194 INSECT LIFE 



XIV 



to count them, and then came the clouds to end my 

 observations and plunge us into that perplexing dark- 

 ness I have already described. At the first drops of 

 rain I hastened to put back the stone and replace 

 the Ammophila people under shelter. I give myself 

 a good mark, as I hope the reader also will, for 

 having taken the precaution of not leaving the poor 

 things, disturbed by my curiosity, exposed to the 

 downpour. 



Ammophila hirsuta is not rare in the plain, but 

 is always found singly on the edge of a road or on 

 sandy slopes, now digging a well, now dragging a 

 heavy prey. It is solitary, like Sphex occitanica, 

 and I was greatly surprised by finding such a 

 number gathered under one stone at the top of Mont 

 Ventoux. Instead of my solitary acquaintance, 

 here was a great assembly. Let us try to educe 

 the probable causes of this agglomeration. By an 

 exception very rare among mining Hymenoptera, 

 Ammophila hirsuta builds in the first days of spring. 

 Toward the end of March, if the season be mild, 

 or at least in the first fortnight of April, when the 

 grasshoppers take their adult form, and painfully 

 cast off their first skin on their thresholds, — when 

 Narcissus poeticus expands its first flowers, and the 

 bunting utters its long-drawn note from the top of 

 the poplars in the meadow, — Ammophila hirsuta sets 

 to work to hollow and provision a home for her larvae, 

 whereas other species and the predatory Hymenoptera 

 in general undertake this labour only in autumn, 

 during September and October. This very early 

 nidification, preceding by six months the date 

 adopted by the immense majority, at once suggests 



