Absence of Butterflies

Abstract

THE most common butterflies—as, for instance, Picris Brassiea, Colcas Rhamni, Vanessa Unicæ—were very rare hereabouts this spring too (cf. NATURE, vol. 1. p. 225), and the same has been observed at Frankfort-on-Maine. As for Picris, this scarcity might have been predicted with certainty last autumn, as, here and at Frankfort, the cabbage-plants in fields and gardens were almost exempt from their usual ravagers. the caterpillars of the said species. If the extraordinary dryness of last year's summer should be connected with these facts, it cannot have acted through the damage done to the food-plants, but must have operated more directly upon the insects themselves.