Thread-waisted Wasps

Sphex sericeus

Sphex sericeus is a species within the genus Sphex, commonly known as the thread-waisted wasps, part of the family Sphecidae. These wasps are known for their distinctive slender waists and their solitary nesting behaviors. Sphex sericeus, like other members of its genus, features a pronounced “thread-waist,” which is a very narrow constriction between the thorax and abdomen. This physical trait gives them a striking appearance and aids in their flexibility and agility. They are typically medium-sized wasps with robust bodies and strong flying abilities.






















Sphex sericeus

Other Information


Sphex sericeus is venomous, using its sting to paralyze prey, specifically for provisioning their nests for the larvae. The venom effectively immobilizes insects, ensuring that the food source remains fresh for the developing larvae.

A Danger to Humans?

While venomous, Sphex sericeus is not considered dangerous to humans. These wasps are generally not aggressive and sting only when threatened or handled directly. Stings can be painful but are typically not harmful unless an individual is allergic to wasp stings.

Population Status

Specific population data for Sphex sericeus is not widely documented. However, species in the genus Sphex are commonly found across their range in suitable habitats, suggesting that they likely maintain stable population levels where environmental conditions are favorable.

Thread-waisted Wasps (Sphex sericeus), Photo by David Lowenthal

Life Span:
The life cycle of Sphex sericeus, from egg to adult, is typically seasonal. Adults usually die after completing their reproductive duties, with new generations emerging the following season.

Weight and Length:
Sphex sericeus, like many wasps in its family, is likely to be relatively large, often reaching lengths of 20-30 mm. Exact weight is generally minimal and not commonly noted due to the small size of these insects.

The distribution of Sphex sericeus can include various regions where climates support their life cycle and behaviors, though specific geographic data might vary. Members of the genus Sphex are found in diverse environments from temperate to tropical regions.

Habits and Lifestyle:
Sphex sericeus is a solitary wasp, with females individually constructing and provisioning nests. These nests are typically burrows in the ground, where the female wasp places paralyzed insects and lays an egg on each.

Diet and Nutrition:
Their diet primarily involves hunting various insects, which they paralyze and store as live food for their larvae. The adults may feed on nectar from flowers.

Mating Habits:
Mating in Sphex sericeus usually occurs shortly after emergence, with males typically seeking out females to mate. After mating, females focus on nest-building and provisioning, while males do not participate in care for the offspring.