Revision of Nearctic species of Esagonatopus, with description of a new species from Florida (Hymenoptera, Dryinidae)

Abstract Esagonatopus floridensis sp. n. is described from Florida, Oklaloosa County (USA). A revision of the three Nearctic species of Esagonatopus Olmi, 1984 is presented. New data on geographic distribution, morphologic variability and opposite sexes of Esagonatopus niger (Fenton, 1924) and Esagonatopus perdebilis (Perkins, 1907) are given. A key to the Nearctic species of Esagonatopus is presented.


Introduction
Dryinidae (Hymenoptera: Chrysidoidea) are parasitoids of Hemiptera Auchenorrhyncha (Guglielmino and Olmi 1997, 2006. Esagonatopus Olmi, 1984 is a genus present in the Nearctic and Neotropical regions and belonging to the subfamily Gonatopodinae. Six species of Esagonatopus have been described from the Americas (Olmi 1984(Olmi , 1986Virla 1997;Virla and Olmi 2007) and the genus was revised by Olmi (1984) and Virla and Olmi (2007). A key to the four Neotropical species of Esagonatopus was presented by Virla and Olmi (2007).
In 2009 and 2010 we have examined additional specimens of Esagonatopus from the United States, Canada and Mexico and have found a new species described herein. Th is material made it possible to revise the entire group of Nearctic species and provide new data on geographical distribution, morphologic variability and opposite sexes of E. niger (Fenton, 1924) and E. perdebilis (Perkins, 1907).

Material and methods
Th e descriptions follow the terminology used by Olmi (1984Olmi ( , 1994Olmi ( , 1999. Th e measurements reported are relative, except for the total length (head to abdominal tip, without the antennae), which is expressed in millimetres. In the descriptions, POL is the distance between the inner edges of the lateral ocelli; OL is the distance between the inner edges of a lateral ocellus and the median ocellus; OOL is the distance from the outer edge of a lateral ocellus to the compound eye; OPL is the distance from the posterior edge of a lateral ocellus to the occipital carina; TL is the distance from the posterior edge of an eye to the occipital carina.
Th e treatments of E. niger and E. perdebilis are updated by adding new localities and morphological variations to the descriptions reported by Olmi (1984).
In the fi gures of male genitalia the right half was removed.