My understanding is that figs will only produce seeds (and thus seedlings) if pollinated by a fig wasp.
Coincidentally, in conversation a few weks ago with a friend who has a large fig tree in his garden, and a son studying entomology at Rhodes, he mentioned that his fig tree is covered with wasps and that his son is considering studying them for his honours project. Now Rhodes has a well established Ento department, and students have been involved with fig wasps in the past, so it's not at all unlikely that there's well established colonies of escaped wasps in this area.
A day or so ago, I noticed a small (~8 to 10mm long) black wasp on one of the leaves of my Cape Brown fig tree, and wondered if it might be a fig wasp. Not having the slightest idea what size fig wasps are or what they look like, I assumed this was more likely some transient visitor.
Today, overcast and drizzly, I was inspecting the status of the fig trees I have planted in pots, and noticed the same wasp on the Cape Brown:
The photo is a bit blurry, but you can see that it looks like it's trying to insert an ovipositor into the ostiole of the fig - or am I imagining this and it's just the rear leg?
Initially it was tucked in at the base of the baby fig (15 to 20mm diameter), sheltering from the drizzle, but as I moved some leaf stems out of the way to try and get a picture, it began moving around, doing it's best to keep away from me. It then climbed onto the baby fig, and then started wandering around on the neighbouring leaves.
Eventually I managed to get a fairly clear shot of it.
At no stage did it try to fly away, and it seems like it's hanging around this particular tree waiting for something to happen. This baby Cape Brown has the largest of the newly developing figs, so presumably it's nearly the right size for the wasp to lay eggs in it?
The nearby White Genoa has much smaller figs:
These are only 3 to 4mm in diameter at present, and no wasps hanging around.
The Kadota has a few small figs growing:
but these are even smaller, only 1 or 2mm across -- and it looks like they might be twinning.
I'll follow up with the entomologist son of my friend to see if he can help identify the wasp. If it is a fig wasp -- which seems possible -- what does this mean? Are there different species of fig wasp? Is this some local species adapted to wild figs or is it the same sort you get in other commercial fig areas? Am I going to get better figs because of them? Or can I grow other more complicated Smyrna type figs? Or is this something that's going to ruin my crop?
Update 21:43
Google doesn't show any fig wasps -- and there are many -- that look like this. So, what is it? And what is it doing on my figs? What pollinated the fig that produced the seedling tree?
Lots of questions!
Update 2017/05/29:
I'm slowly getting better at identifying figs. It looks like the large established fig tree in the garden is a Calimyrna variation of some sort, i.e. a Smyrna type fig requiring caprification. i.e. the fact that this tree is setting fruit and producing seedlings means there are fig wasps about. I just haven't seen any real ones. Yet....
From the entomologist: "[...] late reply. Im confident that everything im about to say is correct, but it is possible im misremembering, ill try and just double check next time I see the professor who specialises in fig wasps. The wasp you identified is not a fig wasp, i believe it is either an Ichneumonidae or a Braconidae (They are very similar and difficult to tell apart, but my initial guess is Braconidae. Fig wasps are much smaller, only measuring about 2-3 mm and they actually burrow through the ostiole of the fig and oviposit within the fig. You are right that they are in fact required to fertilise fig trees, but this only applies to the wild fig trees. Commertial fig trees actually have no interactions with the fig wasps. There are multiple species, the majority of the fig wasps are actually species specific to a single fig tree species. They also do occur in the Grahamstown area in fig trees on campus and in bots at the very least. In terms of yield Im not 100% sure, but it is unlikely to harm your yield if you have fig wasps. As they are required to fertilize the plant the plant has specially adapted its fruits so that only specific seeds within the fig fruit are actually parasitised, so the fruit remains intact and fully edible. If you want to look up more detail they belong to the family Agaonidae. For more information I'd highly recommend any papers written by Steve Compton on the subject, as well as a very useful website called wasp web that will have a large number of pictures"
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