A Day to Remember

Many thanks to everyone who contributed reports to the compilation above.

References

Höjer, J. 1993 a. Gästrikland in Entomologisk Tidskrift etc. - Insectifera 1(1):21-27.

Höjer, J. 1993 b. Gästrikland in Entomologisk Tidskrift etc. 2. - Insectifera 1(2):25-26.

Källander, C. & Frycklund, I. This year's butterfly finds from Gästrikland 1994 (Lepidoptera). - Insectifera 3(1):53-61

A Day to Remember

Nils Westlin has submitted to the editorial office a particularly interesting observation at a sap-weeping birch by the lake Trösken.

Nils calls his letter "A Day to Remember"

Nils writes that during a visit to Trösken, he was alerted by some friends to an unusually strongly scented birch by the water. The strong, almost nauseating odour that could be smelled all the way into a nearby cottage came from the birch's root system.

Nils recounts that the scent attracted a large number of wasps, bumblebees, butterflies and flies. What surprised Nils most, however, was that the wasps left all their normal prey insects completely undisturbed. When Nils wanted to photograph the Admiral we see in the photo below, he had to place his foot right next to one of the holes in the root from which the wasps were swarming. Yet not a single wasp attacked Nils despite about twenty swarming around his head.

In total, about a dozen Admirals and the true "birch sap connoisseur" Mourning Cloak, a barred fritillary and numerous flies, many beautifully gleaming yellow-green, partook of the drinking without being disturbed in the least by all the wasps constantly circling around them in search of suitable feeding spots.

"A spectacle on the third of September anno '96" Nils writes in his diary.

Nils Westlin also tells of the Swallowtail occurrence in the Axmar archipelago, a few miles north of Gävle. Along the Gästrikland coast, the stately Swallowtail butterfly, which Sven Rosendal calls "The Prince of our butterflies," is not abundant. Over the past 30 years, however, Nils has seen it every year.

To this, perhaps the following comment can be added.

Especially along the block-strewn beaches along the Gästrikland coast, the Swallowtail butterfly is easy to observe. It still thrives here on the cloudberry and marsh cinquefoil a short distance up from the shore. It is quite easy to find its fantastically equipped larvae in late summer sitting like caramels along the stem of a larger cloudberry.

The Swallowtail is the world's most widely distributed swallowtail butterfly, though it has declined significantly in many places in recent years. It occurs in North America with several subspecies which have occasionally caused considerable confusion among systematicists. In Europe, North Africa and northern Asia it is fairly constant. In Europe/North Africa we have 2 species closely related to the Swallowtail, namely the Corsican Swallowtail endemic to Corsica and Sardinia and the small Saharan Swallowtail in North Africa and Arabia. The latter looks like a pale yellowish-brown common Swallowtail, but only half the size. Our Swallowtail is also found in North Africa and is there quite identical to our European specimens. Many probably think that the "Saharan" is merely a desert form of the common Swallowtail. Well, what does it really matter. The interesting thing is that it exists and that it is so different. It is absolutely worth protecting.

In Japan flies the very large Papilio hippocrates. This species, or subspecies of our common Swallowtail, shows considerably greater sexual dimorphism than our common Swallowtail. The Hippocrates female is sometimes twice as large as the male and considerably darker!

Perhaps I can develop the Swallowtail with its subspecies and related species further in later issues of "Insectifera".

Göran Sjöberg