ABSTRACT

Study was conducted to record the seasonal incidence, population dynamics, comparative biology of fruit flies, and eco-friendly management strategies in Garcinia spp. in the Central Western Ghats of Karnataka during the year 2021 and 2022. The methyl eugenol trap catches revealed five species of fruit fly viz., Bactrocera dorsalis complex (Bactrocera dorsalis (Hendel) and Bactrocera caryeae (Kapoor)), Bactrocera correcta (Bezzi), Bactrocera zonata (Saunders), and Bactrocera versicolor (Bezzi). Irrespective of study locations and fruit fly species in G. indica and G. morella recorded the maximum fruit flies populations during the 15th SMW, where as in G. gummigutta recorded the maximum fruit flies populations during the 19th SMW in 2021 and 2022. All the fruit flies species trapped were positively correlated with maximum, minimum temperature and afternoon relative humidity and negatively correlated with rainfall and morning relative humidity. Among the total of 18185.40 fruit flies trapped in the Garcinia spp., 61.03 per cent belonged to B. dorsalis complex, while the second and third most common species (B. correcta and B. zonata) represented 34.45 and 3.52 per cent, respectively and B. versicolor constituted only 0.98 per cent. Irrespective of Garcinia spp. the lower elevations viz., Katgal, Bramavara, Sampaje and Charmudi recorded the maximum Shannon diversity index and the Pielou’s evenness (J') index indicated the species present in the locations have equal number of individuals. Whereas the higher elevations viz., Mudigere, Ponnampet, Agumbe, and Sirsi recorded the lowest Shannon diversity index and the Pielou’s evenness (J') index indicated the species present in the locations have unequal number of individuals. The studies on comparative biology of the fruit fly, B. caryeae on G. indica and G. morella indicated that total life cycle starting from egg to death of adults, for males recorded with a pooled mean of 19.38 and 18.88 days respectively, similarly for the female it was recorded as 23.08 and 21.45 days respectively. The male and female could live longer when reared on G. indica compared to G. morella. The fruit fly maggot population was highest in G. indica with a pooled mean of 19.37 maggots per fruit followed by 12.61 in G. morella. The protein baits evaluation indicated that the mean fruit fly trap catches differ significantly among the treatments and colour of traps. Significantly, the maximum total (male + female) number of fruit flies per trap was recorded in casein + banana + sugar (1:1:1) + malathion 50 EC (5.10). followed by yeast + banana + sugar (1:1:1) + malathion 50 EC (4.22) and soybean + banana + sugar (1:1:1) + malathion 50 EC (3.35). Among the colour of traps, the mean maximum total number of fruit flies per trap was recorded in yellow (3.27). The bait containing casein + banana + sugar (1:1:1) + malathion 50 EC with a yellow colour trap recorded the highest total number of fruit flies per trap (5.46).