Weapons of mass insect destruction unleashed

ALIEN vegetation is invading our rivers and lakes, sucking up much-needed water. Now a tiny secret agent has been sent in to destroy them and save our drinking water.

An insect mass-rearing facility in Westlake is the country’s smallest workforce covertly working to destroy Cape Town’s alien invasive plant (AIP) population.

The facility, which has overseen the release of 243 000 biocontrol insects, or agents, transports these creatures to areas overwhelmed by invasive plants every two weeks, creating a cost-effective solution to a widespread problem.

The biocontrol agent is a leaf-eating beetle named Lysathia sp, all of which are reared from larvae. They are collected for release through a device which has two tubes attached to a container. A team member sucks one of the tubes and places the other over the agent, allowing the harvesting of the insects to be hands-free and time-effective.

Brett Herron, a mayoral committee member for transport and urban development, visited the facility.

“Today’s visit has been most fascinating. In order to rear the agents, our team actually grows the plant which the agents are intended for. The aquatic invasive plants are grown in artificial ponds and this is

THE FACILITY ALSO REARS BIOCONTROL AGENTS FOR ONE TERRESTRIAL AIP – THE PRICKLY PEAR

also where the agents grow and complete their life-cycle.

“They are then collected when they are ready to be released on their mission.”

The facility rears agents for four aquatic AIPs – water hyacinth, parrot’s feather, kariba weed and water lettuce – considered the worst invasive weeds in South Africa. The facility also rears biocontrol agents for one terrestrial AIP, the prickly pear.

The staff alluded to the potential of this method, suggesting it could be used to combat all AIPs, provided sufficient funding was given for research and rearing.

As well as tackling AIP issues, the staff was keen to emphasise its focus on the “whole ecosystem”. AIP has been controlled through fire previously, scarring the landscape and endangering wildlife. The facility’s work, the team believes, provides an eco-friendly alternative.

AIP AGENTS: Parrot’s feather beetle larvae (Lysathia sp) is one of the city’s tiniest secret agents, found at the insect mass-rearing facility in Westlake. Over the past four years, more than 243 000 biocontrol insects, also known as agents, have been reared at the facility for release into the environment in an effort to curb the growth of alien invasive plants.