First report of the white-spotted stink bug, Eysarcoris ventralis (Westwood, 1837) (Hemiptera: Pentatomidae) infesting rice agroecosystems in northern Thailand
Wandee Wattanachaiyingcharoen1,2*, Patcharapun Wanitsumran1, Kaweecha Saewa3, Det Wattanachaiyingcharoen2,3,4
1Department of Biology, Faculty of Science, Naresuan University, Phitsanulok, Thailand
2Center of Excellence for Biodiversity, Faculty of Science, Naresuan University, Phitsanulok, Thailand
3Agriculture and Environmental Integration Research and Development Unit, Faculty of Agriculture, Natural Resources and Environment, Naresuan University, Phitsanulok, Thailand
4Department of Agricultural Sciences, Faculty of Agriculture, Natural Resources and Environment, Naresuan University, Phitsanulok, Thailand
*Corresponding author’s email: wandeew@nu.ac.th
Received:06 July2025/ Revised:07 October 2025 / Accepted:11 October 2025/ Published Online: 30 October 2025
Abstract
Insect pests, especially various sucking insects, present significant threat to rice production worldwide including Thailand. This research remarks, for the first time, the occurrence of the white-spotted stink bug (Eysarcoris ventralis Westwood, 1837) in rice fields in northern Thailand. We conducted surveys in 304 rice fields across 12 provinces, collecting data on cultivation practices, water management systems, and rice growth stages, while also recording samples of both nymphs and adult rice pests. The surveys revealed that 26.64% of rice fields were infested by E. ventralis. Morphological analysis confirmed the insect is a member of the genus Eysarcoris, family Pentatomidae. Broadcasting rice fields reported an infestation level at 70.37%, while irrigated rice fields showed a 77.78% of infestation. Ecological factors, such as high moisture, dense plantings, and continuous planting create a favorable condition for the spread of this insect. The susceptible stages of rice are the booting and heading stages. During these stages, both nymphs and adults feed on leaves, stems, and especially developing grains This feeding results in damaged seeds and reduced yields. Six surrounding grass weeds were also found to be alternative host plants for development and off-season survival. Our results emphasize the significance of the white-spotted stink bug, E. ventralis, as a new emerging insect pest of rice in Thailand.
Keywords: White-spotted stink bug, Eysarcoris ventralis, Insect pest infestation, Rice insect pest, Sporadic pest
