الفهرس | Only 14 pages are availabe for public view |
Abstract The present investigations were carried out in Assiut during the period from November 2018 to October 2019 to study some ecological aspects of insect pests inhabiting alfalfa and their associated natural enemies. In addition, laboratory studies were conducted to elucidate the effect of constant temperatures on the development of Phytocoris sp. Results obtained could be summarizing as follows: 1- Ecological studies: 1.1- Survey of pests and their associated natural enemies (predators and parasitoids) collected from alfalfa plants in AssiutA partial taxonomic list of pests and their natural enemies collected by sweep net from alfalfa plants in Assiut were presented. Results indicated the presence of 31 species of arthropods belonged to 23 families and 15 orders. from the species collected, 20 species were considered pests causing damage, 11 beneficial arthropods as well as unidentified species of true spiders. 1.1.1- Phytophagous insects Intensive and extensive observations indicated that collected species could be classified as sucking pests, leaf feeders, and leaf miners. In general, of 8 orders (Orthoptera, Thysanoptera, Hemiptera-Heteroptera, Hemiptera- Sternorrhyncha, Coleoptera, Lepidoptera, Diptera, Collembolla and Acarina) and 13 families(Gryllotalpidae, Agromyzidae, Curculionidae, Lygaediae, Miridae, Pentatomidae, Aleyrodidae, Aphididae, Cicadellidae, Acridiidae, Noctuidae, Thripidae and Tetranychidae) were recorded inhabiting alfalfa plantations in Assiut. Species belonging to order Lepidoptera were collected as larvae either by sweeping net or direct observation on the plants and presented by family of Noctuidae. Just two species were belonged to this order (Agrotis ipsilon (L.) and Spodoptera littoralis (Boisd.). The leaf weevils, Hypera 93 brunneupennis Boheman (Curculionidae) was the only representative of the order Coleoptera that collected by sweeping net method. Larvae and adults of this insect were feeding on the alfalfa leaves. Also, two species of order Orthoptera was recorded during the present study. These species were the mole cricket, Gryllotalpa gryllotalpa L., (Gryllotalpidae) and the grasshopper, Heteraacris (Thisoicetrus) littoralis (Rumb.) (Acridiidar). |