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Collection Data for ALAS Quantitative Samples from La Selva, 1992-2004

| Berlese | Pitfall |Malaise | Canopy Fogging | Blacklight | Salticidae Project| Flight Intercept |MiniWinkler Transect |Winkler | Literature Cited |

Project ALAS has undertaken a series of quantitative sampling programs, involving a variety of sampling methods. Material from these samples is being widely distributed, and taxonomists frequently have questions about the meanings of the collection codes. Also, some taxonomists are beginning to use the quantitative results of ALAS in publications. The purpose of this page is to provide a chronology of sampling programs, descriptions of the sampling methods, and the detailed collection data for each collection code.

The collection code is an important identifier for ALAS material. It is the same as the entomologist's traditional lot number, and serves to unite a set of specimens that all have the same ecological data.

Locality: La Selva Biological Station is located in Costa Rica, Heredia Province, 10 degrees 26 minutes North, 84 degrees 01 minutes West, 50-150m elevation.

Localities within La Selva Biological Station: La Selva is a rainforest reserve of approximately 1500ha (McDade et al. 1993). There is a well-developed system of trails. Each trail has a name and standard abbreviation, and distances along trails in meters are marked on signposts along the trails. Localities at La Selva may be indicated by a trail name followed by the number of meters along the trail. For example, CES300 refers to 300m along the Camino Experimental Sur.

La Selva has a GIS system, marked in the field with a grid of poles delimiting 50x100m grid cells (Wentz & Bishop 1995). All quantitative samples from Project ALAS are referenced to this GIS system. GIS coordinates associated with collection codes are in meters. The x axis (first number in a coordinate pair) is the "long" axis of La Selva, going from the lab clearing side of the property upslope toward Volcan Barba (32 degrees from North). The zero point is well to the north, so that all values are positive. The y axis (second number) has negative values to the west (right side facing south, upslope) and positive values to the east.

This map is a 290k gif file. It shows the layout of the station, the trails with their abbreviations, major habitat types, and the axes of the GIS.

Berlese Samples

A quantitative sampling program was carried out from March 1993 to March 1994. Sixteen areas were selected on a La Selva station map, stratified by soil type (alluvial vs. residual) and forest type (primary vs. secondary). This design yielded four replicates for each soil and forest type combination. Sites were easily accessible from a trail system, but widely dispersed. Soil/litter cores were taken from 10m distance in a random direction from a central point (the pole of a malaise trap at the same site). The sample was taken by quickly placing a 14.5 cm inside diameter, 10cm deep PVC ring on top of the leaf litter, driving it into the ground, dislodging it, and placing the approximately 1.5 l of soil and litter in a plastic bag. The samples were returned to the laboratory on the same day and placed in Berlese funnels. Because tropical soils are often wet, collapsible cloth funnels were used to avoid the condensation that often occurs on more traditional metal funnels. A breathable synthetic fabric (Ultrex) was used for funnel construction. The sample bed was a 35 x 35cm piece of 6.6mm mesh hardware cloth, overlain with several layers of cheesecloth. The soil sample was broken apart and spread out on the cheesecloth. An incandescent light bulb was placed 15-20cm above the sample bed and the bulb and the sample covered with a pyramidal aluminum-foil shield. Samples were left under a 25 watt bulb for two days, then under a 50 watt bulb for a third day. Arthropods were collected in a Whirlpac bag filled with 75% ethanol suspended from the bottom of the funnel.

Berlese Berlese Berlese Berlese

Samples were taken at the beginning and middle of each month for 13 months. After three months of sampling, the sampling regime at four distant sites (3 primary forest residual soil, 1 secondary forest residual soil) was altered because it took too long to reach them. To replace the outlying Berlese sample sites, four new sites were established closer to the laboratory (maintaining the same habitat stratification). Berlese sampling commenced at these new sites, twice per month, 10m distant in a random direction from a central point.

Numerous other less quantitatively structured berlese samples have been taken from various sites. These samples are primarily directed at mite sampling in different microhabitats, and include canopy epiphytes and humus, polypore fungi, edges of swamps, and open pasture sites.

Collection Codes are of the form B/yy/zzz, where yy is a location number (01-16 for the original 16, 17-20 for the relocated sites, 00 when the sample is not part of a replicated series at one site), and zzz is a three digit sample number. Sample number is a sequential number based on all berlese samples, not the samples of a particular location. Thus a batch of 8 berlese samples taken on a particular day will have 8 sequential collection numbers, regardless from which locations they came. Errors resulted in a few sample numbers (but not entire collection codes) being repeated; these are described in the list of collection codes. When referring to ALAS specimens, it is important to use the entire collection code, not just the sequential number.

Locations of Berlese sampling sites for quantitative samples. Sites 1-16 were also Malaise trap sites. Additional site descriptions for these 16 can be found on this page.

List of all Berlese samples, 1993-1999, by collection code.

Pitfall Trap Samples

A program of pitfall trap sampling was carried out from April 1993 to March 1994. Pitfall traps were established in 4 transects of 8 traps each. Traps within transects were about 100m apart. Plastic drinking cups were embedded in the ground, flush with the ground surface. Cups were 7cm wide at the top and 9.5cm deep. A green plastic bag was suspended over the trap, in the form of a slanting roof. Traps were operated one day each month for 12 months. An aluminum bridge was placed over the top of the cup, and a pellet of pig feces placed on the bridge. The traps were left open for a 24hr period before harvest. Thus 32 samples were obtained each month. These samples were processed mainly for Scarabaeinae (dung beetles) and the residues discarded.

pitfall trap

Collection codes are of the form T/yy/zzz, where yy is the trap location number (01-32) and zzz is a unique sample number, starting with 001 and increasing sequentially to the last sample of the program, T/32/352.

Transect and trap locations were as follows:
01-08: starting at CES50 and going to CES750, alluvial soil, primary forest.
09-16: along LOC, starting near GIS line 900 and going to 1600, residual soil, border between primary and secondary forest.
17-24: starting at SSO1350 and going to SSO650, residual soil, primary forest.
25-32: starting at SLV600 and going to SLV1300, alluvial soil, second growth forest.

Dates of samples are as follows:

20-Apr-1993	T/01/1-T/32/32
14-May-1993	T/01/33-T/32/64
12-Jun-1993	T/01/65-T/32/96
9-Jul-1993	T/01/97-T/32/128
21-Aug-1993	T/01/129-T/32/160
17-Sep-1993	T/01/161-T/32/192
15-Oct-1993	T/01/193-T/32/224
12-Nov-1993	T/01/225-T/32/256
14-Jan-1994	T/01/257-T/32/288
11-Feb-1994	T/01/289-T/32/320
11-Mar-1994	T/01/321-T/32/352

Malaise Trap Samples

A program of quantitative sampling was initiated in March, 1993. Sixteen areas were selected on a La Selva station map, stratified by soil type (alluvial vs. residual) and forest type (primary vs. secondary). This design yielded four replicates for each soil and forest type combination. Sites were easily accessible from a trail system, but widely dispersed. A Malaise trap (Marris House,with black vertical panel and white roof) was erected in each area. Malaise traps are open-sided tents with a collecting head in which flying or crawling arthropods are trapped and accumulate. The collecting head was a plastic bottle containing 75% ethanol. Malaise traps were placed in light gaps and potential flyways and maintained from March 1993 to March 1994, for a total of 13 months. At the beginning and the middle of each month, the collecting bottle with accumulated arthropods was removed and replaced with a fresh bottle of ethanol.

Malaise Malaise

The sampling regime at 4 distant sites (6, 14, 15, 16) was changed after 2 months. Samples were harvested once per month instead of once per two weeks.

New traps were installed and a second series of malaise samples were taken from June 1995 until June 1996. The traps were installed at the same sites as previously, excluding the 4 most distant sites.

One malaise trap was installed at a recent treefall at a swamp edge (site 18), and maintained from August 1997 to December 1998.

One malaise trap was installed at a recent treefall between the lab clearing and the River Station (site 19), and maintained from July 1999 to November 2000.

At some point in time we switched to using 95% etoh in the bottles, but I do not remember when. All sampling during ALAS IV, 2001-2005, was with 95% etoh.

In 2004, ten traps were placed at new locations (20-29) to parallel the sampling taking place at the 300m site (Cantarrana) on the Barva transect. Ten traps were run for the same time as the transect sampling. These traps were also used for flight intercept traps for part of the time, again paralleling the sampling taking place at Cantarrana.

Collection Codes are of the form M/yy/zzz, where yy is a location number (01-16 for the original 16, 18 for the treefall site, and 00 when the sample is not part of a replicated series at one site), and zzz is a three digit sample number. Sample number is a sequential number based on all malaise samples, not the samples of a particular location. Thus a batch of 8 malaise samples taken on a particular day will have 8 sequential collection numbers, regardless from which locations they came. Errors resulted in a few sample numbers (but not entire collection codes) being repeated; these are described in the list of collection codes. When referring to ALAS specimens, it is important to use the entire collection code, not just the sequential number.

Brief descriptions of Malaise trap sites, locations 1-19; click here.

List of all malaise samples, 1993-2004, by collection code.

Canopy Fogging Samples

During the 1993-1994 sampling period, eighteen trees were selected for canopy fogging: 6 individual trees of the most common tree species at La Selva (Pentaclethra macroloba (Willd.) O. Ktze., Fabaceae), 6 individual trees of a species of intermediate abundance (Virola koschnyi Warb., Myristicaceae), and one individual each of trees from six additional families. Six areas were chosen on a La Selva station map, such that the areas were dispersed across the available primary forest, and at the same time accessible from the trail system. In each area three trees were selected: a Pentaclethra, a Virola, and one of the six unique species. We chose trees that had large crowns, little overlap with adjacent crowns, and good access for climbing. The three trees in a group were usually fogged on consecutive days, and the 6 groups were fogged at approximately two-month intervals over one calendar year.

A second set of fogging samples was obtained in October and November of 1994. 7 sets of 3 trees were fogged, all compressed into this 2-month period instead of spread over a year. Again each group of three contained a Pentaclethra macroloba, a Virola koschnyi, and a distinct species in the "other" category. 6 of the groups were new trees at new locations. 1 of the groups was a set previously fogged: events 13, 14, and 15 were fogged on 6-9 Nov 1993, and the same trees, events 28, 29, and 30, respectively, were fogged 22-24 Oct 1994.

On the day prior to fogging a tree, the tree was rigged with mountain-climbing ropes and a pulley system, so that the following day an operator could climb to the lower branches of the crown and the fogging machine could be hoisted on pulleys. Ropes were strung from trunk to trunk between the focal tree and neighboring trees to form an irregular network 2-3m high above ground level. Forty funnels, each intercepting an area of 1 square meter, were suspended from these ropes, distributed as evenly as possible in the area beneath the crown of the focal tree. (Nigel Stork had these funnels made for another project in Costa Rica, and very generously donated them to the ALAS project.) The funnels were composed of ripstop nylon mounted on a metal hoop, with a threaded ring at the bottom for the attachment of a plastic sample bottle. Palm leaves and other vegetation immediately above the funnels were clipped or bent back, but otherwise the understory vegetation was left intact.


Funnels were left upside down on the ground overnight to avoid accumulation of debris before fogging. Before dawn the next morning the funnels were re-suspended and the bottles filled with 75% ethanol. An operator climbed to the first branches at the base of the crown, 15 to 20m above ground level, and commenced fogging at about 0600hrs. We used a Golden Eagle DynaFogger, on setting 6, to fog 3.8 l of Pyrethrins 123 insecticide (Summit Chemical Co.). This is a 3% solution of a natural pyrethrin insecticide with synergists, in a petroleum distillate carrier. The operator gradually fogged in a 360 degree circle, attempting to cover the crown evenly. Following fogging, a two-hour drop time was allowed, after which the sides of the funnels were washed down with ethanol and the bottles were collected.

Subsequent fogging samples include the following:

One sample was taken in January 1996.

A set of 6 samples (41-46) were taken in late December 1999 and early January 2000. These were from diverse species in a variety of families, all from one area in primary forest.

A set of 6 samples (47-52) were taken in May 2000, all from one species of tree. Three of these samples were taken using the usual procedure of climbing to the lower crown and fogging from there. Three other samples were taken by fogging from the ground.

Fogging collection codes are of the form Faa/xx/yy, where "F" indicates it is a fogging sample, aa is a two-letter code (OT=other, a variety of species; PM=Pentaclethra macroloba, VK=Virola koschnyi), xx is a unique fogging event number, and yy is funnel number within a fogging event (1-40 funnels).

List of fogging samples, by event number.

Blacklight Samples

Group 1. Quantitative sampling, March 1993 to March 1994

Six sampling sites were chosen, as follows (GIS coordinates in parentheses):

Site 01: primary forest, CEN650 (679, -39).

Site 02: primary forest, CCL300 (900, 1411).

Site 03: second growth forest, SAT600 (1200, -230).

Site 04: lab clearing, nr library (553, 877).

Site 05: arboretum (900, 500).

Site 06: second growth forest, SOR750 (764, 1618).

At sites 1,2,3, and 6 a small shed was constructed, of two side poles and a roof of several sheets of tin. White sheets were hung beneath the sheds or, for sites 4 and 5, in the open. The usual procedure was for 4 ALAS staff to work in pairs, each pair sampling from two of the sites. The site pairs were 1 and 3, 2 and 6, 4 and 5. At each site, one blacklight was lit at about 1730hrs. When collecting commenced at a sheet, a regular white flourescent light was also lit. Hand collecting of focal taxa commenced at the first site at 1900hrs, and continued for about half an hour. The collectors then moved to the second site, and collected for 2 hours. They then returned to the first site for a final half hour of sampling, finishing by around 2200hrs.

Group 2. 27 June to 5 July 1994

A series of samples from various sites, during a visit by Jerry Powell.

Group 3. Quantitative sampling, 5 February to 1 May 1996

These samples used generally similar techniques to the quantitative samples of 1993-4, some of them at the same sites and some at new sites.

Group 4. May 1996

A series of samples from various sites, during a visit by Jerry Powell.

Group 5. Quantitative sampling using lighttraps, January 1998 to June 1999

Entotech light traps were used to carry out an 18-month program of sampling. These traps use a 8 watt blacklight tube surrounded by 3 transparent panes, all perched over a funnel on top of a bucket. The bucket has an internal smaller funnel and screen to allow water drainage from rain. The traps were surrounded by a larger wire cage, mesh size 0.5inch, to exclude large insects. Crumpled paper towels were placed in the bottom of the bucket, and a cloth bag of potassium or sodium cyanide suspended inside. The traps were placed before dusk and harvested the next morning. A light sensor turned the light on at dusk and off at dawn.

light trap light trap light trap

Traps were run in pairs, one suspended in the canopy about 20m high, and one on the ground beneath it. On each night of sampling, one trap pair was run. Trapping was carried out on two or three nights per week, rotating among 6 sites.

For 14 of the 372 individual samples, the trap malfunctioned and the flourescent tube did not light. A few specimens were sometimes captured regardless, so these collection codes have been retained in the database, but with a flag indicating that the light did not function.

The locations of the lighttraps was as follows:

Site number, location, GIS coordinates, canopy or ground
7, SOR750, 778, 1618, canopy
8, SOR750, 789, 1642, ground
9, CCC550, 1019, 898, canopy
10, CCC550, 1035, 876, ground
11, Arboleda, 896, 469, canopy
12, Arboleda, 881, 461, ground
13, CES350, 566, 464, canopy
14, CES350, 529, 485, ground
15, STR650, 0, 0, canopy
16, STR650, 0, 0, ground
17, STR2000, 912, -675, canopy
18, STR1800, 901, -664, ground

Material from a harvested trap was placed on a sorting tray. Macrolepidoptera were discarded. Large insects were separated by eye. The remaining material was examined under a dissecting scope. The residual material was stored in alcohol.

The following taxa were individually mounted and labeled: microlepidoptera (Tortricidae, Tineidae, Gracillaridae, Sesidae, and Choreutidae), Tettigoniidae, focal taxa of Braconidae, Symphyta, Scolytidae, Zygopinae, Buprestidae, Cleridae, Cerambycidae, focal taxa of Phoridae.

The following taxa were separated but left in alcohol: Syrphidae, Tachinidae, non-zygopine Curculionidae, large Coleopter, non-tettigoniid Orthopteroidea, non-focal taxon Hymenoptera (excluding Formicidae).

As a special project, Ronald Vargas separated and examined the males of Ecitoninae (Formicidae).

Non-lepidopteran material was washed in soapy water before mounting or transfer to alcohol.

Group 6. Miscellaneous

Miscellaneous blacklight sheet and trap samples, mostly from January 1998, when Jerry Powell was at La Selva and initiating the light trapping program.

Format of collection codes

Blacklight collection codes are of the form L/xx/xxx, where "L" indicates it is a blacklight sample, xx is a site code, and yyy is a unique blacklight sample number. Sample number is a sequential number based on all blacklight samples, starting in 1993, and not on the samples of a particular location or sampling period.

List of Collection Codes.

Salticidae Project, Sep 1996 — Jan 1997

A major sampling program for Salticidae was carried out between September 1996 and January 1997. Samples were statified by site, habitat, collector, and method. Collection codes reflect this stratification as follows:

Collection codes of form Abcdddee##:

A: capital A for Araneae.

b: site; P = vicinity of successional plots, H = vicinity of Huertos project, S = vicinity of LEP.

c: habitat; C = clearing, B = edge or border, S = understory of mature forest.

ddd: collector; DBM = Danilo Brenes, RVC = Ronald Vargas, MPG = Maylin Paniagua, NOM = Nelci Oconitrillo.

ee: method; GO = beating sheet, a 0.82 X 0.82m beating sheet was used to sample for one hour; BA = looking down, a collector worked on hands and knees for one hour, searching closely for salticids and manually capturing them; RE = sweep net, a sweep net with 0.39m diameter opening and 0.67m depth was used to collect for one hour.

##: sample number for a particular site, habitat, collector, method combination.

This file lists the collection code and the date of collection for all the samples taken as part of the structured inventory.

Flight Intercept Traps, Feb-Mar 2004

Flight-intercept samples were taken from February to March 2004 to parallel similar sampling taking place at the 300m site (Cantarrana) on the Barva transect. Ten plastic trays were placed beneath the center pane of a Malaise trap (Figure). Soapy water was placed in the trays. Trays were checked daily. Each day specimens were netted from the trays and accumulated in a bottle of 95% ethanol. Sampling was carried out to parallel the sample accumulating in the collection head of the Malaise trap. One sample comprised two-weeks of accumulated specimens. On harvest, samples were transported to the ALAS lab, the ethanol was changed once, and samples were stored in a freezer. Samples are listed below.

The data fields, in order, are:

Collection code: a unique code for a collection. The "TN" indicates it is a flight-intercept sample, the following two numbers are the trap number, and the final three-digit number is a serial number beginning with 001 for the first sample and ending with 030 for the last sample. In addition, there is a code for all flight intercept samples pooled.

First collection date: First day of the sample period, in format day-month-year.

Second collection date: Day the sample was harvested.

X and Y coordinates: La Selva GIS coordinates.

TN/20/001	16-Feb-04	24-Feb-04	892	298
TN/20/011	10-Mar-04	21-Mar-04	892	298
TN/20/021	7-Apr-04	18-Apr-04	892	298
TN/21/002	16-Feb-04	24-Feb-04	866	179
TN/21/012	10-Mar-04	21-Mar-04	866	179
TN/21/022	7-Apr-04	18-Apr-04	866	179
TN/22/003	16-Feb-04	24-Feb-04	844	123
TN/22/013	10-Mar-04	21-Mar-04	844	123
TN/22/023	7-Apr-04	18-Apr-04	844	123
TN/23/004	16-Feb-04	24-Feb-04	864	67
TN/23/014	10-Mar-04	21-Mar-04	864	67
TN/23/024	7-Apr-04	18-Apr-04	864	67
TN/24/005	16-Feb-04	24-Feb-04	934	33
TN/24/015	10-Mar-04	21-Mar-04	934	33
TN/24/025	7-Apr-04	18-Apr-04	934	33
TN/25/006	16-Feb-04	24-Feb-04	402	-250
TN/25/016	10-Mar-04	21-Mar-04	402	-250
TN/25/026	7-Apr-04	18-Apr-04	402	-250
TN/26/007	16-Feb-04	24-Feb-04	320	-290
TN/26/017	10-Mar-04	21-Mar-04	320	-290
TN/26/027	7-Apr-04	18-Apr-04	320	-290
TN/27/008	16-Feb-04	24-Feb-04	220	210
TN/27/018	10-Mar-04	21-Mar-04	220	210
TN/27/028	7-Apr-04	18-Apr-04	220	210
TN/28/009	16-Feb-04	24-Feb-04	314	372
TN/28/019	10-Mar-04	21-Mar-04	314	372
TN/28/029	7-Apr-04	18-Apr-04	314	372
TN/29/010	16-Feb-04	24-Feb-04	458	716
TN/29/020	10-Mar-04	21-Mar-04	458	716
TN/29/030	7-Apr-04	18-Apr-04	458	716
TN/00/001-030	16-Feb-04	18-Apr-04		

MiniWinkler transect, 1 June 2004

On 1 June 2004, a MiniWinkler transect was sampled, to parallel similar samples taken on the Barva Transect as part of ALAS IV. We attempted to follow as closely as possible the "miniWinkler" method of Fisher (1999). A 250m long straight-line transect was flagged at 5m intervals. The transect was subjectively oriented. After a period of 24hrs with no rain, a sample was taken at each flagged spot on the transect. A one square meter area was delimited, and the litter and dead wood inside was aggressively minced with a machete. Litter was sifted until all the litter in the plot was sifted or 2l of siftate was obtained, whichever came first. When there was more than enough litter to produce 2l of siftate, the different kinds of litter in the plot (e.g. leaves on soil versus litter from a rotten log) were subsampled so that all were represented (a somewhat subjective process that attempted to include the diversity of litter types found in one plot). The plots were delimited by eye, and in practice the actual area sifted varied from 60x60cm to 1x1m. The siftate was returned to the ALAS lab and hung in Winkler bags for three days. Arthropods were collected directly into whirlpac bags of 95% ethanol.

The beginning point of the transect was in the successional plots and from there went at a compass bearing of 270 degrees. It crossed the Sendero Holdredge and continued in mature forest.

The data fields, in order, are:

Collection code: a unique code for a collection. The "WF" indicates it is a miniWinkler sample, the following two numbers are the transect number, and the final two-digit number is the serial position along the transect, from 01 to 50.

Collection date: day the sample was collected from the field, in format day-month-year.

X and Y coordinates: La Selva GIS coordinates.

WF/01/01	1-Jun-04	954	1842
WF/01/02	1-Jun-04	957	1838
WF/01/03	1-Jun-04	960	1834
WF/01/04	1-Jun-04	962	1829
WF/01/05	1-Jun-04	965	1825
WF/01/06	1-Jun-04	968	1821
WF/01/07	1-Jun-04	971	1817
WF/01/08	1-Jun-04	973	1813
WF/01/09	1-Jun-04	976	1809
WF/01/10	1-Jun-04	979	1804
WF/01/11	1-Jun-04	982	1800
WF/01/12	1-Jun-04	984	1796
WF/01/13	1-Jun-04	987	1792
WF/01/14	1-Jun-04	990	1788
WF/01/15	1-Jun-04	993	1784
WF/01/16	1-Jun-04	995	1779
WF/01/17	1-Jun-04	998	1775
WF/01/18	1-Jun-04	1001	1771
WF/01/19	1-Jun-04	1004	1767
WF/01/20	1-Jun-04	1006	1763
WF/01/21	1-Jun-04	1009	1759
WF/01/22	1-Jun-04	1012	1754
WF/01/23	1-Jun-04	1015	1750
WF/01/24	1-Jun-04	1017	1746
WF/01/25	1-Jun-04	1020	1742
WF/01/26	1-Jun-04	1023	1738
WF/01/27	1-Jun-04	1026	1734
WF/01/28	1-Jun-04	1028	1729
WF/01/29	1-Jun-04	1031	1725
WF/01/30	1-Jun-04	1034	1721
WF/01/31	1-Jun-04	1037	1717
WF/01/32	1-Jun-04	1039	1713
WF/01/33	1-Jun-04	1042	1709
WF/01/34	1-Jun-04	1045	1704
WF/01/35	1-Jun-04	1048	1700
WF/01/36	1-Jun-04	1050	1696
WF/01/37	1-Jun-04	1053	1692
WF/01/38	1-Jun-04	1056	1688
WF/01/39	1-Jun-04	1059	1683
WF/01/40	1-Jun-04	1062	1679
WF/01/41	1-Jun-04	1064	1675
WF/01/42	1-Jun-04	1067	1671
WF/01/43	1-Jun-04	1070	1667
WF/01/44	1-Jun-04	1073	1663
WF/01/45	1-Jun-04	1075	1658
WF/01/46	1-Jun-04	1078	1654
WF/01/47	1-Jun-04	1081	1650
WF/01/48	1-Jun-04	1084	1646
WF/01/49	1-Jun-04	1086	1642
WF/01/50	1-Jun-04	1089	1638

Winkler Samples, 1999

Winkler samples are an efficient method of sampling leaf litter ants. The method involves sifting bulk samples of leaf litter and rotten wood by agitating them vigorously in a bag above a coarse mesh screen. Litter arthropods are concentrated in the finer "siftate" that passes through the screen. Arthropods are then extracted from the siftate by a passive extraction method, in which the siftate is placed in thin mesh sacks and then suspended and enclosed within an outer cloth "Winkler bag." The Winkler bag tapers to a cup of ethanol. After loading the sample the Winkler bag is closed at the top and suspended in a sheltered location. Arthopods fall from the litter and accumulate in the ethanol, and the sample is taken off after 3 days. Methodological variations involve how the bulk litter is selected. The method used here involved a relatively subjective selection of litter to sift, and was not based on a particular area or volume of bulk litter (thus they are not directly comparable to the Fisher MiniWinkler method). The person taking the sample moved through the habitat selecting pockets of moist litter. These accumulations of litter and rotten wood occurred between buttresses, along the sides of rotten logs, around dead stumps, and in soil depressions. When approximately 6l of siftate were obtained, the material was placed in a cloth bag and returned to the lab.

Twenty samples were taken by the ALAS staff in June and July 1999, and 8 were taken by the ALAS staff in December 1999. The 20 samples from June and July 1999 were taken in the same localities as previous Berlese samples.

The data fields, in order, are:

Collection code: a unique code for a collection. The "W" indicates it is a Winkler sample, the following two numbers are the location, and the final two-digit number is a sample number, in a series from 01 to 28.

Collector: person taking the sample in the field.

Collection date: day the sample was collected from the field, in format day-month-year.

Site: usually a La Selva locality using the trail abbreviations and the number of meters along the trail.

X and Y coordinates: La Selva GIS coordinates.

W/01/009	D. Brenes	18-Jun-99	Parc. sucesionales	1034	1880
W/02/010	R. Vargas C.	21-Jun-99	SSE	1236	1910
W/03/011	R. Vargas C.	21-Jun-99	SHO 650 m.	1498	1848
W/04/012	D. Brenes	21-Jun-99	CCL	842	1444
W/05/018	R. Vargas C.	4-Jul-99	CCL	1261	1075
W/06/017	R. Vargas C.	4-Jul-99	CC	2648	1384
W/07/014	D. Brenes	25-Jun-99	SS0	1465	491
W/08/019	R. Vargas C.	13-Jul-99	SSO	2039	324
W/09/003	R. Vargas C.	14-Jun-99	LOC	1507	-126
W/10/005	D. Brenes	18-Jun-99	CES	671	114
W/11/006	R. Vargas C.	18-Jun-99	SCH	448	-208
W/12/007	R. Vargas C.	18-Jun-99	CEN	398	72
W/13/008	D. Brenes	18-Jun-99	SAT	1020	-85
W/14/013	D. Brenes	25-Jun-99	SSA	2292	-1120
W/15/015	R. Vargas C.	25-Jun-99	SSA	3800	-750
W/16/016	R. Vargas C.	25-Jun-99	SSA	3960	-701
W/17/020	ALAS	13-Jul-99	SSO	1600	550
W/18/004	Brenes/Vargas	14-Jun-99	LOC	1500	-50
W/19/002	Oconitrillo/Paniagua	14-Jun-99	LOC	1400	-100
W/20/001	J. Longino	14-Jun-99	LOC	1300	-50
W/21/021	R. Vargas C.	2-Nov-99	Sendero Ribereño	3100	2400
W/22/022	R. Vargas C.	2-Nov-99	LEP	3300	-2150
W/23/023	R. Vargas C.	10-Nov-99	Sendero Holdrige	2200	2000
W/24/024	R. Vargas C.	10-Nov-99	Sendero Hartshorn	1600	1050
w/25/025	R. Vargas C.	15-Nov-99	Lindero Peje	1800	-1650
W/26/026	R. Vargas C.	15-Nov-99	Sendero Tres Ríos	1600	-800
W/27/027	R. Vargas C.	23-Nov-99	Sendero Jaguar	2600	-250
W/28/028	R. Vargas C.	23-Nov-99	Lindero Sur	3400	850

Literature Cited

Fisher, B. L. 1999. Improving inventory efficiency: a case study of leaf litter ant diversity in Madagascar. Ecological Applications 9:714-731

McDade, L. A., K. S. Bawa, H. A. Hespenheide, and G. S. Hartshorn, editors. 1993. La Selva, ecology and natural history of a Neotropical rainforest. University of Chicago Press, Chicago, IL, USA.

Wentz, E. A. and J. A. Bishop. 1995. Geographic Information System and database management at a tropical rainforest research station. Biology International 1995 (30):10-19.

Page author:

John T. Longino, The Evergreen State College, Olympia WA 98505

Date of this version: 21 May 2005.
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