Determining Feeding Habits of Southern Red Wood-Ants (Formica rufa L.) in Elmalı Çığlıkara Cedar Forests Ayhan SERTTAS 1, Halil İbrahim YOLCU 1, Cumhur GUNGOROGLU 1, Halil SARIBASAK 1, Fedai ERLER 2, Mustafa AVCI 3, Neslihan SUNGUR 4 Abstract The present study was carried out in the Elmalı-Ciglikara cedar forest, located in South-western Turkey (Antalya), in 2010 to determine feeding habits of F. rufa (southern red wood-ant). These forests have been threatened by Acleris undulana, the cedar leaf moth for long years. For this purpose, we consciously selected three nests from the study area at the end of April and used two-way ramp system developed by Skinner (1980) for determining their feeding habits. Galvanized steel fences at the length of 4 m x 4 m and height of 70 cm were placed inside 25 cm-depth trenches around the nest. A ramp system made of wood allowed ants to exit and enter. Ants were allowed to enter into and exit from nests in single direction through this ramp system. This method enabled us to accumulate food brought by returning ants for 21 weeks (from the beginning of May to the end of September). Food transferred by ants to nests was collected for 30 minutes at three different hours of the day once a week. This study revealed that southern red wood-ants (Formica rufa L.) readily preyed on numerous arthropods and other animal organisms. Over the 21-week sampling period, a total of 11406 food items were transferred by the F. rufa workers to nests. When these items are classified, the abundance of insect materials in general food items is as follow: Lepidoptera 21.2%, Diptera 17.6%, Coleoptera 14.9%, Hymenoptera14.5%. The rest corresponding to 31.8% of the group consists of other insect groups. Food yield varied according to the times of the days and months. The yield was minimized when the sun rays hit the nests between 12.30 and 13.00. The maximum transfers were made between 16.30 and 17.00 when the samples were taken. As for the feeding habits, they were not selective in terms of food and took any food available in environment (whatever found) to their nests. Key words: Southern Red Wood-Ants, Feeding Habits. Introduction Biologic combating can be described as the use of beneficial organisms such as parasites and parasitoids which are the natural enemies, in other words predators, of pests against them. When compared to several combating methods, biologic combating is the method which should be mostly preferred in the sense that it assists restoration of natural balance, produces permanent outcomes in the long term prospectively and enables us to achieve final goals (OĞURLU, 2000). Living in some of our localities naturally and being an important predator, southern red wood-ants (Formica rufa L.) (Hym.: Formicidae) are exploited in biologic combating with some forest pests. The idea of transferring southern red wood ants (Formica rufa L.) from their natural habitats to other sites for the purposes of biologic combating was first coined by the Italians (GÖKTEPE,1976). Spread of F. rufa is observed in majority part of Europe ranging from interior parts of Spain on the south to Southern Britain and Scandinavia until Lake Baykal in Russia, the Caucasians on the south and Anatolian part of Turkey. Its spread in Anatolia consists of scotch pine and spruce tree forests in Eastern Anatolia, scotch pine, black pine, fir, juniper and spruce tree forests in Western Anatolia and Western Black Sea. Nests are generally located on clearings where canopy is not completed as well as flat and slightly slopped areas between the range of 800 and 2600 meters (AKTAÇ, 1987). F. rufa is the most common southern red wood ant in Anatolia, whereas Formica pratensis Retzius group first identified at the heights of 450 720 meters in Istranca oak forests in Thracian Region is the second species represented in Turkey (AKTAÇ, 1987). Based on national and foreign literature, SERİN (1999) has outlined feeding ecology of ants as the following: Members of Formicidae family get nourished with generally animal and sometimes vegetative food. F. rufa is known to prey on caterpillars, sawfly larva, butterflies, bees, insect eggs and pupas and numerous pests. Besides, feces of leaf beetles (aphids) rich in sugar (nectar- honey item) are emphasized to be important source of food. With reference to Serin (1999) and Aktaç (1987), Results conducted by Pavan (1079) in Italy were mentioned. Accordingly, this group had more than Sayfa 229
1.000.000 nests in Italy. Each nest was calculated to have 300,000 workers. Daily food need of each worker with the weight of approximately 8 mg equals to 1/20 of bodily weight. This calculation gives birth to potentiality in which 72 tons may dispose of more than 14,000 tons of insects over active period of 200 days on average daily. The amount of insects controlled or consumed by ants annually was calculated to be 56,2 tons according to calculations made in Bolu-Şerif Yüksel Research Forestry through the same method (SERİN, 1999). As a result of study conducted in England for the purposes of finding out feeding habits of southern red wood ants, their main food resources were revealed to be honey items of aphides and larva of Diptera and Lepidoptera families. This study also monitored timewise changes in their feeding habits (SKİNNER, 1980). In another study, larva population of Lepidopter on trees without ants was determined to be much more when compared to those on trees with ants (SKINNER and WHİTTAKER, 1981). to Elmalı Çığlıkara cedar forests, to determine those which are eligible for transportation and to reveal their feeding habits. This proceeding deals with only results of feeding habits. Materials and Methods 3 active nests were consciously selected at the end of April with a view to revealing feeding habits of ants. Mechanism which was previously used by G. J. Skinner was employed for collecting food transported to nests in controllable way (Skinner, 1980). These three nests were surrounded with a plate at the height of 4 m x 4m and height of 0,70 meter. This plate was seated inside 24cm-deepth channel and compressed and closed with soil in a way that ants couldn t climb up. Entrance and exit ramps were constructed so that ants could enter into and exit from their nests. Wood material was used in constructing these ramps (figure 1) Sayfa 230 Southern red wood ants make use of several food sources. Carbohydrates are obtained from honey items secreted by aphids, whereas proteins are obtained from the invertebrate. Protein plays an important role in growth period of ant larva in which numerous invertebrate is collected (LENOİR, 2002). Coccoidea (scale insects, coccoidea) species have interesting and multi-directional relations with ants. While ants depend on coccoidea secreting honey items as resource of carbohydrate, protein and lipid, coccoidea get benefits from this relation be being transported to new plants, as a result of which they become resistant against climatic conditions and natural enemies. While the availability of ants on plants increases population of coccoidea, tendency of ants to prey on other harmful insects affects general health of plants positively. Killing or ignoring ants in combating with coccoidea increases population of other plant pests (TURGUTER and ÜLGENTÜRK 2007). Generally speaking, food of ants consist of honey item at the amount of 62%, preyed insects at the amount of 33% and resin at the amount of 5% as well as fungus, dead insects reminiscent and seed (WAY VE KHOO 1992). Ants from the group of Formica rufa kill numerous insects when pests intensively occupy the area. 7% of these killed insects may be among beneficial insects. This ratio may increase up to 15-20% over times when pests are not intensive (WAY VE KHOO 1992). It has been reported that preying area of ants may not exceed 0,5 hectare and it is sufficient to have 4 pests per hectare so that forest can be fully protected (ADLUNG, 1966). The objectives of this study are to create inventories of active nests of southern red wood ants transported Figure 1: Mechanism used in determining feeding habits Food items transported by ants to nests were collected at three different times and once a week since the beginning of May for 30 minutes over ramps (09.00 09.30, 12.30-13.00 and 16.30-17.00). Food collecting activities were maintained until the end of September. Collected food was placed and kept inside bottles of alcohol and food samples were tried to be identified. Results As for the historical distribution of food amount (items) transported by ants to their nests, food transportation in all the nests was too much on May 4 and 25, June 1 and 15, July 6 and August 3 and 10. The most food amount with 1298 items was seen to be transported on August 3. As for the changes in food amounts transported according to collection times and dates, the amounts
brought to nests were reported to be in parallel between 09.00-09.30 and 16.30 17.00. It was observed that food amount and exit and entrance of ants on the ramp declined at 12.30 13.00 when the sun radiant was direct. Activities in nests exposed to direct sun during noon times were observed to decrease. Food yield between 12.30 and 13.00 was seen to be much more than on cool and cloudy days when compared to other days. Food transportation was determined to reach peak between 16.30 and 17.00. Food samples were collected at three different times once a week over 21 weeks. Within this period, 11.406 food samples could be taken from three nests. As for food sets transported to nests mostly, 3221 items of Lepidoptera, 2004 items of Diptera, 1703 items of Coleoptera and 1651 items of Hymenoptera were identified. Distribution of mostly-collected food in historical terms and on set-basis has been provided in Figure 2. Figure 2 : Historical Distribution of Mostly-Transported Food on Set Basis As for the food collected, insects in the form of imago with 6707 items were seen to be preferred mostly. This consisted of foods in larva with 3457 items, which was followed by pupa, leg, head part, abdomen part and wing parts respectively. Diagnosis activities also aimed at finding out whether food was beneficial, harmful or neutral. Accordingly, 1684 food samples out of 11.406 items couldn t be identified to be beneficial, harmful or neutral. Among diagnosed ones, 6939 items were identified to be neutral, 1812 items as harmful and 971 items as beneficial. As for the changes in food amounts transported according to collection times and dates, the amounts brought to nests have been reported to be in parallel between 09.00-09.30 and 16.30 17.00. It was observed that food amount and exit and entrance of ants on the ramp declined at 12.30 13.00 when the sun radiant was direct. Activities in nests exposed to direct sun during noon times were observed to decrease. Food yield between 12.30 and 13.00 was seen to be much more than on cool and cloudy days when compared to other days. Food transportation was determined to reach peak between 16.30 and 17.00 (Figure 2). Figure 2: Changes in Amount of Food Transported According to Times of Food Collection Sayfa 231
Acleris undulana (cedar leaf moth) among the members of Tortricidae family in Lepidoptera set is seen almost every year in cedar forests having large place in Antalya Regional Directorate of Forestry, Elmalı, Kaş, Finike, Kumluca and Antalya Administration of Forest, which is frequently reported. The number of Lepidoptera samples which were transported by southern red wood ants to their nests and could be identified as set reached to 3221 in all the three nests. Among 3221 food items, 1640 items, namely 905 items of imago and 735 items of larva, were determined to be A. undulana samples. No A. undulana pupa was encountered among food items. Pupa grows in suckers and among needles. Ants are estimated not to extract pupa from these needles, thus failing to obtain them. 50,91% of foods included in Lepidoptera set transported consists of A. undulana. Amount of A. undulana historically transported has been provided in Figure 3. A. undulana causes harms during its larva period, which lasts for approximately five weeks. Ants could transport 735 items of A. undulana larva to their nests over this period. Based on observations, cedar tree adjacent to nests of southern red wood ants couldn t escape from the harms caused by A. undulana (Figure 4). Figure 3: Historical Distribution of Acleris undulana Transported to Nest. Figure 4: Relation between southern red wood ant and Acleris undulana. Sayfa 232
Discussion and Conclusion Members of Formicidae family get nourished with generally animal and sometimes vegetative food. F. rufa is known to prey on caterpillars, sawfly larva, butterflies, bees, insect eggs and pupas and numerous pests. Besides, feces of leaf beetles (aphids) rich in sugar (nectar- honey item) are emphasized to be important source of food. Carbohydrates are obtained from honey items secreted by aphids, whereas proteins are obtained from the invertebrate. Protein plays an important role in growth period of ant larva in which numerous invertebrate is collected (LENOİR, 2002). In observations of feeding habits, abdomens of ants exiting from the nests were reported to be small, whereas abdomens of those without any food in their mouths entering inside the nest were reported to be big and fat. Furthermore, abdomens of ants climbing up to the cedar trees were observed to be small, whereas abdomens of ants descending from trees and not carrying any food were observed to be big and fat. Cinara cedri was observed on cedar trees, which was estimated to be an indicator that ants supplied some part of their food from honey items secreted by aphides. Food samples which were suitable for diagnosis could be diagnosed. As for the food sets transferred to nest mostly, 3221 items of Lepidoptera, 2004 items of Diptera, 1703 items of Coleoptera, 1651 items of Hymenoptera were observed. As for food samples collected, the imago insects were seen to be the most preferred group of food items, which was followed by food in larva and subsequently food such as pupa, leg part, head part, abdomen part and wing part. Generally speaking, food of ants consist of honey item at the amount of 62%, preyed insects at the amount of 33% and resin at the amount of 5% as well as fungus, dead insects reminiscent and seed (WAY VE KHOO 1992). Ants from the group of Formica rufa kill numerous insects when pests intensively occupy the area. 7% of these killed insects may be among beneficial insects. This ratio may increase up to 15-20% over times when pests are not intensive (WAY VE KHOO 1992). Food yield varied according to the times of the days and months. The yield was minimized when the sun rays hit the nests between 12.30 and 13.00. The maximum transfers were made between 16.30 and 17.00 when the samples were taken. It was observed that food transportation in all the nests was too much on May 4 and 25, June 1 and 15, July 6 and August 3 and 10. The most food amount with 1298 items was seen to be transported on August 3. Southern red wood ants were transported from Ankara Kızılcahamam and Eskişehir Çatacık forests to Çığlıkara cedar forests between 1970 and 1974 for the purposes of biologic combating with cedar leaf moth (Acleris undulana). A. undulana caused harms during its larva period, which lasted for approximately five weeks. Ants could transport 1640 items of A. undulana, namely 735 items of larva and 905 items of A. undulana imago to their nests. As a result of this study, it was observed that southern red wood ants were not selective in terms of food and took any food available in environment (whatever found) to their nests. However, they were identified to transport also A. undulana imago and larva to their nests, if available. References ADLUNG, G. K., 1966. A Critical Evaluation of the European Research on Use of Red Wood Ants (Formica rufa group) For Protection of Forest Against Harmful Insects. Zeitschriff für Angewnatle Entomologine, 57, 167-189. AKTAÇ, N., 1987. Research on spread and taxonomy of red wood ants (Formica rufa, Hymenoptera: Formicidae) in Turkey. 1st Entomology Congress of Turkey, October 13 16, 1987, İzmir GÖKTEPE T. 1976. Technical News Bulleting of Ministry of Forestry. March 1976, Year: 15, Issue: 57 LENOIR L. 2002. Can wood ants distinguish between good and bad food patches on the forest floor? European Journal of Soil Biology 38 (2202) 97-102 OĞURLU İ. 2000. Biologic Combating, Süleyman Demirel University Issue No:8 Faculty of Forestry. Issue No: 1 PAVAN, M. 1979. Significance of Ants of the Formica rufa Group in Italy in Ecological Forestry Regulation Bulltin Srop, II-3SARIBAŞAK H., SERTTAŞ A. ERLER F., ÇETİN H., 2011. Biology of Acleris undulana Wlsghm. Lep.:Totricidae and Organic and Microbiotic Approaches in Combating with Them. Research Technical Bulletin. Bulletin No: 43 Antalya SERİN M. 1999. Results on Survival Types and Transplantation Possibilities of Ants from Formica rufa L. group in Bolu Forests. Directorate of Western Black Sea Forestry Directorate, Several Issues, Bolu. SKINNER J. G. 1980. The Feeding Habits of the Wood-Ant, Formica rufa (Hymenoptera: Formicidae), in Limestone Woodland in North-West England, Journal of Animal Ecology, 49, 417-433 SKINNER J. G. And WHITTAKER B. J. 1981. An Experimental Investigation of Inter-Relationship Between The Wood-Ant ( Formica rufa ) And Some Tree- Canopy Herbivores. Journal of Animal Ecology(1981) 50, 313-326 TURGUTER S. ve ÜLGENTÜRK S. 2007. Relations between Ants (Hymenoptera: Formicidae) and Coccoidea (Hemiptera: Sternoryncha). Journal of Agricultural Sciences 2007, 13 (3) 312-320 WAY, M.J. and KHOO K.C. 1992. Role of ants in pest managements. Annu. Rev. Entomol. 37:479-503 Sayfa 233