The Wild Cycad Conservancy
Protecting the world’s most threatened plant species from extinction in South Africa
OUR NEWS
New study: Cycad poaching impacts on insect abundance
Paul Janse van Rensburg
Congratulations to Paul Janse van Rensburg, who completed his doctoral studies at North-West University earlier this year, under the guidance of Prof Johnnie van den Berg. Paul was recruited by Tommie Steyn and Hugo Bezuidenhout and was the first bursar of Wild Cycad Conservancy. Paul did excellent work and will continue to work on insect-cycad mutualisms as a postdoctoral fellow. See below for a short overview of his work.
Above: Paul Janse van Rensburg, left, with Tommie Steyn, Dr Hugo Bezuidenhout and Prof Johnnie van den Berg.
A literature review on cycadivorous insects, including the addition of novel records, identified Africa as a diversity hotspot but revealed that less than a third of African cycads and globally less than 50% have been surveyed for pollinators. This study found no pollinators for E. eugene-maraisii and closely related E. middelburgensis and E. dyerianus, although three other insect species were recorded from E. eugene-maraisii: Zerenopsis lepida (Lepidoptera: Geometridae), Apinotropis verdoornae (Coleoptera: Anthribidae), and Amorphocerus cf. setosus (Coleoptera: Curculionidae).
E. eugene-maraisii
Poaching negatively impacted the population structure and associated insect abundance of E. eugene-maraisii, with high poaching areas showing lower host density and smaller clump sizes of E. eugene-maraisii, leading to lower insect abundance.
Unrecorded connection
with Endangered moth
The study also examined herbivory patterns of Z. lepida on E. eugene-maraisii, recording higher herbivory on larger plants and those under sparse canopy cover, and lower herbivory on stems flushing leaves later in the season or in years with high leaf flush incidence. Leaf and cone phenology of E. eugene-maraisii varied by sex and microhabitat, with male stems and those situated under sparse canopy cover flushing more frequently.
Finally, this study documented a previously unrecorded locality and host association with E. caffer of the Endangered moth Callioratis millari (Lepidoptera: Geometridae), providing insights into its habitat requirements. These findings enhance the understanding of cycad-insect interactions and guide conservation strategies, including prioritising protection areas, managing canopy cover and using phenology knowledge for hand pollination and herbivore management.
Our PROJECTS
The Wild Cycad Conservancy (or WCC) takes a three-pronged approach to cycad conservation.