Army of beetles declares war on invader plant
By the time Tony Ferrar arrived at Rimer's with the precious package early on Friday, people who are passionate about conservation, and Friends of the Barberton Daisy, were already there to greet him.
BARBERTON – One of the worst invader plants in our country is growing right here in Barberton and the effects of this infestation can clearly be seen at Rimer’s Creek.
The pereskia cactus (Pereskia aculeata), commonly known in Afrikaans as the Barbados “stekelbessie”, went unnoticed until the area was opened up after being cleared of alien flora roughly two years ago.
Tony Ferrar, chairman of the Umjindi Environmental Committee said, “We suddenly saw this huge thicket of the stuff that I had until then thought was limited to KZN coastal areas and southern Swaziland. Biocontrol was the only practical approach as the patch was very dense and inaccessible on the steep hillside.”
About pereskia cactus:
(Information taken from: www.penningtonconservancy.org.za)
• Pereskia is a problem throughout coastal KwaZulu-Natal and Zululand
• Seeds are spread by birds and animals
• It has established itself in the wild
• It can form an impenetrable thicket
• It readily invades plantations, forest margins and vegetation gaps
• It does extensive damage to forest areas by smothering indigenous trees
• One specimen that had infested a tree had its stems cut at the base, but after four years the “dry” stems of the pereskia that fell from the tree, set root and regrew.
On Friday morning, a package containing 84 valuable biocontrol beetles arrived in Barberton. These little insects, known as the pereskia flea beetles (Phenrica guérini), are a natural enemy of this invader.
Black with eight cream-coloured spots on their backs, these little beetles lay elongated red eggs on the lower surfaces of the leaves and within six to eight days they hatch. The larvae grow to about one centimetre and have three development stages (instars).
Within 23 days they reach maturity and during the last stage, just before pupating, they don’t feed, but drop off the plant and pupation takes place in the soil. Nine to 14 days later, the adult flea beetles appear and start laying eggs after a week or two. They can live up to six months; so hopefully, the 84 arrivals at Rimer’s will feed on the leaves to their hearts’ content, slowly but surely reducing the size of the patch, thus precluding the use of harmful chemicals.
By the time Tony Ferrar arrived at Rimer’s with the precious package early on Friday, people who are passionate about conservation, and Friends of the Barberton Daisy, were already there to greet him.
Daleen Strydom of Working for Water on biological control, explained all about the beetles and they were released into their new environment.
“Friends of the Barberton Daisy would like to thank the sponsors, Barberton Mines, for their financial support – if it were not for them Rimer’s Creek would still be looking like it did two years ago and this massively invasive weed would not have been discovered until it was too late. Also thanks to Roland Jones who initially came up with the idea of using biological control, and the people of Working for Water who are always willing to assist,” said Andrea Botha.
