Journal article
Biological and integrated control of Plutella xylostella (Lep., Yponomeutidae) and Crocidolomia pavonana (Lep., Pyralidae) in Brassica crops in Papua New Guinea



Publication Details
Authors:
Saucke, H.; Dori, F.; Schmutterer, H.; Schmutterer, H.
Publication year:
2000
Journal:
Biocontrol Science and Technology
Pages range:
595-606
Volume number:
10
Start page:
595
End page:
606
ISSN:
0958-3157

Abstract
The major constraint to production of good quality cabbage in Papua New Guinea (PNG) is posed by a complex of insect pests which includes the Diamondback Moth Plutella xylostella (L.) as the most prominent species. In order to evaluate the prospects of a classical control approach economically important major pests and their natural enemies were surveyed in three cabbage growing areas with distinct climatic regimes at low-, mid- and high-elevation. In the PNG highlands (Goroka and Tambul area, Western Highlands Province) the release and successful establishment of the P. xylostella-specific parasitoid Diadegma semiclausum (Hellen) reduced crop losses remarkably since 1995. Favourable circumstances, such as continuous brassica cultivation and low status of associated lepidopteran pests, particularly at Tambul (2400 m above sea level) with an almost temperature climate, were supportive for this approach. In the arid PNG lowlands (Laloki area, Central Province) the introduced P. xylostella-parasitoid Cotesia plutellae (Kurdjumov) exerted 80% parasitism in an experimental site, although a lasting establishment was not achieved in that location. Among several indigenous P. xylostella parasitoids Brachymeria phya (Walker) was a ubiquitous species but did not reduce the pest status of its host. Natural enemies of associated lepidoptera such as Crocidolomia pavonana (Zeller), Spodoptera litura (F.), Helicoverpa armigera (Hubner) and Hellula undalis (F.) were economically insignificant. Thus, insecticidal control, preferably selective, was still a requirement. In comparison to Bacillus thuringinesis-products (Delfin(R) and Thuricide(R)) and the synthetic insect growth regulator Chlorfluazuron (Atabron(R)), best results were achieved in field trials with the commercial neem formulation NeemAzal(R) (Azadirachta indica A. Juss.) and an aqueous neem seed kernel extract from seeds of PNG grown trees. Besides its high efficacy against lepidopterous pests, neem also controlled the false mustard aphid Lipaphis erysimi (Kalt.), being of economic importance in the arid PNG lowlands. The prospects of integrating C. plutellae into a reduced insecticide spraying programs as well as alternative cultural control measures are discussed.


Authors/Editors

Last updated on 2016-24-08 at 16:29