Floral Scent ◽  
Effective Means ◽  
High Sensitivity ◽  
Host Finding ◽  
Food Sources ◽  
Small Range ◽  
Behavioural Activity ◽  
Electroantennographic Detection ◽  
Behavioural Experiments

An effective means of finding food is crucial for organisms. Whereas specialized animals select a small number of potentially available food sources, generalists use a broader range. Specialist (oligolectic) bees forage on a small range of flowering plants for pollen and use primarily olfactory and visual cues to locate their host flowers. So far, however, little is known about the specific cues oligoleges use to discriminate between hosts and non-hosts and how floral scent compounds of hosts and non-hosts are processed in the bees’ olfactory system. In this study, we recorded physiological responses of the antennae (electroantennographic detection coupled to gas chromatography GC-EAD) and in the brain (optical imaging, GC-imaging), and studied host-finding behaviour of oligolectic Andrena vaga bees, a specialist on Salix plants. In total, we detected 37 physiologically active compounds in host and non-host scents. 4-Oxoisophorone, a common constituent in the scent of many Salix species, evoked strong responses in the antennal lobe glomeruli of A. vaga, but not the generalist honeybee Apis mellifera. The specific glomerular responses to 4-oxoisophorone in natural Salix scents reveals a high degree of specialization in A. vaga for this typical Salix odorant component. In behavioural experiments, we found olfactory cues to be the key attractants for A. vaga to Salix hosts, which are also used to discriminate between hosts and non-hosts, and demonstrated a behavioural activity for 4-oxoisophorone. A high sensitivity to floral scents enables the specialized bees to effectively find flowers and it appears that A. vaga bees are highly tuned to 4-oxoisophorone at a very low concentration.

scholarly journals Nocturnal pollination: an overlooked ecosystem service vulnerable to environmental change

2020 ◽  
Vol 4 (1) ◽  
pp. 19-32 ◽  
Author(s):  
Callum J. Macgregor ◽  
Alison S. Scott-Brown
Keyword(s):  
Environmental Change ◽  
Ecosystem Service ◽  
Visual Cues ◽  
Floral Scent ◽  
Wild Plants ◽  
Future Research ◽  
Night Time ◽  
Pollination Services ◽  
Pollen Vectors ◽  
Conservation Concern

Existing assessments of the ecosystem service of pollination have been largely restricted to diurnal insects, with a particular focus on generalist foragers such as wild and honey bees. As knowledge of how these plant-pollinator systems function, their relevance to food security and biodiversity, and the fragility of these mutually beneficial interactions increases, attention is diverting to other, less well-studied pollinator groups. One such group are those that forage at night. In this review, we document evidence that nocturnal species are providers of pollination services (including pollination of economically valuable and culturally important crops, as well as wild plants of conservation concern), but highlight how little is known about the scale of such services. We discuss the primary mechanisms involved in night-time communication between plants and insect pollen-vectors, including floral scent, visual cues (and associated specialized visual systems), and thermogenic sensitivity (associated with thermogenic flowers). We highlight that these mechanisms are vulnerable to direct and indirect disruption by a range of anthropogenic drivers of environmental change, including air and soil pollution, artificial light at night, and climate change. Lastly, we highlight a number of directions for future research that will be important if nocturnal pollination services are to be fully understood and ultimately conserved.

scholarly journals Interspecific and Intersexual Differences in the Chemical Composition of Floral Scent inGlochidionSpecies (Phyllanthaceae) in South China

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Daihong Huang ◽  
Fuchen Shi ◽  
Minwei Chai ◽  
Ruili Li ◽  
Houhun Li
Keyword(s):  
South China ◽  
Floral Scent ◽  
Gas Chromatography Mass Spectrometry ◽  
Floral Volatiles ◽  
Qualitative And Quantitative ◽  
Pollination Mutualism ◽  
Obligate Pollination Mutualism ◽  
Male Flowers ◽  
Female Flowers ◽  
Absorption Technique

Plants of theGlochidion(Phyllanthaceae) genus are pollinated exclusively by host-specificEpicephala(Gracillariidae) moths. Floral scent has been thought to play key role in the obligate pollination mutualism betweenGlochidionplants andEpicephalamoths, but few studies have been reported about chemical variation in floral volatiles ofGlochidionspecies in China. Floral volatiles of male and female flowers of fiveGlochidionspecies in south China were collected by dynamic headspace absorption technique and then were chemically analyzed by using gas chromatography-mass spectrometry. A total of 69 compounds were identified from floral scents of five investigated species.Glochidion hirsutumandG.zeylanicumshowed no qualitative differences in floral scent, whereas there were clear variations of floral scent among other species (G. eriocarpum,G.daltonii, andG. sphaerogynum) and also they distinctly differed from these two species. Male flowers emitted significantly more scent than female flowers.Glochidionplants exhibited qualitative and quantitative differences in floral scent between two sexes of flowers. The findings suggest that the volatile variation of floral scent amongGlochidionspecies reflects adaptations to specific pollinators. Sexual dimorphism in floral scent has evolved to signal alternative rewards provided by each sex toEpicephalamoths.

scholarly journals Sexual dimorphism in floral scents of the neotropical orchid Catasetum arietinum and its possible ecological and evolutionary significance

AoB Plants ◽  
2020 ◽  
Vol 12 (4) ◽  
Author(s):  
Katharina Brandt ◽  
Isabel Cristina Machado ◽  
Daniela Maria do Amaral Ferraz Navarro ◽  
Stefan Dötterl ◽  
Manfred Ayasse ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Chemical Composition ◽  
Floral Scent ◽  
Evolutionary Significance ◽  
Male And Female ◽  
Floral Scents ◽  
First Case ◽  
Male Flowers ◽  
Euglossine Bee ◽  
Female Flowers

Abstract Dioecy in angiosperms is often associated with sexual dimorphism in floral traits other than the sexual organs. Species of the neotropical orchid genus Catasetum produce unisexual flowers characterized by a remarkable morphological sexual dimorphism. Catasetum species emit strong floral perfumes that act as both signal and reward for male euglossine bee pollinators. Although the role of floral perfumes of Catasetum in attracting euglossine pollinators is well investigated, little is known about whether perfumes differ between floral sexes and, if they do, whether this chemical dimorphism influences the pollination ecology of the plants. Taking Catasetum arietinum as a model species, our aim was to observe the behaviour of pollinators on male and female flowers and to compare scent properties (i.e. chemical composition, total amount and temporal fluctuation) of male and female flowers. Floral scent samples were collected by using dynamic headspace methods and were analysed via gas chromatography coupled with mass spectroscopy (GC-MS). Catasetum arietinum is pollinated by males of two Euglossa species (i.e. E. nanomelanotricha and E. securigera). Bees approached male and female inflorescences of C. arietinum in similar proportions but landed significantly more often and spent more time on female flowers, which emitted more scent than male flowers. Furthermore, the amount of scent emitted varied across the different times of sampling, corresponding to the pattern of the diel foraging activity of pollinating bees on male and female flowers. The chemical composition of scents differed significantly between sexes. The two major compounds (Z)-methyl-p-methoxycinnamate and (E)-geranyl geraniol contributed most to this difference. This is the first case of sexual dimorphism reported in orchid floral perfumes. We discuss the influence of sex-specific floral scents on the behaviour of euglossine pollinators and offer new insights into the ecological and evolutionary significance of divergence in floral scents among dioecious plants.

scholarly journals Active pollination favours sexual dimorphism in floral scent

2013 ◽  
Vol 280 (1772) ◽  
pp. 20132280 ◽  
Author(s):  
Tomoko Okamoto ◽  
Atsushi Kawakita ◽  
Ryutaro Goto ◽  
Glenn P. Svensson ◽  
Makoto Kato
Keyword(s):  
Sexual Dimorphism ◽  
Floral Scent ◽  
Choice Test ◽  
Sexually Dimorphic ◽  
Pollen Transfer ◽  
Male And Female ◽  
Unisexual Flowers ◽  
Male Flowers ◽  
Species Specific ◽  
Female Flowers

Zoophilous flowers often transmit olfactory signals to attract pollinators. In plants with unisexual flowers, such signals are usually similar between the sexes because attraction of the same animal to both male and female flowers is essential for conspecific pollen transfer. Here, we present a remarkable example of sexual dimorphism in floral signal observed in reproductively highly specialized clades of the tribe Phyllantheae (Phyllanthaceae). These plants are pollinated by species-specific, seed-parasitic Epicephala moths (Gracillariidae) that actively collect pollen from male flowers and pollinate the female flowers in which they oviposit; by doing so, they ensure seeds for their offspring. We found that Epicephala -pollinated Phyllanthaceae plants consistently exhibit major qualitative differences in scent between male and female flowers, often involving compounds derived from different biosynthetic pathways. In a choice test, mated female Epicephala moths preferred the scent of male flowers over that of female flowers, suggesting that male floral scent elicits pollen-collecting behaviour. Epicephala pollination evolved multiple times in Phyllantheae, at least thrice accompanied by transition from sexual monomorphism to dimorphism in floral scent. This is the first example in which sexually dimorphic floral scent has evolved to signal an alternative reward provided by each sex, provoking the pollinator's legitimate altruistic behaviour.

scholarly journals Characterization of Salix nigra floral insect community and activity of three native Andrena bees

2021 ◽  
Author(s):  
Sandra J. Simon ◽  
Ken Keefover‐Ring ◽  
Yong‐Lak Park ◽  
Gina Wimp ◽  
Julianne Grady ◽  
...  
Keyword(s):  
Insect Community ◽  
Salix Nigra

scholarly journals Interactive Effects of an Herbivore-Induced Plant Volatile and Color on an Insect Community in Cranberry

Insects ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 524
Author(s):  
Cesar Rodriguez-Saona ◽  
Pablo Urbaneja-Bernat ◽  
Jordano Salamanca ◽  
Vanessa Garzón-Tovar
Keyword(s):  
Visual Cues ◽  
Interactive Effects ◽  
Insect Community ◽  
Sticky Traps ◽  
Plant Volatile ◽  
Baited Traps ◽  
Insect Populations ◽  
Herbivore Induced Plant Volatiles ◽  
The Individual ◽  
Selection Of

Synthetic herbivore-induced plant volatiles (HIPVs) could be used to monitor insect populations in agroecosystems, including beneficial insects such as natural enemies of herbivores. However, it is unknown whether insect responses to HIPVs are influenced by visual cues, e.g., color. We hypothesized that the HIPV methyl salicylate (MeSA) interacts with color to affect insect captures on sticky traps. To test this, we conducted a 5 × 2 factorial field experiment in a commercial cranberry farm to monitor numbers of insect predators, parasitoids, and herbivores by using five colored sticky traps that were either baited with a MeSA lure (named ‘PredaLure’) or unbaited. At the community level, PredaLure increased captures of predators. At the individual-taxon level, captures of the hoverfly Toxomerus marginatus (Diptera: Syrphidae) and thrips (Thysanoptera: Thripidae) were higher on PredaLure-baited traps. However, only captures of T. marginatus on PredaLure-baited traps interacted significantly with color such that the numbers of this hoverfly on yellow and white traps were 2–4 times higher when baited with PredaLure. This study is the first to document the interactive effects of synthetic HIPVs and color on an insect community. Our findings have implications for optimal selection of HIPV-baited colored traps to monitor natural enemy populations in agroecosystems.

Insect community diversity in transgenic Bt cotton in saline and dry soils

2016 ◽  
Vol 24 (3) ◽  
pp. 332-340 ◽  
Author(s):  
Junyu Luo ◽  
◽  
Shuai Zhang ◽  
Xiangzhen Zhu ◽  
Chunyi Wang ◽  
...  
Keyword(s):  
Community Diversity ◽  
Bt Cotton ◽  
Insect Community ◽  
Transgenic Bt Cotton

scholarly journals Phytochemical diversity drives plant–insect community diversity

2015 ◽  
Vol 112 (35) ◽  
pp. 10973-10978 ◽  
Author(s):  
Lora A. Richards ◽  
Lee A. Dyer ◽  
Matthew L. Forister ◽  
Angela M. Smilanich ◽  
Craig D. Dodson ◽  
...  
Keyword(s):  
Diet Breadth ◽  
Chemical Diversity ◽  
Community Diversity ◽  
Insect Community ◽  
Trophic Specialization ◽  
Ecological Processes ◽  
Natural Systems ◽  
Plant Chemical ◽  
Natural Products Discovery ◽  
Positive Effect

What are the ecological causes and consequences of variation in phytochemical diversity within and between plant taxa? Despite decades of natural products discovery by organic chemists and research by chemical ecologists, our understanding of phytochemically mediated ecological processes in natural communities has been restricted to studies of either broad classes of compounds or a small number of well-characterized molecules. Until now, no studies have assessed the ecological causes or consequences of rigorously quantified phytochemical diversity across taxa in natural systems. Consequently, hypotheses that attempt to explain variation in phytochemical diversity among plants remain largely untested. We use spectral data from crude plant extracts to characterize phytochemical diversity in a suite of co-occurring plants in the tropical genus Piper (Piperaceae). In combination with 20 years of data focused on Piper-associated insects, we find that phytochemical diversity has a direct and positive effect on the diversity of herbivores but also reduces overall herbivore damage. Elevated chemical diversity is associated with more specialized assemblages of herbivores, and the cascading positive effect of phytochemistry on herbivore enemies is stronger as herbivore diet breadth narrows. These results are consistent with traditional hypotheses that predict positive associations between plant chemical diversity, insect herbivore diversity, and trophic specialization. It is clear from these results that high phytochemical diversity not only enhances the diversity of plant-associated insects but also contributes to the ecological predominance of specialized insect herbivores.

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