Natural Entomophages of Brevicoryne Brassicae (L.) (Hemiptera: Aphididae) in Uzbekistan

Abstract

In our studies phenological phases of cabbage aphids Brevicoryne brassicae (L.) were studied. The influence of external factors (humidity and temperature) was studied under laboratory conditions. The maximum reproductive ability of cabbage aphids was noted in spring and autumn. Some of the parthenogenetic aphids gave about 82 larvae. The daily reproductive ability of aphids was 3-5, and the maximum 5-11. When studying the reproductive ability of parthenogenetic aphids, this indicator was slightly lower than that of the wingless aphids (average 28, maximum 51). The overall development of cabbage aphid seeds averaged 7–9 days in summer and 12–21 days in early spring and autumn. The importance and bioecological features of Metamorphus corollae (F.), Episyrphus balteatus (De Geer, 1776), Syrphus vitripennis (Meigen, 1822), Scaeva pyrastri (L.) Coccinella septempunctata (L.) and Adonia variegata (G.), Chrysopa carnea Steph. with natural control of the cabbage aphid were studied. Studying the biological effectiveness of a simple golden-eyed fly in relation to the cabbage bug, efficiencies were observed at a ratio of II-year-old larvae of simple golden-eyed and cabbage bug in a ratio of 1:5 and 1:10. For 4 day old gold-eyed eggs, this efficiency was observed when the ratio with cabbage bug was 1:1 on the 17th day of the experiment.