When Survival Depends on  Subterfuge

BY AWAKE! WRITER IN SPAIN

IN THE world of insects, each day presents two pressing problems: how to find enough to eat and how to avoid being eaten. Insects are tempting morsels for birds, frogs, and lizards. For many insects, survival depends on blending into their surroundings.

To achieve this disappearing act, a number of insect species display remarkable camouflage. The effectiveness of the camouflage goes far beyond any disguise human ingenuity has produced. Consider three striking examples.

● Dead-leaf butterflies. The brown underside of their wings is practically indistinguishable from a dead leaf. The design includes the coloring as well as the veins and stem of the leaf. The subterfuge is so successful that the butterflies can rest on green foliage and yet look exactly like a dead leaf that has fallen from the canopy above.

● Bush crickets, or katydids. Many bush crickets survive, not by imitating dead leaves, but by mimicking green leaves. “This resemblance is not just in shape and colour: it also extends to the pattern of veins and the mottlings of fungus attack,” explains one source. If you look closely at the accompanying photo, you will see the small mottles, or blemishes, on the insect’s wing, giving its disguise even more realism.

● Treehoppers. These small insects invariably pass unnoticed. And therein lies the key to their survival​—they blend into the background by imitating a row of thorns. In this case, each insect looks like a thorn, and a whole phalanx of treehoppers lined up on a branch give it a thorny appearance. Only a very close inspection will reveal that the “thorns” are nothing more than tiny treehoppers.

The range of insect camouflage is almost as remarkable as its precision. A caterpillar from Costa Rica looks just like bird droppings, whereas stick insects can barely be distinguished from​—you guessed it—​sticks. There is a South African locust that closely resembles a stone, and a bug found in Israel perfectly mimics the flowering plant on which it feeds.

Whatever form the subterfuge may take, it provides protection for the insect and gives us a fascinating glimpse into the astonishing variety in creation.

[Picture on page 22]

A walking stick insect

[Picture on page 23]

A dead-leaf butterfly

[Credit Line]

Zoo, Santillana del Mar, Cantabria, España

[Picture on page 23]

A bush cricket

[Picture on page 23]

Treehoppers

[Picture on page 23]

A caterpillar that resembles bird droppings

[Credit Line]

© Gregory G. Dimijian/Photo Researchers