Catch of the Week: Iowa Orb Weavers

November 18, 2016

Over the past week, we received this picture of an orb weaver spider from one of our customers. Orb weaver spiders are distinctive due to their brightly colored appearance. The most common time to see these little critters is in late summer and early fall when the adult orb weavers have grown to their biggest size and constructed an abundance of webs.

Orb Weaver Appearance 

There are a variety of orb weaver spider species, which can make it difficult to distinguish them from each other. However, what sets orb weaver spiders apart from other spiders is their brightly colored appearance. Orb weavers have eight hairy or spiny legs, a fused-together thorax and head, and a large abdomen. The majority of nocturnal orb weavers are gray or brown in color, whereas diurnal (awake during the day) species are a bright yellow or orange color with black markings.

Orb Weaver Behavior and Diet 

Orb weaver spiders are typically nocturnal and are known to do most of their web building in the evening. Some species of orb weaver spiders possess an interesting habit of tearing down their webs silk when morning begins to dawn to avoid the moisture from dew that prevents prey from getting caught in their web. Orb weaver spiders consume small insects such as beetles, wasps, mosquitoes, flies, and moths. Typical orb weaver habitats include areas around tree branches, outdoor lights, walls, bushes, and fences.

Orb Weaver Fast Facts 

• Female orb weaver spiders produce one or more egg sacs, with each sac containing upwards of several hundred eggs.

• There are approximately 180 species of orb weaver spiders.