Arachnida, class spiders

Phylum Arthropoda is the largest phylum in the animal kingdom. Most of the species are nontoxic. However, Class Arachnida contains spiders. Arach-nidism means envenomation from a spider. Most spiders are venomous however, the black widow, brown recluse, and hobo spiders are responsible for a significant number of toxicity events in humans, so these will be discussed in more detail. 

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. 

Recently, oribatid mites (arthropods that, such as spiders, belong to the class Arachnida) were shown to also produce many of the bicyclic ant alkaloids described in this section including twenty-five 5,8-disubstituted or... 

---