Category: Lepidoptera

My very good friend Rob, former bigMouth chorister, cabinet maker, luthier, painter, photographer, and, as it turns out, amateur lepidopterist built himself a moth trap back in the mid-2000s to entertain his children.

You set the trap up to do its job overnight. It is basically a sealed wooden box full of egg trays, with a big funnel as a collector and an ultraviolet lamp above as an attractor. At night, the flying creatures are attracted to the lamp, find themselves perambulating down the funnel and into the box, and roosting in the egg trays.

There they will happily stay until dawn, when the amateur lepidopterist will pay a visit to see what lurks within, setting them all free again after a few observations are made and photos taken, preferably into undergrowth and bushes some distance away from the trapping site. You can see some of the snaps I took at Rob’s early this morning in a Facebook gallery entitled Mothley Crew, hopefully I will have more species to display tomorrow.

I paid Rob a visit early this morning, by invitation, to see what kind of haul he might have had on a sultry July night. Daytime temperatures have been 30 degrees Celsius plus and nothing lower than about 25 at night. There were plenty of flies and beetles in the trap and no smaller number of moths. Moths of all sizes from tiny little specimens, through White and Buff Ermines, and Large Yellow Underwings 20 millimetres or so from antennae to tail, and at least one much bigger Poplar Hawk Moth.

I snapped a few close-ups with my phone camera while Rob set them free into his garden shrubberies to fly another night or be snaffled up by Pipistrelle Bats. It seemed rather churlish not to offer to borrow the trap to see what kind of mothley crew we might have in our back garden and save a few from the local bats, just for a night. So, almost midday, the trap is set, just need to wait until dark, switch on the lamp, and spend an excitedly restless night dreaming of Elephant Hawk Moths, Netted Carpets, Brimstones, and Angle Shades.

Incidentally, that lamp…it looks like a U-shaped fluorescent tube about 300 mm in length. It’s labelled as an “actinic lamp”. Actinic from the Greek for a ray or beam and pertaining to photography and other areas where light is important. A non-actinic light, such as a red light used in a photography dark room, will not fog photographic film and triggers no photobiological nor photochemical reactions. An actinic light, as used in Rob’s homemade Robinson-type moth trap is the opposite. It’s a full-on bright, white light that reaches deeper into the high-energy blue end of the visible spectrum and is thus highly visible to light-seeking invertebrates.

In terms of etymology, chemist readers will recall the radioactive (beta emitting) element actinium and its relatives the actinides, which will fog photographic film, and much more besides…

As a keen photographer, I am always on the look out for odd and intriguing things to photograph. In the absence of birds other than skylarks and rooks along the St Ives to Cambridge guided busway I photographed what looked like a silky nest in a blackthorn/hawthorn bush. It was on the left-hand side of the walkway as you approach the Oakington stop (about 400m away in fact). And then another.

I posted the photo to Facebook and asked for comments (to be honest I hadn’t even noticed the caterpillars at the time I took the photo and only did so when I was “developing the print”. I had been musing on it being an immigrant funnel web spider’s nest or similar and keeping my distance.

Singing friend Jill Barrett suggested the caterpillars were those of the oak processionary moth (Thaumetopoea processionea). This species has been causing problems for oaks for a number of years, but it seems infestations were, until recent years, limited to London and environs. Graham Bellamy commented that it was more likely to be a Brown-tail moth given that the nest was growing on a thorn bush rather than an oak tree. This was later confirmed by a contact at the Forestry Commission.

If the Forestry Commission had said these were oak processionaries, that wouldn’t have been good news for our local oaks. It would also have been bad news for anyone who comes into contact with these caterpillars. They have myriad tiny hairs which if they touch skin or eyes or fragments are breathed in can sometimes cause serious inflammation [and irritation of skin, eyes, and lungs].

If you see one of these nests, stay well clear. Don’t try and remove it yourself even if there are no live caterpillars present, there will inevitably be toxic hairs and hair particles left behind. There are many species of hairy caterpillar that can cause similar health problems and there are others that damage different trees.

Here’s the science bit:

The oak processionary moth caterpillar hairs carry lots of soluble proteins, one of those extracted and identified in 1986 is found only in the hairs and causes a reaction on skin identical to that produced by contact with the hairs and so is assumed to be the causative toxin of the inflammatory response. Texier et al named this urticating protein thaumetopoein. It is, they explain, formed from two protein subunits and is present in large quantities in the glands producing the caterpillar's urticating hairs.

“Thaumetopoein: an urticating protein from the hairs and integument of the pine processionary caterpillar (Thaumetopoea pityocampa Schiff., Lepidoptera, Thaumetopoeidae)” by Lamy M, Pastureaud MH, Novak F, Ducombs G, Vincendeau P, Maleville J, Texier L. in Toxicon. 1986;24(4):347-356.

I briefly review Daniel Marlos’ latest book, Curious World of Bugs, in Six Sexy Science Books. But, I wanted to know more about the book and so offered Marlos a few questions on which he might wax lyrical.

What makes bugs such a fascinating subject?

Bugs make such a fascinating subject because they are ubiquitous. Bugs can be found all over the world in every conceivable environment. Unlike larger animals that flee when they are being observed, bugs couldn’t care less who is watching them and they are ready subjects to be photographed. Many children have a fascination with bugs, though sadly, most adults outgrow this initial reaction to the lower beasts.

What is the most remarkable bug?

This is of course my opinion, but I find the preying mantis to be the most remarkable bug. They are large and formidable predators. There is something almost human in their gestures and they will follow their prey or a larger predator by rotating their heads nearly completely around.

What’s the biggest? And prehistorically how does it compare to those giants of the past?

I would have to question a definition of biggest. The moth with the largest wingspan at twelve inches is the South American white witch. The moth with the greatest surface wing area is the Southeast Asian atlas moth. The longest insect is probably a walkingstick from Borneo that has been recorded at 14 inches long. The insect with the greatest mass is probably the African goliath beetle but the longest beetle is a South American longhorn beetle called a titan beetle that can cover the palm of an adult man, and that doesn’t include its substantial antennae. All of these are dwarfed by a prehistoric dragonfly that has been recorded in the fossil record as having a 30 inch wingspan.

Social insects are, in a sense, meta-organisms aside from our use of bees, do you think we could somehow engineer colonies to carry out other tasks?

Other than honey bees, I don’t think humans would have much luck tapping the social insect world to perform menial labour tasks. Wasps would sting and termites might eat our wooden homes. Ants would compete for food, so it seems we are limited to apiculture when it comes to having social insects perform a service for people.

Bugs will no doubt be here long after we as a species have burned outselves out, might there be a future with “intelligent” bugs?

Depending upon how intelligence is defined, there are numerous intelligent insects. Cockroaches can be taught to run a maze. Social insects like ants, bees, wasps and termites have a highly developed caste system and the individual will sacrifice for the good of the colony. Though social insects care for their young, they are not the only bugs to do so. Many spiders will defend their eggs and hatchlings including the nursery web spiders and the green lynx spider. Many parasitic wasps like the cicada killer, the great golden digger wasp and the tarantula hawk battle and paralyze insects and spiders to provision a nest for their young. Some predatory fireflies mimic the light flashing patterns of more docile species to entrap them for prey, and certain tropical cockroach males are female impersonators that trick more dominant males into mating and while the dominant male is in a compromising position, the female impersonator bites off its competitor’s wings, virtually emasculating him.

Why do you think so many people are so repelled by bugs, despite their obvious merits?

People are often repelled by things they don’t understand, which is one of the reasons humans are often such an intolerant society.

To us Brits, a bug is a germ, a microbe that causes an illness, could that be the subject of The Curious World of Bugs 2.0?

Not a chance. I am not interested in viewing the world through a microscope. Besides, germs are better left to scientists and not artists with an interest in pop culture like me.