Brown Hairstreaks in June

The Brown Hairstreak (Thecla betulae) flies in late summer. It’s one of the latest species in Finland and can usually be spotted from late July to mid August. Nevertheless, the species can be tracked down almost all year long. This year, I gave it a shot and tried finding caterpillars. I’ve never photographed larvae of this species in the wild, hence I was motivated to find some.

Spring this year has been exceptionally cold. As a result, the two caterpillars I found on June 17th were only about 1cm in size. Perhaps I should also mention that I did not wildly browse random bird cherry (Prunus padus) bushes. I concentrated on such plants where I was able to spot eggs of the species last winter. I remembered one spot that counted three eggs. I was able to first confirm that two eggs did hatch. Moments later, I was also lucky enough to first find one larva, then the second one.

Raising the Brown Hairstreak

To raise the Brown Hairstreak (Thecla betulae) has been a particular joy in 2015. After collecting eggs in the wild (see this post) I had the chance to see one of the caterpillars hatch from the egg while capturing the moment with my camera.

Place a decent twig of food plant in the cage and you’ll have a true meditation moment whenever you try to find the well hidden caterpillar on the bottom side of a leaf. Also the chrysalis can hardly be found. I definitely suggest this species to anyone who likes raising caterpillars that like to hide themselves.

Hatching Hairstreak

Last Friday night I was able to observe a step in the butterfly metamorphosis that I haven’t witnessed before: A caterpillar hatching.

During the afternoon I saw that some of the eggs in the raising box started to show tiny holes. They appeared smaller than those of empty egg shells which I sighted quite commonly while searching for eggs last autumn. In the evening I took a closer look with a magnifying glass. I saw something shiny inside the egg, and it was moving. I quickly realized it was the black head of the tiny caterpillar. Only moments later the caterpillar started to leave the egg. Just enough time to get the camera.

Due to poor light conditions and my camera equipment shooting close-ups it always a challenge. Nevertheless, here’s some photos of the first moments of a young caterpillar. Minutes after hatching, the tiny larva disappeared in a close-by leaf bud. This is where it will spend a couple days.

How to find eggs of the Brown Hairstreak

The Brown Hairstreak (Thecla betulae) is an incredibly beautiful species. Last summer, I had the pleasure to get some good shots of this butterfly. And it left me hungry for more.

For season 2015 I’ve set my priorities to get further engaged with hairstreaks. This includes raising a couple species from eggs to adult butterflies. Raising butterflies from eggs calls for one thing first: finding the eggs. Here’s some tips and tricks for getting started on the search for eggs of the Brown Hairstreak.

As said, last summer I got lucky seeing adults flying (and posing wings open). It was rather coincidence that I entered the habitat of the Brown Hairsteak, the largest species of hairstreaks in Finland, at the right time. It was the first time for me spotting this species. I had a great clue where to search for eggs later autumn.

Knowing a location where the butterfly is present is probably the best to get started. However, hairstreaks are often shy species and may remain unseen. In fact, some people search for eggs during winter as a sign of a species’s presence. This way they know where butterflies can be found flying in summer.

In Finland, Bird Cherry (Prunus padus) is the common food plant of Brown Hairstreak caterpillars. In my search I observed that most eggs are laid quite low on young growth of the plant. The growth ranged mostly from 1 to 2 meters in height, and the eggs were located in a height of ca. 20cm up to 1 meter.

Finding the eggs is not too difficult (assuming you’re on a good spot). The clean white dots area easily found. It’s mostly single eggs, but they can be found in groups of two or three. Forks in branches seem to be preferred spots, even though I’ve found eggs laid directly on a branch or the stock of the bush.

I’ve been checking the habitat during autumn and winter. Snow and frost definitely make it more difficult to browse through the growth. One more thing, while searching eggs I often found empty ones as well (see photo below). These eggs must have hatched earlier, and the eggshell seems to remain quite well. If you see a dark shade in the middle of the egg it may be empty. Hence, focus on eggs that are throughout in a clean white shade.

The Brown Hairstreak

I didn’t know that much about Hairstreaks prior to this summer. Despite of the very common Green Hairstreaks (Callophrys rubi) flying in late spring, I wasn’t expecting to fall in love with with such small butterflies.

Nevertheless, on a recent trip into the greenery a Brown Hairstreak (Thecla betulae) caught my attention, just by accident. That moment made me realize there’s something special about Hairstreaks. I can’t explain if it’s their behavior and the way they like to pose to the camera. Or is it because they’re even more fragile than most of the other butterflies? Perhaps because they’re so hard to detect at first? Either way, I ended up spending every free minute I got chasing them.

In my case. three species shared the same habitat where I, by pure coincidence, found the first individual. It was a female Brown Hairstreak. This one was anything but shy, and even unveiled the stunning beauty of its upper wings. What I didn’t know back then was that it’s rather rare to get such a chance. Hairstreaks are well known to mostly keep their wings closed.

Here’s the top shots I got on this fragile species, shot on several days but always on the same spot. The other two species, the White-letter Hairstreak (Satyrium w-album) and the Purple Hairstreak (Neozephyrus quercus), deserve their individual post later on.