In ‘The Minor Horrors of War,’ we rather neglected the Navy—the senior Service, and till now the more dominant of our two magnificent forces—partly because it is less interfered with by insect pests than is the sister Service, though the common pests of our poor humanity—the flea, the louse, the bug—are, like the poor, ‘always with us.’ Like aeroplanes, insects have captured the air; like motors, they have made a respectable show on land; but they have signally failed at sea. They have nothing corresponding to battleships or submarines; and a certain bug, called Halobates, alone hoists the insect flag on the ocean, and that only in the warmer waters.
Fig. 1.—Periplaneta orientalis, male. × 2. Dorsal view. 1, Antenna; 2, palp of first maxilla; 3, prothorax; 4, anterior wings; 5, femur of second leg; 6, tibia; 7, tarsus; 8, cerci anales; 9, styles. (From Kükenthal.)
Insects are not only highly intelligent animals, but are by far the most numerous and dominant class of the Animal Kingdom; and they have probably come to conclusions about themselves and the sea, comparable to those expressed by Dr. Johnson about man and the ocean: ‘To all the inland inhabitants of every region the sea is only known as an immense diffusion of waters, over which men pass from one country to another, and in which life is frequently lost.’
But one insect at least causes more trouble to sailors than to soldiers—and that is the cockroach. Like the bed-bug, the cockroach came into England at the end of the sixteenth century, and, like the bed-bug, it came from the East. It seems to have been first introduced into England and Holland in the spacious times of Henry VIII by the cross-sea traffic, and from about the end of the sixteenth century the cockroach began gradually to spread throughout the Western world. Like the rat, the bed-bug, and the domestic fly, it has become thoroughly acclimatised to human habitations, and is indeed an associate of man. It is very rarely found living apart from some form or other of human activity.
This insect seems to have been first described in England in Moufet’s ‘Insectorum Theatrum,’ 1634, and he speaks of it as living in flour-mills, wine-cellars, &c., in England, and he tells us how Sir Francis Drake took, in 1584, the San Felipe, a Spanish East Indiaman, laden with spices and burdened with a great multitude of flying cockroaches on board.
This species was Periplaneta orientalis; but there is another and a larger species, which presumably came into England from the West later than its Eastern cousin P. americana—which can frequently be seen in England running about in the cages in our zoological gardens—but it is not on exhibition, it is a by-product, and is not counted in the fee for admission to the gardens.
Latter tells us there are ten species of Blattodea which occur in Britain; but only three of these are indigenous, and these three all belong to the genus Ectobia. Ectobias are smaller than cockroaches, and do not frequent human habitations, but live in shrubs, under rubbish heaps, &c. Some species of Ectobia are, however, very destructive and have been known to destroy in one day the whole accumulation of dried but not properly salted fish in a Lapland village. Of the remaining species of cockroach most are local, and occur sporadically in particular factories, or places where food is stored but they are not very widely spread.
As we have said above, P. orientalis is the common English cockroach, P. americana occurs especially in zoological gardens and menageries; but a third species, P. germanica, sometimes gets established. Mercifully, P. germanica does not seem to spread. Neither P. germanica nor P. americana seem to make much headway against P. orientalis, which appears to be predominant over both these other species.
P. germanica is probably most methodical, very thorough, very brave, very faithful—but rather lacking in the power of understanding the point of view of others. If it has any association with its specific name, it illustrates the most striking example in the world’s history of the divorce of wisdom from learning. ‘O Lord! give us understanding,’ should be the prayer of P. germanica.