824 



NATURAL HISTORY OF ARTHROPODS. 



rarely knobbed; they are inserted in various ways, and generally have eleven joints — 

 sometimes more, rarely fewer ; they are often much better developed in the males than 

 in the females. The elytra usually cover the entire abdomen ; a few genera, however, 

 have very short elytra. The wings are absent in a few species, and the elyti-a connate. 

 The mandibles are very stout, but of variable forms. The species are often beautifully 

 colored, metallic or velvety, and are oftentimes of considerable size, the Cerambycidss 

 probably containing the longest species of beetles. Many longicorns are more or less 

 spiny, some species closely resembling twigs, and, according to Mr. H. W. Bates, 

 ^thomerus lacordairei, a Brazilian species, mimics a butterfly's pupa grown over with 

 fungus. A curious habit of Megadenis bifasciatus, a species found in Texas, is to eat 

 out the printed portions of posters. Certain species are odorous, those of Prionics 

 using their odor as a sexual attraction. CalUcliroma moschata^ a large European spe- 

 cies, derives its specific name from the pleasant musky odor which it exhales, and which 

 is noticeable at considerable distance from the insect. Sonorific organs are possessed 

 by nearly all, probably by all, species of Ceranibycida'. 



The eggs are laid in crevices of bark and of wood ; the lar\'8e feed in both li\'ing 

 and decayed wood. The females of a few species girdle twigs and lay their eggs in 

 the portion beyond the girdling; the twigs thus girdled die and are broken off by- 

 winds, thus furnishing fresh but dead wood for the larvse. The females of certain 

 sJDecies are said to cut oft' or girdle twigs by seizing them in their mandibles and flj'ing 

 rapidly around the twig as a centre ; this mode of girdling is exceptional, if practised 

 by any species, since longicorns mostly girdle twigs while resting on the brancli below 

 the point to be girdled. Some species lay a large number of eggs ; Prionus laticollis 

 has been found, upon dissection, to contain from three hundred to six hundred eggs. 

 The metamorphoses of some species of longic(jrus are supposed to require as long as 

 twenty years, but if this is the case it is excejDtional, for many sjaecies attain full 

 growth in from one to three years. 



The larvEB of Cerambycidai are long, cylindrical, or flattened whitish 

 grubs, with distinct labial palpi, elliptical or circular stigmata, and 

 Y-shaped aual opening. They bore, for the most part, in woody por- 

 tions of trees ; some, however, attack herbaceous plants. The head of 

 the larvse is partly retractile into the first thoracic segment, the an- 

 tennae are very small and concealed in a fold of the head, ocelli are 

 usually absent. The larvse are mostly legless, and when legs are present 

 they are small, with only one claw ; but the larvse assist their peristaltic 

 motion through their mines by means of wart-like processes upon their 

 dorsal and ventral surfaces. The form and mode of plication of these 

 processes are of importance in distinguishing the species of longicorn 

 larvse. Most of the damage done by these larvse is in destroying timber 

 or by killing shade trees, no less than a dozen different species being 

 known to attack hickory. In Europe damage is said to have been done 

 to grain by the larvas of longicorns boring in the ears, and to vegetables 

 such as carrots. The fleshy larvai of Macrotoma corticinum, cooked 

 with rice, are eaten by natives of Madagascar ; and the natives about 

 King George's Sound, in West Australia, eat both larvse and imagos 

 of JBardistus cibarhis. 

 Cerambycidse are among the more difficult beetles to classify satisfactorily, because 

 structural characters, which are usually generic, often become only of specific value in 



Fig. 359. — Larva 

 of Monnham.' 

 mus. 



