Unlike most of the genus Phidippus, P. clarus females die after one brood has left the nest.

In an experiment in 2006, P. clarus showed promise for controlling the fourlined plant bug, Poecilocapsus lineatus, which severely damages the commercially grown sweet basil.

[2]: 61  It lives among flowers, often sharing habitats with the small to medium-sized crab spider Misumena vatia,[7]: 4 [7]: 278  which waits for prey.

[11]: 147 P. clarus, which is large by the standards of salticids, takes prey up to the size of an adult earwig.

[13] Phidippus clarus becomes adult in early summer,[7]: 278  and females about to lay eggs can weigh 400 milligrams (0.014 oz).

[6] By August, most females live in their nests overnight for increasing periods, as this is where they will lay eggs.

[1] Like other spiders and many other arthropods, P. clarus can vibrate surfaces to interact with others of its species, sometimes in conjunction with other communications such as movements, to intimidate rivals and who mates.

[6] One mated female P. clarus can lay well over 100 eggs per sac in a thick silken cocoon.

[11]: 136–137 Competitions between P. clarus males occur on leaves up to 5 cm (2.0 in) long and wide, and the prize is the right to cohabit in the nest of a sub-adult female who is about enter her last molt and become fertile.

Some of these contests escalate to grappling, in which males lock chelicerae (jaws) and legs for relatively longer periods.

However, the weights of the contenders has the most influence, and experience makes a difference only between individuals of similar size.

The female rejects the male by extending her first pair of legs whenever he approaches too closely, or shows acceptance by not blocking his advance.

The turn exposes her genital pore, which lies on the underside of the abdomen, and the male inserts one semen-laden pedipalp.

[18] In an experiment in 2006, P. clarus showed promise for controlling the fourlined plant bug, Poecilocapsus lineatus, which severely damages sweet basil, Ocimum basilicum, a herb commercially grown in greenhouses.

Although cannibalism is likely to prevent mass rearing of P. clarus, it is possible to collect egg sacs or spiders and move them to where they are needed.

Juvenile and adult jumping spiders can be collected via sweep netting or by providing good sites for nests, even in plumber's tubing placed in old fields.