Abstract:
Fruit flies are one of the widely distributed insect pests and they mostly damage economically
important fruits and vegetables in the tropical region. However, there are no recently published
reports of fruit fly assemblages associated with commercial fruit plantations in Sri Lanka. Hence,
the present study aimed to investigate the abundance and diversity of fruit flies attracted to the
methyl-eugenol field traps in a selected mango cultivation (“Karutha kollomban” variety) in
Ambalanthota, Sri Lanka. Six fruit fly traps (5 cm diameter, 10 cm height, two circular opening 1mm radius and a methyl-eugenol coated sponge) were hung (1.5- 4 m above the ground level
and 20m inter-trap distance) in six mango trees which were located in the middle of each
randomly selected six sampling plots (400m2) in the cultivation (0.54 ha). Trapped flies were
collected twice a month from October to December 2021 (during the fruiting season) replacing
new traps in each sampling round. Collected samples were identified using standard taxonomic
keys by observing under the light microscope (Nikon-ECLIPSE-E100) (10×4). Two indices;
Simpson Population Dominance Index and the Abundance Index were calculated. The variation of
species abundance was compared using one-way ANOVA test. Seven fruit fly species; Bactrocera
dorsalis (Hendel), B. kandiansis (Drew and Hancock), B. correcta (Bezzi), B. latifrons (Hendel), B.
tuberculata (Bezzi), B. nigrofemoralis (White and Tsuruta) and B. cacuminata (Hering) were
recorded in this study. Out of the total 803 specimens examined, B. dorsalis had a significantly
higher abundance (412, 51.31%) (P<0.05) than other species, and B. cacuminata had the lowest
abundance (26, 3.24%). The highest Simpson Dominance index (0.26) was recorded for B. dorsalis
while other recorded six fruit fly species were less dominant in the selected mango cultivation.
Study findings will be important for fruit cultivators to design and implement fruit fly control
measures.
