Dropping like flies...
Several backyard poultry farms near the Des Moines river in central Iowa reported numerous deaths among their chickens. One farm lost 17 out of 21 backyard chickens. The referring veterinarian collected and submitted these flies for identification while further diagnostic investigations were being carried out.
These are Simulium flies, which have a characteristic humped appearance. These are small, stout bodied Nematoceran with short antennae having greater than 9 segments (Figure 1). They also have short prominent mouth parts with maxillary palps and distinctive wing venation with large veins crowded towards anterior edge (Figure 2). These flies have been associated with sudden death in backyard poultry flocks and can cause exsanguination and anaphylactic shock in livestock.
Figure 1: Short segmented antennae.
Figure 2: Wing venation.
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