Posted by
crex on 16-11-2007 12:27
#1
The parasiting Hymenoptera often have long thin ovipositors it can use as needles to inject eggs into the host, but Tachinidae are often quite sturdy, bristly and clumpsy looking. Someone mentioned a Tachinids "bite" on a larva. I doubt they actually bite the host, but I don't know. Well, this triggered my question - How do the Tachinidae flies inject their vicious eggs into the hosts?
Posted by
Kahis on 16-11-2007 15:36
#2
They have many different ways to handle this problem. Some have a piercing ovipositor. Some lay many small eggs on suitable foodplants and rely on the host larva eating the egg
. Others skip the egg stage and larviposit on on near the host, leaving the task on penetrating the host to the 1st stage larva.
Posted by
ChrisR on 16-11-2007 16:22
#3
As Kahis said, many lay tiny eggs on the host's larval foodplant and hope that the larvae injest them. Others lay first instar larvae that wait on the host's larval foodplant and grab a larva as it goes past.
As far as I know, no tachinid actually has an 'ovipositor' but many species have 'piercers'. The distinction is that an ovipositor is rather like a chitinous hypodermic needle that pierces the host integument and through which the egg passes into the host's body. But a piercer is a sharp, solid projection made from one of the sternites (I think), which is used to stab the host and create a hole into which the fly can introduce an egg, using its soft egg-laying tube.
