Length: Adult buffalo flies are 3.5 - 4 mm long
Thorax: Grey in colour with parallel stripes
Abdomen: Brownish grey to black
Wings: Spread open at rest
Larvae: Mature larvae are 3 -6 mm in length and yellowish white in colour
The most obvious difference to house flies is that buffalo flies are smaller in size and have strong biting mouthparts that are visible when the flies are at rest (Figures 1 to 3). Buffalo flies can be distinguished from other flies, that may also be found on cattle, by their smaller size, larger numbers and habit of sitting on the back, sides and underbelly of cattle with their wings spread (Figure 4).
Buffalo flies are obligate parasites, they cannot complete their life cycle without exploiting a suitable host. Buffalo flies spend most of their time resting or feeding on cattle. They only leave when disturbed or when cattle defecate. Then the flies leave to lay their eggs in freshly deposited manure. When disturbed buffalo flies usually rise as a cloud and then immediately return to the closest cattle (Figure 5 and Video 1). They are found most commonly on the head and back of cattle although during hot parts of the day, they are often in highest numbers on the belly and lower flanks. They also infest buffalos and sometimes bite and irritate horses, dogs or even humans. However, they don’t breed on animals other than cattle or buffalo.
Figure 1. Buffalo fly (BF), stable fly (SF) and house fly (HF) from above showing their different size (ruler scale in mm) and mouthparts. Image courtesy of Jess Morgan
Figure 2. Buffalo fly. Image courtesy of Mukund Madhav
Figure 3. Close up images of a buffalo fly head showing the piercing mouthparts. Images courtesy of Jess Morgan
Figure 4. Buffalo flies sit on cattle with their wings spread. Image courtesy of Jess Morgan
Figure 5. Cloud of buffalo flies around cattle. Image courtesy of Jess Morgan
Video 1. Buffalo flies rising in a cloud then returning to settle on an animal. Video courtesy of Jess Morgan
Bulls and animals with dark coats tend to have the highest numbers. The bites are extremely irritating to cattle stimulating characteristic behavioural responses including vigorous tail flicking and head tossing and sometimes kicking at ventral parts of the body (Video 2).
Video 2. Animal behavioural responses to irritating buffalo flies. Video courtesy of Jess Morgan