Wasps (Hymenoptera: Chalcidoidea) associated with galls in seed-capsules of Eucalyptus camaldulensis (Myrtaceae) in South Africa : species composition, trophic relationships and effects

The Australian river red gum (Eucalyptus camaldulensis Denhardt) (Myrtaceae) is regarded in South Africa as a valuable general-purpose utility and ornamental tree, as well as an essential source of nectar and pollen to sustain the honeybees which are crucial for pollinating the economically important fruit crops in mainly the Western Cape Province. Despite its utility value, it is regarded as invasive in South Africa, the major concern being the large amounts of water it consumes when growing along watercourses. River red gum is therefore the subject of conflicts in interests between government agencies that target it for control actions, and farmers and beekeepers who utilize it. As a contribution towards resolving this conflict in interests, a research project was initiated to investigate the potential use of host-specific insects that might reduce the number of viable seeds produced by E camaldulensis. The aim was to reduce its invasive potential while retaining its general utilizability for all concerned. From the start, the need for introduced agents from Australia was weighed against the presence of two species of chalcidoid wasps, both regarded as gall inducers, in the seed capsules of E camaldulensis in South Africa. The current study was motivated by the need for information on the biology of these two species and the effect they were having on seed production in their host plant. As it progressed, three more chalcidoid species, all undescribed at that time and probably of Australian origin, were found to be emerging from the seed capsules of E camaldulensis collected in several parts of South Africa, and these became part of the investigation.

Grantor dc:publisher.institution

Department of Biological Sciences

Year dc:date.issued

2009

Author dc:creator

• Klein, Hildegard

Advisor dc:contributor.advisor

• Hoffmann, John

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/9277

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/9277