Theridiidae

Comb-footed spiders (1)

ARACHNIDA > ARANEAE > Theridiidae > Enoplognatha, Parasteatoda, Cryptachaea and Theridon

Theridiidae is a large diverse family of 58 species in 25 genera of which half are categorised as being either rare or scarce. Whilst they are collectively known as 'comb-footed spiders', the name isn't particularly useful to the casual observer as the feature is barely visible.

At present my current observations are limited to just six species.

First up are the 'candy-striped spiders' that have three colour forms; two with red markings, form redimita with a pair of red longitudinal bands, and form ovata with a single broad abdominal band which covers most of the dorsal surface; the other is lineata, which is regarded as the more common form, where the abdomen is completely yellowish-white with two lateral rows of black spots and/or merged markings. I've labelled both of the individuals below as Enoplognatha cf.ovata purely on the basis of pictures I've seen and the fact that it's the more abundant of two very similar species that can only be reliably distinguished from detailed examination. The other is Enoplognatha latimana that seems to be more of a coastal species. An arachnologist would probably correct me, saying that Enoplognatha ovata / latimana would be a better description as many records are confirmed as such. The Enoplognatha genus includes four other clearly different species that don't have the red candy stripe markings.

Unfortunately, the identity of the tiny, immature, out of season Parasteatoda sp. that I found can't be determined at this stage, but it's probably Parasteatoda simulans. There are three species in the genus, all having rather variable colouring and abdominal patterns which, even if this individual was fully developed, could make it difficult to distinguish with certainty. However, each species has different habits and habitat preferences that can help. Parasteatoda tepidariorum can definitely be disregarded in this case, as it's a synanthropic species that's far more likely to be found in heated greenhouses than outside in the middle of winter. However, the other two, Parasteadoda simulans and Parasteadoda lunata, could be confused although, from photos I've seen, the typical forms of each are quite different.

The tiny Cryptachaea blattea spider that I spotted in Ringwood Forest whilst searching for neoliodid mites (as can be seen in the first photo) is really small with a body length of around 2.5mm so very easily missed. Although it's quite distinctive, towards the rear of the abdomen there's a small diagnostic tubercle which is dark anteriorly and white at the back. It's currently listed as an introduced synanthropic species that was first recorded in 2015 and even now, ten years on at the time of adding this update, it's still considered to be rare as there have only been around 170 confirmed sightings. The current status and distribution range remain unclear, but it seems that quite a few records are now coming from woodlands as well as from around buildings

TheTheridon genus includes eight species, three of which are common whilst the others are scarce and/or regional. Microscopic examination is required for formal identification, but from the abdominal markings and the woodland habitat the individual featured below is almost certainlyTheridion mystaceum as the two 'look-alikes' that it's listed with, namely Theridion familiare and Theridion melanurum are mainly found in and around buildings.