Biology of the Leaf Miners

Book excerpt: The development of specialised feeding habits during the course of time by human beings is paralleled in the majority of animals, in particular have developed special peculiarities, and insect larvae which in most cases are quite characteristic of the species concerned. This applies especially to phytophagous insect larvae, and anyone with the requisite experience can say with a fair degree of certainty which insect larva is responsible for any damage to be found on a plant. It leaves behind a definite "feeding pattern" which might be compared to a "visiting card" on which the genus and species are marked in runic characters. Whoever has learned to read the runes can readily determine who has been feeding on the affected spot, solely on the basic of the "visiting card" left behind. From the known factors - the name of the plant and the type of feeding patter- and after some study of the various types of plant infestation, both the genus and species of the larva producing the feeding pattern can be worked out without difficulty. The importance of "feeding pattern investigation" has now far outstripped the successes to be obtained by normal collecting. Previously, when wishing to list the species of insects present in any given locality they were caught with the net, by sugaring and other methods. This always resulted in a very defective "list" of the insects in fact existing in the locality concerned.