Tarantula Hawk

Photo of the Tarantula Hawk

Tarantula Hawk, Spider Wasp (Eng.), (no common Sp. name), Pepsis marginata (Sci), native species, Puerto Rico archipelago.

Photo © www.flightglobal.com. Information compiled by Alan Mowbray, Interpretive Media Writer, EYNF/LEF

General Information

Taxonomy: Class – Insecta, Order –  Hymenoptera, Family – Pompilidae, Genus – Pepsis, Species – P. marginata. Native species of spider wasp that preys upon tarantulas to feed its larvae.


P. marginata can be easily recognized – it typically measures up to 2 inches (50 millimeters) in length – the female’s stinger can measure up to 1/3 inch (7 millimeters). The legs and body are a velvety-black in color while the abdomen is black with a blue reflection in certain lighting. It has orange-yellow wings with dark margins – the antennae of the male are tightly curved while that of the female is only slightly curved. Its long legs have hooked “claws” to assist in grasping prey.


Tarantula wasps are "nectarivorous", consuming juice from fruits and berries.  Their consumption of fermented nectar will occasionally intoxicate them to the extent that flight becomes difficult. While P. marginata wasps have been observed to be most active in the daytime during summer months, they tend to avoid very high temperatures. The male does not hunt; instead, it feeds on flowers and exhibits a behavior called “hill-topping", sitting atop tall plants while watching for females that are ready to reproduce.

Female Tarantula Hawks hunt Tarantulas (Cyrtopholis portoricae) – they prefer female tarantulas, because male tarantulas are typically emaciated from ignoring food while they search for females. They seek females in their burrows, capturing, stinging and paralyzing the spider, dragging the prey back to their own burrow, or to a specially prepared nest with a covered entrance, where a single egg is laid upon the spider’s body.  When the larvae hatch it begins sucking the juices from the paralyzed, but still living spider. As it grows, the larvae plunges deeper into the spiders body, feeding voraciously while avoiding vital organs to keep the host fresh. Eventually, an adult Tarantula Hawk wasp emerges from the nest and the life cycle begins once again.


P. marginata is found in many locations from the island’s coastal plain to forests at elevations near 3,000 feet (900 meters) and in abandoned coffee plantations.

Where to look for this animal in the EYNF

This insect is rarely seen, but the results of its hunting prowess – a tarantula with larvae feeding on it may be occasionally encountered near one of the Forest’s many nature trails.