Observing A Worker Ant Community Environmental Sciences Essay

ABSTRACT. The ant community of Gilimale Forest Reserve in Sri Lanka is of particular involvement as a home ground of the island-endemic Aneuretus simoni. Ant community composing and facets of A. simoni ecology in this wood were investigated utilizing multiple trying methods at the same time, on six visits to Gilimale from February to December 2004. Daytime sampling of emmets was carried out along ten 100 m transects by honey and canned-fish baiting, foliage litter and dirt winnow, manus aggregation, booby trap caparison and mini-Winkler extraction. Honey baits at 1 m height on trees, and honey-baited booby trap traps on the land, were set overnight. Air and dirt temperature, deepness of foliage litter and dirt wet during trying were recorded on each juncture. Fifty species, in 38 genera, were recorded. Aneuretus simoni, Camponotus sp. 1, Carebara sp. , Dolichoderus sp. 1, Lophomyrmex quadrispinosus, Monomorium sp. , Myrmicaria brunnea, Odontomachus simillimus, Paratrechina ( sensu lato ) sp. , Pheidole sp. 2, Pheidole sp. 7, Pheidolegeton sp. , Polyrhachis sp. , Solenopsis sp. , Technomyrmex bicolor and Tetramorium bicarinatum were common and detected on all occasions. Detectability of A. simoni was systematically high and the species comprised 3-6 % of worker emmets collected on each of the six occasions.

Keywords: Aneuretus simoni Emery, Gilimale Forest Reserve, species profusion, rare emmets, multiple methods, repeated trying

Introduction

Since 1955, Gilimale Forest Reserve in Sri Lanka has been known as a home ground of the Sri Lanka-endemic emmet, Aneuretus simoni Emery ( Wilson et al. 1956 ; Jayasuriya & A ; Traniello 1985 ) , the exclusive extant representative of Subfamily Aneuretinae. Gilimale Forest Reserve ( 6° 47 ‘ N and 80° 28 ‘ E, mean altitude 152 m ) occupies about 1147 hour angle and is situated in Ratnapura District, in Sabaragamuwa Province. This moisture evergreen tropical wood receives on mean 4758 millimeter of rainfall yearly and is characterised by extremely dissected terrain with legion watercourses run outing into several rivers. The mean incline ranges from 9o to 15o but certain countries bordering watercourses and rivers are highly steep ( Balasubramanium et al. 1991 ) .

Eleven ant genera ( Aneuretus, Camponotus, Crematogaster, Euponera ( Brachyponera ) , Euponera ( Mesoponera ) , Myrmicaria, Paratrechina ( Nylanderia ) , Pheidole, Ponera, Polyrhachis and Technomyrmex ) were recorded from the wood by Wilson et Al. ( 1956 ) whereas ten genera ( Aneuretus, Camponotus, Crematogaster, Monomorium, Odontomachus, Pachycondyla, Paratrechina, Ponera, Solenopsis and Tetramorium ) were recorded by Jayasuriya & A ; Traniello ( 1985 ) . Our first study of Gilimale Forest, in February 2004, revealed nine subfamilies ( Aenictinae, Amblyoponinae, Aneuretinae, Dolichoderinae, Dorylinae, Formicinae, Leptanillinae, Myrmicinae and Ponerinae ) and 37 species including A. simoni ( Dias & A ; Perera 2005a ) . Three visits in April, June and August 2004 jointly recorded nine subfamilies ( Pseudomyrmecinae added ; Dorylinae non found ) and 35 species from the land and lower canopy of the wood ( Dias & A ; Perera 2005b ) . The study was extended through October and December 2004 and the consequences of the six visits are combined here to characterize the community of ground-dwelling emmets observed by coincident multiple sampling in Gilimale Forest throughout 2004. We besides report on several ecological facets of A. simoni workers in this wood.

Method

Field and laboratory methods

Ten locations of Gilimale Forest Reserve were surveyed for emmets, utilizing several trying methods along a 100 m transect laid at each location, on 23-26 February, 15-18 April, 24-27 June, 24-27 August, 29-31 October and 17-19 December 2004. At each location we carried out extraction of emmets by ( a ) mini-Winkler pokes, ( B ) dirt winnow, ( degree Celsius ) booby trap caparison, ( vitamin D & A ; e ) honey and canned fish baiting, ( degree Fahrenheit ) litter sifting by manus and ( g ) timed manus aggregation. Within each transect:

( a ) Five polyethylene bags were each filled with foliage litter from five different 1 M2 countries, sampled at 20 m intervals along the transect, and the litter in each bag was transferred to a mini-Winkler poke kept in the research lab. The worker emmets emerging after 48 H were preserved in 85 % ethyl alcohol.

( B ) Ten dirt samples ( each 20 x 20 broad x 10 cm deep ) , taken at 10 m intervals along a line which was parallel and 1 m left of the transect, were sifted through mesh into a white tray. All emmets seen with the bare oculus were collected into glass phials filled with 85 % ethyl alcohol.

( degree Celsius ) Ten cups ( volume: 110 cm3 ) , each half-filled with soap H2O, were set in the dirt at 10 m intervals along a line analogue and 1 m right of the transect, with the oral cavity of the cups flower with the surface dirt degree.

( vitamin D, vitamin E ) Twenty-five come-ons each of honey and canned fish ( doodly-squat mackerel in natural juice with added salt ) , on a 5 centimeter x 5cm piece of gauze, were placed alternately on the land at 4 m intervals along the

transect, and the pieces of gauze and go toing emmets were collected after one hr into a fictile bottle filled with 50 % ethyl alcohol.

( degree Fahrenheit ) Ten litter samples ( each of one full screen ) , taken at 10 m intervals along the transect, were sifted into a white tray and emmets seen with the bare oculus were collected into a vial filled with 85 % ethyl alcohol.

( g ) Hand aggregation was conducted for 10 proceedingss, around a point about 10 m apart from the following, with 10s such points in each transect. At each point, emmets creeping on the forest floor along a horizontal line which connects each point at 1 m left and 1 m right of the transect, were collected and emmets were preserved in 85 % ethyl alcohol.

Some of the locations were besides sampled at dark by different methods: ( H ) honey-baited pitfall traps on the land and ( I ) honey baited little plastic phials hung on trees.

( H ) In three of the transects used during the daylight, 10 plastic cups of 110 cm3, each honey-baited and half-filled with 50 % ethyl alcohol, were set in the eventide in the dirt along the 100 m transect.

( I ) At the same three locations in February, and five locations on subsequent occasions, ten honey-baited little plastic phials were hung in the eventides ( 17:00-18:00 H ) on 10 trees, 10 thousand apart along the transects, and were collected at around 07:00 h the undermentioned forenoon.

Collected emmets were preserved in 85 % ethyl alcohol and the presence of A. simoni and other species was recorded. Ants were identified to the furthest possible systematic degree utilizing a low-power stereo-microscope at suited magnifications with the aid of Prof. Seiki Yamane, Kagoshima University, Japan, and by mention to Bolton ( 1994, 2003 ) . Scientific names of the emmets are given harmonizing to Bolton et Al. ( 2006 ) .

Measurement of environmental parametric quantities during the sampling of emmets

During each study, air and dirt temperature at the start, center and terminal points of each transect were measured utilizing a thermometer and the average value per transect was recorded. Depth of the foliage litter bed was measured in the same mode utilizing a swayer, and the average deepness ( centimeter ) per transect was recorded. Similarly, three subsamples of dirt from each transect were brought to the research lab and dirt humidness ( Brower et al. 1998 ) of each transect was recorded. The average value of each parametric quantity during the sampling period was calculated from the 10 locations measured on each juncture.

Consequence

Speciess profusion and composing of worker emmet community

Table 1 shows that worker emmets belonging to 11 subfamilies, 38 genera and 50 species were recorded from the six visits to Gilimale Forest in 2004. The figure of subfamilies observed on the six occasions was 9, 8, 5, 8 and 6, severally. Seventeen species ( Aneuretus simoni Emery, Camponotus sp. 1, Carebara sp. , Dolichoderus sp. , Lophomyrmex quadrispinosus ( Jerdon ) , Leptogenys sp. , Monomorium sp. , Myrmicaria brunnea Saunders, Odontomachus simillimus F.Smith, Paratrechina ( sensu lato ) sp. , Pheidole sp. 2, Pheidole sp. 7, Pheidolegeton diversus ( Jerdon ) , Polyrhachis sp. , Solenopsis sp. , Technomyrmex bicolor Emery and Tetramorium bicarinatum ( Nylander ) ) were common on all occasions and observed throughout the survey period. In add-on Acropyga acutiventris Roger, Cardiocondyla sp. , Cerapachys sp. , Dorylus sp. , Pachycondyla sp. 3, Pheidole sp. 8 and Tetraponera allaborans ( Walker ) were observed on two or more of the six visits. The highest species profusion was recorded in February whereas lowest species profusion was observed in December ( Fig. 1 ) .

Table 1. Worker ant species observed on each visit to Gilimale Forest and overall worker emmet community recorded in 2004. Bold letters show the species observed on all occasions. Speciess Numberss are harmonizing to the first writer ‘s aggregation kept at the Department of Zoology, University of Kelaniya, Sri Lanka. *sensu lato. P = nowadays.

Subfamily

Genus/ species

Visit

1

2

3

4

5

6

1. A Aenictinae

Aenictus sp.

P

P

P

2. Amblyoponinae

Amblyoponesp.

P

P

P

P

3. Aneuretinae

Aneuretus simoni

P

P

P

P

P

P

4. Cerapachyinae

Cerapachyssp.

P

5. Dorylinae

Dorylus sp.

P

6. Dolichoderinae

Dolichoderus sp.

P

P

P

P

P

P

Tapinoma indicum

P

P

T. melanocephalum

P

P

P

A

Technomyrmex bicolor

P

P

P

P

P

P

A

Technomyrmex albipes

P

P

P

P

P

7. Formicinae

Acropygaacutiventris

P

Anoplolepis gracilipes

P

P

P

P

A

Camponotus sp. 1

P

P

P

P

P

P

A

Camponotus sp. 2

P

P

P

P

Lepisiota sp.

P

A

Myrmoteras sp.

P

P

P

A

Paratrechina*sp.

P

P

P

P

P

P

A

Paratrechina longicornis

P

P

P

A

Polyrhachis sp.

P

P

P

P

P

P

A

Pseudolasiussp.

P

P

P

8. Leptanillinae

Leptanilla sp.

P

P

P

P

9. Myrmicinae

Calyptomyrmex sp.

P

P

P

Cardiocondyla sp.

P

A

Carebarasp.

P

P

P

P

P

P

Cataulacus sp.

P

P

P

Crematogaster sp. 1

P

P

P

P

P

A

Crematogaster sp. 2

P

P

Crematogaster sp. 3

P

P

A

Lophomyrmexquadrispinosus

P

P

P

P

P

P

Meranoplus bicolor

P

P

P

A

Monomoriumsp.

P

P

P

P

P

P

Myrmicariabrunnea

P

P

P

P

P

P

Pheidolesp. 2

P

P

P

P

P

P

Pheidolesp. 7

P

P

P

P

P

P

Pheidolesp. 8

P

P

A

Pheidologetonsp.

P

P

P

P

Phosphorus

P

A

Solenopsissp.

P

P

P

P

Phosphorus

P

Strumigenys ( Quadristruma ) sp.

P

P

P

P

Phosphorus

A

Tetramorium sp.

P

P

P

Phosphorus

P

A

Tetramoriumbicarinatum

P

P

P

P

Phosphorus

P

10. Ponerinae

Anochetus sp.

P

P

P

Phosphorus

P

Centromyrmex feae

P

P

P

Phosphorus

Hypoponerasp.

P

P

P

P

Phosphorus

Leptogenys sp.

P

P

P

P

Phosphorus

P

Odontomachus simillimus

P

P

P

P

Phosphorus

P

A

Ponerasp.

P

P

P

P

P

A

Pachycondylasp. 1

P

P

Phosphorus

P

Pachycondylasp. 2

P

Phosphorus

A

Pachycondylasp. 3

P

11.Pseudomyrmecinae

50 ) Tetraponera allaborans

P

Phosphorus

Entire

39

32

34

36

33

29

Fig.1. Species accretion curves for 10 transects on each visit, and overall cumulative figure of species recorded, from Gilimale Forest. ( Night clip come-ons were unsuccessful and did non cod emmets on all occasions. )

Effectss of utilizing several trying methods and transects on recorded species profusion

Using a combination of several coincident trying methods yielded more ant species than utilizing a individual method on each juncture ( Table 2 ) . The cumulative figure of species observed during this survey increased with the figure of transects ( to ten ) and visits ( to six ) ( Fig. 1 ) .

Table 2. Speciess profusion recorded by each trying method and the overall methods on each visit to Gilimale Forest in 2004. Merely daytime trying methods used at all sites are shown.

CB = Canned-fish Bait, HB = Honey Bait, LS = Litter Sieving, SS = Soil Sieving, HC = Hand Collection.

Calendar month

CB

Hemoglobin

Liter

United states secret service

HC

CB+HB+LS+SS+HC

February

19

24

27

22

17

39

April

17

19

22

14

24

32

June

20

19

20

15

20

32

August

22

21

23

12

16

36

October

16

21

17

13

22

32

December

11

13

15

11

14

29

Entire

27

30

37

34

31

50

Environmental parametric quantities

Little differences in environmental conditions among trying periods on the six occasions were noticeable ( Table 3 ) . The highest and lowest dirt comparative humidness were recorded on February and June visits, severally.

Table 3. Environmental parametric quantities of Gilimale Forest recorded on each juncture in 2004 ( mean of 10 measurings A± SD ) .

Parameter

Feb

Apr

Jun

Aug

Oct

Dec

Air temperature ( oC )

27.0 A± 2.8

29.1 A± 1.2

26.0 A± 1.3

28.5 A± 2.0

27.6 A± 1.7

27.5 A± 2.5

Soil temperature ( oC )

24.6 A± 1.3

26.5 A± 0.53

24.4 A± 0.53

26.0 A± 1.7

26.3 A± 1.8

25.3 A± 2.1

Mean litter deepness ( centimeter )

2.3 A± 0.89

4.7 A± 1.7

5.3 A± 0.44

3.9 A± 0.2

4.6 A± 1.0

2.6 A± 1.1

Soil humidness %

35.7 A± 2.2

32.1 A± 1.4

19.6 A± 0.19

23.3 A± 4.6

28.0 A± 2.1

33.0 A± 4.1

Aspects of the ecology of A. simoni

The trying methods varied in effectivity in catching A. simoni workers, between transects and between times of twelvemonth ( Table 4 ) . No trying method was effectual in pulling these workers on all occasions. The species was recorded in all months at Transects 2, 3, 4, 5 and 7 and in all except December at Transects 1, 6 and 9. Percentage frequence of happening ( ( Number of transects positive for A. simoni / 10 ) x 100 ) of this species in Gilimale Forest ranged from 80 % to 90 % on the six occasions. The comparative copiousness of workers ranged from 3 % to 6 % of all collected specimens, with the highest proportion in February ( Table 4 ) . Table 5 shows that all methods except the tree traps were effectual for observing this species on each juncture.

Table 4. Sampling methods that caught A. simoni workers in each transect laid, per centum frequence of happening in transects, and comparative copiousness of this ant species in Gilimale Forest. Numbers in parentheses indicate the entire figure of emmets encountered on each juncture.

CB = Canned-fish Bait, HB = Honey Bait, HC = Hand Collection, LS = Litter Sieving, PT = Pitfall Trapping, SS = Soil Sieving, WM = Mini-Winkler extraction.

Year 2004

Transect figure

Frequency of happening ( % of transects )

1

2

3

4

5

6

7

8

9

10

Feb

CB HB LS

LS PT

HB LS

CB SS

United states secret service

Hemoglobin

HB LS WM

Hemoglobin

80

Apr

HB LS PT

CB HB LS PT

HB LS HC

LS HC

CB HB PT

CB HB

CB LS

LS HC

Liter

90

Jun

Hemoglobin

SS PT

HB LS

CB HB LS PT

CB HB

CB SS HB

LS SS HB

Hemoglobin

Liter

80

Aug

WM

HB LS PT

HB LS PT

HB LS PT

CB

HB LS

CB HB PT

Hemoglobin

CB HB

90

Oct

LS HC PT

HB LS PT

HB LS HC

HB LS PT

HB CB HC

CB HB SS

CB HB LS

Liter

Liter

90

Dec

LS SS

HB LS HC

United states secret service

Liter

Liter

Liter

90

Table 5. Effective sampling method/s for each species. *sensu lato.

CB = Canned-fish Bait, HB = Honey Bait, HC = Hand Collection, LS = Litter Sieving, PT = Pitfall Trapping, SS = Soil Sieving, WM = Mini-Winkler extraction, TT = Tree traps.

Ant species

Effective methods

Aenictus sp.

LS, SS, HC

Amblyoponesp.

LS, SS

Aneuretus simoni

CB, HB, LS, SS, HC, WM, PT

Cerapachyssp.

United states secret service

Dorylus sp.

CB, SS, HC

Dolichoderus sp.

CB, HB, LS, HC, PT, TT

Tapinoma indicum

CB, HB, LS, SS, HC, PT

T. melanocephalum

CB, HB, SS, TT

Technomyrmex bicolor

CB, HB, LS, SS, HC, WM, PT, TT

Technomyrmex albipes

CB, HB, LS, SS, HC, PT, TT

Acropygaacutiventris

United states secret service

Anoplolepis gracilipes

CB, HB

Camponotus sp. 1

CB, HB, LS, HC, WM, PT, TT

Camponotus sp. 2

CB, HB, LS, HC, WM, PT, TT

Lepisiota sp.

LS, SS

Myrmoteras sp.

LS, SS

Paratrechina*sp.

CB, HB, LS, HC, WM, PT, TT

Paratrechina longicornis

LS, SS

Polyrhachis sp.

CB, HB, SS, HC

Pseudolasiussp.

United states secret service

Leptanilla sp.

LS, SS

Calyptomyrmex sp.

SS, PT

Cardiocondyla sp.

United states secret service

Carebarasp.

CB, HB, LS, SS, HC, WM

Cataulacus sp.

HC

Crematogaster sp. 1

CB, HB, LS, HC, PT, TT

Crematogaster sp. 2

CB, HB, LS, HC

Crematogaster sp. 3

CB, HB

Lophomyrmexquadrispinosus

CB, HB, LS, HC

Meranoplus bicolor

HB, LS, PT

Monomoriumsp.

HB, LS, WM

Myrmicariabrunnea

CB, HB, LS, SS, HC, WM, PT, TT

Pheidolesp. 2

CB, HB, LS, SS, HC, WM, PT

Pheidolesp. 7

CB, HB, LS, SS, HC, WM, PT

Pheidolesp. 8

CB, HB, LS, SS, HC, WM, PT

Pheidologetonsp.

CB, HB, LS, SS, WM, PT

Solenopsissp.

CB, HB, LS, SS, HC, WM, PT

Strumigenys ( Quadristruma ) sp.

LS, HC, WM

Tetramorium sp.

CB, HB, LS, HC, PT

Tetramoriumbicarinatum

CB, HB, LS, SS, HC, WM, PT

Anochetus sp.

HB, LS, SS, HC

Centromyrmex feae

LS, SS

Hypoponerasp.

LS, SS

Leptogenys sp.

HB, LS, SS, HC, PT

Odontomachus simillimus

CB, HB, LS, SS, HC, PT

Ponerasp.

CB, HB, LS, SS, HC, PT

Pachycondylasp. 1

Liter

Pachycondylasp. 2

HC

Pachycondylasp. 3

LS, SS

Tetraponera allaborans

LS, HC

Discussion

Twelve subfamilies of emmets have been recorded from Sri Lanka ( Bolton 1995, 2003 ) and all but Ectatomminae were observed during this study. Aneuretinae, Dolichoderinae, Formicinae, Myrmicinae, Ponerinae and Pseudomyrmecinae were observed throughout the survey period. Two subfamilies more seldom encountered in Sri Lanka, Cerapachyinae ( detected merely from dirt winnow, Table 5 ) and Dorylinae ( detected merely from canned fish come-ons, dirt winnow and manus aggregation, Table 5 ) , were detected on individual occasions, and Aenictinae, Amblyoponinae and Leptanillinae were observed on three to four visits ( Table 1 ) , likely due to their deep wont and lower effectivity of these methods. All five ant subfamilies recorded from this wood by Wilson et Al. ( 1956 ) and Jayasuriya & A ; Traniello ( 1985 ) , Aneuretinae, Dolichoderinae, Formicinae, Myrmicinae and Ponerinae ( harmonizing to current categorization ) , were recorded during the present study.

Sixty-two genera of emmets ( Bolton 1995 ; Dias 2006, 2008 ) have been recorded from Sri Lanka and 38 of those were recorded from Gilimale Forest in 2004, bespeaking a high diverseness of emmets in this moisture zone wood. This is the lone study of emmets that has been conducted in Gilimale Forest late utilizing several trying methods at the same time and besides with repeated sampling. Higher species profusion was revealed by the coincident application of several trying methods, as observed in other ant research conducted in Sri Lanka ( Dias & A ; Gunathilake 2007a, B ) and elsewhere.

All ant genera reported antecedently at Gilimale by Wilson et Al. ( 1956 ) were collected during this study. In add-on to the 11 emmet genera reported by Wilson et Al. ( 1956 ) this survey recorded 26 extra genera from the Gilimale Forest. Pheidole, Monomorium, Tetramorium and Paratrechina were reported from this wood in 1979 by Jayasuriya & A ; Traniello ( 1985 ) and were besides observed in 2004 ( Table 1 ) . Other ant genera associated with A. simoni in “ Pompekelle ” , Ratnapura ( another home ground of this species ) in May 2001, Anoplolepis, Cataulacus, Crematogaster, Pachycondyla, Pheidole, Pheidologeton, Solenopsis and Teramorium ( Dias 2004 ) , were besides observed in the present aggregation. The consequences of the present study suggest this wood modesty has continuously been a home ground of A. simoni from 1955 ( Wilson et al. 1956 ) to 2004. It appears that environmental conditions such as dirt temperature ( 24°C to 28°C in 2004 ) and dirt humidness ( 19.6 % to 35.7 % in 2004 ) ( Table 2 ) are favorable for this rare and endemic emmet species when compared with those at a dry-zone wood ( soil temperature: 30.6°C to 31.1°C ; dirt humidness 4.8 % to 6.4 % ) where this emmet was absent ( Kosgamage & A ; Dias, 2009 ) .

Table 4 summarises the trying methods that caught A. simoni workers along each transect laid on each juncture in 2004. The usage of honey come-ons in daylight and leaf-litter winnow resulted in happening the workers of this species more frequently than the other methods. Although overall comparative copiousness seemed to be low ( Table 4 ) this species made up a considerable proportion of persons of this ant community. However this compound step of copiousness is influenced by the effectivity of each method in observing each species, and gives merely an indicant of existent comparative copiousness. Table 4 shows there is a high chance of observing the species utilizing these methods.

The species recorded in Table 1 can be considered a preliminary stock list of the emmets of Gilimale Forest Reserve and the list can doubtless be extended. But it serves as a mention for ant research workers and ecologists. Clearing of this wood for cultivation or development should be prohibited, as such actions may impact the bing favorable conditions for this evolutionarily-important ant species every bit good as for other rare ant species such as Aenictus sp. , Amblyopone sp. , Cerapachys sp. , Dorylus sp. , Leptanilla sp. and Cardiocondyla sp. Further ant studies are recommended to better the current stock list and to look into the nesting ecology of A. simoni.

Recognitions

Fiscal aid from the National Science Foundation of Sri Lanka ( RG/ 2003/ZOO/06 ) and field aid from Zoology pupils and demonstrators are extremely acknowledged. We thank the Forest Department, the Conservator of Forests and the Wildlife Conservation Department of Sri Lanka for allowing permission to come in this wood to carry on the study. Two anon. referees and editors Dr Martin Pfeiffer and Dr John Fellowes, who contributed to bettering this manuscript, are besides acknowledged.