Succulent Oak Gall Wasp – Andricus palustris

Succulent Oak Gall Wasp (Dryocosmus quercuspalustris) Latin Name: Dryocosmus quercuspalustris Common Name: Succulent Oak Gall Wasp Appearance: Egg: The eggs are placed on the buds or leaves of oak trees. Larva/Nymph: Larvae produce galls with their salivary secretions as they hatch; the larvae grow, pupate, and emerge as adults inside the galls. Adult: Adults are around 4.5 mm long, with a characteristic body form known as the “wasp waist.” The first abdominal segment connects to the thorax, while the second form the “waist” shaft, which all wasps share. – Body is dark-brown to black in hue, with three pairs of light-colored legs, long antennae, and transparent wings. Hosts plants:  Pin oaks and other oaks.  Territory: Throughout much of the southeast United States, its host plants are found. Damages caused by succulent oak gall wasp: This wasp makes galls on the plant host, which the hatching larvae consume. Galls are swellings or aberrant plant growths formed of plant tissue. Plants are to blame for these bizarre malformations. The larvae and, most likely, the eggs release growth-regulating compounds or stimuli. Insects that produce galls are not harmful to the plant, but heavy infestations can reduce the plant’s aesthetic appeal, cause leaf and stem formation, and even cause premature leaf drop. Description about Leaf chewers: Insect chewing damage to plants can take several forms. Foliage or flowers may vanish when certain insects eat them. Occasionally, the plant will appear ragged and, upon closer inspection, will reveal bitten edges or cores. Plants can be cut at the root and topple over, or twigs can be girdled and die as a result. Mining or boring is the process of causing harm to a plant through chewing. Only the upper or lower portions are sometimes destroyed, producing a brown, burned look or skeletonization (openings between the veins). Life History and Habits: Legions of small nymphs feed within the gall after hatching, ultimately developing into winged forms. Galls crack apart in late May, allowing winged phylloxerans to emerge and migrate to the underside of leaves, where they lay hundreds of eggs. The galls on pin oaks were started earlier in the year when a female wasp “stung” the leaf, as in the case of the slight spherical galls. The process of egg-laying and the chemicals secreted by the wasp’s larva trigger the growth of plant cells that form the gall, albeit the details are hazy.