Peter Kevan

University of Guelph | UOGuelph · School of Environmental Sciences

Dr. Pieter Oomen, born in 1946, a prominent and inspirational scientist in many areas of the biosafety of pesticides, most notably ecotoxicology, regulatory, risk assessment and bioassays, passed away peacefully on 19th of January 2024. His efforts have had a great and long-lasting impact on bee risk assessment and have improved bee protection. Whi...

Apivectoring, or bee vectoring, employs managed bees to distribute powders containing disease and pest-fighting biocontrol agents during pollination flights to crops. Our research introduces a novel application of this concept, termed inspensing, which leverages bee vectoring for hive-based benefits. In inspensing, bees traverse through a carrier p...

Plant structures that enclose trapped air are morphologically and taxonomically diverse. They range from pubescence (trichomes) on various parts of plants to flowers, inflorescences, stems, culms (above-ground jointed stems of grasses), petioles, peduncles, scapes, fruits, bracts, leaves, galls, algal pneumatocysts, moss sporophytes, lichen podetia...

Evidence is widespread that many species of Bombus are in population and biogeographical decline in response to adverse effects of global climate warming. The complex interactions of the mechanisms at the root of the declines are poorly understood. Among the numerous factors, we posit that heat stress in the nests could play a key role in the decli...

Plants, animals, and fungi display a rich tapestry of colors. Animals, in particular, use colors in dynamic displays performed in spatially complex environments. Although current approaches for studying colors are objective and repeatable, they miss the temporal variation of color signals entirely. Here, we introduce hardware and software that prov...

This is an open letter to the International Commission for Plant Pollinator Relations as presented at the XII International Pollination Symposium in Cape Town, South Africa in Octover 2023

Results from micrometeorological studies within hollow structures of herbaceous plants

The role of climate and weather is well-understood for growth and productivity of agricultural and horticultural crops, both outdoors and indoors. However, the subtleties of temperature within plants-known as microthermal regimes-remains largely unexplored. Gaining knowledge on the natural temperature cycles within plants shows great promise for ma...

It has recently been proposed that hollow structures of herbaceous plants collect heat passively by the “microgreenhouse effect”. The effect occurs when incoming radiation passes through plant tissue, allowing heat to be trapped within the hollow plant part. Plant structures that enclose trapped air are morphologically and taxonomically diverse. Th...

The cultivation of strawberries within greenhouse environments is an increasingly common area of agricultural productivity, affording consistent fruit production of an otherwise highly seasonal crop. However, due to its relative novelty, few management tools have been identified, assessed or registered to date for control of the many known pests of...

This is a Book Review of The Mind of a Bee. Chittka, L. 2022, Princeton University Press, Princeton, USA. 260 pp. ISBN 978-0 691-18047-2, CAN $37.62, cloth.

Entomo-L is a listserv created in 1991 and hosted at the University of Guelph (Guelph, Ontario, Canada) for the free exchange of ideas pertaining to insect science. As part of the revolution in social media, it aims to be respectful of individual privacy and believes in the need of civilized discourse among its members.

Plants, animals, and fungi display a rich tapestry of colors. Animals, in particular, use colors in dynamic displays performed in spatially complex environments. In such natural settings, light is reflected or refracted from objects with complex shapes that cast shadows and generate highlights. In addition, the illuminating light changes continuous...

We write on the life and contributions of Professor D. Eisikowitch, Tel Aviv University.

51) Int. Ci. A replaceable tray for inserting into an exit path of a bee hive includes : (a) a tray body having a base and at least one side wall extending upwardly from the base and surrounding a periphery of the base , the base and the at least one side wall defining an interior of the tray body , and the at least one side wall having an upper en...

Inter-relations of plants, arthropods and fungi in Devonian time

This is a series of short articles on apivectoring out of and into honeybee hives for crop and colony protection

This article is about a successful new device that permits the dispensing of beneficial materials in powder form (biocontrol agents, medicaments) into honeybee hives for pest and disease control within the colony

This article is about the use of a device for the dissemination of beneficial powders (biocontrol agents, botanicals, medicaments) by honeybee into their own colonies for suppression of diseases and parasites

This article is about the use of bumblebee to deliver biocontrol agents against insect pest (thrips) in greenhouse production and protection of strawberries

This article describes a project supported by NSERC-Engage, that assessed how well the biological control agent B. bassiana could be distributed by bumblebees to control thrips in soft and tender fruit greenhouse production.

This srticle is about "apivectoring", the use of managed pollinators to disseminate biological control agents for protection of crops against pests and diseases

This article is about the issue of measuring "ecosystem health" in a objective way by use of accepted ecological principles

Part of the keynote presentation slides by Dr. Peter Kevan's lab, 1-15 June 2022, at the First International Electronic Conference on Entomology. I prepared this portion of the presentation to summarize the methods and results of using apivectoring using Bombus Impatiens to vector Beauveria bassiana to suppress Western Flower Thrips in Commercial G...

Understanding the dinamics of filtration of pollen and spores by plant canopies is crucial to the in the modelling of their dispersal, yet few studies have quantified filtration. Here, we examine the decline in the density of flour particles descending through a 40 m-tall tropical canopy on a windless day at Caxiuanã National Forest, Pará, Brazil....

Near-ground temperatures strongly influence Arctic plant growth, reproduction, maturation and phenological relations with pollinators and herbivores. Those temperatures become further elevated within plant parts through passive solar heating, e.g. dish-shaped blossoms that focus insolation and heat-trapping pubescent structures. Other Arctic plants...

The ability of commercial bumblebees to transfer Clonostachys rosea spores as a biocontrol agent (BVT-CR7 strain) from the hive to sunflower heads for the control of Sclerotinia head rot was studied during 2016 and 2017 in field trials. The bumblebee hives were placed in isolation cages before flowering and allowed to adapt to the new environment....

Ecological intensification refers to the practical management for amelioration of biodiversity and ecosystem management in productivity and sustainability for the benefit of human livelihoods. Pest management is critical for agricultural and forestry production systems and for human health. Chemical pesticides have become increasingly sophisticated...

This paper reports on the implementation of the Apivectoring Technology for the first time in an experimental strawberry crop (Fragaria x ananassa) in Colombia. Honey bees (Apis mellifera) were used as vector of the bio-pesticide Trichoderma harzianum for the control of Botrytis cinerea in an experimental plot of strawberry, in which 6 treatments w...

The fungus gnats, Bradysia impatiens (larvae and adults), were either separately or concurrently exposed for 6 h to growing spores of Fusarium oxysporum and Pythium aphanidermatum, and a powder formulation of Clonostachys rosea on leaf discs of strawberry to determine their capacity in laboratory trials for vectoring these three microbes. We determ...

Losses caused by the coffee berry borer, Hypothenemus hampei (Ferrari) have been decreasing coffee production. This pest causes annual losses over U.S. $500 million. The chemical insecticides have been used to Coffee berry borer control. Due to their effects of pesticides on human and environmental health, some countries decided to ban the use of e...

Using infrared thermometry with false colour imagery, we observed the surface temperatures of various parts of the sweet pepper crop in the shady environment of a production greenhouse located in southwestern Ontario. The results showed that developing fruits are hot in comparison to their leaves, stems and the surrounding air. https://www.greenho...

The book “Atlas of pollen and plants used by bees” was prepared with great care with the data of researchers from Argentina, Brazil, Canada, and Colombia, who are collaborators of RCPol - Online Pollen Catalogs Network. RCPol was conducted during the development of the project entitled “Study of bee flora and pollen grains for the insertion of data...

This essay is about Acer negundo, Manitoba maple, in support of its value in arboriculture

This book examines entomovectoring, which employs crop pollinators to spread biocontrol protections against plant pathogens. The book describes research and development of the process, also known as apivectoring and beevectoring, for use both in pollination and in the delivery of biocontrol agents against crop and pollinator diseases, pests, and pa...

Earth's surface is rising, much to the consternation of the world. Terrestrial life, including human, is almost all restricted to a biofilm of few tens of metres above and below the surface. That life-supporting film, the biosphere, has, by comparison with the atmosphere, lithosphere and hydro-sphere, the greatest historical, seasonal and daily var...

Background: Obtaining an optimal flower temperature can be crucial for plant reproduction because temperature mediates flower growth and development, pollen and ovule viability, and influences pollinator visitation. The thermal ecology of flowers is an exciting, yet understudied field of plant biology. Scope: This review focuses on several attri...

Microthermic regimes within hollow stems of herbaceous plants

Micrometeorology within plant parts, stems and flowers.

Temperature regimes within�􀃀�􀁒� � 􀁇� � � 􀁒� � � 􀁒􀁏� 􀁒� 􀀋�􀁒􀁏� 􀀌� � � 􀁏� � � flo wers and stems show that insol ation (sol ar) warming results in temperature excesses above the ambient air. The add itional heat is important for develo pment of reprod uctive organs (sporophyll s) and presumably for the growth of stems. We review studies on temperature...

Pest management is critical for agricultural and forestry production systems and for human health. Chemical pesticides have become increasingly sophisticated as standard control measures. Other approaches, such as biological control, are also advocated as viable options. Biological control agents are living organisms (or parts thereof) that interfe...

Although there have been studies of the temperature regimes within flowers, micrometeorology within stems seems to have been overlooked. We present ideas, hypotheses, and a diagrammatic model on the biophysical and thermodynamic processes that interact in complex ways to result in elevated temperature regimes within hollow stems of herbaceous plant...

Background: Flower coloration is a key enabler for pollinator attraction. Floral visual signals comprise several components that are generated by specific anatomical structures and pigmentation, and often have different functions in pollinator attraction. Anatomical studies have advanced our understanding of the optical properties of flowers, and...

Thermoregulation in honeybees

RESUMEN La Tecnología Apivector, representa una alternativa sostenible para el manejo preventivo de plagas y enfermedades en cultivos agrícolas, basada en el conocimiento de las relaciones multitrópicas desarrolladas por miles de años entre poli-nizadores, plantas y patógenos; utiliza un innovador método de control: la inoculación de abejas con bio...

Pest management is a critical component of both agricultural and forestry production systems and for human health. In the 20th century, chemical pesticides became increasingly sophisticated as the standard control measures. However, other approaches, such as biological control, were also developed and in the 21st century more and more advocated as...

Erigeron lemmonii A. Gray is extremely rare, but not endangered. There are fewer than 1000 individuals, but they compose an apparently stable, heterozygotic, diploid (2n = 18) population. The plants are perennial and endemic to one small location (about 0.5 km²) in Scheelite Canyon, Huachuca Mountains (Cochise County), Fort Huachuca Army Base, part...

Many pollinating insects acquire their entire nutrition from visiting flowers, and they must therefore be efficient both at detecting flowers and at recognizing familiar rewarding flower types. A crucial first step in recognition is the identification of edges and the segmentation of the visual field into areas that belong together. Honeybees and b...

The goal of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) is to strengthen the science-policy interface for biodiversity and ecosystem services towards conservation and sustainable use of biodiversity, long-term human well-being and sustainable development. To achieve this goal, the Platform has four f...

Most of the world’s wild flowering plants (87.5%) are pollinated by insects and other animals (established but incomplete), more than three quarters of the leading types of global food crops can benefit, at least in part, from animal pollination (well established) and it is estimated that about one-third of global food volume produced similarly ben...

IPBES

Explosive pollen release from staminate plant of Boehmeria caudata recorded during this study. Readers are directed to Figure 11 in Poinar et al. (2016) of amber-fossilized freeze-frame explosive pollen release from a staminate flower of Ekrixanthera ehecatli. At the left, a series of 5 - 6 almost simultaneous, and very rapid, explosions occur with...

The first fossil flowers of Neotropical Urticaceae (Boehmerieae) are described from the Dominican Republic and Mexico as belonging to a new genus, Ekrixanthera. Ekrixanthera hispaniolae sp. nov. from Dominican amber has pentamerous staminate flowers on short pedicels with a pilose pistillode and heteromorphic pilose tepals: two are clavate and thre...

Male flowers of the wind-pollinated, dioecious shrub Boehmeria caudata Sw. release pollen explosively, possibly stimulated by anther dehydration in response to temporarily dry conditions coupled with hydrostatic pressure in the filament. In the Brazilian Atlantic rain forest, the daily frequency of male flower anthesis peaked between 1000–1200 h (G...

In comparing the incidence of dioecy in North American floras, we report a strong, positive correlation with increasing latitude. Dioecy in the High Arctic is highly correlated with woodiness, as elsewhere. It is significantly correlated with fleshy, zoochorous fruits as well documented elsewhere. Correlation with floral inconspicuousness, which we...

In this paper, we present a general discrete-continuous modeling framework to study the effect of swarming on the dynamics of a honeybee colony infested with varroa mite and Acute Bee Paralysis Virus (ABPV) . Two scenarios are studied under which swarming takes place i.e., swarming due to overcrowding and swarming at fixed time intervals. For this...

A quarter millennium of the changing face of pollination biology from 18th Century discovery (thesis) to 21st Century crisis is presented in six overlapping, interdigitating facets. Pollination biology was not regarded as serious science at its onset, but acceptance of the Darwinian theory of evolution has shown its biological value. Disciplinary i...

Climate change decoupling mutualism Many coevolved species have precisely matched traits. For example, long-tongued bumblebees are well adapted for obtaining nectar from flowers with long petal tubes. Working at high altitude in Colorado, Miller-Struttmann et al. found that long-tongued bumblebees have decreased in number significantly over the pas...

A mathematical model for the honeybee-varroa mite-ABPV system is proposed in terms of four differential equations for the: infected and uninfected bees in the colony, number of mites overall, and of mites carrying the virus. To account for seasonal variability, all parameters are time periodic. We obtain linearized stability conditions for the dise...

Diptera are important flower visitors and pollinators for many plant species and in a variety of habitats. Although Diptera are not as well studied as other groups of pollinators, there is a growing literature that we review here about the ecology of their foraging behaviour and their effectiveness as pollinators. We consider (1) how their foraging...

Animals react to salient stimuli via unconditioned responses, Pavlovian conditioning, conditioned manipulation of objects in simple and complex ways (instrumental/operant learning and tool use) and insight learning. Bumblebees are known to learn to manipulate natural and artificial complex flowers to obtain rewards. Even though those tasks involve...

We trained worker bumblebees to discriminate arrays of artificial nectaries (one, two, and three microcentrifuge tubes inserted into artificial flowers) from which they could forage in association with their location in a three-compartmental maze. Additionally, we challenged bees to learn to accomplish three different tasks in a fixed sequence duri...

NORWAYMAPLE Invasive alien species, such as Norway maple (Acer platanoides), are a threat to the improvement and even the long-term survival of sugar maple (Acer saccharum).

Bumblebees move about their environments by flying and by walking. Most experimental studies have addressed navigation during foraging flights, but we presented our experimental bees with the challenge of learning to navigate while walking as they must do in nature within topographically complex spaces containing their nests. We trained bumblebee w...

With the recent discoveries of treatment-resistant AFB and varroa, the face of disease and pest control in apiculture has changed. Control must now enter the realm of integrated pest management (IPM) by which traditional chemical controls are combined with ‘softer’ approaches and with genetic and cultural methods. IPM is needed to reduce the occurr...

The authors are part of NSERC-CANPOLIN, School of Environmental Sciences, Edmund C. Bovey Building, University of Guelph, Ontario, Canada. The Canadian Pollination Initiative (NSERC-CANPOLIN) is a five-year, $5 million research network that has been investigating the complex issues of pollinator declines and sustainable pollination since it was lau...

Mobility of flowers in the wind has been proposed to affect the performances of pollinators in landing on flowers, nectar extraction, and pollen dispersal. Our study examined the preferences of worker Bombus impatiens Cresson (Hymenoptera: Apidae) for landing on and feeding from immobile or mobile artificial flower. Mobile flowers moved at varied f...

Coffee is the second most traded commodity, after petroleum, in the world. Vast areas of tropical landscapes are devoted to coffee production. A coffee bean starts its journey to our table as a flower on a shrub. Flowers require pollination for seeds and fruits to form, but for coffee it is widely believed that either self-pollination or pollinatio...

Diptera are important flower visitors and pollinators for many plant species and in a variety of habitats. Although Diptera are not as well studied as other groups of pollinators, there is a growing literature that we review here about the ecology of their foraging behaviour and their effectiveness as pollinators. We consider (1) how their foraging...

Dichlorvos is an insecticide used in slow-release plastic strips for controlling chalcid wasp parasites, such as Pteromalus venustus Walker, in incubators used to raise alfalfa leafcutting bees (Megachile rotundata F.). Beekeepers need a practical method to detect dichlorvos in air and verify that it has dissipated to levels acceptable for worker r...

node versus internode, need for a rooting hormone application or not, and timing of application-phenology. Once the air-layers are applied to the twigs, the roots will start to show 5 to 12 weeks later (Figure 3). Once roots appear the air-layer can be cut from the tree and the twig with its roots is transplanted into a pot for over-wintering. Do n...

Abstract: Understanding the dinamics of filtration of pollen and spores by plant canopies is crucial to the in the modelling of their dispersal, yet few studies have quantified filtration. Here, we examine the decline in the density of flour particles descending through a 40 m-tall tropical canopy on a windless day at Caxiuanã National Forest, Pará...