Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Arthropod complex of winter wheat crops and its seasonal dynamics.

Abstract

Investigations were carried out in Moscow (1996 and 1998) and Krasnodar (1999), Russia to study the seasonal changes of population distribution of pests and their natural enemies inhabiting the winter wheat crops. Samples were taken in the field centre, on field edges and in adjoining biotopes (forests, forest belts and perennial herb crops) using entomological sweep nets and pitfall traps. In Krasnodar, samples were also taken halfway from the edge to the centre. Spatial and temporal dynamics of mass species of arthropods are described. Some of the species were field residents and able to overwinter there, however, most of them migrated to the field from its grassy margins or from other biotopes of a landscape. Herbivores, such as chrysomelid beetles (Phyllotreta spp. and Oscinella spp.) colonize the field at once and prefer its central parts. The aphid Sitobion avenae and overwintering bugs (Eurygaster integriceps and Lygus rugulipennis) prefer field edges; however, their following generations were more abundant in the central part of the field. Oulema melanopus was concentrated on field margins in the beginning of spring and later colonized the field edges. On the other hand, predators such as carnivorous red mites (Trombidiiformes), some spiders (Tetragnatha extensa, Xysticus ulmi, Hypsosinga pygmea, Pardosa agrestis, Oedothorax apicatus and Trochosa spp.), carabid beetles (Agonum muelleri, Pterostichus cupreus and Harpalus rufipes) prefer the field, particularly its central part. The coccinellid Propylea 14-punctata [Propylea quatuordecimpunctata] inhabited forest belts and field margins, while Coccinella septempunctata, Coccinula quatuordecimpustulata and Hippodamia variegata occurred later in the central part of the field.