Chakra Rajmohana and Veenakumari, 2014

Veenakumari, Kamalanathan, Sreedevi, Kolla & Mohanraj, Prashanth, 2022, Additions to the genus Chakra Rajmohana and Veenakumari, 2014 (Hymenoptera: Platygastroidea: Scelionidae) from India, Journal of Natural History 56 (41 - 44), pp. 1657-1707 : 1658-1659

Chakra Rajmohana and Veenakumari, 2014

Type species Chakra sarvatra Rajmohana and Veenakumari, 2014

Chakra was proposed as a new genus by Rajmohana and Veenakumari (2014). Although specimens of Chakra keyed out to Opisthacantha at couplet 59 of Masner (1976) and 50 of Galloway and Austin (1984), they did not conform to the concept of the genus Opisthacantha Ashmead sensu Masner (1976) , a very large genus in which some diagnostic characters are highly variable:

eyes densely setose, or partially setose or glabrous; skaphion well developed in most species (with posterior rim well developed or absent), or absent as in many Oriental species; notauli either percurrent, or short or absent; metanotal spine present as a short strong tooth, at times broadly subtridentate, or the lateral spines short or the spine represented as a foliaceous triangle or medially excavate; fore wing with submarginalis often ‘broken’ at junction with spurious basalis, or not ‘broken’ with submarginalis straight. T 1 in females generally without horn or with horn as in some cases. Masner (1976, 45–46)

The significant characters that distinguish Chakra from Opisthacantha are detailed in the diagnosis.

With this high degree of variability characterising the genus, Masner (1976) found many genera formerly thought to be distinct from Opisthacantha to in fact be species groups within this genus as each of them fitted somewhere along the continuum of each of the character states defining this genus. Interestingly character states normally of value in distinguishing between genera are here found to be of significance at the specific level ( Galloway and Austin 1984). However, Opisthacantha Ashmead sensu Masner (1976) as currently delineated (and as also pointed out by one of the reviewers) is in need of revision. We are of the opinion that this large genus with highly variable characters may have to be divided into several genera or species groups, each characterised by stable character states.

Diagnosis

Chakra is characterised by the presence of round setigerous tubercles on head, mesoscutum, mesoscutellum and ventral mesopleuron; lateral ocelli far from orbits and closer to median ocellus; a raised interantennal prominence and a Scelio - type ovipositor; skaphion and notaulus absent. Talamas et al. (2017) when expanding the concept of this genus included additional characters: presence of metapleural and paracoxal sulci separately in dorsal half of metapleuron; presence of an epomial carina; coarsely rugose propodeum; presence of facial and malar striae; occipital carina complete; area surrounding interantennal process with lines of sculpture; clypeus dorsoventrally divided by a transverse furrow; palpal formula 4:2 ( Popovici et al. 2017); metascutellum with 1–3 spines of varying lengths.

It was also evident during the course of this study that Chakra is a polymorphic genus, exhibiting variability in some of its character states: eyes (small or large); length of ocular ocellar line and interorbital space; number of metascutellar spines (varying from 1–3 and of variable length); density of round setose protuberances on head, mesoscutum and mesoscutellum (dense to sparse); wings (well developed or brachypterous); horn on female T1 (present or absent); shape of metasoma; shape of the interantennal process; shape and length of male antennomeres.