Tigrosa helluo

In the United States, T. hellio can be found in a large variety of states, in woods, marshes, and even grassy areas in northeastern states such as Connecticut. Females' nests are often found under stones or boards in fields and woods.[5] These nests consist of burrows lined with silk.[6] However, in states like Florida and Mississippi, T. helluo can most often be found in wetter areas such as marshes and lakes.[2]

Tigrosa helluo can be found throughout the United States, Canada, and Mexico. They primarily reside along the east coast in the New England region but can be found along the entire east coast down to Florida. T. helluo resides in most states in the eastern half of the US. They can be found as far west as Kansas and Nebraska.[2]

Tigrosa helluo is sexually dimorphic. In this species, the two sexes dramatically differ in size, with mature females being larger than males. Typically, females will grow to weigh more than 300 mg with carapace widths of around 6.5 mm while males will usually only weigh in excess of 200 mg and have carapace widths of around 4.5 mm.[9]

Like many other wolf spiders, T. helluo will engage in precopulatory and post copulatory sexual cannibalism. The frequency at which females participate in sexual cannibalism depends on a variety of factors. The degree of sexual dimorphism between two spiders has been shown to have an effect on the occurrence of sexual cannibalism. Males who are smaller are more vulnerable to larger females and therefore are more likely to be cannibalized. The larger the degree of size difference between the male and female, the more likely for sexual cannibalism to occur. Thus, sexual cannibalism in T. helluo can be viewed similarly to a predator-prey interaction where size difference affects their actions. Another factor that impacts the degree of sexual cannibalism for T. helluo is the female condition. Females who have been starved and therefore are hungry are more likely to cannibalize than females who are well-fed. It is possible that males can maximize their fitness by only mating with well-fed females. The male condition can also affect the possibility of sexual cannibalism. Older males or males in poorer condition, while they might not be very small, are more vulnerable to females. Therefore, they are more likely to alter their copulatory behavior depending on their perceived risk of being cannibalized. These males can invest more into a single copulation by engaging for longer because they are at a high risk of being eaten after mating.[10]

The process of copulation for T. helluo consists of a series of interactions between the male palp and the female epigynum. First, the male will mount the female such that they are facing opposite from each other. The underside of the male's cephalothorax is positioned against the dorsal section of the female’s abdomen. The male then will signal the female to rotate the abdomen by touching the anterior of the female abdomen. After this, the male will use his palp to engage with the female’s abdomen and epigynum. The right and left palps will interact with the right and left sides of the epigynum. After the palp and epigynum are engaged, the male will expand his hematodocha, causing his embolus to enter the female copulatory duct. Semen is then exchanged. This interaction is called an insertion. During a single insertion, the male may also expand his hematodocha multiple times. However, it is often only a single expansion per insertion. T. helluo will also engage in more than one insertion per copulation. Usually, one insertion will happen per side of the male palp. Copulation for T. helluo will typically lasts around 8 minutes.[11]

Wolf spiders typically eat different kinds of insects or even other smaller spiders like Pardosa milvina.[12] They are nocturnal so they wait for prey and hunt at night.[13] T. helluo can survive on insects such as crickets, fly grubs, cockroaches, mealworms, and even beetles.[14]

Tigrosa helluo is able to feed on a large variety of prey, and thus enjoys a mixed diet of different insects. A 1992 study assessing the effects of polytypic vs monotypic diets on wolf spiders found that T. helluo individuals raised on polytypic diets had significantly higher survivorship and reached sexual maturity earlier than individuals consuming a monotypic diet. Certain body parts like the cephalothorax and legs were also significantly larger at maturity in the polytypic diet group.[14]

A 1999 study examining the effect of feeding on burrow construction for T. helluo reported that hunger level significantly impacts T. helluo’s behavioral decisions. In comparison to starved spiders, well fed individuals had a better nutritional state and made significantly more burrows. Since males do not make burrows, they were not included in the study.[15]

Tigrosa helluo typically switch between a few different foraging sites. Females build burrows of silk and wait for prey to show up in their current foraging site. Males typically roam around and wait for prey. Like all wolf spiders, T. helluo are solitary hunters and will hunt alone, only meeting with other spiders to mate.[14]

A 2001 study examining chemical cues in T. helluo suggests that T. helluo is able to detect chemical cues from recently hunted prey. The spiders will show a preference for chemical cues that match that of their most recently hunted prey. Thus, further hunting activities will show a dietary preference for the prey species most recently consumed.[16]

It has also been shown that the presence of glyphosate-based herbicide affects prey capture behavior of T. helluo. In the presence of herbicide, T. helluo is better able to detect and orient itself towards prey and therefore was able to more efficiently subdue prey[17]

While wolf spiders are solitary and don’t usually associate with others outside of mating, communication between individual spiders does occur occasionally. Wolf spiders have some of the best vision out of all spiders, so they use visual cues, such as waving their pedipalps, to signal to each other for mating. They are also sensitive to vibrations, scent, and taste.[13]

Wolf spiders are usually not aggressive and will not bite unless readily provoked. They also possess venom that is injected into organisms upon biting. However, to humans, wolf spider bites are generally considered minor and not medically significant. Bites typically cause minor swelling and pain, but no severe complications. Antivenom is not usually needed to treat wolf spider bites.[18]