Spider of the Year 2006
The flower crab spider
Misumena vatia (Clerck 1757)
The first European Spider of the Year, chosen for 2006, is the flower crab spider – Misumena vatia (Clerck 1757). Like all crab spiders, Misumena has crab-like legs rotated onto their sides, which give the family its name. The front legs are longer than the back legs. It differs from other European species by its ability to change colour from yellow to white.
Biology and maturity time
The flower crab spider is, like other members of this family, a sit-and-wait predator. It mostly lurks among flower petals waiting for insects to fly by. With the small back legs the spider holds itself steady. The front legs, which are held outwards, are much more powerful, and grab an unsuspecting flower visitor with amazing speed, while at the same time a poisonous bite is administered. Prey is mostly eaten on the flower and is sucked dry through tiny holes, such that an almost complete exoskeleton is left over.
Flower crab spiders are, thanks to their ability to change colour, wonderfully camouflaged on both white and yellow flowers. This active process can only be carried out by adult females and takes a couple of days to complete. Scientific studies suggest that this camouflage makes the spiders hard to see; both for their prey and for potential predators.
Mature spiders can be found from May to July. The much smaller males mate with females in early summer, spending some time on the abdomen of the female and hanging from the underside of it during the mating process. The egg sac is typically hidden between leaves, woven together with silk. Juveniles over-winter in leaf litter and develop to adulthood in the following year.
Habitat and distribution
Typical habitats are open spaces like meadows, moors and fields, but also sunny paths and forest margins, wasteland and gardens. In the UK the species seems to be occurring exclusively in the southern parts. Reports from all regions (with pictures) are very welcome (see the contact address below). In Europe Misumena occurs from Scandinavia to the Mediterranean. It its also found in northern Asia and North America. The other 40 plus species of the genus Misumena occur in the tro and subtropical regions.
Characteristics and similar species
Only mature females show the strong yellow or white colour. Besides these two variants, all sorts of intermediate forms with green–white tones can be found. Additionally, red stripes on the abdomen can occur. The cephalothorax has two dark stripes on the upper side. The much smaller male has a dark brown cephalothorax and dark forelegs, while the back part of the body is yellow with a dark patterning. There is one other species in Europe which can also actively change its colour: Thomisus onustus. Here the range is larger and can go from white to yellow to violet. Furthermore, Thomisus can be identified by two humps on the abdomen and slightly raised lateral eyes. Juvenile Misumena have a greenish colour, since they tend to sit on green plant parts or leaves. Thus they can also be potentially confused with various green crab spider species such as Diaea dorsata, Diaea pictilis, Misumenops tricuspidatus, Heriaeus mellotei and Heriaeus graminicola. Thanks to its bright colour and its variability Misumena vatia has been described under more than 20 different scientific names! Only modern taxonomy and the recognition of relevant characters for working out relationships revealed these synonyms.
Derivation of name
Genus name: μισούμενος [misúmenos] (greek) – hated; μισέω [miséo] (greek) – to hate
Species name: vatius, -a, -um (Latin) – bent outwards (i.e. with bent legs)
European Spider of the Year – ESY
Since 2000 a group of experts from Germany, Austria and Switzerland have chosen a spider species for a year to be the focus on interest. After the water spider (2001) came the wasp spider (2002), the nursery web spider (2003), the green huntsman spider (2004) and the zebra spider (2005). While the project began in the German-speaking countries, Belgian and Dutch colleagues joined in 2005. For 2006 a proper European project was organised for the first time. Thus Misumena will represent spiders from Scandinavia to the Mediterranean and from Ireland to Hungary, and should show the fascinating side of these very useful animals.
Peter Jäger, Martin Kreuels & Jason Dunlop
Contact for Europe
Mr. Peter Smithers, 147 Molesworth Road, Stoke, PLYMOUTH, Devon. PL3 4AJ, E-Mail: P.Smithers(a)plymouth.ac.uk
71 jury members from 21 countries:
Austria, Belgium, Bulgaria, Czech Republic, Denmark, Finland, France, Germany, Great Britain, Hungary, Ireland, Italy, Netherlands, Norway, Poland, Portugal, Sweden, Switzerland, Slovakia, Slovenia, Spain.
ARABEL – Belgische Arachnologische Vereniging (link)
BioNetworX – Münster (link)
ARAGES – Arachnologische Gesellschaft (link)
ESA – European Society of Arachnology (link)
GIA – Grupo Ibérico de Aracnología (link)
SPINED – European Invertebrate Survey-Nederland (link)
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