First record of the leafhopper Asymmetrasca decedens (Homoptera: Cidadellidae) in mainland Portugal

Abstract

Asymmetrasca decedens, a polyphagous leafhopper widely distributed in Mediterranean region, is here reported as a new record to mainland Portugal. Heavy infestations of this species have been found associated with peach, apricot and plum orchards, as well as on Alnus glutinosa, in southern of Serra da Gardunha (Beira Interior Region). Typical symptoms, the so-called ‘hopperburn', with leaves turning yellow and curling their edges downwards before drying-out and shedding, were spotted. Both adults and immature forms cause direct injury and the species also has the ability to be a vector of European Stone Fruit Yellows (16RX-B), among other phytoplasmas. External morphological characteristics of A. decedens, illustration of the male genitalia and a brief description of leaf lesions on peach are presented, in order to enable its identification, since it has a great potential for spreading as a pest. Not only A. decedens reveals a significant resistance to conventional insecticides, which may hinder its control, but also it has a vast host range of economically important plants, like ornamental or fruit trees.