Aulacidea abdita Kinsey, 1920

Feeds on: Induces galls on Lactuca canadensis L. and possibly additional Lactuca L.species

Distribution: Canada: Québec

Aulacidea abdita

This species was described from adults cut out of cells in the pith of Lactuca elongata from Quebec. Doubtfully distinct from the above [A harringtoni].

[Photo caption]

351. On Lactuca elongata. Types were cut out of 40 year old galls from Quebec. Probably a synonym of the above.

Aulacidea abdita
Cryptic lettuce stem gall wasp [same entry applied to A harringtoni]

Hosts: Biennial lettuce (Lactuca biennis), Canada lettuce (L. canadensis), Florida lettuce (L. floridana), and possibly prairie lettuce (L. ludoviciana).

Gall location and description: Galls of these species are cryptic, meaning they are not outwardly visible and can only be located upon dissection of a galled stem. When dissected, the stem will have numerous brown, rounded chambers along the inside of the pith, each with a single insect.

Range: These galls are primarily known from the Northeastern United States and adjacent areas of Canada, from Ontario south to North Carolina and west to Oklahoma, but they are likely under-reported and may probably be found throughout the United States and Canada within the range of their host plants.

These species have unclear taxonomy and may be synonymous or may instead be composed of multiple true species, but each of the hosts listed above is believed to host cryptic galls induced by gall wasps of the genus Aulacidea. Museum specimens identified by Alfred C. Kinsey indicate that these galls may also occur in stems of prairie lettuce (L. ludoviciana), but the authors of this guide have yet to substantiate this claim.

Aulacidea abdita, new species
Plate XXI, Figures 6 and 7

Galls -- None. The insect lives in cavities in the pith of the stems of Lactuca elongata and most likely other species of Lactuca. There is no proliferation of the pith-tissue and scarcely any differentiation of the lining of the cells. These cells average 2.0 mm. by 1.2 mm. Externally, the stem shows no trace of a gall.

Range: Canada: Quebec