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XXIV. A Contribution to the Life History of Hesperia 
sidae, Hsp. By Harotp Powe 1, F.E.S. 
[Read May 3rd, 1911.] 
PuaTeE XLVII. 
THIS is a very local skipper, and is never abundant even 
where it occurs. It is found in moist parts (not marshy) 
of certain valleys in S.E. France as well as in Italy, 
eastern Europe, and Asia. I have come across it in 
several places in the Dept. Var, both on limestone and 
schistous ground. 
In the commune of Hyeres it occurs in the Vallon 
de la Moniere, where it is very scarce now, and in the 
valley of the Plan du Pont, where it is more abundant, 
though in the height of its season a bag of ten or fifteen 
Specimens in one day is a very good one. In the Hyeres 
district it flies from the end of April to about the 20th 
of May. 
For many years I had been hoping to find out some- 
thing about its life history, which, I believe, is so far 
unknown, but it was not until 1909 that I got an oppor- 
tunity to spend some time in its locality at a time when 
the imagines were flying. 
On May 5 of that year I went over the hills to the 
Plan du Pont valley with the intention of getting the 
egg and discovering the food-plant if possible. On this 
day I found sidae well out, nine of the eleven specimens 
taken being quite fresh, one ¢ and one $ having their 
wings still weak and hardly dry. It is decidedly local in 
its habit, keeping pretty closely to certain parts of the 
valley, and never straying to the hillsides enclosing it. 
As the family Rosaceae furnishes food-plants for most 
of the species of the genus, I first looked round to see 
what Rosaceous plants were growing in sidae’s special 
haunts. 
Two species of Rubus were common, also Poteriwm 
sanguisorba and, more locally, Potentilla hirta, L. I saw 
TRANS. ENT. SOC. LOND. 1911.—PART III. (JAN.) 
