Phalantus Stål, 1863

Swanson, Daniel R., 2019, Doomed to a vile lot: new taxa, notes, and an updated generic key for the Old World corsairs (Heteroptera: Reduviidae: Peiratinae), Zootaxa 4700 (2), pp. 196-228 : 209

Phalantus Stål, 1863

Phalantus Stål, 1863: 57 . Type species: Phalantus geniculatus Stål, 1863 ; by monotypy.

Isdegardes Distant, 1909: 365 . Type species: Isdegardes melanocephalus Distant, 1909 ; by monotypy. Syn. nov.

Distant (1909) described the new genus Isdegardes Distant, 1909 in an unspecified subfamily for a single species, Isdegardes melanocephalus Distant, 1909 , from Calcutta. Regarding, generic affinities, he noted only “This genus is somewhat allied to Reduvius .” A conspicuous feature of this new taxon was “anterior tibiae…somewhat broadly compressed and curved”. In the appendix to The Fauna of British India, Distant (1910) placed Isdegardes in Acanthaspidinae “to follow Reduvius ” in the key from his previous treatment (i.e., Distant 1904), at the same time including a figure of the dorsal habitus and lateral view of the head ( Distant 1910, fig. 109).

It is clear from this habitus figure that Distant had placed his new genus in the wrong subfamily, as Isdegardes is congeneric with the peiratine genus Phalantus Stål, 1863 . The curved and compressed protibia are a distinct feature of Phalantus . Although Peiratinae are most often diagnosed by the transverse pronotal suture being distinctly behind the middle (versus at or before middle in Reduviinae ), this suture is situated very nearly at the middle of the pronotum in species of Phalantus (compare Fig. 10 ). Two other species of Phalantus are known from India: Phalantus feanus Distant, 1903 and Phalantus geniculatus Stål, 1863 . The type species of Isdegardes is, for the time being, considered distinct from these based on having the legs wholly ochraceous; in P. feanus and P. geniculatus , the apices of the femora and base of the tibiae are black.

Given the evidence outlined above, Isdegardes melanocephalus Distant, 1909 is transferred to the genus Phalantus Stål, 1863 , resulting in Phalantus melanocephalus comb. nov. This act relegates Isdegardes Distant, 1909 to a junior synonym of Phalantus Stål, 1863 syn. nov. Distant (1909, 1910) generally mentioned similarities to the genus Reduvius but drew no other generic comparisons. However, the obvious similarities with Phalantus would have necessitated comparison with Isdegardes . I have speculated that Distant considered only reduviines after assessing the transverse pronotal suture, despite clearly having been aware of Phalantus , as he had already described P. feanus .

Figures

FIGURE 10. Comparison between Isdegardes (Reduviinae) and Phalantus (Peiratinae): (A) Isdegardes melanocephalus, line drawing of habitus after Distant (1910); (B) Phalantus africanus, adult male. Scale bar =2 mm.