THRIPS SWARM

Sunday was rolling along rather pleasantly, from an overcast morning to a glorious afternoon…but with the warmth and the burning off of the mist, we were invaded!

It wasn’t Vikings (who never took the castle, by the way, and we have almost no archaeological evidence of them in the castle environs)…

It wasn’t tourists…

It was the dreaded THUNDERBUG!

Based on Ernst Heeger’s illustrations from Beiträge zur Naturgeschichte der Insecten. Als Beiträge zur Fauna Oesterreichs, a text in German held in the Smithsonian collections. This is from a section on thrips, but using the old synonymous name “physopod.”

In recent memory, most of us can only recall a single nightmarish day in 2019 when they swarmed the castle. But today, oh, today was much worse than that day. We all know that insects, spiders, and earthworms are a standard part of the job of excavation. We’ve made our peace with that, and usually those little bugs get relocated or brushed away gently, no harm, no foul. But not today.

Today, these little pests covered our arms and necks, so small that you’d be surprised how you could feel every footfall of each miniscule foot. But their little feet were so irritating, tap-dancing across our sun-cream-sticky flesh! No, they didn’t bite us, but they crawled over every inch of exposed skin. They landed on our lips and were smushed as we aggressively tried to wipe our faces clean. They flew into our eyelashes and poked us in the eyes. They squirmed into our ears and nostrils. It was revolting.

So in preparation for all-out war tomorrow, we have done a little reconnaissance on our enemy:

Common blossom thrips with measurements.
Vivek Kumar, University of Florida’s Entomology and Nematology Dept.

SCIENTIFIC NAMES: Thysanoptera (order with over 6,000 species), Thrips (genus with about 280 species)

The genus and generic name for the creature comes from the Ancient Greek for “woodworm,” which is weird because they are definitely not worms (annelids). The University of Chicago’s Classical language app Logeion cites the Lewis & Short Latin dictionary: thrips, thripis (m.), transliterated from the Greek θρίψ. The Greek is found in the Liddell & Scott Greek-English lexicon, but the citations are a bit harder to find. Pliny the Elder refers to the woodworm literally in several passages of his Natural History, for example while describing the resistance of tree species to infestation. Martianus Capella (Late Antiquity/early 5th century, but studied and used throughout Carolingian education discourse) also uses the word, but as a synonym for worthless things, in Book II, Section 164 of his De nuptiis Philologiae et Mercurii (“On the Marriage of Philology and Mercury”). You can also access the Perseus database on which the app is based here.

OTHER ALIASES:  thunder flies, thunderblights, storm bugs, storm flies, corn flies, corn fleas, corn lice, harvest flies, harvest bugs, freckle bugs

DESCRIPTION: 0.5mm-15mm long, slender body, two pairs of fringed or feathery wings folded over its back, only the left mandible (lower jaw), usually black or brown in adult stage except for a few species that stay yellowish like juveniles

As there are over 170 species found in Britain, it would be folly to detail them all, but they all share the same basic characteristics. They have a slurpy tube (that’s not the scientific name) through which they secrete saliva into their food that starts the digestion process and then suck it all back up. Remember those gross little feetsies we mentioned above? They have a grippy pad on each of its six feet called an “arolium” that inflates with the bodily fluids of the insect and helps it climb in any direction, defying both gravity and common decency. There are an astonishing number of thrips-centred websites.

KNOWN HANGOUTS: often among cereal crops and flowers, and, apparently, Bamburgh Castle for the weekend

ACTIVE TIMES: hot and humid weather, and particularly weather systems that can form thunderstorms (correlation, not causation, by the way), in the UK flourish between April-September

They’ve been around since about 300 million years ago, long before the dinosaurs (but probably annoyed them too when they showed up) and around the time of the dolerite magma injection that intruded into the sandstone at Bamburgh. Their entire life-cycle takes about a month, but they can lay 100 eggs in that time. Some can complete their life-cycle in two weeks if the temperature is high enough!

PROS:

Some thrips are pollinators, which is almost always a good thing and why we should be nicer to insects like bees. Some species prey on other thrips, the eggs of wasps and moths, and mites (which are not insects because they only have two body parts). Others eat fungi. Thrips also have a cool means of flight that is worth reading about.

CONS:

Thrips can destroy crops by eating their tissues from aesthetic damage like stippling/mottling or silvery patches (and little poo stains), to the formation of galls, to full defoliation of plants. They can also spread about 20 different plant viruses, such as the Tomato Spotted Wilt Virus. In addition, they are extremely invasive and have been found on every continent. Thrips can also reproduce asexually, where the female lays eggs without a mate. Numerous gardening websites also warn that they become pesticide-resistant quickly, and that biological control (like increasing natural predators) is preferable to chemical control.

THE PLAN:

  1. Wear long-sleeves to cover up.
  2. Cry deeply.
  3. Borrow some of the repellent the Australian students brought all the way from the only continent that is actively trying to harm you.
  4. Get back to work.