Ants of Agricultural Fields in Vietnam (Hymenoptera: Formicinae)

Home , Camponotus rufoglaucus, Ectomomyrmex, Formicinae, Lioponera, Meranoplus bicolor, Odontoponera

Bull. Inst. Trop. Agr., Kyushu Univ. 33: 1-11, 2010

Le Ngoc Anh1)*, Kazuo Ogata1) and Shingo Hosoishi1)

Abstract

List of ants in various agricultural lands of Vietnam is presented based on the surveys in 2009. The samplings by pitfall trapping and time unit sampling were carried out in four different cropping fields: paddy, vegetable, sugarcane farms and citrus orchards in Hanoi City, Hung Yen Province, Thanh Hoa Province, and Binh Duong Province. In total, 49 species of ants belonging to 26 genera of 6 subfamilies were collected from 496 samples of 12 agricultural fields. Among them, the most species rich genera wereTetramorium which included 7 species, followed by Monomorium (6 species), Camponotus (4 species) and Pheidole (4 species).

Keywords: ant, citrus orchards, sugarcane fields, vegetable fields, paddy fields.

Introduction

Recent progress on the study of biodiversity of ants in Vietnam has been made mainly focusing those of forests or conservation areas (Bui, 2002; Bui and Eguchi, 2003; Bui and Yamane, 2001; Eguchi et al., 2004; Yamane et al., 2002). But little has been adverted to ants of agricultural lands, in spite of their important role as predators or monitoring agents (Agosti et al., 2000; Lach et al., 2010; Way and Khoo, 1992). In the course of our study on the ant communities in agroecosystems in 2009, we have surveyed various cropping fields including paddy, vegetable, sugarcane farms and citrus orchards and collected 496 samples from 12 fields of 9 localities. In this paper, we have complied the results of them with taxonomic and biogeographical information. This is the first report that treats with the comprehensive ant fauna of agricultural fields in Vietnam, although the collecting sites are limited in Red River Delta except Binh Duong Province in Mekong Delta.

1) Institute of Tropical Agriculture, Kyushu University, Fukuoka 812-8581, Japan. *Corresponding author: [email protected] Le Ngoc Anh et al.

Materials and Methods

Sampling methods Samplings were conducted in February (spring), June (summer) and December (winter) in 2009, using two methods: pitfall trapping and time unit sampling. Pitfall trapping (PT): Ten pitfall traps were placed within a field and left open for 5 days. Each of the traps contained about 50 ml of ethylene glycol preservative. Time unit sampling (TUS): Time unit sampling is a kind of direct methods that collect ants as many as possible using aspirator, hand sifter, pans by visual search within a limited time (Ogata, 2001). In each field, a 15-minutes sampling was repeated 8 times.

Study sites A total of 12 farm fields was surveyed. Locality names, their abbreviations, geographical coordinates, cropping types and sampling dates with sampling methods are summarized in Table 1.

Table 1. Study sites. Field # Locality (Abbreviation) Coordinates Cropping type Sampling Date and method 11 Feb. (PT); 24 Jun. (PT); 1 Co Bi (CBI), Gia Lam Dist, 21˚01’N, Citrus orchard Hanoi City 105˚56’E (organic) 28 Dec. (PT); 10 Feb. (TUS); 21 Jun. (TUS); 24 Dec. (TUS) 11 Feb. (PT); 24 Jun. (PT); 2 Dong Ngac (DNP), Tu Liem 21˚04’N, Citrus orchard Dist, Hanoi City 105˚46’E (organic) 28 Dec. (PT); 9 Feb. (TUS); 20 Jun. (TUS); 25 Dec. (TUS)

3 ibid. (DNV) Vegetable field ibid. (cabbage) 9 Feb. (PT); 20 Jun. (PT) Vegetable field 4 ibid. (DNV) ibid. (French bean) 9 Feb. (PT); 20 Jun. (PT)

5 Hoan Long (HLO), Hung 20˚54’N, Paddy field 9 Feb. (PT); 20 Jun. (PT); Yen Province 105˚59’E 14 Dec. (PT)

Lien Mac (LMA), Tu Liem Citrus orchard 11 Feb. (PT); 24 Jun. (PT); 6 21˚05’N, Dist, Hanoi city 105˚46’E (commercial) 28 Dec. (PT); 9 Feb. (TUS); 20 Jun. (TUS); 25 Dec. (TUS)

7 Phu An (PAN), Ben Cat Dist, 11˚12’N, Sugarcane field Binh Duong Province 106˚37’E 18 Dec. (TUS); 22 Dec. (PT)

8 ibid. ibid. Sugarcane field 18 Dec. (TUS); 22 Dec. (PT)

11 Feb. (PT); 24 Jun. (PT); 9 Trau Quy (TQU), Gia Lam 21˚00’N, Citrus orchard Dist, Hanoi City 105˚56’E (commercial) 28 Dec. (PT) ;10 Feb. (TUS); 21 Jun. (TUS); 24 Dec. (TUS) 9 Feb. (PT); 18 Jun. (PT); 10 Xuan Hoa (XHA), Tho Xuan 19˚55’N, Sugarcane field 13 Dec. (PT); 31 Dec. (PT); Dist, Thanh Hoa Province 105˚30’E 7 Feb. (TUS); 15 Jun. (TUS); 10 Dec. (TUS); 27 Dec. (TUS)

Xuan Hung (XHU), Tho 9 Feb. (PT); 18 Jun. (PT); 11 Xuan Dist, Thanh Hoa 19˚52’N, Sugarcane field 13 Dec. (PT); 31 Dec. (PT); Province 105˚28’E 7 Feb. (TUS); 15 Jun. (TUS); 10 Dec. (TUS); 27 Dec. (TUS)

12 Yen My (YMY), Yen My 20˚53’N, Paddy field 9 Feb. (PT); 20 Jun. (PT); Dist, Hung Yen Province 106˚02’E 14 Dec. (PT) All the specimens were kept in the collection of Institute of Tropical Agriculture, Kyushu University, Japan. Ants of Agricultural Fields

Result and Discussion

In total, 49 species of ants belonging to 26 genera of 6 subfamilies were collected. The most speciose subfamily was Myrmicinae (25 species), followed by Formicinae, Ponerinae and Dolichoderinae. Sub- families Amblyoponinae and Cerapachyinae contained only one species, respectively. At genus level, Tetramorium (7 species), Monomorium (6 species); Camponotus (4 species) and Pheidole (4 species) were the taxa that included diverse species in farm lands. Although 22 species are left unidentified, most of the ants identified in this study have wide geographical range of the distributions. The ecological analysis and discussions of ant communities of agroecosystems in Vietnam would be presented elsewhere.

List of species

AMBLYOPONINAE 1. Prionopelta kraepelini Forel DNP, 28.xii. 2009. The ant is small and yellowish species, collected only once from a organic farm of Pomelo orchard in this study. The species of the genus Prionopelta is cryptobiotic, usually lives under soil, and rare. P. kraepelini is widely distributed in South East Asia, Australia and Pacific Islands (Brown, 1960).

CERAPACHYINAE 2. Cerapachys sp. CBI, 11. ii,. 24. xii. 2009. The species is easily recognized in having black and shiny head and gaster, and red or brown mesosoma. The ant is a member of the group that was formerly placed under the genus Lioponera, or C. longitarsus group of Brown (1975). C. longitarsus (Mayr) is widely distributed in the tropical and subtropical Asia and Australia (Brown, 1975).

DOLICHODERINAE 3. Dolichoderus thoracicus (F. Smith) XHA, 18.vi; 15.vi. 2009. The species is widely distributed in Oriental, Indo-Malayan and Australian regions including India, China, Taiwan, Myanmar, Laos, Cambodia, Philippines, Malaysia, New Guinea and Australia (Xu, 2001).

4. Ochetellus glaber (Mayr) DIP, 9.ii, 11.ii, 20.vi, 24.vi, 25.xii,.28.xii. 2009. The species is widely distributed in the world, characteristic in having a compressed petiole that forms a vertical plate between the mesosoma and the gaster.

5. Tapinoma melanocephalum (Fabricius) DNV, 9.ii, 20.vi. 2009; YMY, 21.ii, 20.vi; 14.xii. 2009; HLO, 21.ii, 20.vi; 14.xii. 2009; TQU, 11.ii, Le Ngoc Anh et al.

10.ii, 24.vi, 21.vi, 24.xii, 28.xii. 2009; LMA, 11.ii, 9.ii, 24.vi, 20.vi, 25.xii, 28.xii. 2009; CBI,10. ii, 11.ii, 21.vi, 24.vi, 24.xii, 28.xii. 2009; DNP, 9.ii, 11.ii, 20.vi, 24.vi, 25.xii, 28.xii. 2009; XHA, 7.ii, 9. ii, 15.vi, 18.vi, 10.xii, 13.xii, 27.xii, 31.xii. 2009; XHU, 7.ii, 9.ii, 15.vi, 18.vi, 10.xii, 13.xii, 27.xii, 31.xii. 2009; PAN, 18.xii, 22.xii. 2009. The ant is a pan-tropical tramp-species. The species is one of the most common ants in this survey. According to Bingham (1903), This species is distinguished from another similar species, T. indimum, by relative length of the antennal scape that is longer, extending beyond the border of the head in T. melanocephalum.

6. Technomyrmex brunneus Forel LMA, 11.ii, 24.vi. 2009; CBI, 24.vi, 28.xii. 2009; DNP, 11.ii, 24.vi, 28.xii. 2009; XHU, 9.ii. 2009. This species is a member of T. albipes group (Bolton, 2007), and is known to occur in Sri Lanka, India, Brunei, China, Taiwan and Japan, so far. In Vietnam, the genus has been represented by 5 species: additional two species (elatior Forel and yamanei Bolton) of albipes group, obscurior Wheeler of bicolr group, and pratensis (F. Smith) of pratensis group (Bolton, 2007).

FORMICINAE 7. Anoplolepis gracilipes (F. Smith) XHU, 15.vi, 18.vi, 10.xii, 13.xii. 2009; PAN, 18.xii, 22.xii. 2009. The species has been known to occur in tropical and subtropical areas in the world, spread by human activities (Way and Khoo, 1992). The species is one of six most widespread, abundant, and damaging invasive ants of the world (Holway et al., 2002).

8. Camponotus rufoglaucus (Jerdon) XHA, 15.vi, 18.vi, 10.xii, 31.xii. 2009; XHU, 7.ii, 9.ii, 15.vi, 18.vi. 2009; PAN, 18.xii, 22.xii. 2009. This species is one of the most common species of Camponotus in this study, having a blackish body.

9. Camponotus sp.1 XHA, 9.ii, 18.vi. 2009; XHU,9. ii, 18.vi. 2009. This species belongs to subgenus Tanaemyrmex.

10. Camponotus sp. 2 XHA, 15.vi, 18.vi. 2009. Only minors of this species were collected. It may be the same species as sp. 1.

11. Camponotus sp. 3 XHA, 15.vi. 2009; XHU, 9.ii, 15.vi, 18.vi. 2009. This species is characteristic in having two pairs of white spots on the gaster.

12. Paratrechina longicornis (Latreille) DNV, 9.ii, 20.vi. 2009; YMY, 14.xii. 2009; HLO, 21.ii, 20.vi, 14.xii. 2009; CBI, 21.vi, 24.vi, 28.xii. Ants of Agricultural Fields

2009; DNP, 9.ii, 11.ii, 20.vi, 24.vi, 25.xii, 28.xii. 2009; XHA, 7.ii, 9.ii, 15.vi, 18.vi, 10.xii, 13.xii, 27.xii, 31.xii. 2009; XHU, 7.ii, 9.ii, 15.vi, 18.vi, 10.xii, 13.xii, 27.xii, 31.xii. 2009; PAN, 18.xii, 22.xii. 2009. The species is one of the most common ants in our survey.

13. Nylanderia sp. 1 DNV,9. ii, 20.vi. 2009; YMY, 14.xii. 2009; HLO, 21.ii. 2009; DNP, 9.ii, 11.ii, 20.vi, 24.vi, 25.xii, 28.xii. 2009; XHA, 7.ii, 9.ii, 15.vi. 2009; XHU, 7.ii, 9.ii, 15.vi, 18.vi, 10.xii, 13. xii, 27.xii, 31.xii. 2009; PAN, 18.xii, 22.xii. 2009. This species is similar to N. flavipes (F. Smith) with brownish head and mesosoma and dark gaster, but the standing hairs on the mesosoma are more stout and distinct.

14. Nylanderia sp. 2 DNP, 25.xii, 28.xii. 2009; XHA, 15.vi. 2009. This species is similar to N. sp.1, but the hairs on the propodeal dorsum is absent.

15. Plagiolepis sp. XHU, 15.vi, 18.vi. 2009. This is a small blackish species.

MYRMICINAE 16. Cardiocondyla sp. 1 DNV, 9.ii, 20.vi. 2009; YMY, 9.ii. 2009; CBI, 11.ii, 24.vi, 28.xii. 2009; DNP, 9.ii, 11.ii, 20.vi, 24.vi, 25.xii, 28.xii. 2009; XHU, 15.vi, 18.vi, 10.xii, 13.xii, 27.xii, 31.xii. 2009; PAN, 18.xii, 22.xii. 2009. This is a blackish species with blunt propodeal spines.

17. Cardiocondyla sp. 2 YMY, 20.vi. 2009; LMA, 9.ii, 11.ii. 2009; CBI, 10.ii, 11.ii, 21.vi, 24.vi, 24.xii, 28.xii. 2009; DNP, 9.ii, 11.ii, 20.vi, 24.vi, 25.xii, 28.xii. 2009; XHA, 15.vi, 18.vi. 2009; XHU, 7.ii, 9.ii. 2009; PAN, 18.xii, 22.xii. 2009. This is a yellowish species.

18. Crematogaster sp. 1 DNP, 9.ii, 11.ii, 20.vi, 24.vi, 25.xii, 28.xii. 2009. This species is similar to C. longiclava subsp. placens of subgenus Crematogaster.

19. Crematogaster sp. 2 XHA, 7.ii, 9.ii. 2009; PAN, 22.xii. 2009. This small species belongs to the subgenus Mesocrema which is characterized in having two segmented antennal club and undeveloped occipital carinae. Le Ngoc Anh et al.

20. Meranoplus bicolor (Guerin-Meneville) XHU, 15.vi, 18.vi. 2009; PAN, 18.xii, 22.xii. 2009. This species is most common in the genus in the Oriental region, having an unsculptured petiole, long and posteriorly directed spines. Dorsal surface of the body is covered with exceptionally long and outstanding hairs as well as shorter pubescences (Schoedl, 1998).

21. Monomorium chinense Santschi HLO, 21.ii, 20.vi, 14.xii. 2009; YMY, 21.ii, 20.vi. 2009; TQU, 11.ii, 24.vi, 28.xii. 2009; LMA, 20.vi. 2009; CBI, 10.ii, 11.ii, 21.vi, 24.vi, 24.xii, 28.xii. 2009; DNP, 9.ii, 11.ii, 20.vi, 24.vi, 25.xii, 28.xii. 2009; XHU, 15.vi, 18.vi. 2009; XHA, 15.vi, 18.vi. 2009; PAN, 18.xii, 22.xii. 2009. This is a small ant having smooth and shiny black body. So far the distribution has been reported only from China, Japan and Vietnam (Bolton et al., 2006), but the taxonomic identity and biogeographical information should be revised. Here we give a tentatively identification for the material collected in this study.

22. Monomorium destructor (Jerdon) PAN, 18.xii. 2009. This is minute to medium sized species with yellowish head and mesosoma and blackish gaster. The ant is a tramp species, said to be an Indian origin, and widely distributed throughout the tropical zones of the world and even into the temperate zones by commercial activity (Bolton, 1987).

23. Monomorium floricola (Jerdon) HLO, 21.ii, 20.vi. 2009; YMY, 21.ii. 2009; TQU, 11.ii, 24.vi, 28.xii. 2009; LMA, 9.ii, 11.ii, 24.vi, 25.xii, 28.xii. 2009; CBI, 10.ii, 11.ii, 21.vi, 24.vi, 24.xii, 28.xii. 2009; DNP, 9.ii, 11.ii, 20.vi, 24.vi, 25.xii, 28.xii. 2009; XHU, 15.vi, 18.vi. 2009; PAN, 18.xii, 22.xii. 2009. This is also a pan tropical tramp-species, with a characteristic color pattern that shows dark brown to black head and gaster, and yellow to light brown mesosoma (Bolton, 1987).

24. Monomorium pharaonis (Linnaeus) CBI, 24.xii. 2009. The species is easily distinguished from other Monomorium species in having fine punctures on the body, uniformly yellow in color and a single pair of stout standing hairs at the pronotal humeri. Although the species was found only in a single case in this study, this is a typical tramp species of the world.

25. Monomorium sp. 1 CBI, 24.xii, 28.xii. 2009. This is a small and yellow colored species having a smooth and shining body and short antennal scapes that do not reach posterior border of the head.

26. Monomorium sp. 2 CBI, 21.vi, 24.vi, 25.xii, 28.xii. 2009. Ants of Agricultural Fields

This is small and black colored species, similar to M. chinense, but distinguished by the shape of the petiole that has convex ventral outline and an elongated peduncle in sp. 2.

27. Pheidole dugasi Forel XHA, 15.vi, 18.vi. 2009. The identification of the genus Pheidole basically followed the revision by Eguchi (2008). But the key requires a colony material including a set of major and minor workers. Since the specimens here are foraging samples that are mostly minor workers, it is sometimes difficult to identify exact species. Egu- chi (pers. comm.) suggested that among 31 species recorded from North Vietnam, at least 12 species are found in disturbed areas. Thus there will be additional species in cultivated lands. P. dugasi is a large species, characteristic in having a smooth and shiny head, elongated scape and a smooth and shiny mesopleuron. The species occurs in Thailand and south China (Eguchi, 2008).

28. Pheidole parva Mayr DNV, 9.ii, 20.vi. 2009; YMY, 21.ii, 20.vi, 14.xii. 2009; HLO, 21.ii, 20.vi, 14.xii. 2009; TQU, 11.ii, 24.vi, 28.xii. 2009; LMA, 20.vi, 25.xii. 2009; CBI, 10.ii, 11.ii, 21.vi, 24.vi, 24.xii, 28.xii. 2009; DNP, 9.ii, 11.ii, 20.vi, 24.vi, 25.xii, 28.xii. 2009; XHA, 7.ii, 9.ii, 15.vi, 18.vi, 10.xii,13.xii, 27.xii, 31.xii. 2009; XHU, 18.vi. 2009; PAN, 18.xii, 22.xii. 2009. This is one of the commonest ants in our study. The species resembles P. rabo in appearance, but can be distinguished in having shorter antennal scape and smaller eyes. The ants is distributed in tropical and subtropical Asia and western Pacific Islands, including, India, Sri Lanka, Nepal, Thailand, Malaysia, Indonesia, Burnei, Philippines, south China and south Japan (Eguchi, 2008).

29. Pheidole taipoana Wheeler CBI, 24.vi, 24.xii, 28.xii. 2009; DNP, 20.vi, 25.xii, 28.xii. 2009; XHA, 15.vi, 18.vi. 2009; XHU, 18.vi. 2009. The ant is also known from south China (Eguchi, 2008). The species might be difficult to distinguished from P. laevicolor in minor workers, though it is easy to separate in major workers.

30. Pheidole yeensis Forel DNP, 20.vi, 24.vi, 25.xii, 28.xii. 2009; PAN, 18.xii, 22.xii. 2009. The species has been recorded from Thailand and south China (Eguchi, 2008). The ant resembles P. planifrons.

31. Pheidologeton diversus (Jerdon) CBI, 10.ii, 11.ii, 21.vi, 24.vi, 24.xii, 28.xii. 2009; LMA, 25.xii, 28.xii. 2009; XHU, 15.vi, 18.vi. 2009; PAN, 18.xii, 22.xii. 2009. This is a typical polymorphic species, distributed in the tropical Asia. There are several infraspe- cific names of diversus (see Bolton et al., 2006) that needs taxonomic review. Le Ngoc Anh et al.

32. Pristomyrmex punctatus (F. Smith) DNV, 9.ii. 2009; DNP, 9.ii, 11.ii, 20.vi, 24.vi, 25.xii, 28.xii. 2009. The species distributed in South East Asia to East Asia (Wang, 2003).

33. Solenopsis geminata (Fabricius) DNV, 9.ii. 2009; DNP, 9.ii, 11.ii, 24.vi. 2009. In this study, we found this species only in two fields in the same location, but the species is one of six most widespread, abundant, and damaging invasive ants of the world (Holway et al., 2002).

34. Strumigenys sp. CBI, 21.vi, 24.vi, 24.xii, 28.xii. 2009; DNP, 20.vi, 25.xii, 28.xii. 2009. This species will be a member of S. godeffroyi species-group of Bolton (2000).

35. Tetramorium bicarinatum (Nylander) YMY, 9.ii, 20.vi. 2009; LMA, 9.ii, 11.ii, 20.vi, 24.vi, 25.xii, 28.xii. 2009; CBI, 10.ii, 11.ii, 20.vi, 24.vi, 25.xii, 28.xii. 2009; DNP, 9.ii, 11.ii, 20.vi, 24.vi, 25.xii, 28.xii. 2009; XHA, 15.vi, 18.vi, 27.xii, 31.xii. 2009; XHU, 15.vi, 18.vi, 10.xii, 13.xii. 2009; PAN, 18.xii, 22.xii. 2009. This is the most common Tetramorium species in this study. The ant has a bicolored body with a yellowish head and mesosoma, and dark brown gaster. The species is a tramp species occurring the world tropics and subtropics (Bolton, 1977).

36. Tetramorium kraepelini Forel DNP, 25.xii. 2009. The ant spreads eastern part of Asia including China, Japan, Philippines and Indonesia. Although the distribution is rather wide range, the species is not very common (Bolton, 1977). Indeed we have collected only once from Pomelo orchard of northern part.

37. Tetramorium lanuginosum Mayr CBI, 11.ii, 24.xii, 28.xii. 2009. This species was formerly placed under genus Triglyphothrix that has a body covered with dense plilosity equipped with branched hairs. T. lanuginosum is a cosmoptilan tramp species (Bolton, 1976) and can be distinguished by the shape of the petiole that has a gently sloping down posterior portion without a postero-dorsal corner.

38. Tetramorium simillimum (F. Smith) CBI, 11.ii, 21.vi, 24.xii, 28.xii. 2009; DNP, 9.ii, 11.ii, 20.vi, 24.vi, 25.xii, 28.xii. 2009. This species is a pantropcal tramp species of African origin (Bolton, 1977).

39. Tetramorium smithi Mayr PAN, 18.xii, 22.xii. 2009. This species is characteristics in having the 11-segmented antennae and small body size. T. smithi is Ants of Agricultural Fields distributed in tropical Asia, including India, Sri Lanka, Bhutan, Myanmar, Thailand, Malaysia and Indonesia (Bolton, 1977).

40. Tetramorium walshi (Forel) XHA, 15.vi, 18.vi. 2009; XHU, 15.vi, 18.vi. 2009. The species was also placed under genus Triglyphothrix. Posterior portion of the petiole is more or less angled and the petiolar node in the dorsal profile is rounded. The ant is distributed in tropcal and subtropical Asia, including India, Sri Lanka, Philippines and China (Bolton, 1976).

41. Tetramorium sp. A LMA, 20.vi, 25.xii. 2009. The body of this species is covered with dense hairs which are bifurcated or trifurcated. Posterior portion of the petiole is more or less angled and petiolar node in the dorsal profile is flattened.

PONERINAE 42. Diacamma sp. XHA, 7.ii, 9.ii, 15.vi, 18.vi, 10.xii, 13.xii, 27.xii, 31.xii. 2009; XHU, 7.ii, 9.ii, 10.xii, 13.xii, 27.xii, 31.xii. 2009.

43. Hypoponera sp. 1 XHA, 15.vi. 2009. The ant is blackish in color and similar to H. opaciceps (Mayr) with almost parallel posterior and anterior faces of the petiole.

44. Hypoponera sp. 2 CBI, 24.xii, 28.xii. 2009; DNP, 25.xii, 28.xii. 2009. The ant is minute in size and yellowish in color.

45. Leptogenys sp. CBI, 24.xii, 28.xii. 2009. The ant is similar to L. peuqueti (Andre) in size and shape of the petiole.

46. Odontomachus sp. PAN, 18.xii. 2009. The species is somewhat similar to O. simillimus F. Smith that is distributed from South India, through South East Asia, to Pacific Islands (Brown, 1976).

47. Odontoponera denticulata (F. Smith) XHU, 7.ii, 9.ii, 15.vi, 18.vi, 10.xii, 13.xii, 27.xii, 31.xii. 2009. O. dentculata was synonimized under O. transversa (F. Smith) (Bolton, 1995), but was revived as distinct species by Yamene (2009). The is distributed in South East Asia and found in distrubed areas. 10 Le Ngoc Anh et al.

48. Pachycondyla sp. 1 DNP, 9.ii, 11.ii, 20.vi, 24.vi, 25.xii, 28.xii. 2009. This is a medium sized species, and would be a member of the group that was formerly treated as Trachymesopus.

49. Pachycondyla sp. 2 DNP, 25.xii. 2009. The mesopleuron of this ant is divided by a oblique fullow. This species would be a member of the group that was formerly treated as Ectomomyrmex.

Acknowledgements

We would like to thanks the owners of farms in Hanoi City, Hung Yen, Thanh Hoa and Binh Duong Provinces for their helps and supports during the surveys. Special thanks to Dr. Katsuyuki Eguchi, Nagasaki University, for identifying the species including Pheidole, and for his kind comment. This work was supported in part by the Global COE Programe entitiled Center of Excellence for Asian Conservation Ecology as a Basis of Human-Nature Mutualism, MEXT, Japan.

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