Antistrophus sp.
Desert-chicory stem gall wasp

Host: Tuberous desert-chicory (Pyrrhopappus grandiflorus).

Gall location: On the stem, apparently often in the top half. Multiple gall clusters may be found along the same stem.

Description: These galls are somewhat variable, but they typically appear as clusters of single-chambered, rounded galls around 0.5 centimeters in diameter. Green and fleshy when fresh to rough and brown when dried and old. Sometimes solitary rather than clustered.

Range: This species has been reported only from Oklahoma and Texas.

The host plant is also known from Kansas and Nebraska; further sampling may locate this gall in these states. This gall is induced by an undescribed species that may prove to constitute an entirely-new genus of herb gall wasp. Little is known about this species, as it was first found in the late 2010s and was first identified as an undescribed species in 2022.

- Louis Nastasi, Charles Davis: (2022) Field Guide to the Herb and Bramble Gall Wasps of North America^©