Apple Leaf Disease Identification with a Small and Imbalanced Dataset Based on Lightweight Convolutional Networks

The intelligent identification and classification of plant diseases is an important research objective in agriculture. In this study, in order to realize the rapid and accurate identification of apple leaf disease, a new lightweight convolutional neural network RegNet was proposed. A series of comparative experiments had been conducted based on 2141 images of 5 apple leaf diseases (rust, scab, ring rot, panonychus ulmi, and healthy leaves) in the field environment. To assess the effectiveness of the RegNet model, a series of comparison experiments were conducted with state-of-the-art convolutional neural networks (CNN) such as ShuffleNet, EfficientNet-B0, MobileNetV3, and Vision Transformer. The results show that RegNet-Adam with a learning rate of 0.0001 obtained an average accuracy of 99.8% on the validation set and an overall accuracy of 99.23% on the test set, outperforming all other pre-trained models. In other words, the proposed method based on transfer learning established in this research can realize the rapid and accurate identification of apple leaf disease.

Mites from the family Phytoseiidae as an element of an anti-resistant strategy for protecting fruit plantations from spider mites

In the last decade, the acarocomplex of apple orchards in the plain-steppe zone of the Crimea was dominated by two species of mites, fam. Tetranychidae - Amphitetranychus viennensis (Zacher) and Panonychus ulmi (Koch). Their share in the complex of phytophagous mites was 52.5 and 32.0%, respectively. Against the background of repeated acaricidal treatments during the season, the emergence of resistant races of phytophagous mites was recorded. The proposed anti-resistant strategy for controlling the number of spider mites on an apple tree involves the use of Phytoseiulus persimilis (Athias-Henriot), Neoseiulus californicus (McGregor), and Amblyseius andersoni (Chant). The combination of methods of seasonal colonization by phytoseiids serves as the building blocks of an anti-resistant defense system.Resettlement in the spring, by flooding, of two species of acariphages, P. persimilis and A. andersoni , contributes to the formation of acarofauna, so that while the first species reduces the number of phytophagous mites (by 50-60%), the second adapts and starts feeding later, and, at the expense of daughter individuals, it allows to reduce the number of pests by the end of the second decade of June to 2-3 individuals / leaf. In summer, a double release of the predatory mite N. californicus with a norm of 30 thousand individuals / ha (150-300 individuals / every 10 trees) reduces the risk of mass reproduction of spider mites at high average daily temperatures and low humidity.

Acaricide resistance in Panonychus citri and P. ulmi (Acari: Tetranychidae): Molecular mechanisms and management implications

The European red mite, Panonychus ulmi (Koch), and the citrus red mite, P. citri (McGregor) (Acari: Tetranychidae), are destructive mite pests in pome/stone fruit orchards and citrus groves, respectively, the management of these two spider mites species has relied largely on the use of synthetic acaricides. However, frequent, long-term use of acaricides has caused rapid development of resistance in P. ulmi and P. citri populations worldwide. Levels of resistance in P. ulmi and P. citri are exceeded only by that in the two-spotted spider mite, Tetranychus urticae Koch. Recent research on T. urticae has provided new insights into the molecular mechanisms of acaricide resistance. The molecular basis of resistance in P. ulmi and P. citri populations has been less thoroughly studied. In this brief review, the current understanding of the molecular mechanisms of toxicokinetic and toxicodynamic resistance of P. ulmi and P. citri to acaricides, as well as implications of the findings for the resistance management, are discussed.

Population growth performance of Panonychus ulmi Koch (Acarina: Tetranychidae) on different fruit trees

The European red mite, Panonychus ulmi (Acari: Tetranychidae) is an important pest species on deciduous plants in Turkey, especially on apple. In this study, development, survival, and reproduction of European red mite, P. ulmi were studied on different host plants under laboratory conditions (25±2 °C,% 60±10 RH and16:8 L:D photoperiod). Population performance of P. ulmi was obtained on its different host plants including apple (Malus communis L.), quince (Cydonia oblonga Mill.), cherry (Prunus avium L.), and sour cherry (Prunus cerasus L). The life history raw data of P. ulmi were analyzed by using the age-stage, two-sex life table. Results indicated that the highest net reproductive rate, intrinsic rate of increase, and finite rate of increase as well as the longest mean generation time, were obtained on apple cv. Starking delicious. The population projection simulated by using life tables based on the 0.025th and 0.975th bootstrap results of the finite rate of increase displayed the same trend with population growth parameters. Results suggested that apple cv. Starking Delicious was the favorable host for P. ulmi, however, there is potential for the pest to become a serious pest on other host plants tested under favorable conditions.

The assessment of resistance of the acarocomplex formed on apple tree against the background of pesticide treatments

Клещи-фитофаги ежегодно наносят существенный вред промышленным плодовым культурам, наиболее повреждаемой из них является яблоня. Многократное применение химических препаратов в защите от вредителей не только оказывает пестицидный прессинг на агроценоз, но и нарушает экосистему плодовых насаждений, что проявляется в смене одних видов другими, влияет на биоразнообразие, снижает численность полезных членистоногих и приводит к появлению резистентных к пестицидам рас клещей. Целью исследований являлась разработка и испытание системы защиты интенсивных яблоневых садов Красногвардейского и Нижнегорского районов Республики Крым от клещей сем. Tetranychidae - боярышникового Amphitetranychus viennensis (Zacher), красного плодового Panonychus ulmi (Koch) с помощью хищных клещей-фитосейид Phytoseiulus persimilis (Athias-Henriot), Neoseiulus californicus (McGregor) и Amblyseius andersoni (Chant). Производственные испытания системы проводились в 2019-2020 гг. на участках, где в 2015-2018 гг. был сформирован акарокомплекс методами наводнения и сезонной колонизации. После формирования акарокомплекса была проведена оценка его устойчивости к токсическому действию применяемых в хозяйствах средств защиты растений. Исследованиями установлено, что сформированный в течение трех лет акарокомплекс хищных клещей позволил снизить численность диапаузирующих самок A. viennensis на 87 % и плотность популяции вредителей в летний период, предотвратить вспышку численности фитофагов в весенний период 2019-2020 гг. Доказано, что препарат из класса пиретроидов с действующим веществом тау-флювалинат снижает численность хищников на 99 %. Частичное восстановление плотности популяции за счет миграции аборигенных видов хищников наблюдалось через 2-3 месяца. Вспышка численности клещей-фитофагов на участках, где был сформирован акарокомплекс хищных клещей, происходит из-за применения токсичных для них препаратов и появления резистентных к акарицидам рас клещей-фитофагов. Phytophagous mites annually cause significant damage to commercial fruit crops, the most damaged of which is the apple tree. Repeated use of chemical preparations in protection against pests does not only exert pesticide pressure on agrocenosis, but also affects the ecosystem of fruit plantings, replacing one species with others, influencing biodiversity, reducing the number of helpful arthropods and causing the emergence of pesticide-resistant mite races. The aim of the research was to develop and test the system of protecting intensive apple orchards of Krasnogvardeisky and Nizhnegorsky districts of the Republic of Crimea from mites of Tetranychidae family - hawthorn mite Amphitetranychus viennensis (Zacher), European red mite Panonychus ulmi (Koch) with the help of predatory phytoseiidae mites Phytoseiulus persimilis (Athias-Henriot), Neoseiulus californicus (McGregor) and Amblyseius andersoni (Chant). In-process system tests were carried out in 2019-2020 on plots where in 2015-2018 the acarocomplex was formed using methods of population development and seasonal colonization. After the acarocomplex formation, an assessment of its resistance to toxic effect of plant protecting agents used in farms was carried out. The studies confirmed that the acarocomplex of predatory mites developed in three years allowed to reduce the number of diapausing females of A. viennensis by 87% and the pest population density in the summer period, to prevent outbreak of phytophagous population in the spring period of 2019-2020. It was proven that pyrethroid class preparation with the active ingredient tau-fluvalinat reduced the number of predators by 99%. Partial recovery of the population density due to the migration of native species of predators was observed in 2-3 months. Outbreak of the number of phytophagous mites on the plots where the acarocomplex of predatory mites was developed was due to the use of toxic preparations and the appearance of resistant to acaricides phytophagous mite races.

CHANGE IN SPECIES COMPOSITION, BIOECOLOGY AND HARMFULNESS OF MAIN APPLIAN PHYTOPHAGES IN THE CENTRAL REGION OF THE NON-BLACK EARTH ZONE OF RUSSIA UNDER THE INFLUENCE OF CLIMATE FACTORS

The studies were carried out at the Federal State Budgetary Scientific Organization “Federal Horticultural Center for Breeding, Agrotechnology and Nursery” (FSBSI FRCHBAN) in 1995-2020. The aim of the research was to clarify the species composition, bioecology, and the characteristics of harmfulness of the main phytophages of apple trees in the Central Region of the Non-Black Earth Zone of Russia under climate change conditions. Route surveys were carried out in 5 regions of this zone - Bryansk, Kaluga, Moscow, Ryazan, Tula. When studying the bioecological features of the development and dynamics of summer of the codling moth and corrosive arboretum, along with other methods, pheromone traps were used. Trapping belts (sticky and corrugated paper) were used to signal the exit of the apple blossom beetle from wintering places, as well as the method of shaking off in the morning, at a temperature of no higher than 10˚С. The count of four-legged microscopic mites in the early spring period was carried out before the leaves blooming by the method of selecting the tops of annual growths up to 10 cm long, at 10 counting sites (to view the opening buds). During the growing season, 10 leaves were sampled (4 ... 5th leaves from the top of the shoot), at each registration area. The analysis of microscopic objects on the selected samples was carried out using an MBS-10 stereoscopic microscope. In the research area, new dangerous invasive apple phytophages were identified: corrosive arboreal tree Zeuzera pyrina L. (Lepidoptera: Cossidae), apple rusty mite Aculus schlechtendali Nalepa (Acariformes: Eriophyidae), apple felt mite Phyllocmespates malinus (Acariformes: Eriophyidae). The bioecology and harmfulness of autochthonous phytophages have changed significantly. The apple moth Cydia pomonella L. (Lepidoptera: Tortricidae) gives up to two generations, and the summer lasts up to 132 days. Red (Panonychus ulmi Koch. (Acariformes: Tetranychidae)) and brown (Bryobia redikorzevi Reck (Acariformes: Bryobiidae)) fruit mites, depending on weather conditions, develop in 4 ... 5 generations a year, common spider mite (Tetranychus urticae Koch. (Acariformes: Tetranychidae)) at 7. The prevalence of ticks reaches 100%, and the degree of damage to plants by them is up to 3-4 points. Damage to apple flowers by the weevil Anthonomus pomorum L. (Coleoptera: Curculionidae) reaches 60 ... 85%, the colonization of leaves and shoots by the red-gall aphid Dysaphis devecta Walk. (Homoptera: Aphididae) 35 ... 45%, fruit loss from apple sawfly Haplocampa testudinea Klug. (Hymenoptera: Tenthredinidae) 15%

FEEDING PREFERENCE AND BIOLOGICAL TRAITS OF PANONYCHUS ULMI ON LEAVES OF APPLE AND GRAPEVINE

Panonychus ulmi is widely distributed in apple and vineyards worldwide. In Brazil, the first damages were observed in apple orchard and later in grapevine. The aim of this study was to evaluate feeding preference and biological traits of P. ulmi on different grapevine varieties (BRS Vitória, Merlot and Concord) and apple (Fuji) under laboratory conditions. The food preference experiment did not reveal any significant differences, but P. ulmi presented the lowest rate of oviposition in the Concord varietal, demonstrating an oviposition preference in V. vinifera varietals and general preference for apple. Mortality was significantly different between varieties, with the lowest mortality on apple and higher oviposition rate in this host. Higher viability occurred on Merlot and apple. Feeding preference studies are scarce, considering phytophagous mites and grape varieties, although they are important in the development of pest control strategies.

Untersuchungen zum Vorkommen der Phytoseiidae (Acari: Mesostigmata) und Roten Spinne, Panonychus ulmi im Südtiroler Apfelanbau

Von 2014 bis 2017 wurden intensive Untersuchungen zum Raubmilbenvorkommen (Mesostigmata: Phytoseiidae) und Auftreten der Roten Spinne Panonychus ulmi (Prostigmata: Tetranychidae) in ausgewählten Apfelanalgen in Südtirol (Italien) angestellt. Die Populationsdichten der Milben wurden wiederholt an bis zu 50 Standorten im Etschtal und Vinschgau erhoben. In 27 Apfelanlagen wurde im Verlauf der Jahre 2015-2017 die Artenzusammensetzung blattbesiedelnder sowie an Aststrukturen überwinternder Raubmilben eingehend untersucht. Insgesamt wurden 5581 Raubmilben einer morphologischen Artbestimmung unterzogen. Sechs Phytoseiiden-Arten wurden nachgewiesen. Amblyseius andersoni (Chant 1957) konnte an allen Untersuchungstandorten gefunden werden und wies eine Individuendominanz von 80% auf. Ein permanentes Vorkommen von Typhlodromus pyri (Scheuten 1857) und Euseius finlandicus (Oudemans 1915) wurde an 18,5% bzw. 7,4% der Standorte festgestellt. Kampimodromus aberrans (Oudemans 1930), Paraseiulus talbii (Athias-Henriot 1960) und Typhlodromus bakeri (Garman 1948) wurden sporadisch nachgewiesen. Neoseiulus californicus (McGregor 1954) wurde erstmals am Apfel in Südtirol nachgewiesen. Der P. ulmi-Befall im Untersuchungsgebiet erwies sich, sofern gegeben, als äußerst gering. Eine wesentliche Zunahme der Populationsdichten von P. ulmi und eine diesbezügliche Schadwirkung wurden nicht festgestellt.