A new species of the genus Dryinus Latreille (Hymenoptera, Dryinidae) from the USA

Abstract A new species of Dryinus Latreille, 1804, is described from Georgia (USA). D. georgianussp. nov. is morphologically similar to D. mexicanus (Perkins, 1907) and D. splendidus Guglielmino and Olmi, 2013, but is distinguished by the lateral ocelli not touching the occipital carina (in the other two species, the lateral ocelli touch the occipital carina). The key to the females of the Nearctic species of Dryinus group 1 is modified to include the new taxon.


Introduction
Dryinidae is a small family of Chrysidoidea (Hymenoptera) including 16 subfamilies, 50 genera, and approximately 1900 species worldwide (Olmi and Xu 2015;Tribull 2015;Olmi et al. 2019). The species of this family are parasitoids and often also predators of Hemiptera Auchenorrhyncha .

Materials and methods
The description follows the terminology used by Guglielmino et al. (2016aGuglielmino et al. ( , 2016bGuglielmino et al. ( , 2018 and . The measurements reported are relative, except for the total length (head to abdominal tip, without the antennae), which is expressed in millimetres. In the descriptions the following abbreviations are used:

POL
distance between the inner edges of the lateral ocelli; OL distance between the inner edges of a lateral ocellus and the median ocellus; OOL distance from the outer edge of a lateral ocellus to the compound eye; OPL distance from the posterior edge of a lateral ocellus to the occipital carina; TL distance from the posterior edge of an eye to the occipital carina.
The term "ADOs" (= Antennal Dorsal Organs) is here used in the sense of Riolo et al. (2016). It corresponds to the term "rhinaria" sensu Olmi (1984Olmi ( , 1994, Olmi and Virla (2014), Olmi and Xu (2015) and Xu et al. (2013). According to Riolo et al. (2016), ADOs are sensory structures, that might mediate the antennal responses to vibratory stimuli. As far as we know, they are present only in antennae of dryinid females attacking Fulgoromorpha (Olmi 1984(Olmi , 1991(Olmi , 1994. The names of cells and veins of the forewing are here used in the sense of Azevedo et al. (2018). In all previous monographs on Dryinidae (Olmi 1984(Olmi , 1994Olmi and Virla 2014;Olmi and Xu 2015;Xu et al. 2013) different names were used. The correspondence between old and new names is the following (the first name is the old name): median cell = radial cell (R); submedian cell = first cubital cell (1Cu); stigmal vein = second radial cross & radial sector (2r-rs&Rs). In the text, cells and veins will be named by their respective abbreviations, including costal cell (C). The terminology of tegument sculpture follows Olmi and Virla (2014).
The types of all Nearctic species of Dryinus were examined. The holotype of the new species studied in this paper is deposited in the Royal Alberta Museum, Edmonton, Alberta, Canada (RAM). Other examined species from Georgia (USA) are deposited in the Canadian National Collection of Insects, Ottawa, Canada (CNC).
The description of the new species is based on the study of only a single specimen. The authors are aware that descriptions of new taxa should normally be based on more individuals. However, Dryinidae are so rare that it is uncommon to collect more than one specimen of each species. In addition, on the basis of the experience and knowledge of the authors, the new species is sufficiently delimited by unique characters to justify its description.
Hosts. Unknown. Etymology. The species is named georgianus, based on the collecting locality.

Conclusions
The female of the new species has complete notauli ( Fig. 1A) and enlarged claw provided with one strong subapical tooth (Fig. 2). Because of these characters, D. georgianus belongs to group 1 of Dryinus, according to the systematics proposed by Olmi and Virla (2014). In this species, the head is ferruginous (Fig. 1A, C); the mesoscutum is granulate and partly reticulate rugose, notauli complete (Fig. 1A) and the enlarged claw is spatulate (Fig. 2). Because of these characters, D. georgianus is similar to D. mexicanus (Perkins, 1907) and D. splendidus , recorded respectively from Mexico and USA . However, in D. georgianus the lateral ocelli do not touch the occipital carina (Fig. 2), whereas in the other two species they do. The key to the females of the Nearctic Dryinus group 1 presented by , should be modified by replacing couplet 8 as follows: 8 Posterior ocelli not touching occipital carina (Fig. 1C)  Among the Dryinus species recorded from Georgia, D. alatus and D. georgianus belong to group 1, whereas D. testaceus and D. inconsultus belong respectively to groups 2 and 3.