What I’ve done so far
Over the past 40+ years, I’ve published numbers of generic revisions, sorting out the species and interpreting their phylogenetics (see “My publications”). An important early work (1987) was the first to sort out the phylogeny of the early lineages of the family from a cladistic perspective, initially stimulated by the discovery of the first males of a species of Austroconops, a genus with (then) one species but with fossils in the Early Cretaceous (128 million years ago). That laid the groundwork for understanding more about other groups within the family. In the meantime, I undertook various revisions of other genera, gathering more information on other groups within the family, leading to further questions and puzzles.
I have also been active in describing fossil Ceratopogonidae from various amber deposits, mostly from the Cretaceous period. Together with work primarily by my valued Polish colleague Ryszard Szadziewski, we now have a remarkable record of their diversification through time, noted above. There are now 303 fossil species put in either 23 fossil genera or a number of extant genera. A book chapter in 2000 showed how their fossil record tells us about levels of diversity and community structure over time and that the amber samples the local species (rather than distant species).
In working on the extant fauna, of particular importance was a 9 month trip to Costa Rica with my family in 1993-94 and where I was able to devote myself to collecting and studying a tropical fauna firsthand (I’d seen numbers in various collections before that). There were some very interesting discoveries, such as the pupae of a species that gets air as pupae from the underwater roots of floating ferns and the first leaf-mining species in the family and many more undescribed species, with many thousands expertly slide mounted by a gifted technician, Annia Picado. That Costa Rican experience led to being involved in the building of a group of fellow Dipterists and ultimately the production of a 2 volume work “Manual of Central American Diptera” (I was a junior editor). Other important and extensive collecting trips have been to Brunei and other parts of Borneo (5 weeks), peninsular Malaysia, Vietnam, Australia (4 weeks), South Africa (6 weeks), Spain, Cuba, Bolivia (3 months), Nicaragua (3 months), several locales in Mexico and extensively in Canada and the United States.
During my collecting trips, locally and elsewhere, I was always aware that we could not identify the pupae of Ceratopogonidae. Therefore, over the years, I built a collection of reared specimens. That was also a major motivation to go to Western Australia and look for the larva and pupa of the primitive Austroconops, the earliest extant lineage in the family and the most informative for seeing what early members of the family looked like. It’s extant sister group, Leptoconops is of limited value because it is so highly modified – similar to how the echidna and platypus are weird, although they are early mammals. We were successful in finding adult males and females, which laid eggs, which we carried back to Canada and reared, over the space of a year, to larvae to a pupa to an adult. We also found a second undescribed species. The exciting results were published in substantial detail in 2004 (see publication #60).
Understanding what an early lineage Ceratopogonidae looked like, combined with my own and the collections of numbers of others (Bill Wirth, Bill Grogan in particular) resulted in a 327 page monograph published in 2014. It provided the first detailed descriptions of the pupae of Ceratopogonidae at the generic level, the first comprehensive key to these, and a new phylogenetic interpretation of some genera, based on those pupae. A table gave a complete listing of all the many and scattered references describing any immature stage (eggs, larvae, pupae). Of the more than 6,300 species known, only 13% are known as pupae, 9% as larvae and 2% of eggs.
Being an expert in several families has meant contributing chapters to other synthesizing volumes, including the “Manual of Central American Diptera”, “Manual of Afrotropical Diptera”, “Freshwater Invertebrates of the Malaysian Region” and several others (check the list of my publications).
An important part of a taxonomist’s life is knowing which species have been described in the past and how they are presently classified. As such we catalog the names of genera and species and who described them, when, and in what journals. In 1997 I published the first world catalog based mainly on extensive contributions by Willis W. Wirth who had recently passed away (he was our ‘guru’ in the family, having published a tremendous amount of important taxonomic work, worldwide). Together with Patrycja Dominiak, we decided an update was necessary and we published a fresh catalog of 6,206 species in 2020, followed by an errata (hard not to have some errors with that many species) with Florentina Díaz in 2021 reporting a total of 6,276 species. This was followed by another paper with “corrections and additions” in 2025. These resources allows anyone working on the group to know exactly which species are present in a given genus (or subgenus) and which names are valid (and which are synonyms). I’ve also published catalogs of species found just in the Nearctic and Neotropical Regions. The species in Europe are cataloged for each country at a website “Fauna Europaea”, compiled by myself, Ryszard Szadziewski and Patrycja Dominiak, although it is a few years out of date.
This past year (2024) I published a large monograph “The Phylogeny of the Genera of Biting Midges (Diptera: Ceratopogonidae) of the World” (see publication #144) which is the culmination of a lifetime of looking at these lovely flies and a particularly intense past four years of concentrated study. In this work I present an evolutionary tree of all 109 genera of Ceratopogonidae (2 yet unnamed), based on examination of 364 adult characters, painstakingly examined for each genus and with comparisons made. Combined with features from the pupae and larvae, the phylogeny is a reasonable representation of the relationships between these flies. Understanding evolutionary relationships provides a vital window in looking at how the behaviour, biology, habitat and a host of other features have diversified over time. For example, once we understand who is related to who, it is evident that all the early lineages of Ceratopogonidae live in small aquatic habitats. Similarly, the earliest feeding habit of the female adults is to suck blood from vertebrates – only more derived lineages suck blood from other insects or inject an enzyme which liquifies their body fluids and which are then suck up (like spiders do).
Quite recently I was coauthor on a paper headed by Elyssa Loewen summarizing the fossil insect fauna from a fossil amber deposit in Saskatchewan, Canada (see publication #143). These fossils are dated at 67 million years and therefore are exceptionally interesting as it was preserved just before the asteroid hit Earth at the end of the Cretaceous. This coming year we hope to publish a description of one of the fossil Ceratopogonidae in the genus Stilobezzia, which will be the fourth species of this genus known from the Cretaceous period.
2024 saw the completion of a paper (see publication #147), with 7 coauthors, of a species-level analysis of the Ceratopogonidae species we previously reported as present in the 4-hectare cloudforest at Zurquí de Moravia, Costa Rica (as part of Diptera biodiversity project noted elsewhere, see publications #123, 124). We already know that there are 19 genera present and that these include at least 192 different species, previously recognized only as morphotypes. We reported how many of these are named, which requires studying the previously published literature in some depth, and determining how many are undescribed. We also compared this to another nearby site 40 km away at the same elevation and finding that there were, together, 245 species with many of them not shared. Combined with DNA barcoded specimens from BOLD (in Guelph, Ontario) from all of Costa Rica, we estimate that there are likely at least 5,000 species in this small tropical country and these mostly unnamed. This compares to 430 named species for all of Costa Rica and 1,314 named species for the entire Neotropical Region, so it is obvious that a huge number are undescribed and need to be named. Based on further comparisons, we estimate that there are likely around 73,000 species on the planet, again, considering that “only” 6,346 have been named, there is a lot of work to be done!! This is the first time anyone has tried to estimate how many species are in this ubiquitous family. We also give further information on the value of different collecting techniques and the emergence patterns of adults in the tropics (this never has been done before).
Because Ceratopogonidae also vector important parasites and vectors, I contributed a chapter to a book “Biology of Disease Vectors” in 2004 listing all the vectored organisms (at that time including 66 viruses, 15 species of protozoa and 26 species of filarial nematodes). The chapter provides an overview of the family and an evolutionary context for understanding the vectors.
Aside from major projects attempting to broadly interpret this interesting family, I’ve published smaller papers describing a particularly interesting aspect of a limited group or even a single species. For example, a morphological study of peculiar eversible abdominal sacs present in female adult Bezzia (and some other genera) was done with a dear late colleague, Doug Craig in 1994, showing that these were not glandular. Another was the discovery, while living in Costa Rica in 1993/1994 of an observation first pointed out by my wife Annette with “What are those flies on the back of that leatherback turtle?” – it turned out to be hundreds of females of a known species, Culicoides phlebotomus, which also vectors a nematode parasite among coastal fishermen. The photo at the top of this page is of me collecting the midges. More recently, a paper just published in 2023, with Patrycja Dominiak as senior author, describes a new species of Dasyhelea from Costa Rica and which is the first example of a leaf miner in the family. Strangely, the larvae mine the floating leaves of a Salvinia fern and the pupae have peculiar sharp respiratory organs which pierce the upper surface of the leaves to breathe. Quite frankly, the family is rich in all sorts of peculiar modifications that need further study of their morphology and function.
