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Winged Cockroach - Balta sp.
The Balta genus belongs to the Blattellidae family that has many winged species, including the introduced house invading ‘German Cockroach’ pest, which is probably an Asian species. The Blattellidae family is most obviously distinguished from other cockroach families by having antennae longer than half the body length, long sender spiny legs, plus reasonably long tapering cerci that are carried at right angles to the body. Other features involve the genitalia that can only on be seen on the underside.
Most of the Australian Balta cockroaches are endemic and unlike the German Cockroach seldom enter houses, although sometimes they are attracted to house lights. In the Esperance region although these roaches are widespread, they are not particularly common and seldom encountered. Balta are generally small insects with the above being around a cm (3/8”) in head/body length and spend most of their time wandering around on native vegetation.
Only the Balta males are winged, whilst the females have much reduced ones and cannot fly. Like many female wingless insects, they probably release pheromones to attract the similar sized male when ready for mating. Locally, they are most often seen on calm warm evenings, particularly after light rain.