Saturday, 22 July 2023

Mid July in Oslo and bugs are in focus

Since returning to Oslo my interest in winged creatures has been rather reduced and as fits mid July it has been bugs rather than birds that I have focused on.

Over the last few years I have been in Oslo for parts of July far more than ever before and have spent time checking local stands of trees for hairstreak butterflies and have found White-letter and Purple to be relatively common although still far from easy to find. This year I noticed for the first time 3 elms only 50m from the house (goodness knows how I have failed to register them before) and quickly found White-letter on them which means the chance of finding one in the garden must be quite high. I have found them at 4 different sites this year including once when playing tennis with Jr in Oslo’s main park – Frognerparken. Purple Hairstreaks have been a bit harder to find but I have found them at my two regular sites and even had one very briefly on the ground but too briefly to get a photo. The weather has now turned wet and grey so it will be a while before I can again look for them but the White-letters at least were already egg legging so the weather will hopefully not affect their population.

On the dragonfly front I checked out a small forest marsh in Maridalen that I have often thought of visiting with the hope of finding Large Heath (myrringvinge). There was no joy on that front although it may have been too late in the season but to my surprise found two very localised dragonflies – Bog Hawker (torvmoselibelle) and Nothern Emerald (myrmetallibelle). The Hawker was a new species for me and the Emerald a new self-found species after I have previously only seen them at an already known site. This now puts me on a still modest 33 species of odonate in Norway (out of 52 recorded species) but all but one of these is self found which I think is good going. I have previously given up on finding the Bog Hawker due to its similarities with the far commoner Moorland Hawker (starrlibelle) but as soon as I saw them and the very special habitat – just a couple of small pools of open water surrounded by very wet mossy bog which was coated with flesh eating sundew plants – I was sure I was on to something. They were less brightly coloured than Moorland Hawkers and I managed some pictures (they are always in flight which is another thing that has previously reduced my motivation to try to find them) that allowed me to see enough of the few and very small distinguishing features to be confident of their ID.

an exciting little forest bog that I will have to remember to visit earlier next year

my first Bog Hawker (torvmoselibelle). Features that distinguish it from the far commoner and more widespread Moorland Hawker (starrlibelle) are the horizontal line on the face widening at the base, there being some (3?) pale marks between the two wide strips on the thorax, black behind eye (see next picture) and the blue on S2 is split into two (see next picture)


male Northern Emerald (myrmetallibelle)

and a female with characteristic yellow spots on S2

here over a carpet of sundews

English Sundew (smalsoldogg)

and Round-leaved Sundew (rundsoldogg)

my new elm trees by the petrol station over the road from the house

and one of the two White-letter Hairstreaks (almestjertvinge) I saw on them

the one I saw whilst playing tennis
and an egg laying female

a Purple Hairstreak (eikestjertvinge)


a colourful Golden-ringed Dragonfly (kongelibelle) with what looks like a wasp in its jaws

and a Small Pincertail/Green-eyed Hooktail (tangelvlibelle) at a new site for me

and last of all another type of bug altogether - a Musk Beetle (moskosbukk) 


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