Saints and Sinners

The generalized reputation of any group is always suspect because the actions of a few members can tint or taint the collective perception of all members. Any assemblage has its saints and sinners, but most of those associated are just going quietly about their assigned task.

This concept applies to humans, and also to insects. Wasps are a good example of this precept.

The common view of a wasp is as a habitually irritable flying insect which is seeking any provocation to stinging transgressors who comes into its range. Yellow jackets, one infamous native species of wasp, lead many to this erroneous conclusion.

The Florida panhandle is home to many wasp species, most which go unnoticed by the human residents. The obscurity is likely because there are no recorded incidents of these species stinging people.

Oak Gall Wasps

Oak gall wasps are barely visible at 2 millimeters in length, which is about the thickness of a 50 cent piece. The wasp’s petite size notwithstanding, it is responsible for individual galls which can be nearly a foot in length.

North Florida’s laurel oaks are especially susceptible to a collection of knotty, hard tumor-like growths on twigs and limbs. The bulbous lumps may be few and scattered or come in heavy concentrations.

To the uninitiated these arboreal blisters may appear to be oversized and out-of-place acorns, but are really a fundamental part of this insect species’ reproductive process.

The life cycle of these wasps is not completely understood since they have not been studied extensively. It has been confirmed the sequence begins when the female wasps emerge from twig galls in late spring to early summer.

These females quickly lay eggs on the underside of leaf veins. Small vein galls appear within a few weeks in early summer with male and female wasps quickly emerging from the vein galls.

Twig Galls

Mated females then oviposit eggs in young oak twigs. Twig galls appear in the spring of the following year. Two or more years are required for the immature gall wasps to complete development in the twig galls.

The galls provide shelter, protection, and food for the immature wasps. Inside a gall, the larvae are surrounded by nutrient rich tissues.

As the larvae reach maturity small spines or horns become evident on the gall. An adult wasp emerges from each horn.

Another wasp species which has a distinctive profile is commonly known as the Thread-Waisted Wasp. Ammophila procera, is a relatively large ambush predator which immobilizes insect prey with a swift venomous sting.

Mud Daubers

Its powerful jaws are used to drag the numb victim back to its underground lair. A close relative of Mud Daubers, the Thread-Waisted Wasp builds a similar style of burrow in loose dirt. Inside its structure tunnels or cells are excavated and the paralyzed prey is placed inside.

A single egg is laid on the living, but paralyzed food source. When the egg hatches, the parasitic wasp larva begins slowly consuming its motionless victim, eating nonessential parts first.

By the time the meal is completed, the wasp larva has matured into adult form and flies away from the nest to repeat the process.

Adults drink nectar and feed on small insects they catch in the open. Since many plant-consuming caterpillars are taken as larvae food, this insect could be considered beneficial to gardeners and farmers.

They are not known to be aggressive toward humans, though stepping on or rough handling may result in a defensive sting.

Generalizations aside, it is safe to say Florida’s many habitats have a wasp suited to live in each. Only occasionally are stings to people a confirmed threat.

To learn more about north Florida’s wasp population, contact the local UF/IFAS County Extension Office. Click here for contact information.

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