Assessment of Fruit Fly Infestation on Melon Manis Terengganu (Cucumis melo var. inodorus) at Different Fruit Ripening Stages

Cucumis melo var inodorus or known as Melon Manis Terengganu (MMT) is a new variety of rockmelon and has been developed and grown exclusively in Terengganu since 2015. However, pest infestations such as fruit flies have reduced melon production yields, and research on fruit flies is still poorly studied in this new variety. Therefore, this study was aimed to identify the fruit fly’s species infested MMT as well as to determine the infestation rate of fruit flies on MMT at different ripening stages. The infested MMT fruits were randomly collected for three consecutive weeks prior to harvest and each week was represented as unripe stage (Week 1), ripe stage (Week 2) and fully-ripe stage (Week 3). Each week, 10 fruit samples were brought to the laboratory and weighed individually before being placed in plastic containers. The fruits were reared until all larvae transformed into pupae for determination of infestation rates and emergence of adult fruit flies for species identification. A total of 232 of fruit flies adults emerged from 30 MMT fruit samples collected and all the flies were identified as Zeugodacus cucurbitae (previously known as Bactrocera cucurbitae).  Unripe stage fruits recorded the highest infestation rate of fruit flies at 28.24 ± 18.58 pupae/kg and followed by ripe stage at 24.47 ± 8.17 pupae/kg. Whilst the fully-ripe stage had the lowest infestation rate of flies at 13.5 ± 5.07 pupae/kg. However, no significant difference (P>0.05) of infestation rate was recorded among the different fruit stages. This study contributes new information on the fruit fly’s species that attack MMT and its infestation rate. Hence, these findings are expected to help better management of MMT fruit flies in the future.