Elasmus polistis

Burks, 1971

Elasmus polistis is a minute in the Eulophidae, first described by Burks in 1971. It is an ectoparasitoid specializing on the of paper wasps in the Polistes. The has been documented attacking and pupae inside nests, entering despite defensive by wasps. It has been recorded from the United States and Brazil, with confirmed host associations including multiple Polistes species.

Elasmus polistis by the Smithsonian. Used under a CC0 license.

Pronunciation

How to pronounce Elasmus polistis: //ɪˈlæzməs pəˈlɪstɪs//

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Identification

Distinguished from other Elasmus by confirmed association with Polistes nests; minute size typical of Eulophidae (approximately 2 mm). Accurate identification to species level requires examination of morphological characters not described in available sources.

Images

Habitat

Nests of paper wasps in the Polistes, particularly those lacking a protective envelope. Has been reared from abandoned and active nests collected from human structures including door frames and porch eaves.

Distribution

United States (Florida, Georgia, Hawaii, Maryland, Missouri, Kansas); Brazil (Rio Grande do Sul, Minas Gerais).

Seasonality

emerge from nests in late autumn to mid-November in temperate North America; January emergences recorded from overwintered nests in Kansas.

Host Associations

Polistes versicolor - and pupae parasitized; first South American record of attack documented
Polistes metricus - reared from abandoned nests in Kansas
Polistes exclamans - infests young nests while foundress is away foraging
Polistes dorsalis - cited in literature
Polistes instabilis - cited in literature

Life Cycle

Oviposits on and pupae of inside nest . Development occurs within host nest; emerge from host pupal cells.

Behavior

Flies in front of nest before entering; penetrates nest interior to oviposit on host stages. Efficient at parasitizing pupae despite defensive by host . Attack behavior involves entering nest , possibly through open cell tops, to access and pupae.

Ecological Role

Ectoparasitoid of social pupae; contributes to mortality in early developmental stages of Polistes colonies. May impair services provided by wasps due to .

Human Relevance

Occasionally reared by entomologists from collected paper wasp nests; not a direct pest of humans. Presence indicates successful exploitation of urban-nesting paper wasp .

Similar Taxa

Dibrachys microgastri complexAlso reared from Polistes nests; distinguished by hyperparasitoid lifestyle and different (Pteromalidae)
Other Elasmus speciesMany Elasmus are of Lepidoptera; E. polistis distinguished by documented Polistes specialization

More Details

Parasitism Rate

28.57% rate recorded in one study of 14 Polistes versicolor nests in Brazil, with present in four nests. Absence of protective nest envelope in P. versicolor may facilitate parasitoid access.

Collection Method

Successfully reared by placing abandoned or late-season Polistes nests in transparent containers and monitoring for emergences.