Large Grizzled Skipper (Pyrgus alveus)

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2016 photographs highlighted in green. Click on any photograph to go to an enlarged picture, or simply scroll down the page.

27136_male_Hautes-Alpes_14Jul11 21770_male_Alpes-Maritimes_8Jul10 21800_male_Alpes-Maritimes_8Jul10
22250_male_Hautes-Alpes_14Jul10 33515_male_Hautes-Alpes_8Jul13 23332_male_Vaud, Switzerland_27Jul10
30612_male_Hautes-Alpes_6Jul12 36201_male_Hautes-Alpes_15Jul14 27481_male_Isère_18Jul11
   
22837_male_Isère_19Jul10    

The upperside ground colour of the nominate form of alveus is a dark grey-brown sometimes with a yellowish flush, with smallish white marks on the upf, especially in the cell, and very weak marks on the uph. The unh has no particular distinguishing features, the discal marks in s2 and s3 being quite small, but this is not unique to alveus. It is perhaps the most difficult of the French Pyrgus species to identify with any degree of confidence, and I have included some on this page that I am certainly not confident are alveus in order to invite comment. It usually seems to be a case of the "balance of probabilities" rather than "beyond reasonable doubt".

 

The Lafranchis ID book simply says that the uph marks are dull, which is hardly a unique differentiator. The unh ground colour is olive brown. Alveus is a large Pyrgus, larger than most of its cousins, so identification may be based more on this rather than analysis of the photograph. It has a wide altitude range, from 0 to 2100m and flies in June-August.

The subspecies accretus (also, but now largely historically, called centralhispaniae or centralitaliae) is completely different to the nominate form P. a. alveus in that the upf white marks are very well-defined and the uph marks are strong and well-contrasted. The undersides of nominate alveus and accretus appear to be very similar as far as I can ascertain. Accretus flies in south-west Europe including, as its alternative names imply, central Spain and Italy. There seems to be very little information available of the exact distribution of accretus and its relationship to alveus, particularly in respect of whether it can be considered as a separate species.

ref sex

observations

alt. m
27136 M the rather cold, slightly greyish, brown ground colour is indicative of alveus. The white markings on both upf and uph are quite strong by alveus standards. 2010
21770 M

this male matches the illustration in T&L perfectly for the subspecies accretus (centralhispaniae).

1800
21800 M

my feeling is that this is spot-on for male alveus in terms of colouring and markings. The ground colour is a rather cold grey-brown and the cell spot is not sufficiently well-defined to suggest other species, nor is it outwardly concave which would suggest the Carline Skipper (P. carlinae).

1800
22250 M

I suspect this may be a male from the body length. I had some doubts as to whether this is actually alveus; the upf marks are rather strong, and the cell spot has just a suggestion of external concavity which might suggest carlinae, but 22255 is the underside and I think this swings it toward alveus.

2040
33515 M a very fresh specimen, very typical for alveus. 2010
23332 M

I am fairly certain that this is a male alveus as I also have an underside shot and it was ID'd with certainty by a local expert. The upperside markings are just about spot-on for alveus and I recall that it was a large Pyrgus.

1120
30612 M a typical male alveus, the markings being perhaps a little heavier than the norm for this species. 2020
36201 M a fresh male, lightly marked and with a nice sandy basal dusting. 2020
27481 M a rather typical alveus unh. A clear view of the upperside enabled confirmation of alveus. 2160
22837 M

the unh marks here all point to alveus. The discal s2/3 are completely empty, ruling out armoricanus. Basal s7 is rather rounded suggesting carlinae but the marginal mark on v5 is not sufficiently large or well defined, and the altitude is some way below carlinae's normal range.

1120

 

27136_male_Hautes-Alpes_14Jul11

 

21770_male_Alpes-Maritimes_8Jul10

 

21800_male_Alpes-Maritimes_8Jul10

 

22250_male_Hautes-Alpes_14Jul10

 

33515_male_Hautes-Alpes_8Jul13

 

23332_male_Vaud, Switzerland_27Jul10

 

30612_male_Hautes-Alpes_6Jul12

 

36201_male_Hautes-Alpes_15Jul14

 

27481_male_Isère_18Jul11

 

22837_male_Isère_19Jul10