Revised key to world genera of the family Kerriidae, based on adult females

(modified from Kondo & Gullan 2005, 2007)

1(0) With perivulvar pore clusters........................................................................... 2

– Without perivulvar pore clusters......................................................................... 6

2(1) With 3 or more pairs of perivulvar pores clusters, usually with 9–25 pairs......................................... 3

– With only 2, rarely 3 pairs of perivulvar pore clusters......................................................... 5

3(2) Antennae long, usually with 4 or 5 segments. Brachia long, Brachial plates heavily sclerotized, with a distinct terminal constriction behind crater rim...................................................... Metatachardia Chamberlin

– Antennae short, usually with 1 or 2 segments, rarely with 3 or 4. Brachia either long or short. Brachial plate mildly or heavily sclerotized, without a distinct terminal constriction behind crater rim............................................ 4

4(3) Canellar pores present near mouthparts......................................... Kerria (Chamberliniella) Varshney

- Canellar pores absent from near mouthparts....................................... Kerria (Kerria) Targioni Tozzetti

5(2) Marginal duct clusters usually duplex (Fig. 1B), rarely simplex (Fig. 1A). Last antennal segment bearing 3–8 setae........................................................................................... Tachardiella Cockerell

– Marginal duct clusters triplex (Fig. 1C). Last antennal segment bearing only 2 setae........ Austrotachardiella Chamberlin

6(1) Marginal duct clusters each heavily sclerotized, forming a subcircular to oval sclerotized plate (Fig. 1D).................................................................. Neotachardiella Kondo, Peronti, & Pacheco da Silva, gen. nov.

‒ Marginal duct clusters each membranous or only slightly sclerotized, not forming a sclerotized plate................... 7

7(6) Brachial plates often each with an elevated area or accessory projection containing a group of pseudospines.Brachia membranous, very long and often narrow. Dorsal spine situated at end of a long and narrow membranous pedicel... Albotachardina Zhang

– Brachial plates each without an elevated area. Brachia usually short and relatively thick. Dorsal spine not located at end of a long and narrow membranous pedicel..................................................................... 8

8(7) Dorsal spine duct(s) non-dendritic.................................................. Austrotachardia Chamberlin

– Dorsal spine duct(s) dendritic............................................................................ 9

9(8) Each marginal duct cluster with 2 closely associated auxiliary clusters, although auxiliary clusters are occasionally absent from 1 or 2 marginal duct clusters per specimen........................................... Afrotachardina Chamberlin

– Each marginal duct cluster without auxiliary clusters, although some microducts may be found scattered around its border.. 10

10(9) Anal ring divided into 4 separate sections. Derm around microducts in marginal duct clusters often slightly to moderately sclerotized; duct rims of 2 or more microducts often fused, especially around outer margin of cluster... Tachardina Cockerell

– Anal ring not divided into 4 separate sections, but may show partial segmentation. Derm around microducts in marginal duct clusters without any sclerotization; microducts not fused, although they may touch each other. Paratachardina Balachowsky