Gonatopusjaliscanus sp. n., a new Pincer wasp from Jalisco, Mexico (Hymenoptera, Dryinidae)

Abstract A new species of Gonatopus Ljungh, 1810, G.jaliscanussp. n., from Jalisco, Mexico, is described and illustrated. In the Neotropical region, G.jaliscanus is similar to G.forestalis Olmi, 1998, but it is distinguished by the black mesosoma (except prothorax, mesoscutum, and mesoscutellum that are yellow), and the metapostnotum being granulated and not rugose; in G.forestalis the mesosoma is completely black and the metapostnotum is granulated and strongly rugose. In the Nearctic region, the new species is morphologically similar to G.curriei Krombein, 1962, but it is distinguished by the dull and granulated metapostonotum; in G.curriei the metapostnotum is shiny and unsculptured. The new species belongs to Gonatopus group 7. The keys to the females of the Nearctic and Neotropical species of this group are modified to include the new taxon.

Jalisco is a state of Mexico situated in a transition area between the Nearctic and Neotropical regions. Species of Dryinidae collected in this state can belong to either region, so for the identification, researchers have to check the keys of both zoogeographical regions. Dryinidae of the Nearctic and Neotropical regions were studied mainly respectively by Olmi (1984) and Olmi and Virla (2014).

Materials and methods
The description follows the terminology used by Guglielmino et al. (2016Guglielmino et al. ( , 2018a and Olmi and Virla (2014). 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 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.
The types of all Nearctic and Neotropical species of Gonatopus were examined. The material studied in this paper will be deposited in the National Museum of Natural History, Washington, DC, USA (USNM).
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.
Remarks. The female of the new species is apterous, with pronotum crossed by a strong transverse furrow (Fig. 1B), the enlarged claw provided of one small subapical tooth (Fig. 2) and the palpal formula 6/3. Because of these characters, G. jaliscanus belongs to group 7 of Gonatopus, according to the systematics proposed by Olmi and Virla (2014). In this species, the head is excavated, the labial palpus is 3-segmented, the mesoscutum has two lateral pointed apophyses situated in the stalk between pronotum and metapectal-propodeal complex (Fig. 1A), the metanotum is sloping anteriorly (Fig. 1B), the meso-metapleural suture is obsolete, the first abdominal tergum is completely transversely striate, the protarsomere 1 is shorter than protarsomere 4 (Fig. 1A). In the Nearctic region, there is only one species of Gonatopus group 7 with the above characters: G. curriei Krombein, 1962. The new species can be included in the key to the females of the Nearctic species of Gonatopus group 7 presented by Olmi (1984)  In the Neotropical region, G. jaliscanus is similar to G. forestalis Olmi, 1998. The new species can be included in the key to the females of the Neotropical species of Gonatopus group 7 presented by Olmi and Virla (2014) by replacing couplet 51 as follows:

Conclusions
Species of Gonatopus from Mexico are known mainly through the monographs on Dryinidae of the Nearctic (Olmi 1984) and Neotropical regions (Olmi and Virla 2014), the checklist of Moya-Raygoza and Olmi (2010) (Olmi and Virla 2014, Martins et al. 2015a, b, Martins and Krinski 2016, Martins and Domahovski 2017a; in Costa Rica 22 (Olmi and Virla 2014); and in Argentina 47 (Olmi and Virla 2014). The higher numbers of Gonatopus species from Brazil and Argentina suggest that the true number of species in Mexico will ultimately be much higher. Further research, also on the hosts, will be needed to better characterise this fauna. In fact, hosts are known only for 12 of the 26 Gonatopus species recorded from Mexico (Becerra-Chiron et al. 2017: another gap to be bridged, in spite of the contributions of Prof Moya-Raygoza and his research group (Moya-Raygoza and Olmi 2010, Becerra-Chiron et al. 2017). Among these 12 hosts, leafhopper pests of maize in the Neotropical region are economically important (Guglielmino et al. 2006).