Dryininae (Olmi, 1991)

Peinado, Julie, Nel, Andre & Waller, Alain, 2006, A dryinid wasp in Early Eocene amber from the Paris basin (Hymenoptera: Dryinidae), Zootaxa 1168 (1), pp. 31-41 : 38-39

Comparison within Dryininae

In the subfamilial key of Olmi (1984), our fossil would fall into the Dryininae because of the quadridentate mandible, the enlarged claw with only one subapical tooth, and the fifth segment of front tarsus with more than one preapical lamella. Furthermore, our fossil shares with the Dryininae the presence of a visible epicnemium ( Olmi 1993).

All the recent genera included in this subfamily sensu Olmi (1984) can be excluded on the basis of his key except Dryinus Latreille, 1804 . Olmi has since proposed several generic synonymies within this group (1993) and a new generic key (1999).

Following the key to the genera of Dryininae proposed by Olmi (1999) and updated by Olmi & Bechly (2001: 19), the Baltic amber genus Palaeodryinus Olmi & Bechly, 2001 is excluded because of its segment 5 of fore tarsus more than six times as broad as the enlarged claw. Our fossil shares with the three genera Pseudodryinus Olmi, 1991 (five recent Australian, Oriental, and Ethiopian species), Gonadryinus Olmi, 1991 (one recent Neotropical species) and the fossil genus Harpactosphecion Haupt, 1944 (Baltic and Dominican amber), a palpal formula that differs from 6/3.

Gonadryinus can be excluded because our fossil has a subapical tooth on its enlarged claw. Also, Gonadryinus has a palpal formula 4/2, but with very short maxillary palpomeres, unlike our fossil ( Olmi 1991: fig. 47.A).

Harpactosphecion has palpal formula 5–6/2–3 segments instead of 5/ 2 in our fossil, antennal segment 3 more than five times as long as segment 2 (shorter in our fossil) and its enlarged claw with two subapical teeth, instead of one in our fossil ( Olmi 1999; Olmi & Bechly 2001).

Pseudodryinus has a palpal formula 3–4/2 ( Olmi 1991). Its tibial spur formula is 1/1/2, as in our fossil and the other Dryininae ( Olmi 1991: 366) . The only difference between our fossil and the recent representatives of Pseudodryinus is its palpal formula 5/2. Thus, this genus appears as the closest modern relative to our fossil.

Olmi (1984) attributed the fossil genus Cretodryinus Ponomarenko, 1975 (one species C. zherikhini Ponomarenko, 1975 from the Late Cretaceous Taymir amber) to the Dryininae . Its enlarged claw with no subapical tooth excludes it. Nothing is known about its palpal formula and its mandibles are only partly visible ( Ponomarenko 1975b; Olmi 1984). Its fore wing venation is as complete as that of our fossil, but its cell 2Cu is closed by tubular veins and its cell 1R1 is larger than that of our fossil (after the reconstruction of Ponomarenko 1975b).

Affinities with the genus Thaumatodryinus Perkins, 1905 are excluded because of its palpal formula 6/3, and its antennae with tufts of long hairs on segments 5–10. This taxon was considered in a separate subfamily Thaumatodryininae by Olmi (1984) but included into the Dryininae by Olmi (1993, 1999). Nevertheless, our fossil shares with the female of Thaumatodryinus flavus Olmi, 1984 a fore wing venation with the cells 1R1, 1M and 2Cu present.

Because of the great similarities between our fossil and the recent genus Pseudodryinus , we attribute it to this genus, but to a new species, mainly characterized by its palpal formula 5/2.

The rather pronounced differences between our fossil and the Baltic amber Dryinidae supports the previous results concerning the great differences between the faunas of the ‘Oise’ and the Baltic ambers ( Gee et al. 2001; Nel et al. 1998, 2002, 2003a,b, 2004, 2004a,b,c,d; Nel & De Ploëg 2004).

The distribution of the recent species of Pseudodryinus in warm intertropical environments confirms a similar paleoclimate for the Oise amber, already supported by the presence of numerous other organisms ( Nel et al. 1999).