Species of the week: Tegenaria spp.

Figure 1. Tegenaria domestica

Tegenaria Spp.

Domain: Eukarya

Kingdom: Animalia

Phylum: Arthropoda

Class: Arachnida

Order: Araneae

Family: Agelenidae

Genus: Tegenaria 

Species: domestica(Figure 1), atrica, gigantea, parietina and saeva. (This is a list of the UK tegenaria species and is also worth mentioning that not all of these are considered part of the Tegenaria genus but have in fact been moved to a new genus Eratigena).

          Of all the spiders in the UK nothing strikes as much fear in people scared of spiders as the Tegenaria spp. do. They are one of the largest species in the UK and are very common in the household as that is their preferred place of residence. The fear of this spider comes from it's menacing look, large size, its fast speed and the fact that it invades our private residences but despite this they are a relatively friendly species. The only species that they are associated with is T. agrestis, also known as the hobo spider (Figure 2), which in the US it is considered a dangerous species but on closer inspection it is more likely that bites from the hobo spider are actually caused by Loxosceles reclusa, also known as the brown recluse spider (Figure 3). Unlike Tegenaria spp. the brown recluse spider can have a potentially fatal bite. Although the bite has no fatal effects it has been reported that in very large specimens that when they have bitten (Which is rare) that it felt like a pinch with a very small amount of localised swelling.

Figure 2. The hobo spider Tegenaria
agrestis

Figure 3. The brown recluse spider
Loxosceles reclusa

Where to find them:

          As a lot of the people in the UK will know the Tegenaria spp. as the big hairy spider that tries to live in the house with them, this isn't an entirely accurate description of where they live though. Most of the species in the UK tend to live in less used buildings, such as sheds, where they can build a web that isn't going to be destroyed quickly. In the shed they are usually found in corners where there is a crevice that can take them out of view.

 Tegenaria domestica:
          This species is more reliant on peoples homes as it requires the heat for it to survive, especially across the winter period, but it can still be found in cave entrances and in hollow trees and produces the largest web of the five species. This is the most commonly found of the Tegenaria spp. in the UK and attains the smallest size of a body size of 10mm.

Tegenaria gigantea/duellica:
          This species is less reliant on peoples homes but can still be found in them, it tends to live more in out buildings, and in the outdoors in general. This species tends to be found in the southern half of Britain and attains a body size of 18mm.

Tegenaria saeva:
          Essentially this spider is the same as T. gigantea but instead of being found in the south it is found in the northern and western parts of Britain.

Tegenaria parietina:
          This is another species that tends to hang around outside. This species is the largest with a body size of 20mm and can be found across Britain. Because of its large size it is considered to be a nightmare spider by some.

Tegenaria atrica:
          This spider is the same as T. parientina only it is less common and tends to be slightly smaller with an average body size of 18mm.

Web type:

          Tegenaria spp. are a type of funnel web making spider (not to be confused with the Sydney funnel web spider) that makes a tubular web in small crevices and behind walls and furniture. The tubular web then flows into a sheet web that is generally in a triangular shape with a few loose strands trailing off at the end. The strands serve a warning that prey is approaching on the sheet web where the spider will then run up and inject it's prey to immobalise it before dragging it into its funnel to feed on.

Lifespan:

          The lifespans of the Tegensaria spp. are very similar with the male living till mating and after a couple of weeks dying off with the female usually using him as a food supply. The female is able to live for several years and can lay multiple egg sacs a year up until she dies.

Mating:

          Mating time occurs in the Autumn and is the reason you find so many of these spiders in the house during the Autumn. This is because the male goes out in search of a females web in order to mate with her. Once he has found the web he will proceed to find the female in her funnel where he will then produce a packet of sperm, in his pedipalps, to wipe on her epigyne, which is then stored in the sperm receptacle and can be used for the rest of the spiders life. After this exchange the male may then stay in the web with the female or it will wonder off but ultimately it will die after a couple of weeks.

Figure 4. The white egg sac pulled out from its dirt and debris
cover than can be seen in the top left.

          After mating the female will wait until April (Spring) to lay her eggs in an egg sac made of a special kind of silk. These egg sacs are quite interesting in that the female will use dirt and debris to cover the egg sac (Figure 4) so that predators don't recognise it as anything more than a ball of dirt. Online it says that the eggs will hatch around midway through April, from my personal experience though they will hatch from anywhere between 15 and 25 days. 

          After hatching the babies are free to leave the web and go start their own lives. It takes less than a year, and several moults, for them to reach an adult size but the males tend to not mate until there second Autumn.

Feeding:

          Mostly Tegenaria spp. will feed on anything that creeps into its web and triggers the outer trip strands. In a captive environment I have had great success on feeding them with crickets and locusts with the occasional meal worm, but I have these from keeping pet reptiles if you don't have access to captive live food then you can just as easily use other insects from the garden.

Captive care:

Figure 5. My Tegenaria spp. set up with my female Tegenaria
gigantea feeding in the front.

          These species are very easy to keep. I use a smallish plastic faunarium with some sort of cave to be used for a funnel web and a sheet web across the rest of the tank (Figure 5); I then provide twigs and dried leaves to give it a more natural feel to it. I feed the spider about once a week as more than that will make it fat and can reduce its life span. Water isn't necessary in the tank as the spider can get all of its hydration from the insects that it feeds off of. If the spider is young when you get it, or from a previous spiders egg sac, then it should be kept in a smaller environment as it may not be able to find its food, with the size being upgraded every couple of sheds. The food should also be around the same size as the spiders body as any bigger may cause damage to the spider.

I hope this article has helped or taught you something new.

Thanks for reading,

Heyze.