Heterobates bilobatus ( Esaki, 1927 )

Cianferoni, Fabio, Saleem, Rukhshanda, Afsheen, Sumera & Zia, Ahmed, 2021, The water striders of Pakistan (Hemiptera: Heteroptera: Gerridae): new records from Punjab and first checklist for the country, Zootaxa 4996 (3), pp. 469-491 : 475-477

Heterobates bilobatus ( Esaki, 1927)

( Figs. 2 , 3 )

Teratobares bilobatus Esaki 1927: 262 .

Heterobates bilobatus: Hungerford & Matsuda 1958: 201 .

Material examined. Gujranwala District: Upper Chenab canal, Nandipur, Gujranwala, 32.254099° N 74.269467° E, 14. V.2017, 1 ♂ apt., 4 nymphs; idem, 7. VIII .2017, 3 nymphs; idem, 29. VI .2018, 2 ♂, 3 ♀ apt.; Upper Chenab canal, Master City Housing Scheme , Gujranwala , 32.130067° N 74.214012° E, 9.X.2017, 9 nymphs. Gujrat District : Upper Jhelum canal near Pathan Colony, Kharian, 32.719544° N 73.795622° E, 21. V .2017, 2 nymphs; idem, 17.IX.2017, 1 nymph ; idem, 24. VI .2018, 1 ♂, 1 ♀ apt.; Upper Jhelum canal near Village Jaura, Kharian, 32.654499° N 73.816865° E, 18. VII .2017, 1 ♂, 2 ♀ apt., 7 nymphs; idem, 13. VIII .2017, 1 ♀ apt., 7 nymphs; idem, 1 V , 2 IV instar nymphs, det. FC ( CFC); idem, 24. VI .2018, 1 ♂, 2 ♀ apt.; Upper Jhelum canal Grand Trunk Road Sarai Alam- gir, 32.890852° N 73.768194° E, 22.IV.2017, 7 nymphs ; idem, 21. V .2017, 1 ♀ apt., 10 nymphs; idem, 22.IV.2018, 1 ♀ apt .; idem, 24. VI .2018, 1 ♂, 2 ♀ apt.; Upper Jhelum canal near Simbli Sharif Road Sarai Alamgir, 32.865010° N 73.713452° E, 21. V .2017, 1 nymph; idem, 24. VI .2018, 3 ♂; River Jhelum , Grand Trunk Road, 32.917846° N 73.723696° E, 22.IV.2017, 10 nymphs ; idem, 21. V .2017, 1 ♀ apt., 20 nymphs; idem, 13. VIII .2017, 1 nymph; idem, 24. VI .2018, 1 ♂, 2 ♀ apt.; River Chenab near Village Behlolpur, Gujrat, 32.682921° N 74.427151° E, 13. V .2017, 17 nymphs; idem, 10. VII .2017, 1 ♂, 1 ♀ apt., 3 nymphs; idem, 30. VII .2017, 1 ♂, 9 ♀ apt., 16 nymphs; idem, 4. VIII .2017, 7 nymphs; idem, 16.IX.2017, 1 ♂, 2 ♀ apt., 10 nymphs ; idem, 8. XII .2017, 3 ♂, 3 ♀ apt., 7 nymphs. Sialkot District : Marala Ravi link canal near Basi wala pul, 32.222449° N 74.590056° E, 13. V .2017, 12 nymphs; idem, 18. VII .2017, 4 nymphs; idem, 8. XII .2017, 7 nymphs; Marala Ravi link canal near Canal City Housing Society, 32.475159° N 74.422701° E, 30. VII .2017, 3 nymphs; River Chenab , Head Marala, 32.651279° N 74.476924° E, XI. 2016, 1 m apt .; idem, 13. V .2017, 3 ♂, 1 ♀ apt., 10 nymphs; idem, 10. VII .2017, 1 ♂, 5 ♀ apt., 5 nymphs; idem, 2 ♂ apt. ( Figs 2a , 3 ), det. FC ( CFC) ; idem, 4. VIII .2017, 26 nymphs; idem, 16.IX.2017, 2 ♂, 2 ♀ apt .; idem, 8. XII .2017, 8 ♂, 3 ♀ apt., 2 nymphs; 1 ♂, 3 ♀ apt. ( Fig. 2b ), det. FC ( CFC) ; idem, 23. VI .2018, 3 ♂, 2 ♀ apt.; Upper Chanab canal near Malkhnawala Road, 32.432131° N 74.360571° E, 13. VIII .2017, 1 ♀ apt.; idem, 23. VI .2018, 2 ♂, 3 ♀ apt.; Upper Chanab canal near Zafarwali, 32.478587° N 74.376158° E, 30. VII .2017, 17 nymphs; idem, 13. VIII .2017, 1 ♂, 4 ♀ apt., 17 nymphs; Marala Ravi link canal near Motra, 32.367782° N 74.419769° E, 7. VIII .2017, 2 nymphs; idem, 12. VIII .2017, 3 nymphs; Banbawali Ravi Badian canal near Circular Road, Daska, 32.328191° N 74.345216° E, 7. VIII .2017, 6 V instar nymphs; idem, 8. XII .2017, 1 ♂, 1 ♀ apt., 1 nymph.

General distribution. This species is known from northern India and Nepal (see Esaki 1927 and Andersen 1995).

Remarks. Together with the northwesternmost H. dohrandti Bianchi, 1896 occurring in central Asia and H. rihandi ( Pradhan, 1951) from northern and northeastern India, both originally described in the genus Teratobates Esaki, 1927 , this is the only other known representative of the ptilomerine genus Heterobates Bianchi, 1896 (see Andersen 1995 and Thirumalai 2002). The latter appears to be the sister group of the genus Rhyacobates Esaki, 1923 (see Andersen & Chen 1995, Zettel 2009).

Esaki (1927) described Teratobates bilobatus based on three males and one female from Uttarakhand (northern India) and one male from Nepal. Subsequently, Pradhan (1951) described T. rihandi based on four females from Uttar Pradesh (northern India). He distinguished it from Esaki’s species by the shape of the characteristic lobes of the female sixth abdominal segment, which he defined as “rounded” ( Pradhan 1951: 103, figs 1a–c), probably in comparison to those of the drawing by Esaki (1927: 263, figs 2d,e) that appear “more squared”. Hungerford & Matsuda (1958) transferred T. bilobatus to the genus Heterobates Bianchi, 1896 , which was created for H. dohrandti described from Uzbekistan (see Bianchi 1896). Later, Thirumalai (2002) also transferred T. rihandi to Heterobates .

The peculiar lobes in female specimens from Pakistan (current study) seem to match with the figures of both papers (Pradhan’s drawings are more accurate, whilst those by Esaki are more schematic, but there are no substantial differences). Yet, components of the male genitalia, such as endosomal sclerites, parameres, and proctiger (see Figs. 3a–i ), do not match to those figured by Basu et al. (2015, 2016b, 2018) for specimens from Darjeeling and Jalpaiguri districts, West Bengal (foothills of the Himalayas, north-eastern India) identified as H. rihandi ( Pradhan, 1951) . Therefore, although a revision of this genus, currently containing three species, is needed, these Pakistani specimens are assigned to H. bilobatus , the westernmost species of the genus.

These specimens represent first records of the genus and species for Pakistan, extending range of the species westward.

Figures

FIGURE 2. Specimens of Heterobates bilobatus (Esaki, 1927) from River Chenab, Head Marala (Sialkot, Punjab, Pakistan): a) apterous male (genital segment removed) and b) apterous female. Scale bar = 1 mm (photo by F. Cianferoni).

FIGURE 3. Male genitalia of Heterobates bilobatus (Esaki, 1927) from River Chenab, Head Marala (Sialkot, Punjab, Pakistan): a–d) endosoma with sclerites in different positions; e–h) parameres in different positions; i) proctiger. Scale bar = 0.1 mm (photo by F. Cianferoni).