Zeugodacus tau, an economically important fruit fly species, exhibits a preference for infesting the fruits of cucurbitaceae, but it has also been reared from the fruits of several other plant families. Phytosanitary treatments are needed to ship the fruit from some of these host plants out of areas where populations of the fruit fly exist. Based on the guidelines for the development of cold disinfestation treatments for fruit fly host commodities, proposed by the International Plant Protection Convention (IPPC), the cold disinfestation trials were carried out with Z. tau infesting oranges through artificial infestation. The results showed that the third instar of Z. tau was the most tolerant stage among all developmental stages. No survivors were found among 106,204, 96,168, and 9180 individuals of Z. tau in oranges treated at 1.75 °C for 23 d, 2.34 °C for 25 d, and 1.8 °C for 22 d, respectively. These results support for the application of the 22-day treatment at ≤1.67 °C as an additional safety measure. Such a measure mitigates the risk of introduction and establishment of Z. tau through imported citrus. However, for other susceptible hosts of Z. tau, the cold treatment schedules against Z. tau required to achieve quarantine security with larval endpoint would need to be 23 d at 1.75 °C or 25 d at 2.34 °C. These results also indicated that Z. tau exhibits the highest cold tolerance among the other tephritid species for which cold treatment have been reported.
Snake fruit (Salacca zalacca (Gaertner) Voss) is renowned for its taste and nutritional value; however, the snake fruit rot diseases caused by fungal pathogens can lead to significant economic losses. In this study, a fungal isolate was obtained from the rotten snake fruit with brown rot symptoms at the fruit apex upon removal of the peel. The causal agent was identified as Thielaviopsis species based on cultural and morphometric characteristics. Multi-locus phylogenetic analyses of the internal transcribed spacer (ITS) region, translation elongation factor 1-alpha (tef1-α) and beta-tubulin (tub2) genes revealed that the isolates Te 5742 clustered within Thielaviopsis euricoi Bat. & A. F. Vital. Furthermore, pathogenicity tests fulfilled Koch’s postulates, confirming T. euricoi as the pathogen responsible for the observed rot. This is the first report of T. euricoi causing fruit rot on snake fruit worldwide and will provide information on monitoring and management of snake fruit diseases in the garden and market.