THE BIOLOGY OF PHENACOCCUS AZALEAE KUWANA, A PEST OF BUNGE PRICKLY ASH (ZANTHOXYLUM BUNGEANUM MAXIM) FOREST IN NORTHERN CHINA

Abstract

THE BIOLOGY OF PHENACOCCUS AZALEAE KUWANA, A PEST OF BUNGE PRICKLY ASH

(ZANTHOXYLUM BUNGEANUM MAXIM) FOREST IN NORTHERN CHINA.

Phenacoccus azaleae Kuwana (Hemiptera: Coccoidea: Pseudococcidae) is a major new pest of bunge prickly ash forest in northern China, where it causes high tree mortality when present for two consecutive years. This paper reports on the biology of this pest in northern China, where it has been studied since 1995. The life cycle can be divided into eight phases, two of which cause severe injury to the host plant, through the feeding of: (a) the 3rd-instar nymphs and adult females between late March and mid-May, and (b) the young nymphs which are present on the leaves between late June and October. The adult sex ratio was 6-7TM:1¢. The various development stages are described. Of the natural enemies, ladybirds (Coccinellidae) and lacewings (Neuroptera) were the major predators, but they were not abundant in the newly- infested areas. In addition, a few parasitic Hymenoptera were recorded but appeared to be ineffective.

Key words: Aphis gossypii, Papilio xuthus, Podagri comeiashirahatai, Calloides magnificus, Agrilus zanthoxylumi, plum, elm, Azalea, Japan, Korea, voltinism, development, population dynamics, damage, Lasius fuliginosus, L. niger, sex ratio, growth rate, Harmonia axyridis, Coccinella septempunctata, Chrysopa.