Zapatella

Associated with oak trees (Quercus spp.), particularly black oak (Quercus velutina) in the case of Z. davisae. Larvae develop within plant tissue, typically under bark or in stems.

Northeastern United States: documented from Vermont, Long Island NY, Cape Cod MA, Martha's Vineyard MA, Nantucket MA, and coastal Rhode Island. The invasive species Z. davisae was first documented on Long Island in 1990, with subsequent spread to Cape Cod and Martha's Vineyard in 2008, and newer infestations in Nantucket and coastal Rhode Island.

For Z. davisae: larvae develop under bark in late summer; adults emerge in early spring.

Phytophagous; feeds on oak tissue, inducing gall formation. Z. davisae specifically feeds on black oak (Quercus velutina).

• Quercus velutina - primary host plantblack oak; primary host for Z. davisae
• Sycophila nr. novascotiae - parasitoiddominant parasitoid of Z. davisae, ~65% of reared specimens on Long Island
• Sycophila foliatae - parasitoidparasitoid of Z. davisae, co-dominant with S. nr. novascotiae on Cape Cod
• Sycophila globuli - parasitoidparasitoid of Z. davisae
• Sycophila flava - parasitoidparasitoid of Z. davisae
• Sycophila texana - parasitoidparasitoid of Z. davisae
• Eurytoma sp. - parasitoidparasitoid of Z. davisae

For Z. davisae: larvae develop under bark in late summer; adults emerge in early spring. Reproductive mode (sexual vs. asexual) remains uncertain; genetic analyses of populations from Cape Cod and Nantucket showed significant deviations from Hardy–Weinberg equilibrium and excess clonal individuals, but were inconclusive regarding definitive asexual reproduction.

Forms stem galls on oak hosts. Outbreaking populations can cause extensive foliar damage, flagging, leaf clumping, limb loss, and tree mortality when released from natural enemies or introduced to new areas.

Herbivore that induces gall formation on oaks. Serves as host for diverse parasitoid communities, with top-down population regulation by parasitoids demonstrated in some populations. Can become a significant tree pest when natural enemy pressure is insufficient.

Z. davisae is an economically and ecologically significant pest in the northeastern United States, causing extensive damage and mortality to black oak populations. Management efforts benefit from understanding parasitoid community dynamics and infestation progression patterns.

• Other Cynipini gall waspsSimilar gall-inducing lifestyle on oaks; Zapatella distinguished by specific gall morphology, host associations, and molecular markers. Z. davisae specifically associated with black oak distinguishes it from many other oak gall wasps with different host specificities.

• gall wasp
• oak gall
• Cynipidae
• pest
• invasive
• parasitoid
• phytophagous
• Z. davisae
• black oak
• Quercus velutina
• Northeastern United States
• outbreak
• biological control
• Sycophila

• BugGuide
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Life History and Potential Hosts of Zapatella davisae (Hymenoptera: Cynipidae), a Recent Invader on Black Oak in the Northeastern United States
• Development of microsatellite markers for an outbreaking species of oak gall wasp,Zapatella davisae(Hymenoptera: Cynipidae), in the northeastern United States
• Identification of the parasitoid community associated with an outbreaking gall wasp,Zapatella davisae, and their relative abundances in New England and Long Island, New York