Tag Archives: Trichoptera

Twisted, hairy, scaly, gnawed and pure – side-tracked by Orders

I’m supposed to be writing a book, well actually two, but you have to be in the right mood to make real progress. Right now, I’m avoiding working on one of the three chapters that I haven’t even started yet* and I really should be on top of them by now as I have already spent the advance, and have less than a year to go to deliver the manuscript 😦 Instead of starting a new chapter I’m tweaking Chapter 1, which includes an overview of Insect Orders.  While doing that I was side tracked by etymology. After all, the word is quite similar to my favourite subject and a lot of people confuse the two. Anyway, after some fun time with my Dictionary of Entomology, (which is much more of an encyclopaedia than a dictionary), and of course Google, I have great pleasure in presenting my one stop shop for those of you who wonder how insect orders got their names.  Here they are, all in one easy to access place with a few fun-filled facts to leaven the mixture.

Wings, beautiful wings (very much not to scale)

First, a little bit of entomological jargon for those not totally au fait with it.  Broadly speaking we are talking bastardised Greek and Latin. I hated Latin at school but once I really got into entomology I realised just how useful it is.  I didn’t do Greek though 😊, which is a shame as Pteron is Greek for wing and this is the root of the Latin ptera, which features all over the place in entomology.

Since I am really only talking about insects and wings, I won’t mention things like the Diplura, Thysanura and other Apterygota.  They don’t have wings, the clue being in the name, which is derived from Greek; A = not, pterygota, derived from the Greek ptérugos = winged, which put together gives us unwinged or wingless. In Entojargon, when we talk about wingless insects we use the term apterous, or if working with aphids, aptera (singular) or apterae (plural).   I’m going to deal with winged insects, the Exopterygota and the Endopterygota. The Exopterygota are insects whose wings develop outside the body and there is a gradual change from immature to adult.  Think of an aphid for example (and why not?); when the nymph (more Entojargon for immature hemimetabolus insects) reaches the third of fourth instar (Entojargon for different moulted stages), they look like they have shoulder pads; these are the wing buds, and the process of going from egg to adult in this way is called incomplete metamorphosis.

Fourth instar alatiform nymph of the Delphiniobium junackianum the Monkshood aphid.  Picture from the fantastic Influential Points site https://influentialpoints.com/Images/Delphiniobium_junackianum_fourth_instar_alate_img_6833ew.jpg (Any excuse for an aphid pciture)

In the Endopterygota, those insects where the wings develop inside the body, e.g butterflies and moths, the adult bears no resemblance to the larva and the process is described as complete metamorphosis and the life cycle type as holometabolous. It is also important to note that the p in A-, Ecto- and Endopterygota is silent.

Now on to the Orders and their names.  A handy tip is to remember is that aptera means no wings and ptera means with wings.  This can be a bit confusing as most of the Orders all look and sound as if they have wings.  This is in part, due to our appalling pronunciation of words; we tend to make the syllables fit our normal speech patterns which doesn’t necessarily mean breaking the words up in their correct component parts. Diptera and Coleoptera are two good examples – we pronounce the former as Dip-tera and informally as Dips.  From a purist’s point of view, we should be pronouncing the word Di-tera – two wings, and similarly, Coleoptera as Coleo-tera, without the p 🙂 Anyway, enough of the grammar lessons and on with the insects.

Exopterygota

Ephemeroptera The Mayflies, lasting a day or winged for a day J The oldest extant group with wings. They are also a bit weird, as unlike other Exopterygota they have a winged sub-adult stage

Odonata              Dragonflies and Damselflies – think dentists, toothed, derived from the Greek for tooth, odoús. Despite their amazing flight capability, the name refers to their toothed mandibles.  The wings do get a mention when we get down to infraorders, the dragonflies, Anisoptera meaning uneven in that the fore and hind wings are a different shape and the damselflies, Zygoptera  meaning even or yoke, both sets of wings being pretty much identical.

Dermaptera       Earwigs, leathery/skin/hide, referring to the fore-wings which as well as being leathery are reduced in size.  Despite this, the much larger membranous hind wings are safely folded away underneath them.

A not very well drawn (by me) earwig wing 😊

Plecoptera          Stoneflies, wickerwork wings – can you see them in the main image?

Orthoptera         Grasshoppers and crickets, straight wings, referring to the sclerotised forewings that cover the membranous, sometimes brightly coloured hind wings.  Many people are surprised the first time they see a grasshopper flying as they have been taken in by the hopper part of the name and the common portrayal of grasshoppers in cartoons and children’s literature; or perhaps not read their bible “And the locusts went up over all the land of Egypt, and rested in all the coasts of Egypt”. I think also that many people don’t realise that locusts are grasshoppers per se.

Grasshopper wings

Dictyoptera        Cockroaches, termites and allies, net wings

Notoptera           The order to which the wingless Ice crawlers (Grylloblattodea) and Gladiators Mantophasmatodea) belong. Despite being wingless, Notoptera translates as back wings. It makes more sense when you realise that the name was coined when only extinct members of this order were known and they were winged.

Mantodea           Mantids, the praying mantis being the one we are all familiar with, hence the name which can be translated as prophet or soothsayer

Phasmotodea    Phasmids, the stick insects and leaf insects – phantom, presumably referring to their ability to blend into the background.

Psocoptera         Bark lice and book lice, gnawed or biting with wings. In this case the adjective is not in reference to the appearance of the wings, but that they are winged insects that can bite and that includes humans, although in my experience, not very painful, just a little itchy. They are also able to take up water directly from the atmosphere which means that they can exploit extremely dry environments.

Embioptera        Web spinners, lively wings. Did you know that Janice Edgerly-Rooks at Santa Clara University has collaborated with musicians to produce a music video of Embiopteran silk spinning? https://www.youtube.com/watch?v=veehbMKjMgw

Zoraptera            Now this is the opposite of the Notoptera, the Angel insects, Zora meaning pure in the sense of not having any wings.  Unfortunately for the taxonomists who named this order, winged forms have now been found 🙂

Thysanoptera    Thrips and yes that is both the plural and singular, thysan meaning tassel wings, although I always think that feather would be a much more appropriate description.

Feathery thrips wing – Photo courtesy of Tom Pope @Ipm_Tom

Hemiptera          True bugs – half wings.  The two former official suborders were very useful descriptions, Homoptera, e.g. aphids, the same. Heteroptera such as Lygaeids, e.g. Chinch bugs, which are often misidentified by non-entomologists as beetles where the prefix Hetero means different, referring to the fact that the fore wings are hardened and often brightly coloured in comparison with the membranous hind wings.

Coreid bug – Gonecerus acuteangulatus – Photo Tristan Banstock https://www.britishbugs.org.uk/heteroptera/Coreidae/gonocerus_acuteangulatus.html

Phthiraptera      The lice, the name translates as wingless louse. I guess as one of the common names for aphids is plant lice they felt the need to make the distinction in the name.

Siphonaptera     Fleas – tube without wings, referring to their mouthparts

 

Endopterygota

Rhapidioptera   Snakeflies – needle with wings, in this case referring to the ovipositor, not to the wings, which are similar to those of dragonflies.

The pointy end of a female snakefly

Megaloptera      Alderflies, Dobsonflies – large wings

Neuroptera        Lacewings – veined wings

Coleoptera         Beetles – sheathed wings, referring to the hardened forewings, elytra, that cover the membranous hind wings. The complex process of unfolding and refolding their hind wings means that many beetles are ‘reluctant’ to fly unless they really need to.

Strepsiptera       These are sometimes referred to as Stylops.  They are endoparasites of other insects. The name translates as twisted wings. Like flies, they have only two pairs of functional wings the other pair being modified into halteres.  Unlike flies, their halteres are modified fore wings.  Their other claim to fame is that they feature on the logo of the Royal Entomological Society.

The Royal Entomological Society Strepsipteran

Mecoptera         Scorpionflies, hanging flies – long wings.  Again, not all Mecoptera are winged, but those that are, do indeed have long wings in relation to their body size.

Male Scorpionfly, Panorpa communis.  Photo David Nicholls https://www.naturespot.org.uk/species/scorpion-fly

Siphonaptera     Fleas – tube no wings. The tube part of the name refers to their mouthparts.

Diptera                 Flies, two wings, the hind pair are reduced to form the halteres, which are a highly complex orientation and balancing device.

Trichoptera         Caddisflies, which are, evolutionarily speaking, very closely related to the Lepidoptera.  Instead of scales, however, their wings are densely cover with small hairs, hence the name hairy wings.  Some species can, at first glance, be mistaken for small moths. If you want to know more about caddisflies I have written about them here.

Lepidoptera       Moths and butterflies, scaly wings; you all know what happens if you pick a moth or butterfly up by its wings.

Moth wing with displaced scales

 

Hymenoptera    Wasps, bees, ants – membrane wings

Wing of a wood wasp, Sirex noctilio

 

And there you have it, all 30 extant insect orders in one easy location.

 

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Water butterflies and hairy wings – Caddisfly names around the world

“..great variety of cados worms.. “ Thomas Mouffet (1658)  Theatorum Insectorum

Adult Limnephilus caddisfly perched on top of its case-bearing larva.

Despite aphids being my favourite insect group, I have had rather a soft spot for caddisflies since I was about ten years old when I discovered that if I very carefully removed their larval cases and provided them with coloured sand, they would spin a technicoloured replacement 😊

A variety of caddis cases

I have, in the intervening years, moved on somewhat from those early experiments and largely left the wonderful world of freshwater entomology behind, except when I take students pond-dipping and give my once a year lecture on aquatic insects. I’m not going to say much about caddisflies because I am not an expert, but for those of you not overly familiar with these fascinating insects a little bit of background information may be useful.  Unless you are a caddisfly specialist most people don’t give them much thought and if they do know anything about them, it is probably limited to the fact that they are aquatic and live inside a case.

Most people probably wouldn’t recognise an adult caddisfly if they saw one and in my experience those people who do notice them, usually think they are some sort of moth.  This is actually a sensible guess as evolutionarily speaking Lepidoptera (moths and butterflies) and Trichoptera (caddisflies) are very closely related and are in the same Superorder, the Amphiesmenoptera.  Trichoptera literally translates as hairy wings, Lepidoptera as scaly wings and many adult caddisflies do look remarkably similar to micro-moths so it is an easy mistake to make.

Spot the difference – caddisflies on the left, Lepidoptera on the right

The majority of caddisflies have aquatic larvae, although a few have become completely terrestrial and spend their lives foraging in damp leaf litter and hiding in bark crevices.

Wingless female of the terrestrial caddisfly Enoicyla pusilla; doing her best to not look like a caddisfly. http://www.wbrc.org.uk/worcrecd/33/Green_Harry_7–Westwood_Brett–Sightings_of_adult_.html

Very generalised life cycle of a caddisfly.  The eggs are laid in water, on aquatic vegetation or nearby trees. On hatching, the larvae go through several (usual five) moults before pupating and the adults emerge in spring or early summer.

Caddisflies are probably the most successful of the aquatic insects. Data from stream surveys frequently list as many species of Trichoptera, or caddisflies, as species of Ephemeroptera (Mayflies), Odonata (dragon and Damselflies) and Plecoptera (Stonefleis) combined (Mackay & Wiggins, 1979).  Their success can be put down to their use of silk and ability to exploit a range of different aquatic habitats.  They can be described as lotic, those that live in running water, i.e. streams and rivers, or lentic, those that live in ponds and lakes.  Some of the ‘ponds’ can be very temporary, puddles for example, or contained in plants, e.g. Bromeliads. Those that live in running water are well supplied with fresh aerated water, but those living in ponds and pools have to make their own currents to pass ‘fresh’ water over their gills, to avoid suffocating.

Sedentary caddis larvae live in fixed shelters and use silk ‘fishing nets’ to catch their food.  If they live in fast flowing streams, their nets are coarse and tight.  Those living in slow flowing streams use baggy fine-grained nets.

Caddisfly fishing net https://www.flickr.com/photos/janhamrsky/5979065987/in/photostream/

Some caddisfly larvae are free-living foragers with portable cases. They also use silk, leaving a thread behind them, just as many other insects do, to attach themselves to the substrate so they are not floated downstream willy-nilly.  If they live in fast flowing streams their cases are streamlined making it easier for them to move against the current and less likely to be swept downstream.

I had originally started this article as a companion piece to my articles on the naming of thrips, aphids, cockroaches, and most recently, ladybirds, so I guess I had better get on with it. The origin of the word “caddis” is unclear, but according to Wikipedia it dates to at least as far as Izaak Walton’s The Compleat Angler (1653), in which “cod-worms or caddis” are mentioned as being used as bait. Thomas Muffet (Moufet) used the term cados worm in his book Insectorum sive Minimorum Animalium Theatrum which was written earlier (he died in 1604) but not published until 1658.  The term cadyss was being used in the fifteenth century for silk or cotton cloth, and “cadice-men” were itinerant vendors of such materials, but a direct connection between these words and the insects has not yet been established.  What about other languages, what attributes of the caddisfly have non-English speakers latched on to describe these fascinating insects?

Bulgarian – ручейник (rucheinik), which Google Translate will also tell you is rhinoceros 😊

Catalan – Frigànies which also translates as frigates, an indication of the association with water?

Czech – potočníky = stream legs

Dutch – kokerjuffer – the larval form, Schietmotten (pl) Singular: Schietmot – directly translates as shooting moths. Interestingly (or not), dragonfly is waterjuffer.

Finnish – Vesiperhonen – water butterflies, again reflecting the close resemblance to Lepidoptera; Finns call moths night butterflies, yöperhoset

French – Trichoptères – surprisingly not very flowery at all, but the larvae are more satisfyingly described as  à fourreau ou porte bois which roughly translates as with a sheath or wooden door

German – die Köcherfliege – also Frühlingsfliege, Fruhlings = spring, fliege = fly, Kocher = quiver as in arrows which given the shape of some of the cases is quite apt and the larvae are known as Köcherfliegenlarven

Icelandic – Vorflugur – Spring fly, reflecting the time of year when most of the adults emerge.

Polish – Chruścik – the wording on the stamp seems to translate as swamp yellow

Portuguese – o mosca d’água, The water fly

Spanish – el frígano similar to the Catalán and perhaps reflecting their association with wáter?

Swedish – Nattsländan –Natt = night and slandan = dragonfly?

 

Caddis case jewlery – if only I had been a bit more entrepreneurially  minded….

And finally, for those of you interested in exotic cuisine, and a non poultry alternative to red meat; in Japan caddisfly larvae are called Zazamushi and eaten as a delicacy.  They are so popular that they are commercially farmed (Cesard et al., 2015).

Many thanks to Daniela Atanasova, Gia Aradottir, Hannah Davis, Luisa Ferreira Nunes and Marlies vaz Nunes for help with the Bulgarian, Icelandic, German, Portuguese and Dutch respectively. They are much more reliable than Google Translate.

References

Cesard, N., Komatsu, S. & Iwata, A. (2015)  Processing insect abundance: trading and fishing of zazamushi in Central Japan (Nagano Prefecture, Honshū Island). Journal of Ethnobiology and Ethnomedicine, 11:78.

Mackay, R.J. & Wiggins, G.B.  (1979) Ecological diversity in Trichoptera.  Annual Review of Entomology, 24, 185-208

 

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