Pachodynerus erynnis

The species can be distinguished from the similar Pachodynerus nasidens by its coloration: P. erynnis has red markings on a black background, whereas P. nasidens displays yellow and black banding that mimics the Mexican Honey Wasp (Brachygastra mellifica). The red and black pattern of P. erynnis lacks the extra yellow stripe across the front of the abdomen seen in P. guadulpensis.

Nests in holes or crevices of trees, man-made structures, and abandoned nests of other cavity-nesting bees and wasps. Often found in areas with flowering plants near suitable nesting cavities.

Native to North America. Documented observations span much of the eastern and central United States, with records from Florida and northward through the eastern seaboard and into the Midwest.

Specialized predator of caterpillars (Lepidoptera larvae), including armyworms (Spodoptera spp.), cutworms (Agrotis spp.), and loopers (Noctuoidea). Adults consume nectar from flowers.

Females construct solitary nests in pre-existing cavities, provisioning each cell with multiple paralyzed caterpillars. An egg is laid in the cell, which is then sealed with mud. Larvae develop by consuming the stored caterpillars. Gender control has been observed in related mason wasps, with male eggs placed closer to the nest entrance to facilitate earlier emergence.

Females inspect and clean potential nest sites before accepting them. They hunt caterpillars on flowers, foliage, vegetables, and fruit, paralyzing prey with venom. Multiple caterpillars (up to 19 or more per cell) are captured and stored as larval food. Nest entrances are sealed with mud plugs. Adults are rapid fliers and frequently visit flowering plants, particularly mountain mint (Pycnanthemum) and spotted horsemint (Monarda).

Biological control agent that reduces populations of herbivorous caterpillar pests in managed and natural landscapes. Contributes to minor pollination through nectar foraging.

Considered highly beneficial in agricultural and horticultural settings due to predation on pest caterpillars. May utilize artificial nesting structures such as mason bee houses and drilled wooden blocks. No documented negative impacts; stings are possible but unlikely given its solitary, non-aggressive nature.

• Pachodynerus nasidensYellow and black banding versus red and black coloration; P. nasidens is a mimic of the Mexican Honey Wasp
• Pachodynerus guadulpensisHas an extra yellow stripe across the front of the abdomen that P. erynnis lacks
• Monobia quadridensAnother black and white mason wasp in the same subfamily (Eumeninae) with similar nesting habits but different color pattern

• solitary wasp
• mason wasp
• biological control
• caterpillar predator
• cavity nester
• pollinator

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Paralyzing prey in Paradise: Keyhole wasp, Pachodynerus nasidens — Bug of the Week
• Bug Eric: February 2011
• Bug Eric: Spring (Butterfly) Beauties
• Oedemeridae | Beetles In The Bush
• On the prowl to paralyze pests here in the DMV: Four-toothed mason wasps, Monobia quadridens — Bug of the Week
• Red and black mason wasp, Pachodynerus erynnis (Lepeletier)