Astichus
As much as you might like to take walks in the forest you aren’t likely to witness the events going in that bracket (shelf) fungus you just spied out of the corner of your eyes. Tiny cylindrical beetles (family Ciidae – common name minute tree-fungus beetles) may well be tunnelling their way into the fruiting body of the fungus growth. Slowly but surely the female progresses until it finds a good spot to lay its eggs. Having completed her primary task in life she leaves her progeny to their own devices (and fate). After hatching, a larva begins its own feasting, passing through a suitable number of moults during which it will cast off its old skin for a newer, larger one that will accommodate the growing larva. Having reached a desirable size it will then pupate, initiating the miraculous process of reorganizing the organs and tissues in its body, finally popping out into this world, as a perfectly nondescript adult. Unless, of course, a startlingly beautiful parasitoid happens by and catches the unmistakable scent of its host, an unassuming ciid larva. Astichus (Family Eulophidae) is on the prowl. She enters the tunnel and searches out the larva, injecting an egg into it. The egg hatches and the wasp larva attacks.
Astichus is a small genus of 31 species, all of which are thought to be parasitoids of Ciidae in bracket fungi. Species are easily identified by the combination of rich metallic colouration, patterned wings, very small size, and the distinctive antennae of the males. It is only recently (2012) that Astichus was first recorded from the Afrotropical region when four new species were described from South Africa. The collection of Astichus in East Africa (Kenya) adds more evidence to the hypothesis of a migration corridor, with more or less uninterrupted and environmentally favourable habitats suitable for colonization, accounting for the many similarities in the insect fauna shared by these two species-rich areas.
Credits: Dr Robert Copeland