R.A. Abood1 and A. Al-Yousuf2*
(1) Department of Plant Protection, Iraqi Ministry of Agriculture, Basra, Iraq; (2) Department of Plant Protection, College of Agriculture, University of Basrah, Basra, Iraq.
*Email address of the corresponding author: [email protected]
The lesser date moth (LDM) Batrachedra amydraula Meyrick, 1916 (Lepidoptera: Batrachedridae), is a key pest of date palm Phoenix dactylifera L. A field study was conducted over two seasons (2024 and 2025) in date palm orchards. The study aimed to determine suitable sampling units based on cumulative larval-days (Ld) and the number of infested fruits per spikelet, and to estimate the economic injury level (EIL) of LDM on the Sayer cultivar in Basra, Iraq. The infestation rate (%) was assessed in both fallen fruits and spikelets, and the number of larvae in fallen fruits was recorded at 15-day intervals from the Hababouk stage until the Khalal stage. Yield losses caused by LDM infestation were also estimated. Furthermore, the role of the biologically-derived insecticides Radiant (Spinetoram) and Belthirul (Bacillus thuringiensis kurstaki) in reducing economic losses from pest infestation was evaluated. The results obtained showed that the application of Radiant and Belthirul reduced infestation levels to 4.0 and 6.2%, respectively, compared with 9.4% in the untreated control during the 2024 season. In the 2025 season, infestation levels were reduced to 2.1% and 1.3%, respectively, compared to 10.2% in the control treatment. The insecticide applications led to a reduction in estimated economic losses (kg per palm tree). Losses decreased to 4.1 and 6.5 kg/tree with Radiant and Belthirul, respectively, compared to 9.4 kg/tree in the control during 2024. Similarly, in 2025, losses declined to 1.8 and 1.2 kg/tree, respectively, compared to 8.6 kg/tree in the control. For use in the integrated management of LDM, the proposed EIL values were 6.94 and 5.5 kg/tree for Radiant and Belthirul, respectively. The corresponding economic thresholds (ET) were 5.6 and 4.4 kg/tree, respectively, based on the Ld sampling unit. When using the number of infested fruits per spikelet as the sampling unit, the EIL values were 1.98 and 1.57 kg/tree, with ET values of 1.6 and 1.3 kg/tree, respectively.
Lesser date palm moth, date palm, economic injury level, economic threshold, bio-insecticide.
https://doi.org/10.22268/AJPP-001535