The black darters here are a bit of a puzzle. I have seen them every year for the past four or five but have only ever seen mature males, as with these. The absence of females and juveniles means that they almost certainly don't breed here, not surprising as it isn't really the right habitat. Black darters are inhabitants of heathland and moorland and breed in acidic ponds. These are presumably wandering males in search of fresh territories but how far they range and where they come from isn't known. I was pleased to see them, even if they have turned up six weeks later than last year. Their arrival brings to 14 the number of Odonata species I have seen at the pond this year.
A common hawker has been trying to establish a territory on the smaller northern pond. His problem is that it is still being patrolled by an emperor who doesn't fancy sharing, even with a different species. While he was hovering uncertainly near the edge I took a few flight shots but every few seconds he was chased away.
This is an interesting comparison - a migrant hawker in flight a few metres away.
I think the emperors will be gone soon, leaving the field clear for the common and migrant hawkers. This may be the last I see of them until next June.
Migrant hawkers are still few in number but I expect they will increase in the next few weeks. I saw several males,
and one female.
Ruddy darters were making the most of the sunshine.
The common darter season goes on into October so there are still plenty of young looking specimens.
Common blue and emerald damselflies will also be around for a few more weeks.
Smaller butterflies this week included small heath, common blue and wall. Larger species were red admiral,
I was standing watching a dead sycamore in the garden (as you do), holding a camera(as you do), when this little beast landed in front of me. It is a female Gasteruption jaculator, a parasitoid wasp, and it was checking the woodworm holes for signs of a likely host.
Parasitoidism is a type of parasitism characterised by a fatal outcome for the host, making it in between parasitism and predation. A Gasteruption wasp lays its egg in or on the larva of a solitary bee or wasp and its own larva consumes the host larva and its food supply. This one was sniffing the holes with its antennae to locate a target.
The long white-tipped spike at the back is a sheath covering its ovipositor. Once it was satisfied it had located a target it unsheathed the ovipositor which comes out half way along.
Next it manoeuvred the ovipositor into the hole.
The hole was very deep so it had to push in the whole length of the ovipositor and then reverse in the whole of its body, leaving only its antennae protruding.
Deep in the hole it laid its egg on the host's larva. Once the deed was done, which took only a few seconds, it climbed out of the hole and flew off. I didn't get to see how it resheathed its ovipositor.
The whole process was very quick but was amazing to watch. The scale is extraordinary - the woodworm hole is less than 2mm across so the gasteruption eggs must be minute to fit down the ovipositor.
I had another go with BadgerCam, while I was confident of the badgers' location. I set one camera with two auxiliary lights, one to the right as we look at it and one screwed to the tree above, but I am not sure how much they contributed. I also set the camera a bit farther back from the peanuts so the badger would be more likely to be in focus. I reckon it worked out OK but I'll have to continue experimenting with the lights.
The first video is a montage of three short clips.
The second one is cropped but I don't think there is a noticeable loss of image quality.
I was hoping to see this dragonfly although I could have done with a more co-operative example. This is a male migrant hawker but it was in an awkward position for a photo.
I also saw a common hawker this week but it was trying to patrol and constantly being chased off by an emperor so I didn't get a useful photo. I tried a few half-hearted record flight shots and still wasn't confident of the ID until I got home. The photo is terrible but it is possible to make out the colours, the prominent narrow shoulder stripes and the gold costa (leading edge of the wings). This time last year I could spot a common hawker from across the pond so I still need to get my eye in.
The emperors are still going strong, with two or three males patrolling and one female ovipositing. This male was getting his breath back for a few minutes.
Common darters and ruddy darters are still plentiful with lots of mating pairs.
Damselfly species were down to two although I may yet see more blue-tailed damselflies.
There were still plenty of butterflies. Larger species included red admiral, peacock, and painted lady. Smaller species were wall,
common blue,
and small heath.
I'll try hard to get a proper photo of the common hawker(s) next week.
