Browsing by Author "Gunarathna, S. M. D. P."

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Food preferences of Solenopsis geminata workers in anthills located at the premises of Eastern University, Sri Lanka
(Faculty of Science, University of Kelaniya Sri Lanka, 2024) Gunarathna, S. M. D. P.; Vinobaba, M.; Udayakantha, W. S
The tropical fire ant, Solenopsis geminata (Fabricius, 1804) causes ecological disruptions and economic damage in tropical regions of the world. Effective control strategies for tropical fire ants rely on understanding their ecology. The current investigation focused on recording the preferred food type among six food types, with an intention of developing an effective ant bait formulation, which is to be based on the preferred food types later. Three localities, each 100 m apart, were selected at the premises of the Eastern University of Sri Lanka, and two active S. geminata anthills were identified by recognizing worker ants at each site. A 1.1 g weight of selected food items, peanuts, crushed sugar, honey, soybean oil, corn grit, and corn flour, were placed 15 cm away from each anthill at approximately a 60º angle and protected from other animals. The number of ants attracted to each sample of food was counted from 8.00–10.00 a.m. and, remaining food was weighed and deducted from the original weight to determine the amount of the food consumed by the ants. This procedure was done over 12 consecutive sunny days with air temperatures ranging between 28 °C and 37 °C. ANOVA test followed by Tukey's HSD was applied to determine the significant differences between the mean weight of each food type consumed by the ants. Worker ants formed trails to gather soya bean oil and corn grit on all occasions, while only 50–65 of ants were observed around the other types of food. The results showed that S. geminata strongly preferred soya bean oil and corn grit over other commercially available food types (p = 0.01; Tukey's HSD), suggesting their potential use in effective bait formulations. Future research should explore the optimization of bait formulations incorporating soya bean oil and corn grit.
The role of Solenopsis geminata in affecting health and routine activities: A case study of undergraduate students at Eastern University, Sri Lanka
(Faculty of Science, University of Kelaniya Sri Lanka, 2024) Gunarathna, S. M. D. P.; Vinobaba, M.; Udayakantha, W. S.
The tropical fire ant, Solenopsis geminata, is an invasive species that damages agriculture, infrastructure, and human health globally. In Sri Lanka, research is limited. This study examines the impact of Solenopsis geminata on undergraduate students’ health, daily activities, and campus experience at Eastern University. A structured interview-type questionnaire survey, using both closed and open-ended questions, was conducted to investigate details about allergic responses caused by S. geminata stings and other related issues experienced by undergraduate students at the Eastern University of Sri Lanka from July to December 2023. The questionnaire consisted of 20 questions in three major sections, demographics, sting incidents, and other related information. A randomly selected general undergraduate sample of 120 students participated in the questionnaire survey and were shown live samples and photographs of S. geminata for identification. Seventy-eight (n = 78) students who identified the species continued with the survey. Their ages ranged from 21 to 30 years old, with a maleto-female ratio of 4:5. In the group surveyed, 100% reported experiencing S. geminata stings. The most frequent symptoms were a combination of redness, itching, and swelling (51.7%), or just redness and itching (24.1%). Additionally, 13.79% exhibited oozing, and 5.2% developed long-term scars. According to Turkey's HSD, there is no correlation between the number of bites received and gender (p = 0.46), but a significant correlation was found between the average reaction to bites and age (p = 0.005). The survey also revealed that 10.34% reported damage to stored staples, 10.34% to crops, 11.2% to selling items, 8.6% to physical equipment, and 4.3% to seeds. These descriptive statistics highlight the significant impact of S. geminata stings on students' health and daily life, the economic damage to their stored staples, crops, and equipment. Future recommendations include increasing education on the prevention, urging the usage of biopesticides and management of S. geminata stings among students and implementing effective control measures to reduce the population of these ants.