First report of Hierodula transcaucasica (Brunner von Wattenwyl, 1878) predation on the Halyomorpha halys (Stål, 1855) in Georgia

The purpose of this study was to identify the mantid species in the population of the Brown Marmorated Stink Bug – Halyomorpha halys (Stål, 1855). H. halys is an economical pest on crops in Georgia, introduced and established rather recently. Mantids and H. halys were collected in the humid subtropical regions of Western Georgia and the dry subtropical regions of Eastern Georgia in 2018–2020. Based on the morphometric analysis and morphological observation confirmed that from four specimens, three belong to Hierodula transcaucasica Brunner von Wattenwyl, 1878, and one of them– Iris polystictica Fisher-Waldheim, 1846 (Synonims: Mantid polystictica Fisher-Waldheim, 1846; Iris tiflisina Giglio-Tos, 1915) H.transcaucasica characterized with: total length of specimens were ranged from 65 mm to72 mm; knee of the mid and hind femora (HF) with a small spine; the medial face of the fore coxae (FC) without a black spot. I. polystictica had the following remarkable signs: fore femora (FF) with 5 external spines, frontal sclerite (FS) with 2 small round knobs (SRK). Observations in nature and laboratory experimentshave shown that H. transcaucasica predates on H. Halys in all stages of post-embryonic development . It was also established that mantids followed H. halys grouping sitesand migrating population outside the building as well as inside of it. Predation of the adults and nymphs of H. transcaucasica was documented after they underwent starvation periods. The 3rd instar nymph of H. transcaucasica preyed on the 1 st instar H . halys nymphs, while adult H. transcaucasica attacked adult of H. halys . A maximum number of H. halys (7 insect) were eaten by an adult H. transcaucasica on the first day, and in this case, the same number of nymphs (7 insects) were observedwithin the first hours of the experiment. Statistical analysis shows that there is no correlation between the intensity of predation and the time of the day, which is confirmed by the chi-square test, in the case of an adult mantid (χ2 = 80.00, P = 0.355), and in the case of nymph (χ2 = 32,250, P = 0.264) as well.