Important Insect Pests in Madicago sativa L. in Bulgaria

Abstract

This paper describes common insect pests in forage alfalfa in Bulgaria and their seasonal dynamics. The method of sweeping with the entomological net was used. The degree of infestation (attack) of Otiorrhynchus ligustici was established by taking soil monoliths. The most common insect pests of alfalfa from order Coleoptera are Hypera postica, Sitona spp., Apion seniculus, and Otiorrhynchus ligustici. The next species belongs to orders Hemiptera and Thysanoptera. Therioaphis maculata was the main harmful specie, followed by Acyrthosiphon pisum from Aphidodea, as well Adelphocoris lineolatus and Lygus rugulipennis (Hemiptera – Heteroptera). Economic importance species from Hemiptera: Fulgorormorpha and Cicadomorpha were Empoasca pteridis and Agallia ribauti, as well Thrips tabaci and T. atratus (order Thysanoptera). Apion seniculus is reported for the first time in our country as harmful species in alfalfa. The main insect pests, depending on the order to which they belong, were found in high numbers through the different regrowth of alfalfa vegetation period. The determination of the population dynamics of economically important pest species in the alfalfa grown for forage, helps determine the most appropriate time for control and management.