Abstract:
The fig–fig wasp interaction is an obligate mutualistic relationship. Ficus tinctoria
(Moraceae) is a hemi-epiphytic dioecious fig tree species. The present study
investigated the influence of vegetation disturbance regimes on the fig–fig wasp
relationship and syconial characteristics of F. tinctoria across two study sites and was
conducted from October 2024 to February 2025. Study sites were selected based on
the difference of disturbance level in their vegetation after calculating the percentage
vegetation cover. The study sites were the less disturbed Nattarampotha area which
belongs to the Kandy District (Site 1) and the more disturbed urban core within
Matale city (Site 2). Mature syconia were collected, their diameter measured, cut into
two halves and reared until the complete wasp emergence. The number of galls and
florets per syconia, pollinator fig wasps (PFWs) and non-pollinator fig wasps
(NPFWs) were counted and recorded according to their sex. Percentage contribution
of galls in the syconium for fig wasp production was higher in Site 1 (89.00%) than
Site 2 (79.85%). Mean values of syconial diameter (DS), volume (VS) and number
of florets per syconium (Fl/S) were comparatively higher at Site 2 (DS = 9.46 ± 0.40
mm; VS = 473.23 ± 63.67 mm3; Fl/S = 134.60 ± 21.6). The sex ratio of PFWs in Site
1 was 0.06 and in Site 2 was 0.30, indicating that Site 1 is more female-biased. The
pollinator ratio of Site 1 (0.40) was significantly higher (p=2.14 × 10⁻⁸ ) than Site 2
(0.10). At site 1, there was a strong positive correlation between total non-pollinator
fig wasps and pollinator male fig wasps (PMFWs) (r = 0.785) and between non
pollinator male fig wasps and PMFWs (r = 0.824), whereas there was no strong
correlation found at Site 2. Overall, Site 1 showed higher pollinator ratio, proportion
of female wasps and wasp abundance within the syconia, indicating a stable
mutualistic relationship. This study reveals the significant effects of disturbance on
the relationship between F. tinctoria and its associated fig wasp species. The findings
support the conclusion that increased disturbance negatively impacts syconial
characteristics and fig–fig wasp relationships.
