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United States Department of Agriculture

Agricultural Research Service

Research Project: Systematics of Flies of Importance in Agroecosystems and the Environment

Location: Systematic Entomology Laboratory

Title: First new world record of a gall midge from palms: a new species of Contarinia (Diptera: Cecidomyiidae) from Geonoma cuneata in Costa Rica

item Gagne, R.
item Ley-lopez, Juan
item Hanson, Paul

Submitted to: Proceedings of the Entomological Society of Washington
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/8/2017
Publication Date: N/A
Citation: N/A

Interpretive Summary: A new species of gall midge was found preventing seed set on a native palm, an important understory plant in Costa Rica. It is only the second gall midge known to damage palm trees. The gall midge responsible for the damage is named, described and illustrated, and placed in context within its genus and family. The new species can now be readily identified by other scientists for future studies of its impact on the palm in Costa Rica.

Technical Abstract: Contarinia geonomae Gagné, new species (Diptera: Cecidomyiidae), is described from galls found on the infructescences of Geonoma cuneata (Arecaceae) in Costa Rica. The galls are cylindrical in shape and develop concurrently with or instead of the spherical fruit. The larval chamber is located at the base of the gall, partially embedded in the infructescence. Most galls contain a single larva but some contain multiple larvae. As the gall reaches maturity the interior becomes hollow and the pupa pushes through the frayed apex just before adult emergence. Galls are most evident during the last half of the year, coincident with fruit production, but adult emergence appears to be staggered thoughout much of the year. Compared with other Contarinia, the larvae of C. geonomae are unique in having a four-pointed spatula and papillae that are nearly all devoid of setae. The pupae are unique for their prominent prothoracic spiracles.

Last Modified: 09/21/2017
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