ZABIBU

It interests me to try to document the pests that we face in our part of the world and so I have tried to put together a few images to show the incredible internal damage that this grub does to mature vine trunks. 

The vine itself does not appear to be suffering in any way, it produces good fruit and you would not necessarily discover the plant it affected until you cut into the main trunk of the vine while pruning.

You can see that two large holes (1.5 cm wide) have been bored into the trunk at the site of the pruning wound. Clearly the grub is somewhere in there and lower down. We needed to ensure its removal and so we cut down 10 cm at a time. You can see the trunk folded back on itself as we cut lower and lower.

One of the three affected vines we identified this year while pruning, had a tunnel well into the vine base and we had to uproot the entire plant.  If you look carefully on the trunk of the vine you can sometimes find a darker staining and secretion which marks the point of entry.

If you poke a stick into hole you eventually find the culprit. A four or five centimetre long larvae, soft and squidgy! The holes had a gooey pink substance in them which might have been some of the sap from the vine that oozes into the hole as a result of the wound. The grub has a very effective set of mandibles to chissel out the tunnel into the hard wood of the vine.

We think that it is probably the larval stage of a beetle but have yet to see what this thing pupates into.

Any entomologists out there have any ideas?