Who goes there?
Lately, we (in the East Rand) have been treated to an uncommon visitor to our gardens and homes. I’m alluding to the Cream-Striped Owl Moth (Cyligramma latona). They belong to the family Noctuidae. A striking feature of this moth is the owl-eyed markings on its wings. The purpose of such markings is to convince potential predators that it is dealing with something dangerous. Such instances of mimicry or common in the insect world.
Cream-Striped Owl Moths are fairly common across the country at low densities. Their larvae feed on a variety of Acacia (now Vachellia) species. During droughts, the numbers of butterflies and moths fall to very low levels. However, their main predators – wasps and flies – are affected to a far greater extent. If there is a sudden burst of greenery at the end of a drought predators are overwhelmed. A female Cyligramma latona lays hundreds of eggs and from each mating, only one of each sex need to survive to preserve the species. The predators usually kill 98% or more of the offspring, but if the predators’ numbers are low, a high percentage of caterpillar survive and the adults then mate and lay even more eggs that survive. This creates an exponential increase in numbers. This results in the population explosion we are currently experiencing.
The response to this is usually that when numbers reach a critical point, the adults start dispersing and we see thousands of them over a large area. It’s what happens every year with the little white butterflies we see migrating. However, if a drought has been prolonged and severe, even large moths like these can explode in their numbers.
If you are ever in need to identify any South African fauna or flora, we can highly recommend I Spot: