Page:Popular Science Monthly Volume 27.djvu/617

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INSECT FERTILIZATION OF FLOWERS.
597

The proboscis is usually from three to seven centimetres long, but in many tropical moths it attains a length of over twenty centimetres. Fig. 2.—Head of Pierisrapæ (cabbage-butterfly), four times enlarged. I, side view, showing the proboscis coiled up. II, front view of the same. Ill, side view, showing proboscis uncoiled. R, proboscis; P, labial palpi; A, eyes; F, antennæ. It is by the great length of their proboscis that many butterflies are enabled to suck the honey from flowers having very long and narrow corolla-tubes, where it would be quite inaccessible to other insects. We need scarcely say that this feature is a great advantage to the butterfly order, for it means that they have the monopoly of the honey of flowers with a long, tubular corolla. The honeysuckle (Lonicera Periclymenum, see Fig. 3) is a good native example of a flower with a tubular corolla, in which the nectary, a, is so situated as to be beyond the reach of the various bees and butterflies with short proboscides, likely to be attracted by it in the daytime. In this case the Fig. 3.—Flower of Honeysuckle (Lonicera peridymenum), frequented by privet hawk-moth (Sphinx ligustri), natural size. A, nectary; B, entrance to the throat of the corolla. honey is entirely reserved for one of the evening moths (Sphinx ligustri) which possess a proboscis of almost exactly the same length as the corolla of the flower i. e., about forty millimetres. Attracted by their fragrance, the insect will hover over a cluster of flowers for a time. Finally selecting one, it uncoils its long proboscis, thrusts it deep into the innermost recesses of the corolla, and, at its leisure, sucks the sweets denied to less fortunate members of its kind.

As fertilizers the beetles are not so important as the butterflies and moths. Only a small proportion pay regular visits to flowers, the greater number deriving their food from quite other sources. Many species which do frequent flowers only effect injury, devouring, as they do, some of their most important organs—e. g., the stamens or the ovary. Others, however, and especially those whose small size admits of their creeping into the interior of the flower, frequently promote cross-fertilization, the viscid pollen adhering to the general surface of their body, from which it is brushed off by the stigma of the next flower they enter. Such flower-beetles as Anthrenus, Meligethes, Malachias, and certain smaller sorts, are extremely useful in this way.

In other species certain parts of the body are specially adapted for obtaining food from flowers. Thus, in the crown-beetle (Cerocoma