Pearleaf Blister Mite (Eriophyes pyri Pgst.): Biological Features and Measures to Limit its Harmfulness in Pear Plantations of Ukraine

Abstract

Goal. To clarify the biological features of pearleaf blister mite (Eriophyes pyri Pgst.) and investigate the effectiveness of such preparations as: Sivanto Prime 200 SL, PK (flupyradifurone, 200 g/l), Danadim stable, KE (dimethoate, 400 g/l), Oberon Rapid 240 SC, KS (spiromesifen, 228.6 g/l + abamectin, 11.4 g/l), Fufanon 570, KE (malathion, 570 g/l) and Aktofit, KE (aversectin C, 0.2%), reduce the number and harmfulness of this phytophagan, its impact on the productivity of pears in industrial plantations.
 Methods. To determine the colonization of pear plantations by mites in horticultural farms of Ukraine, route surveys were carried out in the industrial pear plantations of Yablunivska variety. The planting scheme was 0.8 × 3.5 m. The planting year was 2014. The crown shape was thinned (improved) and story. The rootstock was a quince tree A. Stages of plant development at the time of treatment were «bursting buds (green cone)» (BBCH 10), «white buds» (BBCH 55), «end of flowering» (BBCH 69) and «fruit development» BBCH 75). The technical effectiveness of pesticides at different application rates was determined. The accounts were performed according to generally accepted methods in horticulture, plant protection and entomology.
 Results. Female pear leaf blister mite overwinter under the upper scales of the buds. In spring, at an average daily temperature above 10°C, they begin to feed with the juice of young leaves, covering them with galls, and lay eggs («bud bursting (green cone)» — «white bud») stages. The development of the first generation ends at the end of «flowering». Females of the second generation appear in late June, the third generation — in the first half of July. After rebirth, they leave galls and populate the buds for wintering (mid-late June to late Julyearly August). During the growing season the phytophagan develops in three generations. The use of Danadim stable, KE, Fufanon 570, KE, Sivanto Prime 200 SL, PK, Oberon Rapid 240 SC and Aktofit, KE provided a reduction in the number of this species by 75.3—93.9%, allowed to increase the effectiveness of basic biometric and biochemical indices of plantations, to obtain high-quality products with a yield of 1.1—1.5 times higher comparing with the control.
 Conclusions. During the growing season, the pear gall mite develops in three generations. Taking into account the peculiarities of the biology of pears and mites in the spring, the peculiarities of the mechanism of action of drugs against this species and other phytophages (leafeating, stem, sucking, including against the brown-marble bug) are most advisable to apply: in the phase of «bud break (green cone)» — Danadim stable, EC (2.0 l/ ha); in the «white bud» phase — Fufanon 570, EC (2.0 l/ha); after the «end of flowering» — Danadim stable, EC (2.0 l/ha). In summer (against the second and third generations of the pest), Sivanto Prime 200 SL, RK (0.75—1.0 l/ha), Oberon Rapid 240 SC, KS (0.6—0.8 l/ha), Aktofit, EC (6.0 l/ha) taking into account the duration of their action.