A New Order


The 1000th species to be added to this site was only discovered yesterday in my back garden, and it not only introduces this new species but also a new order of insects which I haven’t featured before – the Psocoptera.

This order includes the barklice and the booklice, and in some quarters prefer to be called barkflies. They are quite small insects ranging from 1.5-7 mm long, and can be confused with psyllids, jumping plant lice, which do what the names says and jumps when disturbed, where as barklice don’t jump. The reference to ‘lice’ is a bit of a misnomer as they are not parasitic but free-living insects.

Barklice feed on various ‘microflora (algae such as Pleurococcus, lichens and fungi) or on more general organic matter which often occurs on surfaces of bark or the foliage of trees. Not all barklice are associated with trees, as some are found in low vegetation, leaf litter and under stones. Some species are fully winged, and some are only partially winged or wingless.

There are around 4,400 psocid species worldwide, 1,000 in Europe, and 100 in Britain, and many go unoticed and unrecorded, although most every tree is likey a home to them. 68 of these species come under the barklice or barkflies umbrella which are found outdoors, and the remaining booklice are found indoors. These are wingless and grow up to around 2 mm long. They are most commonly found in human dwellings and warehouses where they feed on stored grain, book bindings, wallpaper paste and other starchy products, and on the minute traces of mould found in old books. They can sometimes cause damage to stored museum collections of insects and plants. A few Psocoptera live in bird nests feeding on feathers and dead skin cells.

Psocoptera are regarded as one of the most primitive amongst insects, as their mouth parts show little modification from those of the earliest known fossils.


Valenzuela flavidus – At around 3 mm (1/8 in) long, this is quite an attractive species with pale yellow colouring and distinct brown markings. During summer and autumn it is mainly found on branches of deciduous trees and bushes, though occasionally also on conifers and evergreen branches. During winter and spring it is found in leaf litter.


Valenzuela flavidus

Valenzuela flavidus is a fairly common and widespread species found on trees and shrubs.

Valenzuela flavidus

Seen June to October, it feeds on various microflora that grow on trees and shrubs.


29 thoughts on “A New Order

  1. Congratulations on recording such a large number. I’ve never heard of barklice and booklice so it was interesting to read about them.
    Thanks for sharing, Pete.

    Liked by 1 person

  2. Congratulations – what an interesting insect to round off the 1 000 species! I too am looking forward to the next thousand. You really do either have excellent observation skills or a keen nose for finding such tiny creatures!

    Liked by 1 person

  3. You haven’t disappointed with the inaugural creature of your second thousand!

    Amazing, that an insect so little changed over the eons now thrives on the book bindings and wallpaper pastes provided by humans. Evolutionary heroes.

    Liked by 1 person

  4. They remind me a bit of the winged cockroaches we have around here, which are terrifying.

    Wildlife come in many shapes and forms. Here, we have a huge amount of feral cats that decorate the streets with their different colors, and their playfulness and intelligence. Eyes that piece the dark like something out of a magic fairy tale. And there was an armload of butterflies last spring.

    Liked by 1 person

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