Colourful

Overly colourful, if we're honest. If I'd had more energy this evening, I'd have selectively edited this to dampen the hemp agrimony down a bit, and let the Phasia hemiptera sing out in his full glory. As it is, I'll just have to ask you to imaging that that's what I've done, which you can probably achieve by squinting ferociously at the fly and ignoring everything else.

I went to the Wyre Forest today, for the first time in five years. It's never been a favourite site of mine, not least because it's right over on the far side of the county to us, and it takes an hour to get there. And also - I'll have to whisper this, in the hope of not attracting too much attention - I'm not as crazy about butterflies as many of my friends, and butterflies are the creatures for which the Wyre is largely known. So why go? you ask - especially as this isn't a great time of year for butterflies anyway. Why, because dragons, of course. I'm still after capturing my 2023 photo of a Golden-ringed Dragonfly, ideally without needing to drive to the New Forest to get it, and Golden-rings have been recorded at the Wyre this season.

The fact that I'm posting a fly rather than a dragon tonight tells you all you need to know about the success of my quest, but in a forest as big as this it was always going to be a long shot, so I'm philosophical about it. On the plus side, because it's August rather than May (Pearl-bordered and Small Pearl-bordered Fritillary season) I got into the car park at the first attempt, and because I extended my search from the old railway cutting were the dragons have been seen roosting, down to Dowles Brook where one would assume they'd go in search of special friends, I got back to the car with 12,000 steps under my belt. Given the post-viral malaise I've been suffering recently, that in itself feels like a worthwhile achievement.

There's a lot of hemp agrimony growing along the sides of the cutting, especially around the section which historically was bog, and as I walked I kept a sharp eye out to either side for interesting nectar feeders. When I first saw this fly he was hanging underneath the flower head and angled away from me, but something about his size and those big delta wings with their smoky patterns attracted my attention. I've only ever encountered Phasia hemiptera a couple of times before, but with this species it really is a case of once seen, never forgotten.

This 1cm parasitoid tachinid fly is strongly sexually dimorphic, with the male being larger and more colourful; the female is narrower in the body, and has smaller, unpatterned wings. Phasia hemiptera goes through two generations a year, the first being on the wing from about April to June, and the second from July to September - though within those spans, individual flies live only around three to four weeks. The females lay their eggs on other insects, and the larvae burrow inside the host's body, eventually killing it, at which point they pupate. The main host for the spring generation is the Red-legged Shieldbug (Pentatoma rufipes), and for the summer generation it's the Green Shieldbug (Palomena prasina).

Sad as I find it to think of the fate of shieldbugs that are parasitised in this way (and I admit to getting even more upset when I see a shieldbug with a large white tachinid egg attached firmly to its carapace), I know that tachinid flies have their own niche within the ecosystem, and there's no evidence that Phasia hemiptera poses a threat to its host populations. In fact, commercial foresters and orchard keepers might wish that it did, because the Red-legged Shieldbug, which feeds on various trees including oak, alder, hazel, apple and cherry, is sometimes regarded as an agricultural pest.