Apoica thoracica

Nocturnal Paper Wasp
Apoica cf. thoracica, wasp image from Costa Rica

 

Family: Vespidae

Subfamily: Polistinae

Tribe: Epiponini

 

This Neotropical genus is made up of nine named species, and is found in both Central and South America.

Pickett and Wenzel (2007) called this genus "one of the most bizarre genera of the swarm-founding Polistinae." With the exception of genus Provespa, "no other social wasp genus is primarily nocturnal." Going along with the wasps' nocturnal habits are unusually large ocelli, larger than in any other Polistinae. Another odd trait of the genus is that the queen is not larger than the workers.

The nests are similar to those of Polistes paper wasps, but lack a pedicel, the cells being attached directly to the substrate (usually the underside of a broad tree branch).

On moonlit nights, Apoica wasps "burst off the nest at dusk," an "explosion of activity." On nights without moonlight this explosion does not occur, and in fact the wasps may not forage at all on dark nights (Pickett and Wenzel, 2007).

In forming a swarm, the Apoica wasps demonstrate a unique behavior. "They raise their metasoma and apparently release a volatile odor that 'calls' the other wasps" (Pickett and Wenzel).

The two common Apoica species in Central America are Apoica pallens and A. thoracica. The latter species is somewhat variable but usually is "uniformly dark brown to black." A. pallens has the abdomen dorsally creamy yellow and ventrally light brown. The antennae are mostly brown, but pale at the apex. The scutum is brown and bears 2-4 pale stripes (Pickett and Wenzel, 2007).

Photo location: Tuis, Cartago, Costa Rica (first two photos). Brokopondo district, Suriname (third photo). These wasps were attracted to lights.


Apoica cf. thoracica, nocturnal wasp image from Central America



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