PDF - Wallace Online

NATURAL SELECTIONof trees, as is the habit of that group. There is one curiousexample of a Longicorn mimicking a Longicorn, like thePapilios and Heliconidae which mimic their own allies.Agniafasciata, belonging to the sub-family Hypselominse, andNemophas grayi, belonging to the Lamiinse, were taken inAmboyna on the same fallen tree at the same time, and weresupposed to be the same species till they were more carefullyexamined, and found to be structurally quite different. Thecolouring of these insects is very remarkable, being rich steelblueblack, crossed by broad hairy bands of orange buff, andout of the many thousands of known species of Longicornsthey are probably the only two which are so coloured. TheNemophas grayi is the larger, stronger, and better armedinsect, and belongs to a more widely spread and dominantgroup, very rich in species and individuals, and is thereforemost probably the subject of mimicry by the other species.Beetles mimicking other InsectsWe will now adduce a few cases in which beetles imitateother insects, and insects of other orders imitate beetles.Charis melipona, a South American Longicorn of thefamily Necydalidse, has been so named from its resemblanceto a small bee of the genus Melipona. It is one of the mostremarkable cases of mimicry, since the beetle has the thoraxand body densely hairy like the bee, and the legs are tuftedin a manner most unusual in the order Coleoptera. AnotherLongicorn, Odontocera odyneroides, has the abdomen bandedwith yellow, and constricted at the base, and is altogether soexactly like a small common wasp of the genus Odynerus,that Mr. Bates informs us he was afraid to take it outof his net with his fingers for fear of being stung. HadMr. Bates' taste for insects been less omnivorous than itwas, the beetle's disguise might have saved it from his pin, asit had no doubt often done from the beak of hungryA birds.larger insect, Sphecomorpha chalybea, is exactly like oneof the large metallic blue wasps, and like them has theabdomen connected with the thorax by a pedicel, renderingthe deception most complete and striking. Many Easternspecies of Longicorns of the genus Oberea, when on the wing,exactly resemble Tenthredinidse, and many of the small