Tapinoma ramulorum inrectum Forel 1908

This species occurs in lowland wet forest habitats. It has very distinctive nesting habits and thus is more easily identified in the field than from museum specimens. It makes small carton nests on the undersides of leaves. The carton is coarse, and the nests are usually no more than 2-3cm across and less than 5mmm high. These nests contain workers, brood, and sexuals. They may also cover scale insects, such that multiple scale insects can be found on the leaf surface under the carton, while no exposed scales can be found anywhere on the surrounding plant. Often several nests are found on different leaves of the same plant, in close proximity, suggesting polydomy. On disturbance, several workers emerge and run wildly over the leaf surface for a few seconds, then retreat back inside the nest. Workers may also be found at extrafloral nectaries.

Carton nest of Tapinoma ramulorum inrectum. Individual ants can be seen if you look at the linked original images.

Costa Rica: lowland wet forests throughout the country.

Taxonomic history