Pachypsylla celtidismamma
(Riley, 1881)
hackberry nipplegall maker, hackberry psylla
A plant-parasitic hemipteran that induces distinctive nipple-shaped galls on hackberry (Celtis) leaves. are 3.5–4.5 mm long, resembling tiny cicadas. The overwinters as adults in concealed locations and emerges in fall to seek hibernation sites, sometimes becoming a nuisance pest on building exteriors. Nymphs develop within galls, progressing through five instars before emerging as adults.
Pronunciation
How to pronounce Pachypsylla celtidismamma: //ˌpækiˈsɪlə sɛlˌtɪdɪsˈmæmə//
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Identification
Identified by the presence of nipple-shaped galls on the underside of hackberry leaves; galls are smooth to slightly hairy, typically solitary though double or triple galls occur rarely. distinguished from barklice (order Psocodea) by versus chewing mouthparts. Differentiation from other Pachypsylla requires examination of gall : P. celtidismamma produces rounded nipple galls on leaf undersides, while create distinct gall types (petiole galls, leaf curl galls, etc.).
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Habitat
Associated exclusively with hackberry trees (Celtis spp.), occurring wherever hackberry grows naturally or as an ornamental. Nymphs inhabit galls on leaf undersides; overwinter in protected crevices of tree bark, building siding, window frames, and similar concealed locations.
Distribution
North America; records from Arizona, Colorado, Idaho, Illinois, and Ontario. Range corresponds broadly with distribution of hackberry trees.
Seasonality
emerge from galls in late summer to early fall, seeking sites. Reproductive activity resumes in spring when females deposit on unfolding hackberry leaves, timing oviposition precisely to leaf bud break.
Diet
Phloem sap of hackberry (Celtis spp.) obtained via ; nymphs feed within galls, feed on foliage.
Host Associations
- Celtis - primary Hackberry trees; exclusive for both nymph and feeding
Life Cycle
deposited on unfolding hackberry leaves in spring. Nymphs hatch and induce gall formation through feeding activity; five instars develop within the protective gall. Final instar nymphs possess wing pads and spines used to cut exit holes. emerge from galls in late summer, disperse to sites, and re-emerge the following spring to reproduce. No evidence of multiple per year.
Behavior
Nymphs are sedentary, remaining within individual galls throughout development. are capable of jumping when disturbed. Fall-emerging adults exhibit aggregative , gathering in large numbers on building exteriors to seek hibernation cavities. Females demonstrate precise timing of spring oviposition, laying only when leaves are at correct developmental stage.
Ecological Role
Gall formation creates microhabitats that support . Documented parasitoids include Psyllaephagus spp. (Encyrtidae) and Torymus spp. (Torymidae), which develop on nymphs within galls. Galls appear to have minimal impact on overall tree health.
Human Relevance
Occasional nuisance pest when fall-emerging aggregate on homes and buildings; no structural damage or health risk. Control through simple physical removal (water hose) is sufficient. Presence indicates nearby hackberry trees.
Similar Taxa
- Pachypsylla celtidisvesiculumProduces blister-like petiole galls rather than leaf nipple galls; different gall and location on plant.
- Pachypsylla celtidismagnificaCreates larger, more conspicuous leaf galls with different structural characteristics.
- Pachypsylla venustaInduces hackberry leaf curl galls rather than discrete nipple galls.
- Cecidomyiidae (gall midges)Some create hackberry galls; distinguished by gall and by rearing to identify insects.