Experts warn, invasive caterpillar that feeds on hedges is starting to spread from its established base in London across the UK.
- The Asian box tree caterpillar is chewing its way through London gardens.
- The invasive caterpillar arrived in Europe in 2007 and was first reported in the UK in 2008.
- The box tree caterpillar is the larval stage of a moth native to the Far East and India.
According to Royal Horticultural Society (RHS) it is now receiving three or four reports of infestations a day. There have been more than 150 reports already this year, compared with 20 last year, and just three in 2011.
Dr Hayley Jones, an entomologist with the RHS, said: “The key thing is that it is established it has survived throughout the winter and is breeding. It has a foot in the door and is now building up in numbers.”
Invasive caterpillar was beleived to be originated in China and either flew across the English Channel or stowed away in containers of imported plants, experts said. An infested hedge can contain several hundred of the caterpillars, which leave a ghostly trail of webbing in place of the foliage. Its pale yellow eggs are laid in sheets on the underside of the leaves, making them hard to spot. Once hatched, they begin eating through the host plant, spinning sticky and strong webs around leaves and twigs to hide themselves.
James Crebbin-Bailey, topiary experts, clips the box of some of the prestigious gardens in the UK. He is having a pheromone trap installed in his garden in Twickenham because of the threat posed by the moth.
“The caterpillars just eat the whole thing, it’s unreal,” he said. “But if you are vigilant and keep checking, you can stop them spreading. The first line of defense is to use a pheromone trap to kill the adult moths. Then use a pesticide, or you can pick them off and squash them.”
Caterpillar is the common name for the larvae of members of the order Lepidoptera (the insect order comprising butterflies and moths).
As with most common names, the application of the word is arbitrary and the larvae of sawflies commonly are called caterpillars as well.
Caterpillars of most species are herbivorous, but not all; some are insectivorous, even cannibalistic. Some feed on other animal products; for example clothes moths feed on wool, and horn moths feed on the hooves and horns of dead ungulates.
Caterpillars as a rule are voracious feeders and many of them are among the most serious of agricultural pests. In fact many moth species are best known in their caterpillar stages because of the damage they cause to fruits and other agricultural produce, whereas the moths are obscure and do no direct harm. Conversely, various species of caterpillar are valued as sources of silk, as human or animal food, or for biological control of pest plants.
Caterpillars cause much damage, mainly by eating leaves. The propensity for damage is enhanced by monocultural farming practices, especially where the caterpillar is specifically adapted to the host plant under cultivation. The cotton bollworm causes enormous losses. Other species eat food crops. Caterpillars have been the target of pest control through the use of pesticides, biological control and agronomic practices. Many species have become resistant to pesticides. Bacterial toxins such as those from Bacillus thuringiensis which are evolved to affect the gut of Lepidoptera have been used in sprays of bacterial spores, toxin extracts and also by incorporating genes to produce them within the host plants. These approaches are defeated over time by the evolution of resistance mechanisms in the insects.
Plants evolve mechanisms of resistance to being eaten by caterpillars, including the evolution of chemical toxins and physical barriers such as hairs. Incorporating host plant resistance (HPR) through plant breeding is another approach used in reducing the impact of caterpillars on crop plants.IMAGE/wiki