Gymnetini, Kirby, 1827

Ibarra Polesel, Mario G., Valle, Nestor G., Cave, Ronald D. & Damborsky, Miryam P., 2022, Descriptions of the larva and pupa of Gymnetis pudibunda Burmeister, 1866 (Coleoptera: Scarabaeidae: Cetoniinae: Gymnetini), with notes on natural history and a key to the known larvae of New World Gymnetini, Journal of Natural History 56 (13 - 16), pp. 969-987 : 980-984

Key to the third instars of the species of New World Gymnetini

Adapted from Ibarra-Polesel et al. (2017) and Gasca-Álvarez et al. (2019)

1. Palidia present........................................................................................................................................ 2

– Palidia absent (south-western USA to north-western Mexico)................................................ ........................................................................................... Gymnetina cretacea (LeConte, 1866)

2. Raster with each palidium with 2 or more irregular rows of pali ..................................... 3

– Raster with palidia monostichous.................................................................................................. 6

3. Pretarsus with 7 setae. Maxillary stridulatory area with 5 teeth. Terminal antennomere with 3 ventral sensory spots (southern USA to Honduras)....................................................... .............................................................. Hologymnetis cinerea (Gory and Percheron, 1833)

– Pretarsus with 10–12 setae. Maxillary stridulatory area with 7–9 teeth. Terminal antennomere with 3–11 ventral sensory spots ..................................................... 4 ( Cotinis )

4. Raster with palidia set closely together with pali directed medially. Septula long and very narrow ............................................................................................................................................. 5

– Raster with palidia set separated. Septula oblong and wide (southern USA to northern South America) ........................................ Cotinis mutabilis (Gory and Percheron, 1833)

5. Terminal antennomere with 3–7 sensory spots. Epicranium dorsally with 5–9 small, irregularly distributed epicranial setae. (south-eastern USA)................................................... ........................................................................................................ Cotinis nitida (Linnaeus, 1758)

– Terminal antennomere with 8–11 sensory spots. Epicranium dorsally with 8–10 small, irregularly distributed epicranial setae. (Florida Keys, USA)...................................................... ......................................................................................................... Cotinis aliena Woodruff, 2008

6. Abdominal tergite VII with 3 annulets ......................................................................................... 7

– Abdominal tergite VII with 2 annulets ....................................................................................... 11

7. Terminal antennomere with 10–20 sensory spots .................................................................. 8

– Terminal antennomere with 5–8 sensory spots ....................................................................... 9

8. Stemmata present. Haptomeral region with 14–16 fairly stout setae in a transverse row. Each palidium a row of 17–20 pali ( Mexico to Panama).................................................. ......................................................................................... Amithao haemotopus (Schaum, 1848)

– Stemmata absent. Haptomeral region with 10–15 fairly stout setae in a transverse row. Each palidium a row of 23–26 pali (southern Mexico to Ecuador).............................. ................................................................................................... Argyripa lansbergei (Sallé, 1857)

9. Terminal antennomere with 8 sensory spots. Maxillary stridulatory area with 7 teeth. Septula very narrow, elongated, length 9 times width ( Argentina, Brazil, Paraguay, and Uruguay)............................................................................. Blaesia atra Burmeister, 1842

– Terminal antennomere with 5–6 sensory spots. Maxillary stridulatory area with 5 teeth. Septula oval or elongated, length 2.5–3.5 times width.... 10 ( Gymnetis in part)

10. Terminal antennomere with 6 sensory spots. Haptomeral region with a transverse row of 19–20 heli. Septula oval, length 2.5 times width ( Argentina, Brazil, Peru, Paraguay, and Uruguay)........................................ Gymnetis chalcipes (Gory and Percheron, 1833)

– Terminal antennomere with 5 sensory spots. Haptomeral region with a transverse row of 14 fairly stout setae. Septula elongated, length 3.5 times width (South America east of the Andes from greater Amazonia to Argentina and Paraguay)....................................... ................................................................................................. Gymnetis rufilateris (Illiger, 1800)

11. Pretarsus with 5–7 setae .................................................................................................................. 12

– Pretarsus with 8–15 setae................................................................................................................ 14

12. Distance between 2 lobes of spiracular plate slightly less than dorsoventral diameter of bulla, or as long as such diameter. Right mandible with 2 scissorial teeth ( Figure 4 ). Terminal antennomere with 5 sensory spots. ( Argentina, Brazil, Paraguay, Peru, and Uruguay).................................................................... Neocorvicoana reticulata (Kirby, 1819)

– Distance between 2 lobes of spiracular plate much less than dorsoventral diameter of bulla, or almost surrounding it. Right mandible with 3 scissorial teeth. Terminal antennomere with 5–10 sensory spots.......................................................... 13 ( Marmarina )

13. Terminal antennomere with 10 sensory spots. Maxillary stridulatory area with row of 9 acute teeth. Each palidium an irregular row of 12–13 pali ( Argentina, Brazil, Paraguay, and Uruguay)........................................ Marmarina tigrina (Gory and Percheron, 1833)

– Terminal antennomere with 5–7 sensory spots. Maxillary stridulatory area with row of 6 acute teeth. Each palidium an irregular row of 19–20 pali (southern Mexico to Amazon regions of Brazil, Colombia, Peru, and Bolivia)............................................................. ............................................................................................ Marmarina maculosa (Olivier, 1789)

14. Distance between 2 lobes of spiracular plate slightly less than dorsoventral diameter of bulla, or as long as this diameter................................................................ 15 ( Hoplopyga )

– Distance between 2 lobes of spiracular plate much less than dorsoventral diameter of bulla, or almost surrounding it.............................................................. 17 ( Gymnetis in part)

15. Right mandible with 3 scissorial teeth. Haptomeral region with transverse row of 12– 19 fairly stout setae. Each palidium an irregular row of 14–18 pali............................... 16

– Right mandible with 2 scissorial teeth. Haptomeral region with transverse row of 8–11 fairly stout setae. Each palidium an irregular row of 18–25 pali ( Argentina, Brazil, Paraguay and Colombia)............. Hoplopyga singularis (Gory and Percheron, 1833)

16. Pretarsus with 9–10 setae. Haptomeral region with transverse row of 12 fairly stout setae. Terminal antennomere with 4 dorsal sensory spots ( Mexico to northern Argentina) ........................................................................... Hoplopyga liturata (Olivier, 1789)

– Pretarsus with 11–12 setae. Haptomeral region with transverse row of 17–19 fairly stout setae. Terminal antennomere with 3 dorsal sensory spots (South America)......... ............................................................ Hoplopyga brasiliensis (Gory and Percheron, 1833)

17. Each palidium an irregular row of 16–23 pali ......................................................................... 18

– Each palidium an irregular row of 10–16 pali ........................................................................ 20

18. Anterior frontal setae absent. Terminal antennomere with 1 ventral sensory spot. Right basal region of hypopharyngeal sclerome with unsclerotised circular area ( Argentina, Bolivia, Brazil, and Paraguay).... Gymnetis pudibunda Burmeister, 1866

– Anterior frontal setae present. Terminal antennomere with 3–5 ventral sensory spots. Hypopharyngeal sclerome completely sclerotised ............................................................... 19

19. Abdominal spiracles I–VIII increasing in size posteriorly. Pretarsus with 8 setae. Anterior frontal setae present, well developed ( Mexico to Costa Rica)............................... ............................................................................................. Gymnetis difficilis Burmeister, 1842

– Abdominal spiracles I–VIII similar in size. Pretarsus with 9–13 setae. Anterior frontal setae small, sometimes not visible ( Costa Rica to northern Argentina).............................. ........................................................................................ Gymnetis pantherina Blanchard, 1842

20. Stemmata absent. Anterior frontal setigerous punctures absent. Haptomeral region with transverse row of 12–14 fairly stout setae. Septula narrow, elongated, length 5 times width ( Bolivia, Brazil, Ecuador, Colombia, French Guiana, Guyana, Peru, Suriname, and Venezuela)....................................... Gymnetis holosericea (Olivier, 1789)

– Stemmata present. Anterior frontal setigerous punctures present. Haptomeral region with transverse row of 10–12 fairly stout setae. Septula oval, length 2.5 times width ( Mexico, Belize and Guatemala?)........................................ Gymnetis sallei Schaum, 1849

Figures

Figures 4–7. Gymnetis pudibunda, third instar.(4) Left mandible, in (a) dorsal,(b) lateral,and (c) ventral views; (5) right mandible, in (a) ventral, (b) lateral, and (c) dorsal views; (6) left maxilla, (a) dorsal view, (b) apex of mala showing unci, and (c) stridulatory teeth on maxilla; (7) labium, (a) dorsal view, (b) hypopharyngeal sclerome, and (c) lateral view.