Phylogeny and Classification

According to Kukalova-Peck (1991), the early Collembola were semiaquatic. The earliest fossil collembolan, Rhyniella praecursor, from the Lower Devonian of Scotland resembled modern isotomids. Other fossils are known from the Lower Permian of South Africa, the Upper Cretaceous of Canada, and Tertiary amber deposits, the latter being assignable to extant genera. Currently, the two most primitive families are thought to be the Hypogastruridae and Isotomidae, with the Entomobryidae and Sminthuridae among the most advanced. Early classifications [e.g., that of Gisin (1960)] arranged extant species of the order Collembola in two suborders, Arthropleona and Symphypleona, principally on the basis of the striking difference in body form, and five families. Nowadays, up to 14 families are recognized, and these are allocated among three orders within the class Collembola, the round-bodied Neelidae being separated from the Arthropleona in their own order Neelipleona. However, lack of information prevents the construction of a phylo-genetic tree. Of the extant families, the largest and most common are the Hypogastruridae, Neanuridae, Onychiuridae, Entomobryidae, Isotomidae, and Sminthuridae.

Order Arthropleona

Superfamily Poduroidea

The HYPOGASTRURIDAE (580 species) are generally 1-3 mm in length, whitish, pinkish, or darkly colored Collembola with a predominantly holarctic distribution. They have an obvious prothorax, a granular cuticle, and short antennae, but a postantennal organ may or may not be present. They are found in a wide range of habitats though most species live among decaying vegetation, in soil, in cracks in the bark of trees, or in fungi. Some hypogastrurids are known as "snow fleas" through their being found, sometimes in immense numbers, jumping about on snow, usually shortly after a period of mild weather. One widely 117

distributed form, Hypogastrura (Ceratophysella) denticulata (likely a complex of several

species), sometimes becomes a pest in mushroom cellars. hexapods

The majority of NEANURIDAE (1160 species) are found under stones and bark, or in soil and leaf litter where they feed on fungal hyphae that they pierce with their sharp mouthparts. Other species, however, are predaceous, eating rotifers, other Collembola, and their eggs. ONYCHIURIDAE (600 species) are soil- and litter-dwelling collembolans that lack ocelli and a furcula.

Superfamily Entomobryoidea

The characteristics of the ISOTOMIDAE (over 1000 species) are highly varied, and future work may well result in its being subdivided into several additional families. Isotomids are found worldwide, in a range of biomes, including the polar regions, arid areas, and seashores, though many are conventional inhabitants of soil or leaf litter. Many species, especially the soil dwellers, are cosmopolitan. The family ENTOMOBRYIDAE (Figure 5.1B), with 1365 species, includes many of the larger Collembola that reach 5 mm or more in length. Species have a greatly reduced prothorax and a smooth cuticle; a postantennal organ may or may not be present. They may be found in soil or leaf litter, under bark, in moss, and on vegetation. Some species are naturally cosmopolitan, and others have been transferred around the world by human activity.

Order Neelipleona

The approximately 25 species in this order are included in a single family NEELIDAE. These tiny collembolans (0.5 mm or less long) live in soil and leaf litter. They differ from Symphypleona in that their rounded body is formed from expansion of thoracic rather than abdominal segments.

Order Symphypleona

Superfamily Sminthuroidea

Most of the 890 species of SMINTHURIDAE (Figure 5.1A) are 1-3 mm in length and have a roundish body, hypognathous head, and conspicuous ocelli. A postantennal organ is absent. Often there is sexual dimorphism, with the antennae of males having hooks and spines. Most sminthurids are epigaeic, living near the surface of leaf litter, or on grasses or other low-growing vegetation. A number of species are economically important. For example, Sminthurus viridis, the lucerne flea, a European species introduced into Australia, has become an important pest on alfalfa (lucerne) and other leguminous crops. Other species may do considerable damage in greenhouses and to many garden vegetables at the seedling stage.

Beekeeping for Beginners

Beekeeping for Beginners

The information in this book is useful to anyone wanting to start beekeeping as a hobby or a business. It was written for beginners. Those who have never looked into beekeeping, may not understand the meaning of the terminology used by people in the industry. We have tried to overcome the problem by giving explanations. We want you to be able to use this book as a guide in to beekeeping.

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