The tiger spider (Scytodes globula) is a spider of the suborder Araneomorphae of the Scytodidae family. They are also known as "spitting" spiders because, as a hunting method, they "spit" a sticky substance that directly affects the mobility of their prey..
Like other scythoid species, the tiger spider is strongly associated with the human environment, being considered a synanthropic species. Their activity is preferably nocturnal, so it is difficult to locate them during the day.
S. globula uses its front legs asymmetrically during prey capture and immobilization activities. This characteristic indicates a certain degree of laterality of behavior in arachnids and an asymmetric use of the limbs..
Many observational experiments both in nature and in laboratories indicate that this species of spider uses legs I and II on the left side more often than on the right..
Due to this, there is a more frequent loss of the legs on the left side either by interaction with prey (some of which may be potential predators) or as a consequence of predators as a defense method by autotomy..
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The tiger spider shows a high degree of tolerance with members of the same species, so it is common to register several specimens that are close to each other. In their foraging activities, the initial catalyst to initiate prey capture is direct contact.
S. globula it can be distinguished from other species with which it lives in sympatry by having a uniform brown abdomen with scattered dark markings. The legs and pedipalps have a brown color with dark bands.
The plunger in males is markedly curved with a distal denticulation originating at the base of the plunger. Females have on their external genitalia excavations with a crescent-shaped crest that are absent in species such as Scytodes univitatta.
The first two pairs of legs, like other similar species of spiders, are characterized by being longer and having a greater coverage of mechanoreceptors and chemoreceptors than the third and fourth pairs..
The gender Scytodes presents around 173 species worldwide, of which 42 have a neotropical distribution. Many of the species present in some countries such as Brazil have been reassessed and considered as synonymy of more widely extended species such as S. globula, S. univitatta Y S. longipes.
Species like Scytodes maculata, S. annulata, S. scholaris Y S. aguapeyanus are currently synonymous with S. globula.
The tiger spider is widely distributed in South America, specifically in countries such as Brazil, Chile, Bolivia, Argentina and Uruguay. Based on this, it has been pointed out that S. globula it is exclusive to the south.
This species prefers cold and humid habitats, which is consistent with its wide distribution in the countries mentioned above. Geographical areas with higher temperature and humidity constitute an important geographical barrier for the species.
In natural ecosystems, it is found in a wide variety of forests and grasslands, either on vegetation or under logs, and even at ground level among leaf litter. In addition, it is a species that tolerates human intervention well and can occupy cracks in walls, walls and other human constructions such as refuges and hunting grounds..
Currently in many of the distribution areas it overlaps with Scytodes univitatta, another more common and widespread species that has been recently introduced in the south, especially in populations of Chile.
Their main hunting method is to "sit and wait." This strategy is to stay close to their shelter and wait for a prey to pass close enough or to make contact, to attack and capture it. In general, they can be observed active at night.
When a potential prey is detected, the spitting spider initially attacks it with a mixture of a viscous substance and venom that it expels through the chelicerae, in a determined zigzag pattern that ends up immobilizing the prey..
After this happens, a second phase of definitive immobilization begins through the use of silk and the fixation of the prey to a substrate to later inoculate its venom and feed on it..
These spiders use only the first and second pair of legs for immobilization activities of the prey. They can consume a wide variety of invertebrates including Lepidoptera, Diptera, Coleoptera, and even other spiders and groups of arachnids such as Opiliones..
Scytodes globula tends to occupy microhabitats with particular characteristics of humidity and temperature that are also used by species of greater medical importance such as those belonging to the genus Loxosceles. On multiple occasions, observations of S. globula predating specimens of Loxosceles laeta.
These observations have indicated a certain tendency to S. globula due to arachnophagia, although it has not been demonstrated as a common and corroborated trend. Generally these interactions can result in the death of one of the two spiders, since L. laeta it is also capable of preying on S. globula.
In addition, the predation of S. globula about spiders of the genus Loxoceles interesting as a measure of control of the populations of L. laeta around human settlements affected by the high incidence of loxocelism.
Few reproduction data are available on this species of spider and on the Scytodidae family in general. Females are usually larger than males and sometimes during reproductive events they can kill and feed on them..
The abundance of this species compared to L. laeta indicate that the progeny is usually short for each female. On the other hand, there is little data on juveniles and their presence in the diet of spiders such as recluse has also been indicated..
In other species of the genus Scytodes, females respond to pheromones produced by the male. This determines the selection of the male to reproduce because through the use of these chemicals transmits information about their reproductive status and general condition.
The female chooses the male in better condition. The choice of the male is correlated with the production of larger and heavier egg sacs, as well as with greater fertility and fecundity in the female..
On occasion, the females of Scytodes They can feed on the egg sac, however, the typical thing is that they take care of the egg sac by loading it in their chelicerae or hanging them on their net.
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