Oviposition and Cues in Black Flies: Possible Clues for Boom of Adult Population

The population dynamics of aquatic insects in a heterogeneous environment has been attributed to their patterned spatial distribution and cues. These two factors have been reported to determine the distribution of invertebrate propagules and ultimately influence the survivorship and spatial distribution of their progeny. Aquatic insects are frequently understood to have non-selective oviposition habits, but experimental data are scarce and selective oviposition may be quite common. Previous observations indicated that water velocity current such as sequential stream seeps of shallow and fast flowing rivers and streams to large rivers, tree trunks, physico-chemical parameters, submerged objects substrates available in streams such as fallen leaves, rock surfaces, log of woods or tree roots, aquatic vegetations, mud, stones and seasonal variations and type of species were important determinants of the mass distribution of black flies and oviposition sites. We quantitatively surveyed five micro habitats on three different dates to determine the community composition and the species of invertebrates at sites and to ascertain if oviposition or survival is thriving at each successful level of collections of larvae of Assop Falls. In consideration of the instars stages that were measured, it was recorded that more late instars were collected as compared to the early instars. This indicates oviposition is at an anti-climax as compared to the survival of the larval stages. In conclusion, it could be inferred that there is a great invasion of black flies in the human community which calls for a serious concern for governmental and non-governmental organizations to increase more funding to curtail health hazards that could come from black flies bites. This study provides a framework for more sophisticated questions relating to the influence of oviposition site selection on structuring populations of microinvertebrates.