Obituary Professor Gwilym O. Evans (1924-2017)

With the sad death of Gwilym Owen Evans on 6th June of this year, the acarological community lost one of its great researchers and teachers, and a good friend and mentor to many of us around the world.

Gwilym was born in the village of Llandre, Ceredigion, west Wales, on 25th May 1924. He attended schools in England and Wales before beginning his biological education at the University College of Wales, Aberystwyth (now Aberystwyth University). After the award of his Bachelor of Science in 1944, he took a job in England at Birmingham’s Water Pollution Research Laboratories, where he worked on early research into the effect of pesticides on the fauna and flora of waterways. Subsequently, Gwilym returned to his native Wales and Aberystwyth University to carry out research for a Master of Science (awarded in 1947) and then his Ph.D. (1949). His Master’s project concerned the bionomics of the sheep ked Melophagus ovinus, most pertinent to the economic welfare of the sheep farmers of Wales, which Gwilym would tell you is a country with more sheep than people! The improved method he devised for observing the ked life cycle was the subject of his first scientific paper, published in the prestigious journal Nature in 1946. Gwilym continued to work on ectoparasites of domesticated animals for his doctorate, initially focussing on the sheep ked, but later changing to a study of the bionomics and economic importance of the tick Ixodes ricinus in Wales.

Following university, Gwilym joined the famous Rothamsted Experimental Station in Hertfordshire, England, to study the feeding behaviour and population dynamics of small arthropods, particularly insects and mites, and their contribution to soil fertility. This area of ecology was in its infancy and the work, which included frequent visits to the arachnid section of the then British Museum (Natural History), fuelled Gwilym’s life-long interest in mite taxonomy. In 1951, he was appointed to the Museum’s permanent staff as Head of Arachnida and, once there, applied his energy and enthusiasm to developing much needed taxonomic work on the Acari. He soon built up the staff complement by bringing in additional researchers and upset the Museum’s rigidly hierarchical structure of the time by actually allowing his junior staff to carry out research projects. Just one year into this appointment, he participated in the Museum’s expedition to the East African Ruwenzori Mountains. On his return, he presented one of the authors (DG) with a slide bearing just one specimen of Don’s favourite mite, Acarus siro, Linnaeus, 1758, which Gwilym said he had taken from a tree-hole half way up Ruwenzori Mountain. This was impressive, since, to Don’s knowledge, it is the only ‘natural’ record for this species outside of stored foodstuffs. The two came to the mutual explanation that it was down to some previous intrepid African explorer finding an eco-friendly place to deposit the remains of their sandwich lunch!

Gwilym’s time at the Museum was his most prolific in terms of publications produced. The majority of papers concerned the morphology and taxonomy of the Mesostigmata, and included his fundamentally important studies of the chaetotaxy of their appendages. The setal nomenclature and positional formulae he devised are still routinely used by authors in descriptions today, so gradually adding to the character data available for systematic studies. His revisions of numerous mesostigmatid families, plus reports of new faunal records and descriptions of unnamed taxa in other orders, greatly enhanced our knowledge of British mites. These data were synthesized in two of the few comprehensive works on the native fauna. The first, published in 1961 with Gordon Sheals and Don Macfarlane, was Terrestrial Acari of the British Isles, which served as an introduction to mites and ticks. The second, Mesostigmatic mites of Britain and Ireland (1979, with W.M. Till), included keys to all the recorded families and genera. Gwilym’s detailed and well-illustrated morphological accounts have stood the test of time and his publications are still sought after and routinely used for specimen identification. Because his studies based on the British fauna cover many taxa with a much wider geographical distribution, they also have a worldwide relevance. The significance of Gwilym’s acarological research was acknowledged in 1967 when Aberystwyth University awarded him a Doctorate of Science for a body of work entitled ‘Contribution to the external morphology, classification and ecology of the Acari: Anactinochaeta’. In the same year, he left the Museum.

Following his departure, Gwilym held short appointments as Professor of Zoology at the University of Maryland, USA (1967-68) and as a Senior Fellow at the New University of Ulster, Coleraine, Northern Ireland, now Ulster University at Coleraine (1969). He joined University College Dublin (UCD) in 1970, as Professor of Agricultural Zoology in the Faculty of Agriculture, which was then based at Glasnevin, on the opposite side of the city to the main College campus at Belfield. His arrival coincided with a decade of great change, when student and staff numbers were expanding greatly despite limited facilities and accommodation at Glasnevin. At this time, a process of substantial departmental consolidation and movement to the Belfield campus was well underway, although the transfer of the Agriculture Faculty was not completed until 1979. In the interim, improvisation was the order of the day, and Gwilym demonstrated considerable flair in that regard. A memorable example of this was his oversight of the adaptation of a commercial vehicle for fieldwork. The vehicle was equipped with all necessary facilities, and modified to accommodate the tallest research student (at the time 193 cm, and aptly named Longworth). Although it quickly became known as the ‘ice-cream van’ because of its external appearance, internally it was well designed, and served its intended purpose admirably for several years.

Extensive changes in teaching programmes at UCD were also occurring in the 1970s, and Gwilym was an enthusiastic participant in the various discussions and curriculum design/ development-related activities which were taking place at that time. He had a considerable influence on the upgrading and development of course modules in Applied Zoology in particular, one very tangible outcome of his input being the much-improved draftsmanship that was evident in laboratory manuals. Those of us at UCD who had participated in the University of Nottingham Acarology courses were particularly aware of the enthusiasm and flair that Gwilym brought to the teaching of his chosen subject, and it was gratifying to see the same qualities being brought to the teaching of a wide range of topics at undergraduate and postgraduate level. He was intensely interested in students, and constantly challenged them to engage with the subject matter rather than being passive recipients of information. He could be equally challenging to staff, and would occasionally emerge from his office in order to have his say when a particularly interesting tutorial was taking place in the adjacent seminar room. Gwilym arrived at UCD at a time of considerable expansion in both domestic and international opportunities for research funding. His enthusiasm was infectious, and he created an atmosphere in which research and scientific enquiry were highly valued. He was an acknowledged leader in the field of acarology, which remained his core area of interest. He was also very supportive of research across a wide spectrum of the applied Biological Sciences, notably in areas such as Invertebrate Ecology, Animal Parasitology and Wildlife Ecology. He was always particularly enthusiastic about work with an acarological content, especially when rare or possibly new species were encountered, as they frequently were during soil ecology studies. Unsurprisingly, postgraduate students who displayed an aptitude for acarine taxonomy and systematics received his encouragement as he sought above all to pass on his particular skills and knowledge. He, for example, passed his enthusiastic interest in ticks, particularly Ixodes ricinus, to one of the authors (JG), who he appointed as a junior lecturer more than 40 years ago and is still working in this field of research.

It was largely due to Gwilym’s efforts that the aforementioned Acarology course was established and ran from 1962 to 1987. It was held biennially in the summer on Nottingham’s Agriculture campus at Sutton Bonington and provided a comprehensive introduction to mites and ticks. Gwilym, his good friends and fellow lecturers Don Griffiths and Don Macfarlane, and organiser Paul Murphy made learning fun, not least via the repartee that flashed between them, especially Gwilym and DG. Indeed, the latter still remembers the argument the two had for over 10 summers about the exact form and function of the acarine mouthparts, resolved eventually, most amicably, at the local public house. Passing on his knowledge was of great importance to Gwilym and it must have been very rewarding for him to see so many of the students go on to become eminent researchers in institutes around the world. Fortunately, Gwilym’s contribution to the course lives on in his much consulted book Principles of Acarology (1992), which was based on the lectures he gave on acarine functional morphology, biology and taxonomy. Gwilym took on a variety of responsibilities in the scientific community. An important example was his term as a Commissioner of the International Commission on Zoological Nomenclature (ICZN), serving as British representative from 1960 to 1970. In 1965, he was made Secretary to the Commission, but resigned in 1967 after his appointment as Professor of Zoology at the University of Maryland. From 1967 to 1968, he was also a member of the International Trust for Zoological Nomenclature, an organisation set up to provide financial support to the ICZN Secretariat. He served as a Council member of the Linnean Society of London (1959-1962, 1966-1967) and the Systematics Association (1955-1958), and was appointed Chairman of the joint Royal Irish Academy and National Science Council Committee on ‘Man and the biosphere’ (1979). Gwilym was President of the Sixth International Congress of Acarology held in Edinburgh, Scotland, in 1982, and edited the Proceedings of the Second International Acarology Congress (Sutton Bonington, England, 1967) published in 1969. Other roles in scientific publishing were an editorship of the Journal of Natural History (1957-73) and membership of the editorial boards of Acarologia (1962-2000), International Journal of Acarology (1975-1994) and Parasitology (Cambridge) (1962-1966). Gwilym’s expertise was called upon as an external examiner for Queen’s University Belfast, Ulster University at Coleraine, and the universities of Bangor, Leeds, Nottingham and Reading.

The distinction of Gwilym’s research and service were honoured by numerous awards. Foremost among them was his election in 1973 to Membership of the Royal Irish Academy (MRIA), the highest academic honour of the Republic of Ireland and given in recognition of the excellence of his published work. He was made a Fellow of the UK’s Institute of Biology, now the Royal Society of Biology, for his contribution to the advancement of the biological sciences. After being Honorary Secretary of the Ray Society (named for the eminent British naturalist John Ray) from 1957 to 1961, he was made an Honorary Vice-President in 1961. Honorary Vice-Presidencies are given in recognition of conspicuous service to the Society and are lifetime appointments. For his outstanding contribution to acarology, Gwilym was awarded the International Berlese Award (1978) (reported in Int. J. Acarol., 1979, 5: 168) and Honorary Lifetime Membership of the International Congress of Acarology (1998). Since his death, his legacy has been commemorated as an Eternal Member of the Congress.

Gwilym was a most personable and sociable person, although his enthusiasm for Welsh rugby was not always appreciated on Monday mornings at UCD following yet another Irish defeat by Wales during their period of dominance in the 1970s. His retirement from UCD in 1983 following a period of poor health was premature. Fortunately, he subsequently made a good recovery and lived to enjoy a lengthy retirement with his wife Angela in West Sussex, England, memorably revisiting UCD after he left during a holiday cruise stopover. However, he did not leave acarology and continued to publish until 1998. One of the authors (AB) was fortunate to enjoy the hospitality of Gwilym and Angela at their home after they moved back to the UK. Gwilym was always interested in acarological news and to hear about the many changes that were happening at the Museum. His continued readiness to discuss aspects of acarology and to be a valuable source of advice was greatly appreciated.

Gwilym was one of the few remaining acarologists with such a complete knowledge of the subject, not just of systematics, but also of biology and ecology. He was a high energy character with an ever-present enquiring mind and sense of fun. He will be much missed.

This account was prepared with the help of friends and colleagues. Particular thanks go to Mrs Angela Evans who kindly allowed the use of the photograph of Gwilym and provided details about his life and career. Information was also gratefully received from: the Development and Alumni Relations Office and Julie Archer, Records Manager, Aberystwyth University, Wales; Nick Evans, The Ray Society, England; Eddie Friel and Sandra Irwin, Development and Alumni Relations Office, Ulster University, Northern Ireland; Martyn Low, Secretary ICZN, National University of Singapore; Don Macfarlane, Gillingham, England, and Carol Martin, Royal Irish Academy, Dublin, Republic of Ireland.

1940s

Evans G.O. 1946 — A method for observing the life-cycle of Melophagus ovinus (Linn.) — Nature, Lond., 157: 773. doi:10.1038/157773a0

Pollard E.P., Owen R.W., Evans G.O. 1949 — Phenothiazine for the control of helminthiasis in lambs: monthly dosing compared with a phenothiazene-salt mixture — J. Comp. Pathol. Therapeutics, 59: 54-69. doi:10.1016/S0368-1742(49)80006-3

1950s

Evans G.O. 1951 — The seasonal incidence of Ixodes ricinus (L.) on cattle in Mid-Wales — Bull. Ent. Res., 41: 459-468. doi:10.1017/S0007485300027759

Evans G.O. 1951 — The distribution and economic importance of Ixodes ricinus (L.) in Wales and the Welsh border counties with special reference to N.W. Cardiganshire — Bull. Ent. Res., 41, 469-485. doi:10.1017/S0007485300027760

Evans G.O. 1951 — The distribution of Ixodes ricinus (L.) on the body of cattle and sheep — Bull. Ent. Res., 41: 709-723. doi:10.1017/S0007485300027942

Evans G.O. 1951 — Investigations on the fauna of forest humus layers — Rep. Forest Res., Lond., 1950: 110-113.

Evans G.O. 1952 — Terrestrial Acari new to Britain. I — Ann. Mag. Nat. Hist., Ser. 12, 5: 33-41. doi:10.1080/00222935208654261

Evans G.O. 1952 — British mites of the genus Brachychthonius Berl., 1910 — Ann. Mag. Nat. Hist., Ser. 12, 5: 227-239. doi:10.1080/00222935208654286

Evans G.O. 1952 — A new typhlodromid mite predaceous on Tetranychus bimaculatus Harvey in Indonesia — Ann. Mag. Nat. Hist., Ser. 12, 5: 413-416. doi:10.1080/00222935208654311

Evans G.O. 1952 — Terrestrial Acari new to Britain. II — Ann. Mag. Nat. Hist., Ser. 12, 5: 660-675. doi:10.1080/00222935208654337

Evans G.O. 1952 — On a new predatory mite of economic importance — Bull. Ent. Res., 43: 397-401. doi:10.1017/S0007485300040566

Evans G.O. 1953 — On a collection of Acari from Kilamanjaro (Tanganyika) — Ann. Mag. Nat. Hist., Ser. 12, 6: 258-281. doi:10.1080/00222935308654421

Evans G.O. 1953 — On some mites of the genus Typhlodromus Scheuten, 1857, from S.E.Asia — Ann. Mag. Nat. Hist., Ser. 12, 6: 449-467. doi:10.1080/00222935308654444

Evans G.O., Browning E. 1953 — Some inter-tidal mites from south-west England — Bull. Br. Mus. Nat. Hist., Zool., 1: 413-422. doi:10.5962/bhl.part.21638

Evans G.O. 1954 — A revision of the genus Thinoseius Halbert, 1920 (Acarina-Laelaptidae.) — Ann. Mag. Nat. Hist., Ser. 12, 7: 615-622. doi:10.1080/00222935408651761

Evans G.O. 1954 — On the genus Asternolaelaps Berlese, 1923. (Acarina-Mesostigmata.) — Entomologist's Mon. Mag., 90: 88-90.

Evans G.O. 1954 — Some new and rare species of Acarina — Proc. Zool. Soc. Lond., 123: 793-811. doi:10.1111/j.1096-3642.1954.tb00205.x

Evans G.O. 1954 — The genus Iphiseius Berl. (Acarina-Laelaptidae.) — Proc. Zool. Soc. Lond., 124: 517-526. doi:10.1111/j.1469-7998.1954.tb07793.x

Evans G.O. 1954 — The Harvest Mite — Br. Mus. Nat. Hist., Zool. Explanatory Leaflet No. Z.1: 1-7. [Author not attributed]

Evans G.O., Browning E. 1954 — Pseudoscorpiones — Synopses Br. Fauna, Linn. Soc., Lond., 10: 1-23.

Evans G.O. 1955 — British mites of the genus Veigaia Oudemans (Mesostigmata: Veigaiaidae) — Proc. Zool. Soc. Lond., 125, 569-586. doi:10.1111/j.1096-3642.1955.tb00618.x

Evans G.O. 1955 — A collection of mesostigmatid mites from Alaska — Bull. Br. Mus. Nat. Hist., Zool., 2: 285-307.

Evans G.O. 1955 — A revision of the family Epicriidae (Acarina-Mesostigmata) — Bull. Br. Mus. Nat. Hist., Zool., 3: 169-200. doi:10.5962/bhl.part.4122

Evans G.O. 1955 — A stridulating organ in the Acarina — Bull. Natn. Inst. Sci. India, 7: 107-109.

Evans G.O. 1955 — Identification of terrestrial mites — In: Kevan D.K.McE. (Ed.). Soil zoology. London: Butterworths Scientific Publications. p. 55-61.

Evans G.O. 1955 — Notes on preserving, clearing, mounting and storing terrestrial mites — In: Kevan D.K.McE. (Ed.). Soil zoology. London: Butterworths Scientific Publications. p. 421-424.

Evans G.O. 1955 — A review of the laelaptid paraphages of the Myriapoda with descriptions of three new species (Acarina: Laelaptidae) — Parasitol., Cambridge, 45: 352-368.

Evans G.O., Browning E. 1955 — Techniques for the preparation of mites for study — Ann. Mag. Nat. Hist., Ser. 12, 8: 631-635.

Evans G.O., Browning E. 1955 — Some British mites of economic importance — Econ. Ser. Br. Mus. Nat. Hist., 17: vi-x, 1-46.

Evans G.O. 1956 — On the classification of the family Macrochelidae with particular reference to the subfamily Parholaspinae (Acarina: Mesostigmata) — Proc. Zool. Soc. Lond., 127: 345-377. doi:10.1111/j.1096-3642.1956.tb00474.x

Evans G.O., Browning E. 1956 — British mites of the subfamily Macrochelinae Trägårdh (Gamasina-Macrochelidae) — Bull. Br. Mus. Nat. Hist., Zool., 4: 1-55.

Evans G.O., Hyatt K.H. 1956 — British mites of the genus Pachylaelaps Berlese (Gamasina: Pachylaelaptidae) — Entomologist's Mon. Mag., 92: 118-129.

Evans G.O. 1957 — A revision of the genus Leptolaelaps Berl. with a description of an allied genus, Pseudopachylaelaps n. gen. (Mesostigmata: Laelaptidae) — Ann. Natal Mus., 14: 45-57.

Evans G.O. 1957 — An introduction to the British Mesostigmata (Acarina) with keys to families and genera — J. Linn. Soc., Zool., 43: 203-259.

Evans G.O. 1957 — On the genus Scarabaspis Womersley (Acarina-Mesostigmata) — Ann. Mag. Nat. Hist., Ser. 12, 10: 409-416. doi:10.1080/00222935708655977

Evans G.O. 1958 — A revision of the British Aceosejinae (Acarina: Mesostigmata) — Proc. Zool. Soc. Lond., 131: 177-229. doi:10.1111/j.1096-3642.1958.tb00685.x

Evans G.O., Hyatt K.H. 1958 — The genera Podocinum Berl. and Podocinella gen. nov. (Acarina: Mesostigmata) — Ann. Mag. Nat. Hist., Ser. 12, 10: 913-932. doi:10.1080/00222935708656095

Evans G.O. 1958 — Some mesostigmatid mites from a nest of social spiders in Uganda — Ann. Mag. Nat. Hist., Ser. 13, 1: 580-590. doi:10.1080/00222935808650985

Evans G.O. 1958 — A new mite of the genus Phytoseiulus Evans (Acarina: Phytoseiidae) from Southern Rhodesia — J. Ent. Soc. South. Afr., 21: 306-308.

Evans G.O., Fletcher D.S. 1958 — Ruwenzori Expedition 1952. Introduction with list of localities. Volume 1(1) — London: British Museum. p. iii-vii.

Evans G.O. 1959 — The genera Cyrthydrolaelaps Berlese and Gamasolaelaps Berlese (Acarina: Mesostigmata) — Acarologia, 1: 201-215.

Evans G.O., Sheals J.G. 1959 — Three new mesostigmatic mites associated with millepedes in Indonesia — Ent. Ber., Amst., 19: 107-111.

1960s

Evans G.O., Hyatt K.H. 1960 — A revision of the Platyseiinae (Mesostigmata: Aceosejidae) based on material in the collections of the British Museum (Natural History) — Bull. Br. Mus. Nat. Hist., Zool., 6: 25-101. doi:10.5962/bhl.part.26843

Evans G.O., Sheals J.G., Macfarlane D. 1961 — The terrestrial Acari of the British Isles. An introduction to their morphology, biology and classification — London: British Museum. pp. 219.

Evans G.O. 1962 — A new mite of the genus Thinoseius Halbert (Mesostigmata: Eviphididae) — Ann. Mag. Nat. Hist., Ser. 13, 4: 553-556. doi:10.1080/00222936108651175

Evans G.O., Macfarlane D. 1962 — A new mite of the genus Phytoseius Ribaga (Acari: Mesostigmata) — Ann. Mag. Nat. Hist., Ser. 13, 4: 587-588. doi:10.1080/00222936108651183

Evans G.O., Till W.M. 1962 — The genus Dermanyssus De Geer (Acari: Mesostigmata) — Ann. Mag. Nat. Hist., Ser. 13, 5: 273-293. doi:10.1080/00222936208651246

Evans G.O. 1963 — The systematic position of Gammaridacarus brevisternalis Canaris (Acari: Mesostigmata) — Ann. Mag. Nat. Hist., Ser. 13, 5: 395-399. doi:10.1080/00222936208651263

Evans G.O. 1963 — Observations on the classification of the family Otopheidomenidae (Acari: Mesostigmata) with descriptions of two new species — Ann. Mag. Nat. Hist., Ser. 13, 5: 609-620. doi:10.1080/00222936208651292

Evans G.O., Hyatt K.H. 1963 — Mites of the genus Macrocheles Latr. (Mesostigmata) associated with coprid beetles in the collections of the British Museum (Natural History) — Bull. Br. Mus. Nat. Hist., Zool., 9: 325-401. doi:10.5962/bhl.part.16344

Evans G.O. 1963 — Observations on the chaetotaxy of the legs in the free-living Gamasina (Acari: Mesostigmata) — Bull. Br. Mus. Nat. Hist., Zool., 10: 275-303. doi:10.5962/bhl.part.20528

Evans G.O. 1963 — The genus Neocypholaelaps Vitzthum (Acari: Mesostigmata) — Ann. Mag. Nat. Hist., Ser. 13, 6: 209-230. doi:10.1080/00222936308651345

Evans G.O., Fain A., Bafort J. 1963 — Découverte du cycle évolutif du genre Myialges avec description d'une espèce nouvelle (Myialgidae: Sarcoptiformes) — Bull. Annls Soc. R. Ent. Belg., 99: 486-500.

Evans G.O. 1964 — Some observations on the chaetotaxy of the pedipalps in the Mesostigmata (Acari) — Ann. Mag. Nat. Hist., Ser. 13, 6: 513-527. doi:10.1080/00222936308651393

Fain A., Evans G.O. 1964 — On three mites of the genus Epidermoptes Rivolta (Acari) — Ann. Mag. Nat. Hist., Ser. 13, 6: 595-608. doi:10.1080/00222936308651404

Evans G.O. 1964 — Errata. Some observations on the chaetotaxy of the pedipalps in the Mesostigmata (Acari) — Ann. Mag. Nat. Hist., Ser. 13, 7: 63. doi:10.1080/00222936408651439

Evans G.O. 1964 — [Section Editor's address] Systematics and terminology. 1. Chaetotaxy, ontogeny and phylogeny — Acarologia, 6 (hors sér.): 44-46.

Evans G.O. 1964 — The value of the chaetotaxy of the pedipalps in the classification of the Gamasina and Uropodina (Acari: Mesostigmata) — Acarologia, 6 (hors sér.): 55-61.

Evans G.O., Till W.M. 1964 — A new species of Dermanyssus and a redescription of Steatonyssus superans Zemskaya (Acari: Mesostigmata) — Acarologia, 6: 624-631.

Till W.M., Evans G.O. 1964 — The genus Steatonyssus Kolenati (Acari: Mesostigmata) — Bull. Br. Mus. Nat. Hist., Zool., 11: 511-582. doi:10.5962/bhl.part.4724

Evans G.O. 1965 — The ontogenetic development of the chaetotaxy of the tarsi of legs II-IV in the Antennophorina (Acari: Mesostigmata) — Ann. Mag. Nat. Hist., Ser. 13, 8: 81-83. doi:10.1080/00222936508651543

Evans G.O., Till W.M. 1965 — Studies on the British Dermanyssidae (Acari: Mesostigmata). Part I. External morphology — Bull. Br. Mus. Nat. Hist., Zool., 13: 247-294. doi:10.5962/bhl.part.16752

Lindquist E.E., Evans G.O. 1965 — Taxonomic concepts in the Ascidae, with a modified setal nomenclature for the idiosoma of the Gamasina (Acarina: Mesostigmata) — Mem. Ent. Soc. Can., 47: 1-64. doi:10.4039/entm9747fv

Evans G.O., Till W.M. 1966 — Studies on the British Dermanyssidae (Acari: Mesostigmata). Part II. Classification — Bull. Br. Mus. Nat. Hist., Zool., 14: 107-370.

Evans G.O., Till W.M. 1966 — A new laelapine mite from the golden mole, Chrysochloris stuhlmanni Matschie — Ann. Mag. Nat. Hist., Ser. 13, 8: 629-634.

Fain A., Evans G.O. 1966 — The genus Proctotydaeus Berl. (Acari: Iolinidae) with descriptions of two new species — Ann. Mag. Nat. Hist., Ser. 13, 9: 149-157. doi:10.1080/00222936608651647

Till W.M., Evans G.O. 1966 — The genus Chelanyssus Zumpt and Till (Acari: Mesostigmata) — Acarologia, 8: 401-414.

Edwards M.A., Evans G.O. 1967 — Some observations on the chaetotaxy of the legs of larval Ixodidae (Acari: Metastigmata) — J. Nat. Hist., 1: 595-601. doi:10.1080/00222936700770561

Evans G.O., Fain A. 1968 — A new Hirstionyssine mite from Trichys lipura Gunther — Acarologia, 10: 419-425.

Evans G.O. 1969 — The external morphology of the post-embryonic developmental stages of Spinturnix myoti Kol. (Acari: Mesostigmata) — Acarologia, 10: 589-608.

Evans G.O. 1969 — Contributions to the Symposia of the 2nd International Congress of Acarology, Sutton Bonington, England, 1967. Preface — Acarologia, 11: 355.

Evans G.O. (Ed.). Proceedings of the 2nd International Congress of Acarology, Sutton Bonington,1967; Budapest: Akadémiai Kiadó. pp. 652.

Evans G.O. 1969 — A new mite of the genus Thinoseius Halbt. (Gamasina: Eviphididae) from the Chatham Islands, New Zealand — Acarologia, 11: 505-514.

Evans G.O. 1969 — Observations on the ontogenetic development of the chaetotaxy of the tarsi of legs II-IV in the Mesostigmata (Acari) — In: Evans G.O. (Ed.). Proceedings of the 2nd International Congress of Acarology, Sutton Bonington, 1967; Budapest: Akadémiai Kiadó. p. 195-200.

1970s

Evans G.O. 1972 — Leg chaetotaxy and the classification of the Uropodina (Acari: Mesostigmata) — J. Zool., Lond., 167: 193-206. doi:10.1111/j.1469-7998.1972.tb01729.x

Evans G.O., Loots G.C. 1972 — Scanning electron microscopy in the study of the gnathosoma of the Acari — Wetensk. Bydr. Potchefstroom. Univ., Reeks B Natuurwet, 49: 1-13.

Loots G.C., Evans G.O. 1972 — Scanning electron microscopy and the functional morphology of the acarine gnathosoma — Proc. South. Afr. Electron Microsc. Soc., 2: 39-40.

Evans G.O. 1973 — Some aspects of the morphology of the gnathosoma of Heterozercon (Acari: Mesostigmata) — In: Daniel M., Rosický B. (Eds). Proceedings of the 3rd International Congress of Acarology, Prague, 1971; The Hague: W. Junk, Prague: Academia. p. 343.

Evans G.O., Loots G.C. 1975 — Scanning electron microscope study of the structure of the hypostome of Phityogamasus, Laelaps and Ornithonyssus (Acari: Mesostigmata) — J. Zool., Lond., 176: 425-436. doi:10.1111/j.1469-7998.1975.tb03213.x

Cusack P.D., Evans G.O., Brennan P.A. 1975 — A survey of the mites of stored grain and grain products in the Republic of Ireland — Scient. Proc. R. Dubl. Soc., Ser. B, 3: 273-329.

Cusack P.D., Evans G.O., Brennan P.A. 1976 — The origin and sources of mite infestation of stored grain and related products in the Republic of Ireland — Ann. Appl. Biol., 82: 178-179. doi:10.1111/j.1744-7348.1976.tb01688.x

Evans G.O., Till W.M. 1979 — Mesostigmatic mites of Britain and Ireland (Chelicerata: Acari-Parasitiformes). An introduction to their external morphology and classification — Trans. Zool. Soc. Lond., 35: 139-270. doi:10.1111/j.1096-3642.1979.tb00059.x

Emmanuel N., Evans G.O. 1979 — Survival of mites associated with growing barley through harvest and into storage — In: Rodriguez J.G. (Ed.). Recent advances in acarology, Volume 1; New York etc: Academic Press. p. 299-303.

1980s

Evans G.O. 1980 — Adults of the genus Crassicheles Karg (Acari: Mesostigmata) — Int. J. Acarol., 6: 33-38. doi:10.1080/01647958008683190

Athias-Binche F., Evans G.O. 1981 — Observations on the genus Protodinychus Evans, 1957 (Acari: Mesostigmata) with descriptions of the male and phoretic deuteronymph — Proc. R. Ir. Acad., Sect. B, 81: 25-36.

Evans G.O. 1982 — Observations of the genus Protogamasellus Karg (Acari: Mesostigmata) with a description of a new species — Acarologia, 23: 303-313.

Purvis G., Evans G.O. 1982 — Astigmatic mites of the genera Schwiebea Oudms. and Nanacarus Oudms. from S. E. Ireland — J. Nat. Hist., 16: 815-821. doi:10.1080/00222938200770651

Evans G.O. 1984 — Presidential address — In: Griffiths D.A. & Bowman C.E. (Eds). Acarology VI, Volume 1. Chichester, Ellis Horwood. p. 1-7.

Emmanouel N.G., Evans G.O. 1984 — Studies on stored-products mites associated with barley during growth — In: Abstracts. XVII International Congress of Entomology, Hamburg, 1984; 17. p. 639.

Emmanuel N., Curry J.P., Evans G.O. 1985 — Studies on the mite populations of barley and weeds — Proc. R. Ir. Acad., Sect. B, 85: 37-46.

Emmanuel N., Curry J.P., Evans G.O. 1985 — The soil Acari of barley plots with different cultural treatments — Exp. Appl. Acarol., 1: 101-113. doi:10.1007/BF01270590

Kennedy T.F., Evans G.O., Feeney A.M. 1986 — Studies on the biology of Tachyporus hypnorum F. (Col. Staphylinidae), associated with cereal fields in Ireland — Ir. J. Agric. Res., 25: 81-95.

Evans G.O., Purvis G. 1987 — A new ascid mite from St Helena with observations on the Protogamasellus complex (Acari: Mesostigmata) — J. Nat. Hist., 21: 855-861. doi:10.1080/00222938700770511

Evans G.O. 1987 — The status of three species of Phytoseiidae (Acari) described by Carl Willmann — J. Nat. Hist., 21: 1461-1467. doi:10.1080/00222938700770921

Evans G.O. 1988 — Two new species of phytoseiid mites from southern England with a redescription of Typhlodromus tiliae — J. Zool., Lond., 214: 71-79. doi:10.1111/j.1469-7998.1988.tb04987.x

Evans G.O., Momen F. 1988 — The identity of Seiulus rhenanus Oudms. and Typhlodromus foenilis Oudms. (Acari: Phytoseiidae) — J. Nat. Hist., 22: 209-216. doi:10.1080/00222938800770151

1990s

Pugh P.J.A., Evans G.O., Fordy M.R., King P.E. 1991 — The functional morphology of the respiratory system of the Holothyrida (= Tetrastigmata) Acari – Anactinotrichida — J. Zool., Lond., 225: 153-172. doi:10.1111/j.1469-7998.1991.tb03808.x

Evans G.O. 1992 — Principles of acarology — Wallingford: CAB International. pp. 563.

Blackman S.W., Evans G.O. 1994 — Observations on a mite (Poecilochirus davydovae) predatory on the eggs of burying beetles (Nicrophorus vespilloides) with a review of its taxonomic status — J. Zool., Lond., 234: 217-227. doi:10.1111/j.1469-7998.1994.tb06070.x

Flechtmann C.H.W., Evans G.O., McMurtry J.A. 1994 — Some noteworthy features of the chelicerae and subcapitulum of Phytoseiulus longipes Evans (Acari: Mesostigmata: Phytoseiidae), with observations on the preoral channel in the Phytoseiidae — Exp. Appl. Acarol., 18: 293-299. doi:10.1007/BF00132318

Evans G.O., Fain A. 1995 — A new phoretic deuteronymph of Halodarcia Karg (Acari: Mesostigmata: Halolaelapidae) associated with carabid beetles in Belgium with a review of the genus — Bull. Inst. R. Sci. Nat. Belg., Entomol., 65: 63-71.

Evans G.O., Edland T. 1998 — The genus Anthoseius De Leon (Acari: Mesostigmata) in Norway — Fauna Norv., Ser. B, 45: 41-62.

Edland T., Evans G.O. 1998 — The genus Typhlodromus (Acari : Mesostigmata) in Norway — Eur. J. Entomol., 95: 275-295.

In the first line of the second paragraph of page 1113, the birth place of Gwilym is incorrectly given as the village of Borth, when it should be the village of Llandre.

The updated pdf version (2019-05-24) is correct.