The ever-challenging Purple hairstreak

The flying season of the Purple hairstreak (Neozephyrus quercus) has recently past. It was my 3rd summer trying to get decent close-ups of this tricky species. Despite of 9 collected eggs last autumn I only managed to raise one to an adult butterfly. 7 eggs never hatched and one caterpillar died.

Fortunately, we recently relocated to a new home with a decent oak forest nearby. This means that the species flies just around the corner. I got a couple photos from the specimen that I raised, a male. Some additional shots I managed to make in the wild. It looked like the butterflies were mostly active in the early morning hours. They also came down to low-hanging branches which made it possible to try catch them with the camera.

The First Apatura Caterpillar

For a long time I’ve wanted to raise caterpillars of the Purple Emperor (Apatura iris) or the Lesser Purple Emperor (Apatura Ilia). Before getting that chance there was one challenge thought: Finding eggs or caterpillars.

After spending quite some time on the quest I finally found what I was after a couple days ago. A hibernating caterpillar of the Purple Emperor on Goat Willow (Salix caprea). Here’s some images on the specimen, including a photo of the growth where the larva was found (see red marking).

How to find eggs of the Orange Tip

The Orange Tip (Anthocharis cardamines) is a common butterfly (that counts at least up here in Finland) and finding eggs is not too difficult. However, as with any species, the time and place must be right.

The shape of the eggs is pretty similar to those of the Common Brimstone (Gonepteryx rhamni). Eggs will be around only for a short period as the caterpillars tend to hatch already after 5-7 days. Once you start seeing the first males flying, wait for another moment. I waited two weeks this spring after spotting the first male, and got lucky. The first female I actually sighted after first finding the first eggs.

Here’s a couple photos from my search this spring. I also tried to capture the larval habitat to show what kind of surrounding I found eggs in.

How to find caterpillars of the Scarce Tortoiseshell

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In summer 2014 one of my primary targets was to find caterpillars of the Scarce Tortoiseshell, also known as Yellow Legged Tortoiseshell (Nymphalis xanthomelas). My aim was to get a closer view on this species rearing caterpillars to adult butterflies.

The Scarce Tortoiseshell is a rather occasional visitor in Finland. However, in 2013 the species mass migrated from East towards Finland. As a result, early spring 2014 this butterfly was one of the most sighted species in southern Finland. A great baseline to try tracking down caterpillars early summer.

Please note that all my knowledge and data has been collected during one summer and within one region only. Behavior may vary depending on location, and in a “normal” year finding caterpillars will most likely be difficult if not impossible (due to the lack of the species’ presence). Nevertheless, I’ve been browsing through the greenery nearby. Here’s my wrap up from the experience I collected.

Location 1: Caterpillar colony

This location relates to one of my season highlights last summer, finding the actual caterpillars. On a cold and windy day I got lucky. On June 19th, the caterpillars appeared late that summer which must have been a direct response to poor weather conditions.

I knew in advance this location would be good as I continuously spotted Scarce Tortoiseshells flying early spring. Since late May I started monitoring willow in this area. Though I had little knowledge what kind of breeding behavior this species would have.

The caterpillars were found on willow, Salix phylicifolia to be precise. They were feeding above a small ditch. I’ve once read that Mourning Cloaks (Nymphalis antiopa) prefer similar conditions. The ditch keeps the growth doing well while providing some level of humidity to the caterpillars above. This particular location has continuous and direct sunlight.

Location 2: Abandoned colony

This sight was located just about 50 meters across a field from location 1 (see photo in the conclusion). It is well possible this colony was laid by the same female as the caterpillars found nearby. In this case (actually my first finding on the search), there were no caterpillars left. Clearly visible from a distance were the feeding traces. A closer look also provided details such as twigs covered by web and moulted skins.

Compared to location 1 this colony must have been further developed already. Caterpillars on location 1 were just moulting to the last instar. Location 2 looked like moulting took place already some time ago. Perhaps the twig was abandoned as the adult caterpillars separated (which I believe is a common behavior for this species at this stage).

Here the facts about the location. Again, caterpillars were feeding on Salix phylicifolia, a common type of willow in Scandinavia. The differences to location 1 were that no ditch was nearby. The caterpillars fed on a twig hanging low and outside of the growth, which in this case was much older already. The sight has direct sunlight from noon until evening.

Location 3: Abandoned colony

Later on in summer 2014, around mid July, I accidentally sighted a third location where caterpillars had been feeding. This location took me by surprise as it was just around the corner where we live. I did spot adult butterflies flying in spring though, but I didn’t expect caterpillars this close.

This time it must have been already weeks since the caterpillars pupated, most likely the butterflies had already hatched as well. The habitat had very much in common with location 1. The caterpillars were, yet again, feeding on the same type of willow (Salix phylicifolia). The growth was located in a ditch with the twigs hanging over water. The location has direct sunlight throughout the day. This spot is just between a small road and a walking path. Just 50 meters away there’s apartment buildings and a much frequented street.

Conclusion

Based on my findings in 2014 the common conditions for all sightings were following: The caterpillars were feeding on Salix phylicifolia and they were located on twigs clearly separated from other growth of the plant. The “colonies” were located in a height of 20-50cm above ground. As in location 1 and 3 they fed on twigs growing in the ditch, which causes them to be located very low.

Direct sunlight and open terrain were other conditions matched at all sights. Nevertheless, location 2 was next to higher growth. Tracking down a twig with caterpillars¬†(or traces left by them) was pretty easy, assuming the location was right. Caterpillars feed the twigs completely “naked”. Should there be caterpillars left they color the twig black as they feed in large numbers. Other traces are skins after moulting and a web covering the twig.

Due to the poor weather conditions in 2014 it was difficult to get hint on the exact time when caterpillars could be found. As a result, I had to accept finding abandoned sights as well. Despite of the butterfly flying in large quantities in spring the species almost disappeared in summer when the next generation was expected. Spring 2015 will show if there’s any individuals left, or if Finland has to wait for the next mass migration to enjoy the beauty of the Scarce Tortoiseshell again.

I’m definitely hoping to get another chance to raise these caterpillars. By the way, approximately 90% of the caterpillars had parasites. I was able to observe the larvae of some Tachinidae species leaving its host before building a snow-white cocoon, usually hanging at the tail of the dead caterpillar. Therefor, young caterpillars or eggs would be yet a better finding.

Beautiful caterpillars: The Puss Moth

The caterpillar of the Puss Moth (Cerura vinula) is definitely one of the most peculiar larva in the Palearctic. Though the adult moth looks rather usual it is the caterpillar that makes this species special.

The photos below will act better than words to describe this amazing caterpillar. When being threatened it will form a position where the head gets bigger and a red appendage appears from the fork at the tail. In fact, the the fork at the tail has also been used in many languages to determine the name of this species. So e.g. in German, the Puss Moth is called “Grosser Gabelschwanz“, which translates to Large Forktail in English.

How to find caterpillars

As with many species keep your head low. The caterpillar can be found most likely on young bushes (not the adult trees) of the food plants. Due to its size the caterpillar will also leave well recognizable feeding traces. In one case I found a caterpillar that just moulted and the old skin was also visible well. Finding such a skin, which might be tough though, will directly indicate a caterpillar has been around. Here’s some footage that might be of help.

The Grayling

At the rocky coast line and archipelago of the Baltic Sea in Finland a particularly funny butterfly holds its habitat: The Grayling (Hipparchia semele). This species is master in disguise, and it’s practically impossible to spot an individual that’s resting on a rock. You need to catch it flying.

A friend of mine, Helmut, introduced me to the harsh habitat of this butterfly. Once we arrived on sight, we had to wait for an individual to fly by that could then be chased. The Grayling has a beautiful eye on it’s upper wings. However, it may not be willing to show this eye. After the butterfly lands it takes about two seconds, and the eye “shuts”. Graylings only show the eye when they’re disturbed (they’re very careful, and rather fly away instead of showing the eye to a threat) . Nevertheless, it seems that while feeding on flowers they also keep the beauty on their wings visible.

Luckily, we saw multiple individuals flying. And we also caught them with our lenses. Definitely a good day for a hobby lepidopterist.