Grey Cross Spider

L. sclopetarius exhibit a slight sexual dimorphism, where females are heavier than males. Females typically weigh around 60 mg, whereas males weigh around 38 mg. However, males may be slightly larger than females. Females can range from 4.5- 6.25 mm in length. Males vary from 4.25 mm -7 mm in length. L. sclopetarius differs from its close relatives, L. patagiatus and L. cornutus, with a few defining characteristics. Unlike the latter two species, L. sclopetarius has white hairs that provide a silhouette for their heads and dark markings on its abdomen.

In North America L. sclopetarius is most common in the Great Lakes states, but can be found throughout the country. It is mostly found near buildings. L. sclopetarius is also found in Central Europe, often near water. They are also most commonly found near artificial sources of light near water bodies such as bridges and boats. They often aggregate in high densities near light sources. The lights tend to attract more insects which increases the spider's prey capture. Their light-seeking behaviors may have some genetic basis. In these feeding-locations, adult females tend to occupy the best foraging areas. Juveniles and immature spiders are relegated to worse feeding areas when competition is high. These behaviors may be observed because juveniles are unable to compete for better territories. However, when these spiders mature, they often search for more illuminated areas to create their webs and lay their eggs.

These spiders are primarily nocturnal foragers. Their prey capture fluctuates with the seasons. Their prey capture is highest in the summer months, declining in the spring and fall. Chironomids consist of a significant portion of their diet. These small flies may comprise up to 94% of the spiders' diets. Their prey's average size ranges from 1.2 to 6.8 mm.