Lepidopterous enemies are numerous all over the world.
Sugar-canes suffer from the sugar cane borer (Diatioca sacchari) in the West Indies; tobacco from the larvae of hawk moths (Sphingidae) in America; corn and grass from various Lepidopterous pests all over the world.
As a commercial product spider-silk has been found to be equal, if not superior, to the best silk spun by lepidopterous larvae; but the cannibalistic propensities of spiders, making it impossible to keep more than one in a single receptacle, coupled with the difficulty of getting them to spin freely in a confined space, have hitherto prevented the silk being used on any extensive scale for textile fabrics.
Such cases are the habits of " shamming dead " and the combined posturing and colour peculiarities of certain caterpillars (Lepidopterous larvae) which cause them to resemble dead twigs or similar surrounding objects.
The Tenthredinidae, or true saw-flies, are distinguished by two spines on each fore-shin, while the larvae are usually caterpillars, with three pairs of thoracic legs, and from six to eight pairs of abdominal prolegs, the latter not possessing the hooks found on the pro-legs of lepidopterous caterpillars.