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Maui Invasive Species Committee (MISC)

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Insolent Pennant Ant

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Insolent Pennant Ant

Tetramorium insolens

Species Info General

Other common names include: n/a

Though widespread on Maui, this ant doesn’t invade houses and it persists in relatively low numbers, so it is not often encountered.  It is a good-sized reddish-yellow ant that might easily be mistaken for a Tropical Fire Ant (Solenopsis geminata) by the casual observer.  But this is an unaggressive, monomorphic species, while Tropical Fire Ants are highly aggressive and polymorphic.  Furthermore, Insolent Pennant Ants are more likely to be encountered (if at all) in wetter parts of the islands, while Tropical Fire Ants are common in dryer leeward areas.

Though this ant has been turning up in tropical Pacific locales since at least the 1960s, very little has been published about its habits.  Wang et al. (2022) wrote that “Tetramorium insolens is associated with a wide variety of different habitats in Singapore, from mangrove back forest to urban cultivated patches, also disturbed secondary forest fragments in urban or semi-urban settings”, and that this species has been noted nesting arboreally.  Roberts & McGlynn (2004) suggested that on Mauritius this ant has the potential to interfere with pollination systems in undisturbed forests, particularly with native orchids.

Attribution: Mason Salem, CC BY-NC 4.0, via iNaturalist obs 175692377
Attribution: Jonghyun Park, CC BY-NC 4.0, via iNaturalist.org obs 255217531
Attribution: antpassionant, CC BY-NC 4.0, via iNaturalist obs 263595900 (cropped)
Attribution: Max Devis, CC BY-NC 4.0, via iNaturalist obs 309819500 (cropped)
Attribution: elpeltier, CC BY-NC 4.0, via iNaturalist obs 334824003

Identification/Description

This is a biggish red-yellow ant with a bright gaster.  It is very similar to the Bicolored Pennant Ant (Tetramorium bicarinatum), a far more common and widespread species.  The gaster of the Insolent Pennant Ant is usually a bright yellow, while that of the Bicolored Pennant Ant is consistently dark.

Attribution: Oliver Yung, CC BY-NC 4.0, via iNaturalist.org obs 257077722
Attribution: Damon Tighe, CC BY-NC 4.0, via iNaturalist obs 300606626

Impacts

  • Very little is known about this ant’s habits and potential impacts.  It appears to exist in low numbers on Maui, suggesting that any impacts it does have are relatively light.

History

  • The first record of Insolent Pennant Ants in the Islands dates to 1993 (Kumashiro et al. 2001).  The earliest record for Maui is 2014 (Maui Invasive Species Committee, unpub. data).  It has not been recorded on Molokaʻi, Lānaʻi or Kahoʻolawe.

Resources/References

  • Tetramorium insolens – AntWiki
  • Kumashiro, B. R., Heu, R. A., Nishida, G. M. & Beardsley, J. W.  2001.  New State Records of Immigrant Insects in the Hawaiian Islands for the Year 1999. Proceedings of the Hawaiian Entomological Society 35: 170–184.
  • Roberts, D. L. & McGlynn, T. P.  2004.  Tetramorium insolens Smith (Hymenoptera: Formicidae): a new record for Mauritius, Indian Ocean. African Entomology 12(2): 265–267.
  • Wang, W. Y., Soh, E. J. Y., Yong, G. W. J., Wong, M. K. L., Guénard, B., Economo, E. P. & Yamane, S.  2022.  Remarkable diversity in a little red dot: a comprehensive checklist of known and species in Singapore (Hymenoptera: Formicidae) with notes on ecology and taxonomy. Asian Myrmecology 15: 1–152..