Ants: Important Component of Insect Community
Forest areas support a great diversity of insect fauna. Ants form an important component of the insect community in forest areas as well as urban areas. As the forest provides a wide range of ecological niches, vegetation, food, and woody debris for nesting, these habitats are widely studied by researchers for ecological studies. Research associated with ants has been reported in the following chapter. Different stages of sampling include collection, segregation, and later followed by identification. These sampling techniques are discussed on the basis of the methodology used by myrmecologists. Ants collection is done using different techniques viz, hand pick, pitfall traps, leaf litter, bait traps, and soil sifting are commonly used to sample ants. Torchote et al. studied the ant composition of Thailand in three different habitats and utilized five sampling methods. Authors recorded higher diversity in handling capture than the other four methods. King and Porter collected ants using four sampling methods. Different sampling techniques all-out search, pitfall traps, leaf litter traps, bait traps, etc, are utilized to collect the ants from the study areas. Bharti et al. employed six methods for ant collection from different altitudes in Jammu and Kashmir. Bharti had performed scanning, studying, and comparing the literature on ants with his work and others' work in the Himalayan region. Silva et al. employed three sampling methods in the forest of Sri Lanka. Lawes et al. sampled ants trapping in three ways and leaf litter. Ribas et al. reviewed the sampling techniques and stated that bait traps, hand collection, pitfall traps, Winkler’s extractors, and Barlese extraction most common sampling methods in Brazil. Tiwari and Tiwari employed hand picking, sweeping, and bait traps at Sanctuary in Orissa. Dad et al. employed five techniques at eight sites and reported the lowest richness at Manalar, while the highest at Tiger reserve. Gayathri and Roopavathy surveyed ant diversity by a combination of four methods at Kerala. Saumya et al. used a combination of methods from the forest of Sri Lanka.
All out search: Chantarasawat et al. from the forest of Northern Thailand; Wilkie et al. from the Ecuador forest reported high diversity was recorded in hand collection than pitfall traps. Leong et al. sampled hand collection combined with Winkler extractor from the hills and island of Macau (China). Ellison et al. had discussed comparisons of sampling efficiency by hand collecting accumulated species more efficiently than other commonly used pitfall traps or baits. Ryder Wilkie et al. reported more diverse species by hand search as compared to the pitfall trap method. Amarasinghe reported hand collection recorded higher species than other methods from the home garden in Sri Lanka. Sabitha et al. utilized intense all-out search and bait traps from the forest of Kerala (India). Sundareswari et al. from Sivakasi (Tamil Nadu) employed all-out search and pitfall traps for ant collection. Azhagu et al., employed the combination of all out search, bait traps, and hand collection from College Campus (Tamil Nadu). Hashimoto and Mohamed, utilized hand sampling for the ant sampling in the soil cores from the forest in Malaysia.
Pitfall trap: Lasmar et al. sampled the collection of ants using only pitfall traps both ground and arboreal traps (familiarization effect) from the Brazilian forest. However, Majer suggested a combination of methods should be used for a complete census of ant sampling. Wang et al. from the USA utilized only pitfall trapping from the forest, treated with microbial pesticides. Wang et al. reported that the pitfall trap served to be more predominant than the bait trapping method. Pacheco and Vasconcelos reported that subterranean traps trapped fewer species than conventional traps from the forest in Brazil. The authors used a combination of sardine and oil to attract ants in the trap. Basu employed pitfall traps in the primary forest and logged forest of Western Ghats (India). This method was also used by Greenslade to sample the populations of coleopterans.
Leaf litter and Winkler method: Delsinne and Arias-Penna utilized ALL (Ants of the Leaf Litter) in the Ecuadorian forest and reported that moisture content in the leaf litter, might descend the abundance of ants. Fisher; Delabie et al.; and Bestelmeyer endorsed the use of the Winkler method from the leaf litter of forest habitats. Groc et al. from the forest of French Guiana (South America); Wiezik et al. from the forest in Boky Nature Reserve (Slovakia); a used a combination of pitfall traps and the Winkler method. Many myrmecologists, Fischer, have favored Winkler sacks of leaf litter. However, Gotelli et al. reported this method to be more effective in forests and shrublands.
Bait traps: Stanley and Ronbinson, conducted an experiment using bait traps focusing on the preference of Paratrechina longicornis and reported their attraction towards Tuna and Xstinguish than the sweets provided. Nyamukondiwa and Addison reported the bait preferences of three ant species (Linepithema humile (Mayr), Anoplolepis custodians (F. Smith), and Crematogaster peringueyi (Emery)) from Stellenbosch Winelands region (South Africa). Authors reported that wet baits were more preferred than dry baits, due to easy transporting conditions. Yamaguchi and Hasegawa used bait traps (live mealworms as bait) at different depths (10, 20, 30, and 50 cm) and captured Tetramorium caespitum and Solenopsis japonica.
During sampling, environmental conditions also play an important role, hence seasons were also accountable for the sampling protocols, however analyzing the best season or method will be uncertain. Tiede et al. sampled ant species from southern Ecuador and reported that the species occurrence was more in the dry season. Azcarate et al. reported that Messor barbarus species was the first to repair the nest structure after the rainfall from the Mediterranean grassland near Madrid. Kharbani and Hajong had reported that ant abundance was higher in the warmer season than in dry and cold seasons from the ant's species collected from Meghalaya. Ant species were noted to be abundant in the dry season than wet, from the urban and peri-urban regions reported by Chate and Chavan.
Post collection and identification plays a major part, and discussion of subfamilies, genus, and species was provided by many researchers, including Brown (1952, 1959, 1960, and 1975); Bolton (1974, 1977); Shattuck (1992). A huge number of Formicidae population operates the forest habitat with their varied roles in its ecosystem. The study of ants was conducted from the forest habitat of various countries for multiple reasons. Dostal et al., recorded the influence of ants on the soil properties of the forest habitats in Slovakia. Similar observations were noted by Beattie and Culver, (1983); Carlson and Whiteford, (1991); Dean et al., (1997), discussing the fluctuations in the soil properties and their positive effects on the plants. Bruhl et al., (1999), reported that specialized feeding ants had enough food like springtails in the leaf litter of the primary forest in Malaysia resulting in high numbers and diversity. Norasmah et al., (2012) studied the foraging pattern of Tetraponera rufonigra from Malaysia. Authors stated that they forage for about 12 hours and decreased in the afternoon and this provided opportunity for other species (Pheidole sp, Crematogaster sp) to forage for the food. Camarota et al., 2016 recorded Camponotus, Crematogaster, Solenopsis, and Tapinoma as the frequent genera from Neotropical savanna (Brazil). Knaden and Graham (2015), reported the navigation of ants involves different styles to recollect their path. Kovar et al., (2001) recorded the effects of ant mounds and their vegetation in the mountain grassland of Slovakia. Petal, (1978) observed ants and termites' behavior; Levan and Stone (1983) studied the soil effect; Torgersen and Bull (1995) observed woodpecker behavior from the forest of Oregon (U.S); McIver et al., (1997) observed the mountain ants and these authors reported that ants serve to be the prey for various birds, amphibians and reptiles. Hosoishi et al. reported Camponotus and Pheidole as the most dominant genera from the forest in Cambodia. Clouse (2007) stated that Tetramorium smithi is widely distributed in the Indomalayan and Australian regions, along with several pacific islands.
Andersen and Jonathan, (2004) in Australia, reported that invertebrate monitoring does not require comprehensive surveys, and should be provided to the land managers as a powerful tool for environmental monitoring. Piper et al., (2009) reported the genus Pheidole as a potential rainforest indicator in tropical and subtropical Australia. Majer et al., (2007) reported that ants prove to be the best bioindicators as compared to other invertebrates and vertebrates in bauxite and mineral sand mines in Australia.
Nakamura et al., (2007) suggested that shade is essentially needed for the colonization of rainforest ants in eastern subtropical Australia. Souza- Campana et al., (2016), reported Pheidole, Camponotus, and Solenopsis as the richest genera in the Atlantic Forest biome. Azuma et al., (2006) reported the geographical distribution as per the genetic diversity of Oecophylla smaragdina from 35 localities in Japan. Higgins et al., (2017) from Canada; Lindgren and MacIsaac (2002) from British Columbia; and Warren et al., (2012) from British Columbia stated that woody debris serves as an essential asset for the ant community in the forest. Gunawardene et al., (2008) recorded low species richness in the unlogged forests than in logged forests and forest dynamics in Sri Lanka. Walter et al., (2018) reported that nesting of ant species in undisturbed woody habitats was more favorable for than the disturbed locations in Puerto Rico. Cannicci et al., (2008) reported that ants had a positive effect on mangrove performance. Nielsen et al., (2003), recorded the carbon dioxide concentration of the Polyrhachis Sokolova (mangrove ant) and suggested that ants undergo physiological changes to survive in the intertidal zone of mangrove forest. Grampurohit and Karkhanis (2013), reported Lasius niger, Camponotus pennysylvanicus, and Formica (Wood ants) from the Godrej mangrove ecosystem in Mumbai (India).
