Titre du document / Document title

Presence of Ixodiphagus hookeri (Hymenoptera: Encyrtidae) in two Connecticut populations of Ixodes scapularis (Acari: Ixodidae)

Auteur(s) / Author(s)

STAFFORD K. C. ⁽¹⁾ ; DENICOLA A. J. ⁽¹⁾ ; MAGNARELLI L. A. ⁽¹⁾ ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

⁽¹⁾ Department of Entomology, Connecticut Agricultural Experiment Station, 123 Huntington Street-Box 1106, New Haven, CT 06504, ETATS-UNIS

Résumé / Abstract

Two Connecticut populations of the black-legged tick, Ixodes scapularis (Say), the vector of Lyme disease spirochetes, Borrelia bugrdorferi sensu stricto Johnson, Schmid, Hyde, Steigerwalt & Brenner, in the northeastern United States, are parasitized by the encyrtid wasp Ixodiphagus hookeri (Howard), formerly Hunterellus hookeri. The wasp was first detected in ticks from a forested site in Bridgeport in 1992. I. hookeri was reared from 18.6% of 148 host-seeking I. scapularis nymphs. In 1993 and 1994, this wasp was found to parasitize 26.0% of 192 engorged nymphs from Bridgeport and 21.8% of 101 nymphs from the Bluff Point Coastal Preserve in Groton. Each parasitized nymph produced an average of 6-8 wasps (range, 3-16) with a female to male sex ratio of 1.9-1. Both study sites are wooded, geographically isolated tracts (Bridgeport, 176 ha and Bluff Point, 326 ha) with high densities (51-72/ km²) of white-tailed deer, Odocoileus virginianus (Zimmerman), and superabundant tick populations similar to that of Prudence Island, RI, where I. hookeri also has been reported. We found that I. hookeri emerged from 16.3% of 399 engorged nymphs and 13.7% of 1,081 engorged nymphs collected as unfed ticks from Prudence Island in 1990 and 1991, respectively. No wasps were obtained from nymphs collected in Stamford (n = 38) or Old Lyme, CT (n = 241). A high proportion (23.1% of 39) of engorged nymphs obtained from Bridgeport deer produced I. hookeri. However, only 2 nymphs (6.7%) recovered from white-footed mice, Peromyscus leucopus (Rafinesque), at Bridgeport were parasitized by the wasp. None of the engorged larvae recovered from deer or mice and fed as nymphs in the laboratory produced I. hookeri (n = 26 from deer and n = 384 from mice). The presence of this wasp in I. scapularis at these 2 insular-like sites on the Connecticut mainland supports the observation that high tick densities are required for the establishment and maintenance of I. hookeri and that the potential role of this wasp in the biological control of I. scapularis is limited.

Revue / Journal Title

Journal of medical entomology   ISSN 0022-2585   CODEN JMENA6 

Source / Source

1996, vol. 33, n^o1, pp. 183-188 (24 ref.)

Langue / Language

Anglais

Editeur / Publisher

Entomological Society of America, Lanham, MD, ETATS-UNIS  (1964) (Revue)

Mots-clés anglais / English Keywords

Parasitoid ; Entomophagous ; Population density ; Prevalence ; Geographical variation ; Biological control ; Vector ; Connecticut ; Lyme disease ; Ixodidae ; Encyrtidae ; Odocoileus virginianus ; Peromyscus leucopus ; United States ; North America ; America ; Borrelia infection ; Spirachaetosis ; Bacteriosis ; Infection ; Ixodida ; Parasitiformes ; Acari ; Arachnida ; Arthropoda ; Invertebrata ; Chalcidoidea ; Hymenoptera ; Insecta ; Artiodactyla ; Ungulata ; Mammalia ; Vertebrata ; Rodentia ;

Mots-clés français / French Keywords

Parasitoïde ; Entomophage ; Densité population ; Prévalence ; Variation géographique ; Lutte biologique ; Vecteur ; Connecticut ; Lyme maladie ; Ixodidae ; Encyrtidae ; Odocoileus virginianus ; Peromyscus leucopus ; Ixodes scapularis ; Etats Unis ; Amérique du Nord ; Amérique ; Borréliose ; Spirochétose ; Bactériose ; Infection ; Ixodida ; Parasitiformes ; Acari ; Arachnida ; Arthropoda ; Invertebrata ; Chalcidoidea ; Hymenoptera ; Insecta ; Artiodactyla ; Ungulata ; Mammalia ; Vertebrata ; Rodentia ; Ixodiphagus hookeri ; Cervidae ; Muridae ;

Mots-clés espagnols / Spanish Keywords

Parasitoide ; Entomófago ; Densidad población ; Prevalencia ; Variación geográfica ; Lucha biológica ; Vector ; Connecticut ; Artritis inflamatoria epidémica ; Ixodidae ; Encyrtidae ; Odocoileus virginianus ; Peromyscus leucopus ; Estados Unidos ; America del norte ; America ; Borreliosis ; Espiroquetosis ; Bacteriosis ; Infección ; Ixodida ; Parasitiformes ; Acari ; Arachnida ; Arthropoda ; Invertebrata ; Chalcidoidea ; Hymenoptera ; Insecta ; Artiodactyla ; Ungulata ; Mammalia ; Vertebrata ; Rodentia ;

Localisation / Location

INIST-CNRS, Cote INIST : 11536, 35400005315875.0320