Superfamily: Bombycoidea, Latreille, 1802
Wind Beneath My Wings
The Diverse Emperor, Imbrasia ertli, (wingspan 11-13 cm) flies in Namibia, Botswana, Zimbabwe, Zambia, Malawi, Tanzania and south-eastern Zaire (Congo), just reaching into north-eastern Namibia.
Larvae are reported as an important human food in the Bas Congo province of the Democratic Republic of the Congo.
In the Bas Congo province, this moth is much appreciated for its gregarious larvae. The moth is on the wing from October to February.
Female moths deposit eggs in groups on the leaves of Ricinodendron heudelotii, Petersianthus macrocarpus (African stinkwood), Funtumia africana (False rubber tree) or Holarrhena floribunda.
Frass found below the trees is a good indicator caterpillars are present. The larvae move and feed in groups where the individual larvae maintain close contact. Initially larvae have long hairs, but in the final instar, when they are collected, most of the hairs are lost.
These caterpillars also descend the tree trunks to between 1 and 2m above ground level when shedding their skins.
Normally, harvesters gather the entire colony to roast, boil or sun dry the prize for later use.
Imbrasia ertli, Congo, gathered for human consumption,
Image courtesy of Bruce G. Marcot, Ph.D., research wildlife ecologist, at EPOW
Larvae feed on Julbernardia and Brachystegia and on Acacia.
Eggs are deposited in large clusters on tips of foodplant stems.
Larvae are gregarious in all instars and descend foodplant at maturity (90 mm) to pupate in the soil. The black larvae with their red heads and rear ends are covered with dense, long, white hairs.
Image from Rolf Oberprieler's The Emperor Moths of Namibia.