Abstract:
Zeugodacus cucurbitae Coquillett is one of the most detrimental pests on cucurbits. Control of this pest species
often uses insecticides and Polyscias guilfoylei is a potential source for bio insecticides. This research aimed to study
the influence of P. guilfoylei leaf extract application on Z. cucurbitae mortality and to determine the LC50 value.
The research was conducted at Pest Invertebrate Plant Pest Science Laboratory, Department of Plant Protection,
Faculty of Agriculture, Universitas Gadjah Mada. Toxicity test was done using contact, oral and residue methods
by applying leaf extracts in ethanol and n-hexane extracts with concentrations of 0; 1.25; 2.50; 5.00; 10.00; and
20.00%. The research used a complete randomized design with six replicates. Parameters observed included the
number of dead melon flies at 72 hours after treatments and LC50 value of each extract. Data was analyzed using
Probit analysis via 1.02 version of Lenora software Polo Plus. Result showed that ethanol and n-hexane extracts
of P. guilfoylei leaf using oral and residue methods affected Z. cucurbitae mortality. However, in contact method
using ethanol and n-hexane extracts of P. guilfoylei leaf did not affect Z. cucurbitae mortality. LC50 values of ethanol
extracts using oral and residual methods were 6.168% and 3.658%, respectively. LC50 values of n-hexane extracts
using oral and residual method reached 5.311% and 6.607%, respectively. This research showed that ethanol and
n-hexane extracts of P. guilfoylei leaf contained secondary metabolites that were toxic against melon fly Z. cucurbitae
