Life history and life table parameters of Panonychus ulmi (Acari: Tetranychidae) on two European grape cultivars

The development of Panonychus ulmi feeding on apple leaves has been widely studied, but nothing is known about its development on grapevine leaves. This study aimed to gather biological information on P. ulmi based on its life table on leaves of Cabernet Sauvignon (CS) and Pinot Noir (PN) grapevine cultivars, and check the oviposition rate of populations on apple and grapevines. The development of P. ulmi started with 30 eggs on CS and 30 eggs on PN, and oviposition tests were performed with four combinations (C1: ♂ Apple X ♀ Apple; C2: ♂ Grapevine X ♀ Grapevine; C3: ♀ Apple Isolated; and C4: ♀ Grapevine Isolated). This study was carried out at 25 ± 3 °C temperature, 14 h of photoperiod, and 70 ± 5% relative humidity. There was no significant difference (P > 0.05) in the grapevine cultivars studied, except for larval and egg-adult period of females and males. A significant difference (P ≤ 0.05) was observed for preoviposition and adult longevity. Life table parameters on CS were R0 = 7.88, T = 17.78 days, TD = 5.97 days, rm = 0.12, λ = 1.12; and on PN they were R0 = 5.20, T = 16.45 days, TD = 6.91 days, rm = 0.10, and λ = 1.11. Females of cross C1 laid an average of 3.44 ± 1.6 eggs daily, in C2 they laid 2.70 ± 1.76 eggs, in C3 they laid 4.19 ± 1.88 eggs, and females of C4 laid 3.6 ± 1.19 eggs. Data in our study allowed us to conclude that the development of P. ulmi is similar on the two grapevine cultivars studied. However, when its performance is compared to apples, reproductive potential on vineyards is lower.