Plant-galls induced by insects in the Maltese Islands

Abstract

Galls (in Latin cecidia) are defined as any deviation from the normal pattern of plant growth produced by a specific reaction to the presence and activity of a foreign organism. Galls often support species-rich and closed communities of inquilines and parasitic Hymenoptera. It is often possible to identify the gall inducer if the host plant is known and if adequate identification keys are used. Plant-galls are caused by different organisms such as bacteria, protozoans, fungi, nematodes, mites and insects. Insect orders, such as Thysanoptera, Hemiptera, Hymenoptera, Diptera, Coleoptera and Lepidoptera are among those known to cause galls in plants.