|Only the males of the Eresus sandaliatus species are so brightly colored|
Ladybird spiders like to live in sheltered areas, creating burrows that they line with silk. Silk is also radiated out from the burrow to act as a sort of tripwire. If prey touches the silk, it signals the spider to attack. They feed on various species, including some sizable species of beetle. Females don't leave their burrows much, so as you can imagine this could make life somewhat difficult for the males. When out searching for a female, they have to pluck at the females' silk threads to let her know they aren't prey and avoid being eaten.
The species is European and their numbers aren't great, to the point of them being Endangered in the United Kingdom. Times were tough in the 1990's when it was believed only fifty of these spiders were left in Britain. Captive breeding and other conservation actions have done a lot, and now there are around six hundred wild spiders.
Source is ARKive. Image is from Wikimedia Commons under a Creative Commons license.