Nematodes

Ants can serve as developmental, definitive, intermediate, or carrier hosts of a variety of nematodes. Parasitic ant nematodes include members of the families Mermithidae, Tetradonematidae, Allantonematidae, Seuratidae, Physalopteridae, Steinernematidae, and Heterorhabditidae. Those nematodes that are phoretically associated with ants, internally or externally, are represented by the Rhabditidae, Diplogastridae, and Panagrolaimidae. Fossils of mermithids, tetradonematids, allantonematids, and diplogastrids associated with ants show the evolutionary history of these relationships, some of which date back to the Eocene (40 mya). (Poinar, 2012)

Photo Gallery

Mermithid exposed in the gaster of Camponotus sp. from the Sierra Nevada, California (Poinar, 2012, Fig. 2).
Parasitic juveniles of Allomermis solenopsi removed from the gaster of a fire ant worker. Photo courtesy of S. D. Porter, USDA-ARS (Poinar, 2012, Fig. 2).
The fossil nematode, Heydenius formicinus, emerging from a male Prenolepis henschei in Baltic amber (Poinar, 2012, Fig. 3).
Heydenius formicinus adjacent to its worker ant host in Baltic amber (Poinar, 2012, Fig. 4).
Heydenius myrmecophila adjacent to its Linepithema ant host in Dominican amber (Poinar, 2012, Fig. 5).
Two mermithid-infected soldiers (mermithostratiotes) (arrows) of Pheidole pallidula adjacent to smaller workers and an uninfected soldier (with large head). Note smaller heads on infected soldiers. Photo courtesy of Luc Passera (Poinar, 2012, Fig. 7).
Pheromermis villosa in a carpenter ant from Holland (Poinar, 2012, Fig. 8).
Mature female of Myrmeconema neotropicum in the early stages of egg production removed from a pupa of Cephalotes atratus. Arrow shows position of vulva (Poinar, 2012, Fig. 9).
Mature females of Myrmeconema neotropicum packed with eggs in the gaster of a Cephalotes atratus worker in Peru (Poinar, 2012, Fig. 10).
Eggs of Myrmeconema neotropicum released from the gaster of an infected Cephalotes atratus worker in Peru (Poinar, 2012, Fig. 11).
Worker of Cephalotes atratus infected with Myrmeconema neotropicum. The raised, red abdomen occurs when the nematode eggs are infective and ready for transport by birds. Photo courtesy of Stephen P. Yanoviak (Poinar, 2012, Fig. 12).
Worker of Cephalotes serratus infected with Myrmeconema antiqua in Dominican amber. Note microscopic eggs widely distributed in the amber that were released from a hole in the ant’s gaster (Poinar, 2012, Fig. 13).
Detail of eggs of Myrmeconema antiqua in various stages of development in Dominican amber (Poinar, 2012, Fig. 14).
Female of the allantonematid Formicitylenchus oregonensis removed from the body cavity of Camponotus vicinus in Oregon, USA (Poinar, 2012, Fig. 15).
Parasitic female of an undescribed allantonematid from workers of Cephalotes christopherseni in Peru (Poinar, 2012, Fig. 17).
Three dauer juveniles of Formicodiplogaster myrmenema adjacent to a worker of Azteca alpha in Dominican amber (Poinar, 2012, Fig. 23).
Detail of a dauer juvenile of Formicodiplogaster myrmenema adjacent to a worker of Azteca alpha in Dominican amber (Poinar, 2012, Fig. 24).
Developing stages of Steinernema carpocapsae removed from the body of an infected queen of Solenopsis invicta (Poinar, 2012, Fig. 25).
From: Steiner et al. 2019; five immature nematodes removed from a worker of Myrmica sabuleti trapped in a pitfall near Jena, Germany.

Pheidole symbiotica

Borowiec and Salata (2015) found that the workers of the previously described species Pheidole symbiotica were simply workers of Pheidole pallidula that were infested with mermithid nematodes.

Sommimyrma symbiotica

Csosz (2012) - Bolton (1988) reported that the holotype of Sommimyrma symbiotica might have been a developmentally abnormal specimen, avoiding any further speculations. According to the images (Figs. 1a, b) probably two or three nematode worms (confirmed by nematologists, Gábor Majoros and George Poinar) nearly completely fill in the gaster of the type individual. The worms are not completely developed; these parasites apparently did not attain the preadult stage. In general characteristics of external morphology the symbiotica holotype specimen is reminiscent of the workers or mermithogenic phenotypes of Myrmica scabrinodis, hence I conducted a PCA based morphometric comparison of the type with both infested and uninfected classes of M. scabrinodis. Results demonstrate that M. symbiotica holotype is nested in the cluster of infested M. scabrinodis individuals (Fig. 2). Based on these results I propose new junior synonymy with M. scabrinodis.

Known Ant Hosts

Ant	Nematode	Locality	Source	Notes
Acromyrmex crassispinus	Panagrolaimus sp.		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Acromyrmex octospinosus	Steinerema carpocapsae		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Aphaenogaster subterranea	Mermithidae (unspecified "Mermix")	Germany (Wuerzburg)	Gösswald, 1938; Laciny, 2021
Atta cephalotes	Panagrolaimus sp.		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Atta cephalotes	Pristonchus sp.		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Azteca	Diploscapter lycostoma		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Azteca alpha	Formicodiplogaster myrmenema	Dominican amber	Poinar, 2011	Dominican amber
Camponotus aethiops	Camponotimermis bifidus		Ipateva et al., 1990
Camponotus aethiops	Comanimermis clujensis		Coman, 1953
Camponotus atriceps	Mermithidae (unspecified "Mermix")	Mexico	Wheeler, 1933; Laciny, 2021	as ''Camponotus abdominalis stercorarius''
Camponotus castaneus	Rabbium paradoxus	Florida, United States	Poinar et al., 1989
Camponotus claripes	Mermithidae (unspecified "Mermix")	Australia (NSW)	Wheeler, 1933; Laciny, 2021
Camponotus consobrinus	Mermithidae (unspecified "Mermix")	Australia (NSW)	Wheeler, 1933; Laciny, 2021
Camponotus herculeanus	Mermithidae (unspecified "Mermix")	Italy	Finzi, 1930; Laciny, 2021
Camponotus herculeanus	Oscheius dolichura		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Camponotus herculeanus	Oscheius dolichura	Ontario	Nickle & Ayre, 1966
Camponotus pompeius cassius	Mermithidae (unspecified "Mermix")	Congo	Wheeler, 1928; Laciny, 2021
Camponotus punctulatus minutior	Mermithidae (unspecified "Mermix")	Argentina	Wheeler, 1929; Laciny, 2021
Camponotus vicinus	Formicitylenchus oregonensis	Oregon, USA	Poinar, 2003
Cephalotes atratus	Myrmeconema neotropicum	Peru, Panama	Poinar & Yanoviak, 2008
Cephalotes minutus	Agamomermis cephaloti	Brazil	Poinar et al., 2006
Cephalotes serratus	Myrmeconema antiqua		Quevillon, 2018	encounter mode unknown; indirect transmission; transmission outside nest
Cephalotes serratus	Palaeoallantonema cephalotae	Dominican amber	Poinar, 2011; Quevillon, 2018	Dominican amber; encounter mode unknown; indirect transmission; transmission outside nest
Cladomyrma	Diploscapter sp.		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Cladomyrma	Sclerorhabditis sp.		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Colobopsis	Mermithidae (unspecified "Mermis")	Papua New Guinea	Maeyama et al., 1994 Laciny, 2021
Colobopsis	Mermithidae (unspecified taxon)	Brunei, KBFSC	Laciny et al., 2017	ant identified as ''Colobopsis'' sp. nrSA
Crematogaster	Diploscapter sp.		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Crematogaster	Sclerorhabditis sp.		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Eciton burchellii	Agamomermis ecitoni	Venezuela	Poinar et al., 2006
Ectatomma ruidum	Meximermis ectatommi	Mexico	Poinar et al., 2006	see also Weber, 1946 (Trinidad)
Ectatomma tuberculatum	Mermis sp.		Quevillon, 2018	encounter mode secondary; indirect transmission; transmission outside nest
Ectatomma tuberculatum	Mermithidae (unspecified "Mermix")	Panama, Trinidad	Wheeler, 1930; Laciny, 2021
Ectatomma tuberculatum	unidentified nematode	French Guiana
Formica	Diploscapter lycostoma		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Formica	Diploscapter lycostoma		Wahab, 1962
Formica fusca	Comanimermis clujensis		Coman, 1953
Formica fusca	Mermithidae (unspecified "Mermix")	Germany	Gosswald, 1930; Laciny, 2021
Formica polyctena	Oscheius dolichura		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Formica rufibarbis	Mermithidae (unspecified "Mermix")	Germany	Gosswald, 1930; Laciny, 2021
Lasius	Diploscapter lycostoma		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Lasius	Diploscapter lycostoma		Wahab, 1962
Lasius	Koerneria histophora		Wahab, 1962
Lasius	Pheromermis myrmecophila		Crawley & Baylis, 1921
Lasius	Pheromermis myrmecophila		Quevillon, 2018	encounter mode secondary; indirect transmission; transmission outside nest
Lasius	Pristionchus lheritieri		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Lasius	Pristionchus lheritieri		Wahab, 1962
Lasius alienus	"Mermis"	England (Oxford, Cornwal)	Crawley & Baylis, 1921
Lasius alienus	Mermis myrmecophila	Germany	Gosswald, 1929; Laciny, 2021
Lasius alienus	Mermithidae (unspecified "Mermix")	Germany (Wuerzburg)	Gösswald, 1938; Laciny, 2021
Lasius americanus	Allomermis (sensu Cobb)	Massachusetts, United States	Wheeler, 1928; Laciny, 2021
Lasius brevicornis	Allomermis (sensu Cobb)	Massachusetts, United States	Wheeler, 1928; Laciny, 2021
Lasius brunneus	Diplogasteroides spengelii		Kohler, 2012
Lasius brunneus	Diplogasteroides spengelli		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Lasius brunneus	Diploscapter sp.		Kohler, 2012
Lasius brunneus	Halicephalobus similigaster		Kohler, 2012
Lasius brunneus	Koerneria histophora		Kohler, 2012
Lasius brunneus	Oscheius dolichura		Kohler, 2012
Lasius brunneus	Oscheius dolichura		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Lasius claviger	Oscheius dolichura		Nickle & Ayre, 1966
Lasius claviger	Oscheius dolichura		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Lasius flavus	"Mermis"	England (Oxford, Cornwal)	Crawley & Baylis, 1921
Lasius flavus	Mermithidae (unspecified "Mermix")	Germany (Wuerzburg)	Gösswald, 1938; Laciny, 2021
Lasius flavus	Oscheius dolichura		Janet, 1893; Wahab, 1962
Lasius flavus	Oscheius dolichura		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Lasius flavus	Pheromermis myrmecophila	Ireland	O'Rourke, 1946; O’Grady & Breen, 2011; Laciny, 2021
Lasius flavus	Pheromermis villosa	Austria	Kaiser, 1986a, 1986b
Lasius neoniger	Mermithidae (unspecified "Mermix")	Europe	Wheeler, 1928; Laciny, 2021
Lasius niger	"Mermis"	England (Oxford, Cornwal)	Crawley & Baylis, 1921
Lasius niger	Mermithidae (Pheromermis sp.?)	Austria, Burgenland	Laciny, 2017
Lasius niger	Mermithidae (unspecified "Mermix")	Germany (Wuerzburg)	Gösswald, 1938; Laciny, 2021
Lasius niger	Oscheius dolichura		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Lasius niger	Pheromermis lasiusi		Rubstov, 1970
Lasius niger	Pheromermis myrmecophila	Ireland	O'Rourke, 1946; O’Grady & Breen, 2011; Laciny, 2021
Lasius niger	Pheromermis villosa	Austria	Kaiser, 1986a, 1986b
Leptothorax acervorum	Mermithidae (unspecified "Mermix")	Germany	Gosswald, 1930; Laciny, 2021
Linepithema	Heydenius myrmecophila		Quevillon, 2018	encounter mode unknown; indirect transmission; transmission outside nest
Linepithema	Heydenius myrmecophila	Dominican amber	Poinar et al., 2006	Dominican amber fossil
Linepithema humile	Diploscapter lycostoma		Markin & McCoy, 1968
Myrmecia forficata	Mermithidae (unspecified "Mermix")	Australia (Victoria)	Wheeler, 1933; Laciny, 2021
Myrmica	Steinerema carpocapsae		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Myrmica gallienii	Mermithidae (unspec.)	Hungary	Csosz & Majoros, 2009; Laciny, 2021
Myrmica rubra	Mermithidae (unspec.)	Poland	Czechowsk et al., 2007; Laciny, 2021
Myrmica rubra	Mermithidae (unspecified "Mermix")	Germany	Gosswald, 1930; Laciny, 2021
Myrmica ruginodis	Mermithidae (unspecified "Mermix")	Germany	Gosswald, 1930; Laciny, 2021
Myrmica rugulosa	Diploscapter lycostoma		Wahab, 1962
Myrmica rugulosa	Mermithidae (unspec.)	Poland	Czechowsk et al., 2007; Laciny, 2021
Myrmica rugulosa	Mermithidae (unspecified "Mermix")	Germany	Gosswald, 1930; Laciny, 2021
Myrmica sabuleti	Hexamermis/Agamermis	Germany	Steiner et al., 2019; Laciny, 2021
Myrmica sabuleti	Mermithidae (unspec.)	Poland	Czechowsk et al., 2007; Laciny, 2021
Myrmica scabrinodis	"Mermis"	Hungary, France, Austria, Italy	Csosz, 2012; Laciny, 2021	infected ant described as ''Sommimyrma symbiotica'', now ''Myrmica scabrinodis''
Myrmica scabrinodis	Mermithidae (unspecified "Mermix")	Germany	Gosswald, 1930; Laciny, 2021
Myrmica schencki	Mermithidae (unspecified "Mermix")	Germany	Gosswald, 1930; Laciny, 2021
Myrmica sulcinodis	"Mermis"	Hungary, France, Austria, Italy	Radchenko & Elmes, 2003; Csosz, 2012; Laciny, 2021
Neoponera inversa	Mermithidae (unspecified "Mermix")	Colombia	Wheeler, 1928; Laciny, 2021
Neoponera villosa	Mermithidae (unspecified "Mermix")	Neotropics	Wheeler, 1928; Laciny, 2021
Odontomachus chelifer	Mermithidae (unspecified "Mermix")	Neotropics	Wheeler, 1928; Laciny, 2021
Odontomachus haematodus	Mermithidae (unspecified "Mermix")	Neotropics	Wheeler, 1928; Laciny, 2021
Odontomachus hastatus	Agamomermis costaricensis	Costa Rica	Poinar et al., 2006
Pachycondyla fuscoatra	Mermithidae (unspecified "Mermix")	Neotropics	Wheeler, 1928; Laciny, 2021
Pachycondyla striata	Mermithidae (Mermithidae (unspecified "Mermis")	Paraguay	Strelnikov, 1928; Laciny, 2021
Paraponera clavata	Mermithidae (unspecified "Mermix")	Neotropics	Wheeler, 1928; Laciny, 2021
Pheidole absurda	Mermithidae (unspecified "Mermix")	Neotropics	Wheeler, 1928; Laciny, 2021
Pheidole dentata	Mermithidae (unspecified "Mermix")	Texas, United States	Wheeler, 1901; Wheeler, 1928; Laciny, 2021	as ''Pheidole commutata''
Pheidole gouldi	Mermithidae (unspecified "Mermix")	Guatemala	Wheeler, 1928; Laciny, 2021
Pheidole pallidula	Hexamermis	France	Passera, 1976; Laciny, 2021
Pheidole pallidula	Mermithidae (unspecified "Mermix")	France	Wheeler, 1928; Laciny, 2021
Pheidole sauberi	Mermithidae (species unspecified)	Philippines	General & Buenavente, 2021
Pheidole susannae	Mermithidae (unspecified "Mermix")	Guatemala	Wheeler, 1928; Laciny, 2021
Pheidole vorax	Mermithidae (unspecified "Mermix")	Guatemala	Wheeler, 1928; Laciny, 2021
Pogonomyrmex	Steinerema carpocapsae		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Pogonomyrmex barbatus	Skrjabinoptera phrynosoma	Texas, United States	Lee, 1957
Polyrhachis delecta	Mermithidae (unspec.)	Australia (N. Queensland)	Downes, 2017; Laciny, 2021
Polyrhachis monteithi	Mermithidae (unspec.)	Australia (N. Queensland)	Downes, 2017; Laciny, 2021
Prenolepis henschei	Heydenius formicinus	Baltic amber	Poinar, 2002	Baltic amber fossil
Prolasius advena	Diploscapter formicidae		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Prolasius advena	Diploscapter formicidae	New Zealand	Zhao et al., 2013
Solenopsis	Steinerema carpocapsae		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Solenopsis fugax	Mermithidae (unspecified "Mermix")	Germany	Gosswald, 1930; Laciny, 2021
Solenopsis fugax	Mermix	Germany	Gosswald, 1929; Laciny, 2021
Solenopsis geminata	Mermithidae (unspec.)	USA, Florida	McInnes & Tschinkel, 1996; Laciny, 2021
Solenopsis geminata	Mermithidae (unspec.)	USA, Florida	Mitchell & Jouvenaz, 1985; Laciny, 2021
Solenopsis geminata	Steinerema carpocapsae		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Solenopsis invicta	Allomermis solenopsi	Argentina	Poinar et al., 2007; Laciny, 2021
Solenopsis invicta	Diploscapter sp.		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Solenopsis invicta	Heterorhabditis bacteriophora		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Solenopsis invicta	Mermithidae (unspec.)	USA, Florida	McInnes & Tschinkel, 1996; Laciny, 2021
Solenopsis invicta	Mesorhabditis longespiculosa		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Solenopsis invicta	Oscheius dolichura		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Solenopsis invicta	Sclerorhabditis sp.		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Solenopsis invicta	Steinerema carpocapsae		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Solenopsis invicta	Steinernema carpocapsae		Poinar, 2012
Solenopsis invicta	Tetradonema solenopsis	Brazil	Nickle & Jouvenaz, 1987
Solenopsis pergandei	Mermithidae (unspec.)	USA, Florida	McInnes & Tschinkel, 1996; Laciny, 2021
Solenopsis richteri	Heterorhabditis bacteriophora		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Solenopsis richteri	Steinerema carpocapsae		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Solenopsis richteri	Tetradonema solenopsis	Argentina	Jouvenaz & Wojcik, 1990
Temnothorax interruptus	Mermithidae (unspecified "Mermix")	Germany	Gosswald, 1930; Laciny, 2021
Temnothorax ravouxi	Mermithidae (unspecified "Mermix")	Germany	Gosswald, 1930; Laciny, 2021	as ''Epimyrma gösswaldi''
Temnothorax tuberum	Mermithidae (unspecified "Mermix")	Germany	Gosswald, 1930; Laciny, 2021
Temnothorax unifasciatus	Mermithidae (unspecified "Mermix")	Germany	Gosswald, 1930; Laciny, 2021
Tetramorium caespitum	Mermithidae (unspecified "Mermix")	Germany (Wuerzburg)	Gösswald, 1938; Laciny, 2021
Tetramorium caespitum	Mermithidae (unspecified "Mermix")	Switzerland (Wallis)	Kutter, 1958; Laciny, 2021
Tetramorium caespitum	Oscheius dolichura		Quevillon, 2018	multiple encounter modes; indirect transmission; transmission outside nest
Tetramorium caespitum	Oscheius dolichura		Wahab, 1962

References

Borowiec, L. & Salata, S. 2015. Pheidole symbiotica Wasmann, 1909, an enigmatic supposed social parasite, is a nematode infested form of Pheidole pallidula (Nylander, 1849) (Hymenoptera: Formicidae: Myrmicinae). Sociobiology, 62, 181-186 (doi:10.13102/sociobiology.v62i2.181-186).
Csősz, S. 2012. Nematode infection as significant source of unjustified taxonomic descriptions in ants (Hymenoptera: Formicidae). Myrmecological News, 17, 27-31.
Poinar, G., Jr. 2012. Nematode parasites and associates of ants: Past and present. Psyche, 2012, Article ID 192017, 13 pages (DOI 10.1155/2012/192017).
Steiner, F.M., Kohler, G., Seifert, B., Arthofer, W., Schlick-Steiner, B.C., Buschinger, A. 2019. A worker-like female of Myrmica sabuleti Meinert, 1861 (Hymenoptera: Formicidae: Myrmicinae) in a pitfall trap with five mermithids (Nematoda: Mermithidae) protruding from the gaster. Sociobiology 66(3): 400-407 (doi:10.13102/sociobiology.v66i3.4338).