21-05-2025
Charles Dewhurst, entomologist whose work on the armyworm helped to save crops in Africa
Charles Dewhurst, who has died aged 78, was a professional entomologist who worked around the world on projects from controlling armyworms in Africa to the introduction of dung beetles in Australia.
When Charles Frederick Dewhurst was born on August 29 1946 he was the first European baby to be born at the Naval Hospital in Trincomalee, Ceylon (now Sri Lanka), where his father, Colonel Frederick Dewhurst, RM, was stationed. Frederick had served at Gallipoli and later became CO of the Commando Training Centre at Lympstone, Devon.
Charles was christened on the frigate Glasgow, and after the war, when the family moved to a farm in Devon, he became fascinated by natural history; one of his first entomological memories was squeezing warble fly larvae (Hypoderma bovis, now eradicated from the UK) out of the backs of cows and feeding them to the farm's Muscovy ducks. He also discovered the pleasures of the moth-trap.
From Mount House School, Tavistock, he went on to Milton Abbey School, where he kept a tame tawny owl and enjoyed cross-country because it took him out to the countryside, where he filled collector's tubes with specimens.
After taking A-levels in chemistry and biology at Plymouth Polytechnic (now Plymouth University), he moved to London in the mid-1960s as a lab assistant at the Anti-Locust Research Centre in Kensington. Then at the age of 23 he headed for Africa to work for the East African Agriculture & Forestry Research Organisation on a project monitoring seasonal movements of the African armyworm, Spodoptera exempta, a migratory and highly destructive moth pest affecting cereal crops and pasturelands in Africa, Asia, Australia and the Pacific.
With the female moth laying between 400 and 1,300 eggs, and with just 10 days between hatching and larval pupation, in plague years the moth can devastate crop yields. Early signs of mass emergence are critical to controlling the pest, and the project involved running light traps, and later pheromone traps, in various areas throughout East Africa.
Dewhurst worked with the entomologist Eric Brown in Kenya, and with him and others wrote several publications on Spodoptera control including The African Armyworm Handbook (1997) In 1970 he gained a pilot's licence which allowed him to cross national borders easily in a Piper Cherokee.
In the early 1970s Dewhurst returned to London to take a degree in botany, zoology and geology at Sir John Cass College (now part of London Metropolitan University). After graduation he spent two years in Pretoria, South Africa (1974-76), working on a dung-beetle evaluation and introduction programme for Australia's Commonwealth Scientific and Industrial Research Organisation.
Under the programme, launched in 1965, 55 species of dung beetle were imported into Australia from Hawaii, Africa and southern Europe to help with livestock dung removal, improve grazing and reduce fly populations. Dewhurst's role included visiting southern France, Spain and Morocco to collect suitable species and to rear them in captivity. In order to develop healthy, pest-free populations of the beetles, three generations of beetles needed to be reared before they could be shipped to Australia.
In 1977 Dewhurst married Lindsay, an ophthalmic nurse he had met in London, and they moved to Kenya, where they spent 16 happy years, Lindsay working to help restore people's vision and bring up their two children, and Charles working on migrant pest control with responsibility for Djibouti, Ethiopia (later also Eritrea), Kenya, Somalia, southern Sudan, Tanzania, Uganda and Yemen.
Criss-crossing the region in extremely short shorts and sandals, and equipped with a Leatherman multi-tool set, Dewhurst inspired colleagues with the amiable enthusiasm with which he would bring his Land Rover skidding to a halt in the hope of finding ungulate nose-fly larvae in the nasal passages of large items of road-kill. He had a microlite, and on one occasion, while working on an armyworm project, he became distracted by a huge wildebeest herd, eventually crash-landing as he had forgotten to keep an eye on the fuel gauge.
Returning to the UK in the 1990s, he and his family settled at West Wittering, West Sussex, though he continued to travel extensively, working on projects around the world. But he eventually got itchy feet again, and in 2005 he took up a posting as head of entomology for the Papua New Guinea Oil Palm Research Association on the island of West New Britain.
There, as 'Dudu' (Swahili for insect), he was a regular at the Kimbe Hash House Harriers and was instrumental in establishing the Swallowtail and Birdwing Butterfly Trust, which is helping to protect the critically endangered Queen Alexandra's Birdwing, the largest and most spectacular butterfly in the world. A pair have recently mated successfully in captivity and are expected to lay eggs in the newly named Charles Dewhurst flight cage.
In 2014 Dewhurst finally retired, to Winchcombe, Gloucestershire, where he immersed himself in native insect species, serving as a macro-lepidoptera recorder. He was also a council member and trustee of Nature in Art, Gloucestershire, and the host of a radio show on Radio Winchcombe.
Before he died he gave his collections to the Natural History Museum in London and the Oxford University Museum of Natural History, including donating one of only two known males of the giant stick insect Eurycantha portentosa, from Rossel Island, Papua New Guinea, to the latter.
Dewhurst was editor of the Journal of the East Africa Natural History Society and National Museum (1989-1992), a trustee of the Kafue River Trust, Zambia, and a specialist group member (Orthoptera) of the IUCN Species Survival Commission. His favourite insect was the extremely rare botfly Gyrostigma, the largest adult fly in Africa, whose larvae inhabit the stomachs of rhinoceroses.
Charles Dewhurst is survived by his wife and their son and daughter.
Charles Dewhurst, born August 29 1946, died March 7 2025
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