Small orders

Primitive hexapods

The primitive hexapods, some previously included in the Apterygota, are a paraphyletic grouping of insects and their close relatives with no wings, comprising almost 10,000 known species in the Collembola (springtails), Diplura (two-pronged bristletails), Microcoryphia (jumping bristletails), Protura (coneheads) and Zygentoma (silverfish and firebrats).

Collembola (springtails)

The Collembola, or springtails, are small (0.25 to 6 millimetres long) and currently recognised as a sub-class within Hexapoda, containing over 6,000 described species. Springtails are aptly named after a unique forked structure attached to their abdomen called a furculum. The furculum is usually held under tension. When released, it springs against the surface, propelling the springtail up to one hundred times its length. Springtails are omnivorous and prefer moist conditions. The Museum’s collection comprises both spirit preserved and microscope slides.

Diplura (two-pronged bristletails)

The Diplura, or two-pronged bristletails, are an order consisting of 800 currently described species. They are elongated and small, from 2 to 7 millimetres in length. They are hemimetabolous, live in moist habitats and feed on dead organic matter. Some species are known to be predatory and have pincer-like mouthparts to capture prey. The Museum’s collection is primarily preserved in spirit or as microscope slides.

Microcoryphia (jumping bristletails)

The jumping bristletails, previously known as the Archaeognatha, are an order consisting of 350 known species. Bristletails have small elongate bodies, large compound eyes, and three tails. Much of their body is covered with flat scales giving the bristletails a shiny appearance. They are known to live up to four years, feeding primarily on algae, lichens, mosses and decaying organic detritus. They are very active and can jump up to 30 centimetres using their tails! The Museum’s collection is primarily prepared as microscope slides.

Protura (coneheads)

The Protura are an order of simple hexapods consisting of approximately 800 described species. The Protura are very small, being 0.6 to 1.5 mm long, and have no eyes or antennae but can sense their surroundings through their front legs. They have rudimentary mouthparts and feed on decaying organic and fungal matter. The Museum’s collection is preserved in spirit or as microscope slides.

Zygentoma (silverfish and firebrats)

The Zygentoma, previously known as the Thysanura, contains the groups commonly known as silverfish and firebrats. They are similar to the Microcoryphia with three tails but do not jump. The Zygentoma have elongated bodies 7 to 19 millimetres in length. Silverfish are aptly named after their shiny scales, which the firebrats lack. They are often found in domestic environments, feeding on cereals, starch, paper, fabrics and dried meat. The Museum’s collection is primarily preserved in spirit or as microscope slides.

Important historical collections

The major historical collections within these groups are the C. Börner collection of 853 identified specimens, including much of his type material which was added to the Museum’s collection in 1907. A.D. Imms added further important collections in 1912. H. Womersley first worked on the collection in the 1930s, and F.G.M. Westropp compiled the first full species index. Peter N. Laurence greatly enhanced the collection from 1954 during his 35 years of Museum service. R.S. Bagnall’s collections were added in 1959. Much material was added in this period by using the new Berlese funnel collecting method.

Dermaptera

The Dermaptera, commonly known as earwigs, are an order of insects with 2,000 known species. While a common misconception is that they are named after their habit of crawling into our ears, it is generally agreed that the name originates from the shape of the hindwing, which resembles a human ear when unfurled. Earwigs are characterised by a pair of large forceps-like pincers on their abdomen, which are used to assist with wing folding, prey capture and defence. They are also one of the few non-social insects which show maternal care of the developing eggs and very young nymphs. Two small groups of earwigs are considered to be commensal or ectoparasitic: the Arixeniidae live with bats in caves in Borneo, and the Hemimeridae are ectoparasitic, living in the fur of African giant pouched rats. Both groups have developed viviparity, offspring developing in a uterus in the female.

Important historical collections

The St. Helena earwig is the largest known species, reaching a length of approximately 8cm. Endemic to the island of St. Helena, the earwig has not been seen alive since 1967 despite numerous searches for it. As a result, this species has been listed as extinct by the IUCN. The Museum’s collection includes two specimens from a Belgian expedition in 1965.

Ephemeroptera

The Ephemeroptera, or mayflies, are an ancient order of freshwater insects dating back to the Carboniferous with 3,340 known species.

Larval mayflies live in both standing and running water and along with stoneflies, caddisflies and several other invertebrate groups, are used to assess water quality due to their differing tolerance to pollutants.

Mayflies are unique among insects because they have two adult stages with wings. The first adult stage, called a subimago, assists with the transition between freshwater and terrestrial environments, while the second stage, the mature imago, is the breeding stage. The adult stage of most mayfly species is very short, frequently less than a few days and in some mayfly species, the adult stage is so short that the subimago has become the sexually mature final life stage.

Some mayfly species exhibit a synchronised mass emergence of the adults in numbers so great they can be seen on weather radar and result in blizzard-like conditions, covering roads and vehicles which they mistake for water.

Important historical collections

The Museum’s Ephemeroptera collection includes historical material from Rev. A.E. Eaton, who joined the Challenger Expedition (1872-1876) and the Transit of Venus Expedition (1874-1875) as a naturalist.

The Martin Mosely collection of sealed watchglasses contains many good examples of freshwater insects, including several mayflies. More recently, the substantial collection of Mick Gillies, containing many species from sub-Saharan Africa, was added to the collection and has been digitised as part of ongoing recuration in the order.

Mantodea

The order Mantodea, more commonly called the praying mantises due to their upright posture and bent raptorial forearms, is the sister group to the cockroaches and termites, with over 2,500 known species. Mantids are voracious predators of other arthropods and possess the first confirmed stereo vision outside of vertebrates. Night-flying winged mantids also possess a ventral abdominal ear which enables detection of ultrasound and hence avoidance of echolocating bats.

Many mantids are green and live in bushes so well camouflaged, other species may be bark-like or straw-coloured in similar habitats, and the early stages are often very different. For example, in the orchid mantis, Hymenopus coronatus, the nymphs may be white or pink and blend perfectly with orchid flowers.

Megaloptera

The order Megaloptera includes the dobsonflies, alderflies and fishflies. The order is not very diverse, with only 380 known species globally. Megaloptera larvae are voracious underwater predators, however, the adults are short-lived and typically feed on nectar, if at all. The males of some species develop impressive mandibles used in courtship.

Notoptera

The order Notoptera, meaning no wings, is a group which includes the wingless ice crawlers (previously order Grylloblattodea) and gladiators or heelwalkers (previously order Mantophasmatodea). There are only 57 known species in the group. As their name suggests, the ice crawlers live in extremely cold environments at the tops of mountains and the edges of glaciers and live in a very narrow temperature window of 1 to 4°C. Gladiators, on the other hand, are found in the hot climates of Namibia and South Africa.

The first known ice crawler was described in 1914 from Canada, and 34 species are now known from North America and East Asia, the first heelwalker was described in 2002, and 21 species are now known.

Orthoptera

The Orthoptera are known for their sound production and jumping ability. They may also be recognised by their saddle-shaped pronotum, which extends backwards to cover the thorax and wing bases, often with a median keel or crest.

Orthoptera is divided into two suborders:

Ensifera

The Ensifera, which means sword-bearing, have distinctive, often elongated and blade-like ovipositors (egg-laying organs) and long delicate antennae (feelers), their songs are produced by using their forewings to stridulate, and their hearing organs are near the base of their foretibiae; included are the major group of bush-crickets, also known as katydids in North America, Australia and other countries, with the cave crickets, camel crickets, dune crickets, Jerusalem crickets, and the true crickets and mole-crickets.

Caelifera 

The Caelifera, which means chisel-bearing, have short ovipositors like engraving tools and short, sturdy antennae. They produce their songs by scraping their hind legs against raised veins on their forewings, with their hearing organs on the side of their abdomens; included are grasshoppers, locusts, bladder grasshoppers of South Africa, stick or horsehead grasshoppers of South America, monkey grasshoppers and others, groundhoppers and pygmy mole-crickets. 

The bush-cricket groups are often crepuscular. Some predatory species have long spines on the fore and mid legs to catch their prey; the mole-crickets have forelegs highly modified for digging.

The grasshopper groups are herbivorous, diurnal, and active in sunny weather.

All orthopteroid insects may show some camouflage. Many look like leaves, bark or grasses. Some grasshoppers show startle or flash colouration, having brightly coloured hind wings which are visible in flight but which disappear when folded away on landing – so the insect may escape notice by predators.

Certain grasshopper species are known as locusts and produce large seasonal outbreaks of millions of hungry insects that may devour vital crops. This is a great risk to agriculture. Both biological and chemical control measures are now utilised.

Globally, there are over 29,000 known species.

Strengths of the Orthoptera collection

In 1996, the Natural Resources Institute (formerly the Anti-Locust Research Centre) presented its collection of over 82,000 specimens of grasshoppers and locusts, mainly identified, which resulted in the expansion of the Acridoidea collection by nearly 50%.

Psocodea

The order Psocodea is an amalgamation of two groups previously regarded as orders, the Phthiraptera (true lice) and the Psocoptera (bark lice or book lice). Globally there are 10,500 known species of Psocodea.

Phthiraptera 

Lice are permanent, obligate ectoparasites of birds and mammals. Three of the suborders (Amblycera, Ischnocera and Rhynchophthirina) are known as chewing or biting lice, and the fourth (Anoplura) forms the sucking lice. There are about 5,000 known species, present in roughly 4,000 species of birds and 800 mammals. Most are highly host-specific, and consequently, lice are present in every continent and virtually every habitat occupied by birds and mammals.

The Museum’s collection began with the acquisition of the Henry Denny collection of 200 species with 90 primary types in 1852. In 1928 the Edouard Piaget collection of 10,000 specimens of European Lice with c. 300 primary Types was acquired. In the 1930s, both the L. Harrison collection and 17,530 James Waterstone slides were added. Theresa Clay worked on the collections from 1935, and in 1951, 58,800 Colonel Richard Meinertzhagen slides, including 1,791 types, were added. In 1961, the G. H. E. Hopkins collection (10,000 slides including 1,500 paratypes) was added to the collection. The most recent addition has been the R. S. Balter slide collection of Louse eggs on 7,000 microscope slides. There is a smaller secondary collection housed in spirit. A major work describing new species from Museum Brueelia specimens was completed by Daniel Gustafsson and Sarah Bush in 2017. Recently the whole louse microscope slide collection has been imaged by the Museum's Digital Collection Programme.

Psocoptera 

Book lice or bark lice are small (1-10 mm long), soft-bodied, with long antennae and large compound eyes. They feed on lichens, algae, moulds, cereals, pollen and detritus in leaf litter, tree bark and living plants. A few species are pests of stored food products and the starch found in book bindings. There are at least 5,000 known species, and like aphids, many psocids are parthenogenic, and the presence of males may even vary between different races of the same species. The Museum’s collection is equally split into a microscope slide collection, a dry pinned collection and a spirit collection. Dave Hollis greatly added to the collection in the second half of the 20th century.

Thysanoptera

The Thysanoptera are a group of insects commonly known as thrips. They are small insects, mostly smaller than 1 millimetre, although some species can be over 1 centimetre long. They all share fringed wings and uniquely asymmetrical mouthparts. Thrips mainly eat plant liquids, although some species ingest small fungal spores or are predatory on other small arthropods. Their feeding activity often causes damage to plants, leading to galls and scarring, and they can transmit plant viruses. Globally there are 6,200 known species.

The Museum’s collection consists mostly of microscope slide preparations, mounted using Canada balsam to ensure a good state of preservation. The body contents are cleared using warm Potassium hydroxide to allow light through to study the taxonomic features.

The collection was started by Francis Walker, developed by Fred Laing from 1914 and greatly enhanced by R. S. Bagnall’s collection. Dr Lawrence Mound worked on the collection from 1964 during his 30 years of active Museum service. There are extensive collections from the Americas, Africa, Asia and Australasia.