Hugh Loxdale

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Hugh Loxdale
Hugh Loxdale Utting 09.09.2016.jpg
Hugh Loxdale, September 2016

Hugh David Loxdale is an entomologist. He was professor of ecology at the Institute of Ecology, University of Jena from 2009 to 2010,[ citation needed ] president of the Royal Entomological Society from 2004 to 2006, and honorary visiting professor at the School of Biosciences, Cardiff University. Loxdale works on the population biology, ecology, and genetics of insects, especially aphids and their wasp parasitoids. [1]

Contents

Education and early career

Hugh Loxdale was educated at Corner Hall Secondary Modern Boys’ School, Hemel Hempstead, Hertfordshire, England from 1962 to 1967, and Apsley Grammar School, Hemel Hempstead (now Longdean School) from 1967 to 1969. On leaving school, he joined the Entomology Department at Rothamsted Experimental Station (now Rothamsted Research), in Harpenden, Hertfordshire, working in the Insect Survey, then run by L.R. (Roy) Taylor (1924–2007), [2] studying the demography of moths and aphids as part of the national light trap and 12.2-metre-high (40 ft) suction trap surveys, respectively. [3]

Scientific contributions

Loxdale's research demonstrated that as the tansy aphid, parasitized by its specialist wasp parasitoid Lysiphlebus hirticornis, underwent increased genetic variation, so did that of its parasitoid. This suggested a fine-grained co-evolutionary tracking to be in operation. [4] Such a scenario is supportive of the Red Queen hypothesis, whereby a host organism (here an aphid) is attempting to evolve away from its antagonist (here a parasitoid), which is meanwhile co-evolving in order to retain the ability to attack it, i.e. keep pace with it in an ecological-evolutionary sense. [5] Loxdale also determined the insecticide resistance status of the serious agricultural pest the peach-potato aphid, Myzus persicae (Sulzer). From this work, the spatial and temporal dynamics of this important (and now highly cross-resistant) pest aphid could be followed, thereby leading to more rational and effective control measures in the field. [6] [7] [8]

Loxdale has written reviews on absence of strict genetic uniformity in populations of clonal organisms such as aphids. This lack of uniformity is due to the rapid rate of mutation resulting from various mechanisms (e.g. point mutations due to errors of replication, inversion polymorphisms related to transposon effects, etc.) amplified by the huge reproductive potential of the animals concerned, e.g., not only do aphids show ‘telescoping of generations’ such that an adult asexual female has her children and grandchildren within her, but also the ability to produce a large number of asexual copies (10-100 offspring) in a short time (10-14 days). Hence, a single aphid can, in theory produce enough offspring to cover the entire planet to a depth of many kilometres in a single growing season! [9] This of course has serious potential consequences for the agricultural, horticultural and forestry industries worldwide. [10]

Loxdale has also co-authored overviews on several key areas of biological thought and research. These include the migration and dispersal of insects in relation to their genotype and habitat; [11] intra-clonal genetic variation; [12] rapid evolution in insect populations due to various genetic-ecological mechanisms; [13] population proteomics; [14] and on the improbability of generalism in nature, with special reference to insects [15] [16] The consensus of these articles is that the act of filling a new ecological niche is the fundamental act of specialization for any new species or sub-specific population. Whilst some species may be polyphagous to varying degrees, nevertheless diet breadth tends to involve preference for certain prey items in predatory as well as herbaceous species. Generalism, if it exists, is highly dependent upon an animal's morphology-anatomy, genetics, physiology-biochemistry, and chemistry, especially chemical ecology. This in turn governs the behaviour of the animal concerned and restrains it in terms of its habitat choice and what it can eat. In this light, the age old ‘arms race’ of insect herbivores with plants has led to the plants evolving an armoury of secondary chemical defenses which cause, more often than not, specialisms in terms of host and indeed habitat on the part of the herbivore/s involved. Ultimately, even apparently highly polyphagous species such as the aphid M. persicae, said to attack plants in 40 families, [17] may be because of its highly specialised biochemistry-enzymology.

Poetry

Loxdale has published ten volumes of poetry:

Honours and awards

Loxdale was made an Honorary Fellow of the Royal Entomological Society in 2016. [18] In 2017 he was awarded an MBE in the Queen's New Year Honours list for services to entomology. [19]

Related Research Articles

<span class="mw-page-title-main">Biological pest control</span> Controlling pests using other organisms

Biological control or biocontrol is a method of controlling pests, whether pest animals such as insects and mites, weeds, or pathogens affecting animals or plants by using other organisms. It relies on predation, parasitism, herbivory, or other natural mechanisms, but typically also involves an active human management role. It can be an important component of integrated pest management (IPM) programs.

<span class="mw-page-title-main">Aphid</span> Superfamily of insects

Aphids are small sap-sucking insects and members of the superfamily Aphidoidea. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white woolly aphids. A typical life cycle involves flightless females giving live birth to female nymphs—who may also be already pregnant, an adaptation scientists call telescoping generations—without the involvement of males. Maturing rapidly, females breed profusely so that the number of these insects multiplies quickly. Winged females may develop later in the season, allowing the insects to colonize new plants. In temperate regions, a phase of sexual reproduction occurs in the autumn, with the insects often overwintering as eggs.

<span class="mw-page-title-main">Hemiptera</span> Order of insects often called true bugs

Hemiptera is an order of insects, commonly called true bugs, comprising over 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, assassin bugs, bed bugs, and shield bugs. They range in size from 1 mm (0.04 in) to around 15 cm (6 in), and share a common arrangement of piercing-sucking mouthparts. The name "true bugs" is often limited to the suborder Heteroptera.

<span class="mw-page-title-main">Parasitoid</span> Organism that lives with its host and kills it

In evolutionary ecology, a parasitoid is an organism that lives in close association with its host at the host's expense, eventually resulting in the death of the host. Parasitoidism is one of six major evolutionary strategies within parasitism, distinguished by the fatal prognosis for the host, which makes the strategy close to predation.

<span class="mw-page-title-main">Aphididae</span> Family of true bugs

The Aphididae are a very large insect family in the aphid superfamily (Aphidoidea), of the order Hemiptera. These insects suck the sap from plant leaves. Several thousand species are placed in this family, many of which are considered plant/crop pests. They are the family of insects containing most plant virus vectors with the green peach aphid being one of the most prevalent and indiscriminate carriers.

<span class="mw-page-title-main">Parasitoid wasp</span> Group of wasps

Parasitoid wasps are a large group of hymenopteran superfamilies, with all but the wood wasps (Orussoidea) being in the wasp-waisted Apocrita. As parasitoids, they lay their eggs on or in the bodies of other arthropods, sooner or later causing the death of these hosts. Different species specialise in hosts from different insect orders, most often Lepidoptera, though some select beetles, flies, or bugs; the spider wasps (Pompilidae) exclusively attack spiders. More rarely, parasitoid wasps may use plant seeds as hosts, such as Torymus druparum.

<span class="mw-page-title-main">Insect ecology</span> The study of how insects interact with the surrounding environment

Insect ecology is the scientific study of how insects, individually or as a community, interact with the surrounding environment or ecosystem.

<i>Myzus persicae</i> Aphid of peach, potato, other crops

Myzus persicae, known as the green peach aphid, greenfly, or the peach-potato aphid, is a small green aphid belonging to the order Hemiptera. It is the most significant aphid pest of peach trees, causing decreased growth, shrivelling of the leaves and the death of various tissues. It also acts as a vector for the transport of plant viruses such as cucumber mosaic virus (CMV), potato virus Y (PVY) and tobacco etch virus (TEV). Potato virus Y and potato leafroll virus can be passed to members of the nightshade/potato family (Solanaceae), and various mosaic viruses to many other food crops.

<i>Coccinella undecimpunctata</i> Species of beetle

Coccinella undecimpunctata, the eleven-spot ladybird or eleven-spotted lady beetle, it is native to central Asia, though commonly found in Europe, and formerly North America as its populations are decreasing. It is of the family Coccinellidae, commonly referred to as ladybugs or lady beetles.

<span class="mw-page-title-main">John A. Pickett</span> British chemist (born 1945)

John Anthony Pickett CBE DSC FRS is a British chemist who is noted for his work on insect pheromones. Pickett is Professor of Biological Chemistry in the School of Chemistry at Cardiff University. He previously served as the Michael Elliott Distinguished Research Fellow at Rothamsted Research.

<i>Aphis gossypii</i> Species of insect

Aphis gossypii is a tiny insect, an aphid ("greenfly") in the superfamily Aphidoidea in the order Hemiptera. It is a true bug and sucks sap from plants. It is a widely distributed pest of a variety of agricultural crops in the families Cucurbitaceae, Rutaceae and Malvaceae. Common names include cotton aphid, melon aphid and melon and cotton aphid.

<i>Acyrthosiphon pisum</i> Species of true bug

Acyrthosiphon pisum, commonly known as the pea aphid, is a sap-sucking insect in the family Aphididae. It feeds on several species of legumes worldwide, including forage crops, such as pea, clover, alfalfa, and broad bean, and ranks among the aphid species of major agronomical importance. The pea aphid is a model organism for biological study whose genome has been sequenced and annotated.

<i>Macrosiphum euphorbiae</i> Species of true bug

Macrosiphum euphorbiae, the potato aphid, is a sap-sucking pest insect in the family Aphididae. It infests potatoes and a number of other commercially important crops.

Lionel Roy Taylor was a British ecologist, president of the British Ecological Society 1984/85, and editor of the Journal of Animal Ecology.

<i>Pandora</i> (fungus) Genus of fungi

Pandora is a genus of fungi within the order Entomophthorales of the Zygomycota. This has been supported by molecular phylogenetic analysis.

<span class="mw-page-title-main">Tritrophic interactions in plant defense</span> Ecological interactions

Tritrophic interactions in plant defense against herbivory describe the ecological impacts of three trophic levels on each other: the plant, the herbivore, and its natural enemies. They may also be called multitrophic interactions when further trophic levels, such as soil microbes, endophytes, or hyperparasitoids are considered. Tritrophic interactions join pollination and seed dispersal as vital biological functions which plants perform via cooperation with animals.

<i>Rhopalosiphum rufiabdominale</i> Species of aphid

Rhopalosiphum rufiabdominale, the rice root aphid or red rice root aphid, is a sap-sucking insect pest with a wide host range and a global distribution. As a member of the superfamily Aphidoidea, it is one of 16 species of the genus Rhopalosiphum. Adults and nymphs are soft-bodied and usually dark green with brown, red, or yellow tones. Like all aphids, reproduction is sexual and asexual, depending on the environmental conditions and host plant. Rice root aphids cause injury to external plant parts, namely the roots or stem, by feeding on plant sap and vector several important plant viruses. The hosts of this pest extend across multiple plant families with most belonging to Rosaceae, Poaceae, and Solanaceae. R. rufiabdominale is universally associated with Prunus species but also infests various field crops, greenhouse vegetables, cannabis, and other ornamental plants. While this aphid originates from east Asia, it spans nearly every continent. Dispersal is particularly widespread across the United States, India, and Australia, with crop damage documented in multiple instances, although economic losses are primarily associated with Japanese rice crops. Nonetheless, it remains a pest of serious concern due to its high mobility, discrete habitat, and adaptive plasticity, giving it the rightful reputation as a successful invader.

Linda M. Field FRES FRSB is a British scientist noted for her work on the insecticide mode of action and resistance.

Saskia A. Hogenhout FRES, is a Dutch professor of entomology and ecology specialising in molecular plant, microbe and insect interactions.

<i>Lysiphlebus testaceipes</i> Species of wasp

Lysiphlebus testaceipes is a species of small braconid parasitoid wasp in the subfamily Aphidiinae. L. testaceipes can utilize numerous species of aphids as hosts and has often been used as a biological control agent against aphid pests. It is considered an invasive species in several European countries.

References

  1. "Professor Hugh Loxdale MBE". Royal Entomological Society. Retrieved 14 July 2020.
  2. Taylor, Robin A. J. (2007). "Obituary: Roy (L. R.) Taylor (1924-2007)". Journal of Animal Ecology. 76 (3): 630–631. doi: 10.1111/j.1365-2656.2007.01243.x .
  3. Harrington, R. (2014) The Rothamsted Insect Survey strikes gold. Antenna38, 159–166.
  4. Nyabuga FN, Loxdale HD, Heckel DG, Weisser WW. (2012) Coevolutionary fine-tuning: evidence for genetic tracking between a specialist wasp parasitoid and its aphid host in a dual metapopulation interaction. Bulletin of Entomological Research. pages 149 – 155.
  5. van Valen, L. (1973) A new evolutionary law. Evolutionary Theory1, 1–30.
  6. Tatchell GM, Thorn M, Loxdale HD, Devonshire AL. (1988) Monitoring for insecticide resistance in migrant populations of Myzus persicae. In: Proceedings of Brighton Crop Protection Conference - Pests & Diseases - 1988. pages 439-444.
  7. Foster SP, Harrington R, Dewar AM, Denholm I, Devonshire AL (2002) Temporal and spatial dynamics of insecticide resistance in Myzus persicae (Sulzer). Pest Management Science pages 895–907.
  8. Loxdale HD (2009) What’s in a clone: the rapid evolution of aphid asexual lineages in relation to geography, host plant adaptation and resistance to pesticides. pages 535-557 IN: Lost Sex: The Evolutionary Biology of Parthenogenesis, (ed. by Isa Schön, Koen Martens & P.J. van Dijk), Springer-Verlag, Berlin.
  9. Harrington, R. (1994) Aphid layer (letter). Antenna18, 50.
  10. Loxdale, H.D. (2016) Insect biology - a vulnerable discipline? Entomologia Experimentalis et Applicata159, 121–134.
  11. Loxdale HD, Lushai G. (1999) Slaves of the environment: the movement of insects in relation to their ecology and genotype. Philosophical Transactions of the Royal Society, Series B, Biological Sciences354, 1479–1495.
  12. Loxdale HD, Lushai G. (2003) Rapid changes in clonal lines: the death of a ‘sacred cow’. Biological Journal of the Linnean Society79, 3-16.
  13. Loxdale HD. (2010) Rapid genetic changes in natural insect populations. Ecological Entomology (special issue) 35, 155-164.
  14. Biron DG, Loxdale HD, Ponton F, Moura H, Marché L, Brugidou C, Thomas F. (2006) Population proteomics: an emerging discipline to study metapopulation ecology. Viewpoint article. Proteomics6, 1712–1715.
  15. Loxdale HD, Lushai G, Harvey JA. (2011) The evolutionary improbability of ‘generalism’ in nature, with special reference to insects. Biological Journal of the Linnean Society103, 1-18.
  16. Loxdale HD, Harvey JA. (2016) The ‘generalism’ debate: misinterpreting the term in the empirical literature focusing on dietary breadth in insects. Biological Journal of the Linnean Society119, 265–282.
  17. Blackman RL, Eastop VF. (2000) Aphids on the World’s Crops: An Identification and Information Guide, Second Edition, John Wiley & Sons Ltd., Chichester.
  18. "Royal Entomological Society Honorary Fellowship". www.royensoc.co.uk. Retrieved 1 September 2020.
  19. "Queen's birthday honours: MBEs". The Guardian. 2007. Retrieved 14 July 2020.

Cardiff University School of Biosciences