Are there other ways to determine where the butterfly was collected? Pollen studies?; The San Francisco area of western California

Are there any other possibilities to find out where the butterfly has been collected? Pollen Studies?

Here I want to thank my namesake Fredrik Sjöberg of Runmarö in the Stockholm archipelago when he told me that they used to check for pollen on the legs of flower flies to see which flowers they visited! Yes, this information then became a research task! If we could find any pollen grains on the butterflies' feet or legs, we should be able to derive from which plant these belonged and see if this plant was either only in Hawaii or from along the Strait of Magellan. So it should be worth a try. I contacted the Academy of Sciences and presented my hypotheses and wishes for their help. Professor Sivert Nilson thought the idea was interesting and promised to help me with this. I also got in touch with the experts at BMNH but got an almost shocked surprised response when they talked a bit vaguely about “we had probably thought about this” and that “we should check this too”. Well Well!!

At a very nice meeting at the Academy of Sciences, we examined the feet and the wing underside of some of the ponteni-specimens. See a photo under “Footnotes”

But oh! - this was too good to be true. We unfortunately did not find a single pollen grain! This then felt like a big failure, but now many years later, this, together with some other hypotheses, has made me question whether Samuel Pontén actually collected these butterflies as adults, but more about this below.

Professor Sivert Nilsson and his assistant investigating pollen on Colias ponteni’s feet.

San Francisco Area in Western California

The very large area of the androconia, along with the enormously large egg-shaped antennal clubs make one wonder and to speculate on where Colias ponteni´s closest relatives fly and who these are. This, as well as an investigation of Kinberg's notes, or rather the shortage of these, Pontén's collection, and Master Andersson's notes together with the butterfly's appearance, point in several aspects in the same direction: Hawaii? Or maybe eastern California? However, can it really been found in California? When talking to Arne Anderberg and Bertil Nordenstam at the National Museum's Botanical Department, it has been shown that a large amount of plant material was collected during the visit to San Francisco in 1852. Unfortunately, this material has been brought to the National Museum in Stockholm and divided up on the basis of classification etc. which made the material difficult for me to investigate. There are probably also plants collected by Samuel Pontén perhaps even also from Oahu, because he also collected plants for his brother's school in many places along the Eugenie's journey. The plants at Pontén's school in Strängnäs have also been transferred to the Natural History Museum in Stockholm.

Personally, I increasingly question this practice of splitting special collections from different places especially now with the digitization and modern computer technology it is so easy to still look for special copies of different collections even though these are preserved in their original collections. Think how much easier it would have been to get a grip on Ponten´s private collection of butterflies and plants if they had all been preserved together. It should have been enough to photograph them and digitize them. Here I can't help but think of my old friend Eric von Mentzer's hugely fine and almost complete European Heterocera collection, which now unfortunately has been completely divided when the Swedish Museum of Natural History took over his collection. Imagine if it had been intact as I saw it some year before his death. I, very much because of what happened with von Mentzer's collection, chose not to bequeath my nearly 2000 drawers of butterflies and moths from all over the world to the Natural History Museum in Stockholm.

Can the San Francisco area be Colias ponteni source? It could be so. The area has many unique species, but I still have to doubt that this spectacular species had existed there and that the inexperienced Samuel Pontén or Kinberg, who was not an entomologist at all, could have collected at least five, but perhaps as many as eight specimens of such a butterfly on a single visit and that the species has then never had been found since. No, the San Francisco area can with all certainty be dismissed as a possible locality for Colias ponteni because of the many entomologists who in the mid nineteenth century investigated the area around San Francisco.