Arachnids spider

Kovoor, J. (1987). Comparative structure and histochemistry of silk-producing organs in Arachnids. In Ecophysiology of Spiders (W. Nentwig, Ed.), pp. 160-186. Springer, Berlin, Heidelberg, New York. 

Table 13.1 Venomous arachnids (scorpions, spiders, ticks)...

Arachnids (scorpions, spiders, and ticks) Scorpions Stinger - neurotoxin, no enzymes Localized pain, mostly dangerous to children... 

Schuster et al. (21) identified cotton plant resistance to the two-spotted spider mite (Tetranycus urtlca Koch) by mass screening seedlings. Later Schuster and Lane (22) were able to show that high tannin lines, particularly TX-1055, showed resistance to this arachnid and the bollworm. 

Spiders are an important order of carnivorous arachnids having a great impact on many ecosystems. Because most of their prey consists of insects, they can play an important role in controlling pest insects in agricultural crops. There are currently about 36000 described species, out of an estimated overall number of 60000-80000 species (Platnick, 1999). Unlike the situation with insects (Francke and Schulz, 1999), pheromones and other semiochemicals of arachnids, and especially spiders, have received little attention from researchers. What information is available on the use of semiochemicals by spiders will be reviewed and discussed in this chapter. 

Chemical cues from spiders are also used by non-arachnid predators to locate their prey. For example, the ichneumonid wasp Gelisfestinans parasitizes the spider Erigone atra, which lives in wheat fields. Contact with the silk of its host elicits increased searching behavior from the parasitoid, whereas contact with silk from other spider species does not, indicating a high degree of specificity (Baarlen et al.,... 

In Chapter 16 Trabalon and Bagneres present an overview of non-insect contact pheromones with emphasis on long-chain hydrocarbons and derivative compounds in Arachnids. Apart from studies on spider and scorpion venoms, the first semiochemical studies in these... 

Most of the present book is dedicated to one class of Arthropoda, the Insecta, because chemical communication research in this class is the most complete and broadly illustrated. This type of research on the chelicerate arthropods of the class Arachnida is, by contrast, poorly developed. We saw for example in Chapter 7, studies of chemical ecology interactions with Acari and particularly mite-insect interactions, and a few examples of chemical interaction with spiders were also shown in the same chapter on chemical mimicry, even though spiders are the most familiar and numerous of the arachnids. We undertook some work and about 15-10 years ago on contact chemical signal description and its relationship with behavior, physiology and reproduction, in different types of Aranea (spiders). We will present here a distillation of this work with a review of studies on the subject by different authors. Most notable here is the poverty of research on contact recognition signals and relative behavioral works on the order Scorpionida, the scorpions. Some of the few chemical data available are published here for the first time. 

From the viewpoint of zootaxa, the silkworm and the spider belong to insect and arachnid of arthropod, respectively. Their silk proteins (fibroin for silkworm silk and spidroin for spider major ampullate silk) do not have any genetic heritage in common and their amino acids sequence compositions are different too. However, the silkworm and spider employ a similar spinning process to produce silk. Furthermore, the silkworm silk and the major ampullate silk have a number of similar structural characteristics, both at the level of the secondary protein structure and the condensed silk morphology. Therefore, for the sake of convenience, they are discussed together in some parts of this text. 

Another prominent class of arthropods that contains parasitic species is the arachnids. Though this group is more commonly known for spiders and scorpions, its parasitic members include ticks and mites. 

The hairpin-like structure has been conserved in the course of evolution, since it was found in many peptides isolated from various classes of arthropods, such as the primitive horseshoe crabs (tachyplesins [110,111] and polyphemusins [112,113]), arachnids (androctonin in scorpion [114] and gomesin in spider [115]) insect (thanatin [116]), in two classes of vertebrates, mammalian (protegrin [117,118], lactoferricin B [119] and hepcidins [120]) and fish (hepcidins [121]), and in plants (76-AMPl[122]). 

Anderson EJ (1987) Recognizing the recluse spider bite in children Necrotic arachnidism. The Journal of the Louisiana State Medical Society 139 33-36. 

There are five representative species of the widow spider in the United States. The species are the Black Widow (L. mactans, L. hesperus, L. variolus). Red Widow (L. bishopi), and the Brown Widow (L. geometricus). The five species of Loxosceles documented to produce necrotic bites are L. arizonica, L. deserta, L. laeta, L. reclusa, and L. rufescens. The L. reclusa is responsible for most cases of clinical significance of necrotic arachnidism. 

There is no routine test for the diagnosis of trivial or cutaneous arachnidism. The use of a passive hemagglutination inhibition test has been used successfully to identify venom from Brown Recluse spider bites in animal studies. This test has not yet been used for diagnostic purposes in human trials and is not routinely available to clinicians. 

Sulfate formation has also been demonstrated in a variety of other Invertebrates including spiders, scorpions and ticks (7), although the arachnids appear to possess no alternative glycosTde mechanism for phenol conjugation. 

Sometimes, however, truth is stranger than fiction. A Greek physician had a visit from a patient who developed a strange sensation in her ear while on a motorcycle ride. The physician was shocked to see, inside her ear, a spider s web with a spider ensconced in it, apparently comfortable in its warm surroundings. Recognizing that this was an epic moment, he ran for his video camera and managed to record the arachnid s hasty departure from its new home. 

Spiders. Family name for the Araneae, with more than 30000 species, belonging to the arachnids (Arach-nida), not to the insects. These arthropods, to which the scorpions (see scorpion venoms), mites (with ticks and red spider mites), and also daddy longlegs belong, have 4 pairs of legs (insects only 3), 2 mandibles (chelicera), and 2 maxillary palpi (pedipalpi) as well as 1 -4 pairs of separate eyes. A tube-like poison... 

Descriptions and pictures for all orders of arachnids, plus societies, special spider pages, and even arachnids in literature... 

---