. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. TASTE AND SMELL IN LEPIDOPTEROUS LARVAE 19 Monarch larvae came to rest on the squares of milkweed only. If, how- ever, the squares of milkweed were treated with perfume or turpentine, the larvae were found resting indiscriminately on any square. If every square was treated with either of the two substances mentioned, the larvae again were found resting on any. square, without so much as nibbling a piece of the leaf. Here it appears that the perfume and turpentine obscured that property of the milkweed by which the larvae rec
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. TASTE AND SMELL IN LEPIDOPTEROUS LARVAE 19 Monarch larvae came to rest on the squares of milkweed only. If, how- ever, the squares of milkweed were treated with perfume or turpentine, the larvae were found resting indiscriminately on any square. If every square was treated with either of the two substances mentioned, the larvae again were found resting on any. square, without so much as nibbling a piece of the leaf. Here it appears that the perfume and turpentine obscured that property of the milkweed by which the larvae recognized it. The following experiments designated as " screen tests " prove definitely that this property is odor. Whatever leaves were used in the tests were laid on the floor of the breeding cage. A square of clean wire screen whose area coincided. i FIG. 4. 1 and 2. Diagrams of typical paths of A. plexippus larvae over their food plant (milkweed) during a " screen ; 3 and 4. Diagrams of typical paths of A. larvae over a foreign leaf (oak) during a "screen ; The grouped arrows indicate locations where the larvae felt around in all directions. with that of the cage floor was pressed over the leaves and fastened tightly into position. Care was taken that no portion of the leaves projected through the screen. A larva was then placed in the cage. As it crawled about its path was plotted and various movements of its head noted. The diagrams represent typical paths (cf. Fig. 4). Monarch larvae passing over '' foreign " leaves maintained a straight path. When they passed over a milkweed leaf, they described a zigzag path, a sort of " feeling ; They never, with one exception, tried to bite through the screen or to get at the leaves in any other manner. When they tended to pass off the leaf, however, they raised the anterior portions of their bodies and felt about. In 50 per cent of the cases the. Please note that
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
