As cotton crops in many parts of the world end either with the onset of winter or of the dry season, it is natural that the larval diapause which becomes more and more conspicuous as the crop ripens should have come to be regarded as an instance of either hibernation or aestivation; yet in the West Indies where the following observations were made, there is no winter, nor does the ripe boll phase of the crop necessarily fall in the dry season. The latter moreover is not one of complete drought but rather dry only by comparison. Indeed in some islands, such as Montserrat and St. Kitts, the crop is harvested in the wet season. Yet long-cycle or resting larvae are regularly found in all of these islands.