Toxic!

June 16th 2016

The spring brings out all kinds of interesting creatures, both human and animal. Fortunately we live in a country where very few of our fauna are poisonous.

However, spring does bring out some undesirables - and one species which is currently hitting the news is the Brown tail moth caterpillar.

The problem is that the caterpillars have millions of tiny hairs called "setae" which are poisonous to humans and can cause allergic reactions, severe dermatitis and endophthalmitis and even severe breathing difficulties in asthma and hayfever sufferers if they are inhaled.

The caterpillars are predominantly found in more temperate areas in the UK, but have been noted as far north as Spurn Point in Yorkshire. They are brown with two white "stripes" on their side of their backs and can be identified be the two distinctive red spots on the back of their tails.

The Brown tail moth caterpillar emerges in spring and is a problem through until this time of year (early June). This year it has been noted in a number of public places including Canvey Heights Park as well as in a number of private and council-owned areas. 

During the winter, the brown tail moth caterpillars shelter together in silk nests, which are normally quite visible in trees. This presents an opportunity to deal with them. The simplest way to do this is to physically prune out the nest and burn it - taking necessary precautions and wearing appropriate personal protective equipment. If burning is not possible but you can remove the nests, then these can be double-bagged in plastic bags and placed in refuse bins. This should not be attempted by householders in the active season. 

Many local authorities have used "pheromone traps" to disrupt the breeding cycle of the brown tail moth, with varying degrees of success - but I do wonder, when we are losing such large numbers of all kinds of native bird species, whether this heavy-handed approach is what's best. Obviously we want to minimise the negative effects on humans - but there will potentially be knock-on effects for species which we value more highly than the brown tail moth... 

Dan M