253 DARWINISM chap. 



found at Choii tales. The pretty longicorn, Callia albicornis, 

 closely resembles two species of malacoderms (Silis chaly- 

 beipennis and Colyphus signaticollis), all being small beetles 

 with red head and thorax and bright blue elytra, and all 

 three have been found at Panama. Many other species of 

 Callia also resemble other malacoderms ; and the longicorn 

 genus Lycidola has been named from its resemT)lance to 

 various species of the Lycidse, one of the species here figured 

 (Lycidola belti) being a good mimic of Caloj^teron corrugatum 

 and of several other allied species, all being of about the same 

 size and found at Chontales. In these cases, and in most 

 others, the longicorn beetles have lost the general form and 

 aspect of their allies to take on the apj^earance of a distinct 

 tribe. Some other groups of beetles, as the Elateridse and 

 Eucnemidse, also deceptively mimic malacoderms. 



Wasps and bees are often closely imitated by insects of 

 other orders. Many longicorn beetles in the tropics exactly 

 mimic wasps, bees, or ants. In Borneo a large black wasp, 

 whose wings have a broad white patch near the apex (Myg- 

 nimia aviculus), is closely imitated by a heteromerous beetle 

 (Colol^orhombus fasciatipennis), which, contrary to the general 

 hal)it of beetles, keeps its wings expanded in order to show 

 the white patch on their apex, the wing-coverts being reduced 

 to small oval scales, as shown in the figure. This is a most 

 remarkable instance of mimicry, because the beetle has had to 

 acquire so many characters Avhich are unknown among its allies 

 (except in another species from Java) — the expanded wings, 

 the white band on them, and the oval scale-like elytra.^ 

 Another remarkable case has been noted by Mr. Neville 

 Goodman, in Egypt, where a common hornet (Vespa orientalis) 

 is exactly imitated in colour, size, shape, attitude when at 

 rest, and mode of flight, by a beetle of the genus Laphria.^ 



The tiger -beetles (Cicindelidae) are also the subjects of 

 mimicry by more harmless insects. In the Malay Islands I 

 found a heteromerous beetle which exactly resembled a 

 Therates, both being found running on the trunks of trees. 

 A longicorn (Collyrodes Lacordairei) mimics Collyris, another 

 genus of the same family ; while in the Philippine Islands 



1 Tmns, Eat. Soc, 1885, p. 369. 

 * Proc. Cambridge Phil. Soo., vol. iii. part ii., 1877. 



