The ant Ph. flavens was frequent and widespread in small mixed populations of D. gigantea and P clavata and distributed in several chambers, therefore, it is believed to be a facultative resident species in nests as this ant is commonly found in leaf-litter samples. Ph. flavens is a tiny ant of approximately 1mm length, which can circulate without being inconvenienced in the nests of those giant ants. This ant possible feeds on prey remains and other resources available in detritus accumulated in different places in the chambers of these nests (Delabie et al. 2007).
The presence of small species of Pheidole in the nests of Dinoponera has been sometimes reported in Dinoponera and Pheidole studies, for example, different species of Pheidole in nests of D. quadriceps by Vasconcellos et al. (2004); Pheidole rudigenis Emery, 1906 in nests of Dinoponera lucida Emery, 1901 and Pheidole dinophila Wilson 2003 in nest of Dinoponera australis [= Dinoponera grandis (Guérin-Menéville, 1838)] (Wilson 2003); and Ph. flavens in nests of P. clavata (Moreira et al. 2020).
The other ant species found in the nests were Brachymyrmex heeri Forel, 1874, Carebara sp.1, Centromyrmex brachycola (Roger, 1861), Gnamptogenys moelleri (Forel, 1912), Hypoponera sp.1, Pheidole sp.2 (grupo diligens), Pseudomyrmex gracilis (Fabricius, 1804), Pseudomyrmexsp.1, Pseudoponera gilberti (Kempf, 1960), Solenopsis sp.1, Solenopsis sp.2, Strumigenys elongata Roger, 1863, Strumigenys perparva Brown, 1958, Strumigenys sp.1, were considered tourist species in this study (Belshaw and Bolton 1993, 1994). Here we call “tourist” the ants whose workers occasionally forage outside or even inside the nests of other ants, but which are never resident.
Mites were the most abundant group in the nests of D. gigantea and P. clavata with more than 30% of the total abundance. This group is frequently found in nests of different groups of ants such as Ponerinae and Formicinae in a range of environments (Arroyo et al. 2015; Lopes et al. 2015; Moreira et al. 2020). In Mexico Rocha et al. (2020) found mites in more than 98% of Neoponera villosa (Fabricius, 1804) nests.
The Laelapidae family is cosmopolitan and includes mites living in a diversity of habitats and associations. These mites can live freely in the soil or associated with other arthropods, and some of them have parasitic habits, living as ectoparasites of mammals (Casanueva 1993). Silva et al. (2018) showed that a species of genus Cosmolaelaps Berlese, 1903 is associated with Neoponera inversa (Smith) and suggested that the mite uses the ant for phoresis. Rocha et al. (2020) observed another species of the same genus living in nests of Neoponera villosa (Fabricius, 1804). In this case, the authors considered this genus kleptoparasite, as this mite was observed in groups or alone on the ventral region of ant larvae feeding directly on it or from the food brought by the workers. In our study, no evidence of kleptoparasitism was observed.
The mites of genus Uroobovella (Urodinychidae) probably use ant nests as shelters, or looking for food. The adults use ants for phoresy (Lehtinen 1987).
Between the oribatid mites, species of Galumnidae maintain phoretic relationships with the Ponerinae N. villosa (Rocha et al. 2020).
Regarding the springtails (Collembola) found in our study, the genera that stood out were Seira, Proisotoma and Cyphoderus. Cyphoderus is extremely common in ant nests, since it is abundant and found in the nests of several ant species (Castaño-Meneses et al. 2014, 2015; Oliveira et al. 2023). Recently, Mota-Filho et al. (2021) found Cyphoderus innominatus Mills, 1938, in Atta sexdens nests in an Atlantic Forest-Cerrado transition area of the state of São Paulo. The occurrence of this genus is attributed to the large amount of resources available, as these organisms have a special attraction for the mycelium of the fungus cultivated by ants (Kistner, 1982).
In their study with the army ant Eciton burchellii (Westwood, 1842) Rettenmeyer et al. (2011) observed more than 300 species associated with this ant. The authors point out that mites and springtails are part of this fauna, and they recorded phoretic mites from the families Scutacaridae and Pygmephoridae as well as other Uropodina mites living in garbage deposits. A large number of Collembola, including some Cyphoderus, were also found in the waste dumps. Given the frequency and abundance observed in nests of different ant species, some mites and springtails, along with other invertebrates, can be considered authentic myrmecophiles, benefiting from the social habits of their hosts.
Glasier et al. (2018) preferred not to include mites and springtails in their analyses, as, according to these authors, there are few conclusions about the myrmecophily of these organisms, in addition to the difficulty of identifying these arthropods. However, at the light of our own observations, we consider mites and springtails as myrmecophiles as other authors (Rettenmeyer et al. 2011; Castaño-Meneses et al. 2015; Araújo et al. 2019; Castaño-Meneses et al. 2017, 2019; Moreira et al. 2020; Rocha et al. 2020 ) .
We observed the occurrence of Blatellidae and more frequently, Isoptera (Blattodea), in some chambers. In general, ants are considered termite predators (Tuma et al. 2020). Furthermore, the occurrence of termites in our samples is justified by the fact that certain ant nest were very close to the termite mounds, leading to the intersection of the ant chambers with the termite mound galleries. Elsewhere this is a commonly observed situation (see Santos et al., 2010). For these reasons, the observation of termites in giant ant nests requires a more detailed study.
Some spiders use ant nests as shelter to actively hunt prey around (Cushing 2012). In some cases, they even feed on the ants themselves (Rosa, 2008).
Other Arachnids, such as Pseudoscorpiones and Opiliones, may have a relationship of predation on the ant larvae in the nests and may also use the place as a shelter. Rocha et al. (2020) suggested that the relationship between pseudoscorpions and N. villosa was predation, since individuals of Chelodamus mexicolens Chamberlin, 1925 were clearly observed feeding on the ant larvae.
The myriapods found in our study, represented by the orders Scolopendromorpha and Geophilomorpha, are organisms that penetrate larger ant nests where they seek a favorable humid microclimate. Individuals also usually build systems of galleries in the ground or under rocks and logs that give them access to a cavity where the animal hides. It is suspected too that, as they are predators of several types of invertebrates including small arthropods, ants could be a particularly interesting food resource for this group of animals (Voigländer 2011).
Several immatures and adults of beetles were observed during our study, in particular, Staphylinidae, which are common in ant nest of many species (Parker 2016). These are organisms that present different levels of association, ranging from simple visitors to parasites. Some beetles enter to ant nests to feed on living or dead insects or even ant larvae; other eat detritus, nest residues and fungi that grow around (Lacau et al. 2001; Staniec and Zagaja 2008; Lapeva–Gjonova 2013).
The Psocotera family Liposcelididae has been reported to occur in nests of Formica rufa or Formica pratensis (Ostrovsky and Georgiev 2020). Many species of this family are anthropophile and are widely distributed (Lienhard 1998). In general, these animals prefer places with a microclimatic stability: an average temperature of 30ºC and relative humidity of 70%, ideal conditions for the realization of their biological cycle (Rees and Walker 1990). The ant nests offer these conditions that must be particularly favorable for these organisms.
Other groups of invertebrates were also sampled, such as Chordeumatida, Dermaptera, Diplura, Hemiptera, Opiliones and Thysanoptera. All of these have appeared with some frequency in studies that address commensals of poneromorph ants (Araújo et al. 2019; Moreira et al. 2020; Rocha et al. 2020). Most of them are detritivorous animals, acting mainly in decomposition and nutrient cycling (Hopkin and Read 1992). Their occurrence in ant nests studied seem due to its type of diet and the high amount of decomposing organic material available as a food source.
On the other hand, Plecoptera appears for the first time as a myrmecophilous organism. The diet of adults is variable, with some genera depending on spores and pollen while others feed on green algae or lichens (Tierno de Figueroa and López-Rodríguez 2019). Its occurrence here is certainly casual, since we found a specimen only once.
The record of an Amphisbaenidae (unidentified) was also due to the fact that these animals spend the entirety of their life cycle underground, and that their diet is based on the consumption of arthropods, especially ants (Esteves et al. 2008; Balestrin and Cappellari 2011), which could explain its presence in the ant nests. In the ant nest, several observations of associations between ants and reptiles have been reported, mainly as predation (Goldsbrough et al. 2006; Whitfield and Donnelly 2006; Balestrin and Cappellari 2011) or inquinilism (Oliveira and Della Lucia 1993).
Gastropod have been recorded in the nests of Diacamma, Mayaponera and Neoponera (Verdcourt 2002; Witte et al. 2002; Eguchi et al. 2005; Araújo et al. 2019; Castaño-Meneses et al. 2019; Dias-Soares et al. 2024). In these nests, the differents interactions of myrmecophily and also the gastropod species were varaible, as example, in netss of Leptgenys processionalis distinguenda (Jerdon, 1851) events of facultative commensalisms or obligate symbiosis were observed only between the ant and Allopeas myrmecophilos (Janssen and Witte, 2002) according with Witte et al. (2002). Also Eguchi et al. (2005) recorded, in nests of Diacamma scalpratum (Smith, 1858), the trasport of four species of gastropods by ant workers and also the active entry of these mollusks into the ant’s nests. In the Neotropics, of the eight species of gastropods recorded in nests of N. verenae there are observations of interactions such as antennal touches between ant workers and six species of gastropods, in addition to the movement of mollusks in the nest chambers in the field and in the laboratory recorded by Dias-Soares et al. (2024).
Other groups considered as commensals in the nests were symphylans and other groups corroborate the studies by Araújo et al. (2019); Castaño-Meneses et al. (2019); Hölldobler and Wilson (1990); Lapeva-Gjonova (2013) and Rocha et al. (2020), which include these organisms as commensals in ant nests of different species.
Table 2
Fauna associated to nests of the giant ant species D. gigantea and P. clavata, collected in three municipalities in the state of Maranhão.
Class/subclass | Order/Suborder | Family | Genus/Species | Abundance |
Arachnida | Araneae | Araneidae | Araneus | 2 |
Arachnida | Araneae | Corinnidae | | 6 |
Arachnida | Araneae | Corinnidae | Attacobius | 4 |
Arachnida | Araneae | Corinnidae | Abapeba | 10 |
Arachnida | Araneae | Nemesiidae | | 2 |
Arachnida | Araneae | Theridiidae | | 1 |
Arachnida | Araneae | Ctenidae | Parabatinga | 3 |
Arachnida | Mesostigmata (Oribatida) | | | 77 |
Arachnida | Mesostigmata (Oribatida) | Ameroseiidae | | 1 |
Arachnida | Mesostigmata (Oribatida) | Ascidae | | 3 |
Arachnida | Mesostigmata (Oribatida) | Chaetodactylidae | | 1 |
Arachnida | Mesostigmata (Oribatida) | Laelapidae | | 24 |
Arachnida | Mesostigmata (Oribatida) | Macrochelidae | | 3 |
Arachnida | Mesostigmata (Oribatida) | Parasitidae | | 153 |
Arachnida | Mesostigmata (Oribatida) | Phytoseiidae | | 6 |
Arachnida | Mesostigmata (Oribatida) | Podocinidae | Podocinum | 1 |
Arachnida | Mesostigmata (Oribatida) | Rhodacaridae | | 12 |
Arachnida | Mesostigmata (Oribatida) | Uropodidae | | 9 |
Arachnida | Mesostigmata (Oribatida) | Uropodidae | Uropoda sp. | 3 |
Arachnida | Mesostigmata (Oribatida) | Uropodidae | Trachyuropoda | 3 |
Arachnida | Opiliones | | | 2 |
Arachnida | Pseudoscorpiones | | | 88 |
Arachnida | Sarcoptiformes | Glycyphagidae | | 8 |
Arachnida | Sarcoptiformes | | | 99 |
Arachnida | Sarcoptiformes | Carabodidae | | 2 |
Arachnida | Sarcoptiformes | Euphthiracaridae | | 1 |
Arachnida | Sarcoptiformes | Galumnidae | | 2 |
Arachnida | Sarcoptiformes | Haplochthoniidae | | 1 |
Arachnida | Sarcoptiformes | Malaconothridae | | 1 |
Arachnida | Sarcoptiformes | Nothridae | | 2 |
Arachnida | Sarcoptiformes | Oppidae | | 9 |
Arachnida | Sarcoptiformes (Astigmata) | Acaridae | | 1 |
Arachnida | Sarcoptiformes (Astigmata) | Histiostomatidae | | 2 |
Arachnida | Sarcoptiformes (Astigmata) | Histiostomatidae | Histiostoma sp. | 2 |
Arachnida | Sarcoptiformes (Astigmata) | Hyadesiidae | | 1 |
Arachnida | Sarcoptiformes (Astigmata) | | | 1 |
Arachnida | Tombidiformes | Trombidiidae | | 4 |
Arachnida | Araneae | Idiopidae | Idiops | 1 |
Arachnida | Mesostigmata | Urodinychidae | Uroobovella | 146 |
Chilopoda | Geophilomorpha | | | 1 |
Chilopoda | Scolopendromorpha | | | 1 |
Chilopoda | | | | 6 |
Chilopoda | | | | 3 |
Clitellata | | | | 2 |
Diplopoda | Chordeumatida | | | 18 |
Entognatha | Collembola/Entomobryomorpha | | Seira | 103 |
Entognatha | Diplura | | | 1 |
Entognatha | Diplura | Campodeidae | | 15 |
Entognatha | Diplura | Parajapygidae | | 8 |
Entognatha | Collembola/Entomobryomorpha | Istomomidae | Proisotoma | 46 |
Entognatha | Collembola/Entomobryomorpha | Paronellidae | Cyphoderus | 66 |
Entognatha | Collembola/Entomobryomorpha | Isotomidae | Folsomina | 21 |
Gastropoda | | | | 5 |
Insecta | Blattodae/Blattaria | | | 20 |
Insecta | Blattodae/Termitidae | | Syntermes sp. | 7 |
Insecta | Blattodae/Termitidae | | Subulitermes | 363 |
Insecta | Coleoptera | | | 11 |
Insecta | Coleoptera | Staphylinidae | | 4 |
Insecta | Dermaptera | | | 2 |
Insecta | Hemiptera | Aphididae | | 1 |
Insecta | Hymenoptera | Formicidae | | 26 |
Insecta | Hymenoptera | Formicidae | Brachymyrmex heeri Forel, 1874 | 9 |
Insecta | Hymenoptera | Formicidae | Carebara sp.1 | 4 |
Insecta | Hymenoptera | Formicidae | Centromyrmex brachycola (Roger, 1861) | 1 |
Insecta | Hymenoptera | Formicidae | Gnamptogenys moelleri (Forel, 1912) | 1 |
Insecta | Hymenoptera | Formicidae | | 1 |
Insecta | Hymenoptera | Formicidae | Hypoponera sp. 1 | 3 |
Insecta | Hymenoptera | Formicidae | Pheidole flavens Roger, 1863 | 277 |
Insecta | Hymenoptera | Formicidae | Pheidole sp.2 (grupo diligens) | 2 |
Insecta | Hymenoptera | Formicidae | Solenopsis sp.1 | 23 |
Insecta | Hymenoptera | Formicidae | Solenopsis sp.2 | 1 |
Insecta | Hymenoptera | Formicidae | Strumigenys sp.1 | 1 |
Insecta | Hymenoptera | Formicidae | Strumigenys elongata Roger, 1863 | 41 |
Insecta | Hymenoptera | Formicidae | Pseudomyrmex gracilis (Fabricius, 1804) | 1 |
Insecta | Hymenoptera | Formicidae | Strumigenys perparva Brown, 1958 | 1 |
Insecta | Hymenoptera | Formicidae | Pseudomyrmex sp.1 | 1 |
Insecta | Plecoptera | | | 1 |
Insecta | Psocoptera | | | 4 |
Insecta | Psocoptera | Caeciliusidae | | 1 |
Insecta | Psocoptera | Liposcelididae | | 2 |
Insecta | Thysanoptera | Thripidae | | 1 |
Insecta | Coleoptera | Cantharidae | | 2 |
Insecta | Coleoptera | Chrysomelidae | | 4 |
Insecta | Hemiptera | | | 3 |
Insecta | Lepidoptera (Imaturo) | | | 16 |
Insecta | Diptera (Imaturo) | | | 4 |
Reptilia | Squamata | Amphisbaenidae | | 1 |