Barcoding of white-spotted stink bug, Eysarcoris ventralis (Westwood) (Hemiptera: Pentatomidae) attacking Egyptian barley and its population density

Abstract

White-spotted stink bugs, were noticed as a first time in a few numbers of the Egyptian barley cultivar Giza 138 plants in mid of January of 2019/2020 season at soil improvement and conservation Research department at Sakha Agricultural Research station, farm, Kafr El-Sheikh Government, Egypt. Morphological identification and DNA barcoding of mitochondrial gene cytochrome c oxidase subunit I (COI) were used identified the species of collected bugs. The results revealed a new record of Eysarcoris ventralis (Westwood 1837) (Hemiptera: Heteroptera: Pentatomidae). The results of pest insect survey of directly accounts on barley cultivar weekly during two growing winter 2019/2020 and 2019/2021 seasons displayed a significant effect of seasons on the E. ventralis population density. Positive significantly correlation was found between the E. ventralis population density and growth stages of barley under 2019/2020 and 2019/2021 seasons by (0.311 and 0.531) respectively. Regression coefficient, revealed that decrease of temperature by 1 °C increased population of E. ventralis by 0.051 and 0.036 insects per 10 tillers in 2019/2020 and 2019/2021 seasons respectively, while increase of relative humidity by 1% decreased population of E. ventralis by 0.047 and 0.31 insects per 10 tillers in 2019/2020 and 2019/2021 seasons. High population of E. ventralis was found in Anthesis stage of barley. Minor damage was found in immature grain at dough stage. Thus these results are so important to using feature integrated pest management (IPM) programs in barley to avoid the damage of Eysarcoris ventralis (Westwood 1837). Partial DNA sequence of collected sample using cytochrome c oxidase I (COI) mitochondrial gene with clear alignment of 576 bp. The tested sequence more related to Eysarcoris sp. and far from Nezara sp.). For more accuracy, BLAST was used for tested sequence with Eysarcoris sp. and found it closely related to E. ventralis. DNA sequence of COI as type effectively precludes the finding of a new evidence to resolve taxonomic problems.