Egg Parasitoids Collected From Amblypelta Lutescens Lutescens (Distant) (Hemiptera: Coreidae) in North Queensland

Abstract

A hymenoprei-ous parasitoid complex attacking the eggs of the banana-spotting bug, Arnblypelta lutescens lufescens (Distant), is reported for the first time from north Queensland. It includes an Anastatus sp. (Eupelmidae), Ooencyrtus sp.nov. (Encyrtidae) and a Cryon sp. (Scelionidae), and is similar to other complexes known to attack eggs of related coreids in Africa, Indonesia and Papua New Guinea. Parasitism ranged from 37.5-91.670 in eggs collected at three sites from Orange Jessamine, Murraya paniculata (L.) Jack. The Anastarus sp. was the dominant parasitoid.The banana-spotting bug, Amblypelta lutescens lutescens (Distant) is a severe pest of tree fruits and nuts, including avocados, cashews, custard apples, guavas, lychees, macadamias and papaws, in coastal and subcoastal Queensland (Ironside 1981; Donaldson 1983). Its range extends to the northern parts of the Northern Territory and Western Australia (Smith 1985). Nymphs and adults pierce parenchyma cells of plant growing points or developing fruits and nuts, generally leaving blackened spots which frequently split. Premature fruit and nut fall is common (Waite 1990). Effective control in susceptible crops is usually achieved through regular applications of endosulfan.Natural enemies have been considered unimportant in the life history of the banana-spotting bug, with only some general predators and the tachinid parasitoid, Pentatomophaga bicincta de Meijere, known (Ironside 1981). An unidentified hymenopterous egg parasitoid was reported by Ironside (1981). but no details of the insect or the locality record are available. A . lutescens lutescens lays its eggs singly and sparsely, making monitoring in crop situations exceedingly difficult. This undoubtedly accounts for the lack of available information on the natural enemies which attack this life stage. Studies in other parts of the world have, howevcr, revealed a range of egg parasitoids attacking related coreids (Table I).Permanent populations of A . lufescens lutescens are known to have occupied certain clumps of Orange Jessamine (sometimes referred to as Mock Orange), Murrayapaniculafa (L.) Jack (Rutaceae) in Mareeba (17"OO'S 145"25 'E) for many years. Recent close scrutiny of these plants was undertaken as part of a study of the banana-spotting bug and its host plant relationships. Three sites, each containing several plants of M. puniculata u'p to 3 m in height, were monitored regularly in October and November 1992. Sites 1 and 2 were 100 m apart with Site 3 approximately 2 km away. Both sides of M. paniculafa leaves were searched for eggs of A. lutescens lutescens. All eggs collected were examined under a binocular microscope to determine whether or not they were intact. Those which were not intact were considered to havecontained parasitoids if the emergence holes exceeded one in number or were irregularly positioned and had uneven margins, and parasitoid-free if the operculum was neatly detached (Brown 1959). Intact eggs were placed individually in 25 mL screwcap polystyrene jars and he...