Sunday 12 September 2021

Watch out for this caterpillar species.



Thaumetopoea processionea (Oak processionary moth). 

In late summer the oak processionary moth will lay its eggs on branches and twigs high in the canopy of Quercus spp (oak) trees in masses, or plaques of about two hundred eggs covered in scales that are greyish they spend the winter in this phase.


The eggs hatch in late April the larvae will eat the foliage of the oak trees always in groups.


When they are not feeding they spend most of their time in a group nest which is made of silk webbing and shed skin.


They get their name OPM (oak processionary moth) due to the way they travel as larvae following each other nose to tail in long processionary lines when moving between their nest and feeding areas.



The larvae can moult up to five times shedding their skin in the nest the older caterpillars spend most of their time in the nest.

Caterpillars pupate when they have been feeding for 9-12 weeks after this they remain in the nest for up to 2 weeks more before leaving the nest in July-August as adult moths which starts the whole process again.


They are harmless in their adult moth stage and quite beautiful.




The mature caterpillars have hairs emerging from warts and due to a natural chemical in them can be harmful to humans and animals. They can cause health problems such as conjunctivitis, respiratory problems, rashes, and allergic reactions.







This is especially a problem as even an empty abandoned nest is still just as bad due to the larvae shedding their skins in the nest up to five times each and the hairs will keep their toxicity. They should be treated the same as live larvae with great care and by professionals.



The best way to deal with abandoned nests is with controlled fire which burns all the harmful hairs.



Chemicals can be effective at the early stages of the larvae stage when most of their time is spent in their nest either individually targeted nests or if possible spray the whole tree.


The other ways of controlling and removing are vacuuming





The whole tree can be removed in some cases cut down carefully and bagged up to be burnt in a controlled and safe area.




Removing from the tree by climbing and bagging the nests carefully to be transported away and burned.



But all these and any other methods should be carried out by professionals with the correct training.


The Oak processionary moth is mostly found in London.




To report a sighting or suspected sighting email to opm@forestrycommission.gov.uk
or telephone to 0300 067 4442.












 





















Tuesday 31 August 2021

Carabidae an agriculturist friend ?

Carabidae or more commonly known as Carabid

The UK has approximately 360 species of Carabidae, most of which can be observed with the naked eye. Making these species a great introduction to the world of beetles for adults and children just walking through the woods or in the countryside. The carabid species mainly nocturnal hunting other insect species and general movement at night but can still be seen during the day.


 

Some of the carabid species a beautiful, for example:

 
The two species above are one of the largest species that is common in the UK. They can be between 20-30mm (2-3cm), and they look very familiar, but in fact, different species can tell the difference. The Carabus violaceus has smoother elytra with fewer dimples.



Take a look at these the same species just the male is a bright metallic green, but the female is plain brown or black the difference is impressive.




A large (15 mm) tiger beetle that is iridescent green with yellow markings. A large (15 mm) tiger beetle that is iridescent green with yellow markings. They are widespread in Britain. It can be found in bare ground and areas of little to no vegetation. Both adults and larvae are predators of other invertebrates. The larvae dig a burrow in the ground, often on or near paths to pitfall-trap unwary insects.




The Elaphrus cupreus (Bronze and purple spots figure 6) Length 8- or 9-mm. Bronze with conspicuous purple ocellate depressions on the elytra. Antennae are black, tibiae are brown, and the rest of the legs are black but often with metallic, usually bluish, reflections. The head is wider than the quadrate pronotum. The Elaphrus riparius (green Figure 7) Length 6.5 to 7.5 mm. Metallic green elytra with pale lilac markings and a pair of round violet depressions that appear to be edged with silver in strong light. Legs long, femora metallic green, strongly micro sculptured, tibiae red but darkened and metallic at the apex. Tarsi shining metallic green.


 

 

How to identify.
1  Filiform (threadlike) antenna (in the British sub-families).
2  Five segmented tarsi.
3  Hind coxae forming triangular plates that divide the first sub-abdominal segment.
4  Hind trochanters are lobed, extending partway along the third hind margin of the femora.

The image below (figure 8) will help to visualise the biology of the average Carabidae spp.

 

 

Just showing a few that I find interesting of the 360 species of Carabidae found in the UK and Ireland. These species are essential to agriculture providing free green pest control as predators hunt and keep the local populations of pest species in check. So, it is best to encourage them onto your land, and they will help protect your crops and reduce the need for pesticides which is good for us and the environment. To attract more of these species, you only really need to do two things; have water sources on the land, for example, ponds or lakes and cover. This could be in the form of rocks or dead wood scattered around. This could also be accomplished with mulch somewhere for them to hide during the day. I would suggest a mixture of these as some species prefer different habitats, so the more habitats you provide, the more species-rich the land will be.