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Journal article
Chemistry of floral rewards: intra- and interspecific variability of nectar and pollen secondary metabolites across taxa
Floral chemistry mediates plant interactions with pollinators, pathogens, and herbivores, with major consequences for fitness of both plants and flower visitors. The outcome of such interactions often depends on compound dose and chemical context. However, chemical diversity and intraspecific variation of nectar and pollen secondary chemistry are known for very... -
Journal article
For antagonists and mutualists: the paradox of insect toxic secondary metabolites in nectar and pollen
The plant kingdom produces an extraordinary diversity of secondary metabolites and the majority of the literature supports a defensive ecological role for them, particularly against invertebrate herbivores (antagonists). Plants also produce secondary compounds in floral nectar and pollen and these are often similar to those produced for defense against invertebrates...Stevenson, Philip C.
Bombus, Bee pathogens, Nicotine, Caffeine, Pollinator specialization, Nectar chemicals, and Crithidia bombi
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Journal article
Rosmarinic acid in Canna generalis activates the medial deterrent chemosensory neurone and deters feeding in the tobacco hornworm Manduca sexta
For all but a very few highly specialized insect feeders, Canna generalis L. (Cannaceae) is unacceptable as a food plant and is a highly potent feeding deterrent for the tobacco hornworm Manduca sexta Johan. (Lepidoptera). The present study describes the isolation of an active deterrent compound, rosmarinic acid (RA) from...Simmonds, Monique S.J. ; Stevenson, Philip C. ; Hanson, Frank E.
sensory coding, feeding behaviour, phagodeterrents, phytochemistry, Lepidoptera, and insect neurophysiology
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Journal article
A comparison of coffee floral traits under two different agricultural practices
Floral traits and rewards are important in mediating interactions between plants and pollinators. Agricultural management practices can affect abiotic factors known to influence floral traits; however, our understanding of the links between agricultural practices and floral trait expression is still poorly understood. Variation in floral morphological, nectar, and pollen traits...Prado, Sara Guiti ; Collazo, Jaime A. ; Stevenson, Philip C. ; Irwin, Rebecca E.
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Journal article
From plant fungi to bee parasites: mycorrhizae and soil nutrients shape floral chemistry and bee pathogens
Bee populations have experienced declines in recent years, due in part to increased disease incidence. Multiple factors influence bee-pathogen interactions, including nectar and pollen quality and secondary metabolites. However, we lack an understanding of how plant interactions with their environment shape bee diet quality. We examined how plant interactions with... -
Journal article
Flagellum Removal by a Nectar Metabolite Inhibits Infectivity of a Bumblebee Parasite
Plant phytochemicals can act as natural ‘‘medicines’’ for animals against parasites [1–3]. Some nectar metabolites, for example, reduce parasite infections in bees [4–7]. Declining plant diversity through anthropogenic landscape change [8–11] could reduce the availability of medicinal nectar plants for pollinators, exacerbating their decline [12]. Existing studies are, however, limited... -
Journal article
Field Margin Vegetation in Tropical African Bean Systems Harbours Diverse Natural Enemies for Biological Pest Control in Adjacent Crops
Non-crop vegetation around farmland can be valuable habitats for enhancing ecosystem services but little is known of the importance of field margins in supporting natural enemies of insect pests in tropical agriculture. This study was conducted in smallholder bean fields in three elevation zones to assess the importance of field...Mkenda, Prisila A. ; Ndakidemi, Patrick A. ; Stevenson, Philip C. ; Arnold, Sarah E. J. ; Belmain, Steven R. …
ecosystem service, parasitoids, pest regulation, predators, and non-crop vegetation
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Journal article
Characterization of Hymenopteran Parasitoids of Aphis fabae in an African Smallholder Bean Farming System through Sequencing of COI ‘Mini-Barcodes’
Parasitoids are among the most frequently reported natural enemies of insect pests, particularly aphids. The efficacy of parasitoids as biocontrol agents is influenced by biotic and abiotic factors. For example, hyperparasitoids can reduce the abundance of the primary parasitoids as well as modify their behavior. A field study was conducted... -
Journal article
Phytochemical Analysis of Tephrosia vogelii across East Africa Reveals Three Chemotypes that Influence Its Use as a Pesticidal Plant
Tephrosia vogelii is a plant species chemically characterized by the presence of entomotoxic rotenoids and used widely across Africa as a botanical pesticide. Phytochemical analysis was conducted to establish the presence and abundance of the bioactive principles in this species across three countries in East Africa: Tanzania, Kenya, and Malawi....Mkindi, Angela G. ; Tembo, Yolice ; Mbega, Ernest R. ; Medvecky, Beth ; Kendal-Smith, Amy …
deguelin, chemotype 3, botanical insecticides, spatial-temporal variation, and rotenoids
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Journal article
Multiple ecosystem services from field margin vegetation for ecological sustainability in agriculture: scientific evidence and knowledge gaps
Background Field margin and non-crop vegetation in agricultural systems are potential ecosystem services providers because they offer semi-natural habitats for both below and above ground animal groups such as soil organisms, small mammals, birds and arthropods that are service supplying units. They are considered as a target area for...