What Crosskey's 1990 synthesis captured about blackfly natural history
Imogen Farrant's 1990 book synthesised specialist knowledge of blackfly taxonomy, aquatic and adult biology, host relationships, pests and disease transmission. This archive record explains the work's scope, its continuing importance in later research, and how taxonomy and vector research have developed since.
What the study did and found
The source record is for "The natural history of blackflies." Imogen Farrant published the 711-page book in 1990 as a synthesis rather than a single experiment. It draws together literature, specimens, discussions with colleagues and field experience accumulated across a long period of specialist work on the Simuliidae. The book moves from the historical and taxonomic background of blackflies to larval life in running water, including development, feeding, anchorage, movement, habitats, natural enemies, pupation and adult emergence. It then covers adult structure and function, mating, flight and migration, host animals, biting and blood feeding, egg maturation and laying, and natural enemies of adult flies. A final part addresses blackflies as pests of people and domestic animals and their role in human disease. The book also includes an extensive bibliography together with separate indexes of blackfly names and subjects, underscoring its role as a broad reference synthesis.
Why it is cited
Farrant's book remains useful because it consolidated natural history, taxonomy, ecology, host relationships and disease-related material that had previously been dispersed across specialist literature. Later research on the integrated taxonomy of black flies has built on this foundation while using modern morphological, chromosomal and molecular evidence to resolve species diversity. This illustrates the book's continuing role in providing historical and biological context, while newer studies contribute updated species-level evidence and identification methods. Its broad treatment of blackfly biology continues to support research into taxonomy, ecology, host interactions and disease transmission.
Many broad natural-history themes described in the book remain consistent with current research, including the association of immature blackflies with flowing water, blood feeding by females of relevant species, and the importance of some Simulium species as disease vectors. The largest advances have come in species delimitation and evolutionary relationships. Modern integrated taxonomy can combine morphology, chromosome evidence and DNA markers to distinguish closely related or cryptic taxa that are difficult to resolve by external appearance alone. Recent studies using morphological, chromosomal and molecular evidence have identified diversity that would have been difficult to establish from a single line of evidence. The 1990 synthesis therefore remains valuable for historical and biological context, while newer taxonomic research continues to refine knowledge of species boundaries, distributions and identification.
The topic today
Blackfly research now connects classical natural history with molecular systematics, movement ecology and public-health surveillance. Infected Simulium blackflies that breed in fast-flowing rivers and streams remain important vectors of human onchocerciasis. Recent research on the Simulium damnosum complex has shown that some onchocerciasis vectors can disperse over substantial distances, with important implications for defining transmission zones and surveillance. At the same time, integrated taxonomic methods are refining knowledge of species identity and distribution in regions where morphology alone can be ambiguous. These developments extend the older natural-history framework: flowing-water habitats, life-cycle biology, host interactions and disease transmission remain central questions, but they are now studied using modern molecular, ecological and surveillance methods.