Twin-spot Fritillary (Brenthis hecate)
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2019 photographs highlighted in yellow. Click on any photograph to go to an enlarged picture, or simply scroll down the page.
This butterfly of the far south of France is quite uncommon (except in one region of eastern Var and western Alpes-Maritimes) and could easily be confused with the Lesser Marbled Fritillary (B. ino) based on the upperside alone. The male hecate is a clear bright orange and the female more heavily suffused with a faint purplish sheen, dulling the orange; the sheen sometimes seems to confuse the camera, especially at certain angles. Hecate has series of quite round post-discal spots on both upperside wings, as well as a series of submarginal spots which are shown in T&L as being essentially round on the uph, and a continuous black margin. Ino is very similar and is usually depicted as having a series of somewhat indistinct non-round submarginal marks. This originally had me fooled, as the submarginal marks of some individuals (e.g. 29423) look non-round and more like ino than hecate according to T&L.
But hecate has a complete series of post-discal spots on both the upf and uph of similar size, and ino has no (or very small) spot in the upf s4 and a significantly smaller spot in the uph s4 (see illustrations below). Curiously, I can't seem to find any mention of this in the books. The underside is quite distinctive, though. The two series of unh black spots are characteristic of hecate and give it its name.
The flight period is stated as from the end of May to mid-June, so unless you are visiting possible sites at this time, you are unlikely to see it. However, in central Var it is on the wing from mid-May onward. I originally saw one hecate in 2000 at this time, and it was not until 2006 that I started to visit Var regularly in May, since when I have seen it at many locations within the region indicated opposite. One of these sites was at an altitude of 1400m, which is about the upper limit of the altitude range for this species.
The larval hostplant is Filipendula vulgaris (English name: Dropwort), a white-flowered plant of about one metre height. It is not uncommon in the region, and I have found that wherever Filipendula grows, there is often hecate to be found there.
|29423||M||a fresh male, just beginning to roost at the end of the day, when hecate seems to like basking in the final rays of the sun. 29487 is the underside, after it had closed up for the night.||220|
|34971||M||a typical male.||220|
|37332||M||a fresh male with rather heavy black borders.||220|
|35481||M||a male, from a location at higher altitude.||780|
this is the female from the mating pair in 10833. The weather was dull and the pair remained as in 10833 for some time, but then the sun came out briefly and the female opened up, still connected to the male although this is not obvious and needs a close look at the photograph to confirm that the foreground obstruction is, in fact, the male.
|29730||F||a female, also enjoying the last rays of the sun. The sheen gives the orange a rather dulled appearance and makes it almost impossible to capture the image as seen in the field.||220|
|29487||M||a male, known to be so as the upperside is 29423.||220|
the mating pair (the same as 10875), female on the right, posing nicely in dull weather. The foothold of the male seems tenuous to say the least.
difficult to say whether this is a male or female, as the series of unh post-discal black spots is rather midway between the heavy spots of the female and the lighter spots of the male.