The horsefly, scientifically known as Tabanus maculicornis, is a large, stout fly recognized by its strikingly patterned wings and robust body. Generally, adult horseflies are 10-25 mm in length. They have large, bulging, compound eyes that are often brightly colored or iridescent, providing them with excellent vision. The body color can range from black to gray, often adorned with varying patterns of stripes or patches. Their mouthparts are adapted for piercing and sucking, making them notorious for their painful bites. Despite their unpleasant reputation, horseflies play a significant role in the ecosystem, including pollination and serving as prey for various animals.
Horseflies, including Tabanus maculicornis, are distributed widely across different continents, including the diverse ecosystems of Borneo Island. Borneo’s rich and varied landscape comprises tropical rainforests, freshwater swamps, mangroves, and mountainous regions, all providing suitable habitats for horseflies. Often found near water bodies like rivers, lakes, and marshes, these insects thrive in humid environments, which are plentiful on Borneo. The availability of moist and shaded areas with abundant vegetation is crucial for the breeding and lifecycle of horseflies, as these conditions support the larvae before they metamorphose into adults. Their affinity for such habitats in Borneo ties them intrinsically to the island’s ecological web.
Despite their tough and agile nature, horseflies, including those of Tabanus maculicornis, have a range of predators that help regulate their populations. Birds, particularly insectivorous species found in Borneo, such as the Kingfisher or the Drongo, are significant predators. These birds are adept at catching horseflies mid-flight. Additionally, amphibians like frogs and toads, commonly found around water bodies in Borneo, prey on both horsefly larvae and adults. Various species of spiders and predatory insects, including wasps and beetles, also feed on horseflies. While horseflies are a nuisance to mammals, including humans, their role as prey makes them an integral part of the food chain in Borneo’s ecosystem.
Horseflies have a varied diet, crucial to their survival and the sustenance of their lifecycle. The dietary patterns of Tabanus maculicornis can be divided between larval and adult stages. The larvae are carnivorous and primarily feed on other invertebrates, including small insects, larvae, and annelids, contributing to soil aeration and nutrient cycling within their habitat. Adult horseflies have a notorious reputation for their blood-feeding habits. Female horseflies require a blood meal to reproduce successfully, and they specifically target mammals and birds, including livestock and, occasionally, humans. Their bites can be painful and, in some cases, may transmit diseases. On the other hand, male horseflies, which do not bite, primarily feed on nectar and plant juices, playing a modest role in pollination. Thus, the diet of horseflies connects them closely to both their prey and the flora within the Borneo ecosystem.