One of my Guests had been enjoying an after-lunch siesta in the shade of her Sala, listening to the muted sounds of the African bush, when her peaceful serenading by a variety of birds was interrupted by what she described as "a mini-helicopter" doing acrobatics!
As the "helicopter" got closer and revealed itself, the sunlight reflecting the blue sheen on the wings, she correctly identified it as a wasp. And for those of you who don't like spiders, this colourful wasp may become your new best friend...
The female spider-hunting wasps (Pompilidae) locate their prey and sting them with venom that causes paralysis but does not kill. The wasp then drags its immobilized prey backwards over the ground, towards a suitable nesting place. Once this has been reached the female wasp starts to excavate the site. She uses her front legs which have been adapted into 'rakes,' to help dig the hole, pilling the excavated material on one side. Once the burrow is deep enough she drags the prey into the nest, and carefully lays a single egg on the back of the paralyzed spider's abdomen.
This achieved, the pompilid wasp grooms herself and then proceeds to close the burrow. This she does by backing into the burrow, drawing in the previously excavated soil by passing it underneath her body and using her legs to pack it into place behind her. The wasp then levels off the entrance of the burrow, flies up and does a tour to inspect her site from the air. Should she not be satisfied she'll go back and make the necessary improvements. Loose debris is finally scattered over the site and with some final grooming, flies off. In her lifespan of a few weeks, the female pompilid wasp will construct several further nests.
The pompilid wasp egg, that is now underground, hatches after about 2 days, the larvae feeding off the live, but immobilized food. The larva eats all the soft tissue of the paralyzed spider, starting with the abdomen and eventually leaving only the hollow cephalothorax and legs. After approximately 7 days the larva then spins a silken cocoon where it pupates to emerge as an adult wasp the following summer - and yet another "mini helicopter" takes to the skies!
A spider-hunting wasp dragging a paralyzed spider to the nesting site
As the "helicopter" got closer and revealed itself, the sunlight reflecting the blue sheen on the wings, she correctly identified it as a wasp. And for those of you who don't like spiders, this colourful wasp may become your new best friend...
The female spider-hunting wasps (Pompilidae) locate their prey and sting them with venom that causes paralysis but does not kill. The wasp then drags its immobilized prey backwards over the ground, towards a suitable nesting place. Once this has been reached the female wasp starts to excavate the site. She uses her front legs which have been adapted into 'rakes,' to help dig the hole, pilling the excavated material on one side. Once the burrow is deep enough she drags the prey into the nest, and carefully lays a single egg on the back of the paralyzed spider's abdomen.
This achieved, the pompilid wasp grooms herself and then proceeds to close the burrow. This she does by backing into the burrow, drawing in the previously excavated soil by passing it underneath her body and using her legs to pack it into place behind her. The wasp then levels off the entrance of the burrow, flies up and does a tour to inspect her site from the air. Should she not be satisfied she'll go back and make the necessary improvements. Loose debris is finally scattered over the site and with some final grooming, flies off. In her lifespan of a few weeks, the female pompilid wasp will construct several further nests.
The pompilid wasp egg, that is now underground, hatches after about 2 days, the larvae feeding off the live, but immobilized food. The larva eats all the soft tissue of the paralyzed spider, starting with the abdomen and eventually leaving only the hollow cephalothorax and legs. After approximately 7 days the larva then spins a silken cocoon where it pupates to emerge as an adult wasp the following summer - and yet another "mini helicopter" takes to the skies!
A spider-hunting wasp dragging a paralyzed spider to the nesting site
Michelle Swemmer - Field Guide