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.

Side Effects of Sulfur Dust on the European Grapevine Moth Lobesia botrana and the Predatory Mite Kampimodromus aberrans in Vineyards

To reduce the impact of synthetic insecticides on human health and the environment, eco-friendly alternatives must be investigated. Knowledge of the side effects on pests and natural enemies of natural products applied to vineyards is very useful. Sulfur dust, which is used in vineyards to control powdery mildew, is investigated in laboratory and field bioassays for its effects on Lobesia botrana egg laying, egg hatching, and larval settlement. In field trials, the efficacy of sulfur dust against the two L. botrana carpophagous generations is compared with that of Bacillus thuringiensis and kaolin, and its side effects on the phytoseiid mite Kampimodromus aberrans are evaluated. In the bioassays, sulfur dust reduced female survival by 43%, egg laying by around 80%, egg hatching by 10%, and larval settlement by 55%. In field trials, sulfur dust caused a significant decrease in the number of L. botrana larval nests of both generations, even though the efficacy was lower than that of B. thuringiensis. No negative effects of sulfur dust on the predatory mite population density was observed. On the basis of these results, in the context of Integrated Pest Management strategies in vineyards, the activity of sulfur dust against L. botrana could be exploited by timing its application to the beginning of egg laying.

Effect of pollen with different predator release ratios on biological control of Tetranychus urticae by the predaceous mite Kampimodromus aberrans

The purpose of this study was to examine the impact of birch pollen (Betula pendula Roth.) on the efficacy of the predatory mite Kampimodromus aberrans (Oudemans) (Acari: Phytoseiidae) as a biological control agent for the two spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) at different predator release ratios. The experiments were conducted on apple cv. Golden Delicious at 1:5, 1:15 and 1:30 predator-prey release ratios in a climate room (25±2°C, 65±10% RH and 16:8 L:D). The predatory mites were also offered pollen grains daily (0.5-0.10 mg/leaf) on the apple seedling during the experiments. One week after the release of K. aberrans, significant reductions in T. urticae density were observed at a ratio of 1:5; and the density remained at low levels thereafter, especially in the pollen experiments. The highest mean numbers of T. urticae in the control group (no predator release) were observed in week 3 with 4067 mites per leaf and 4922 mites per leaf, respectively for the pollen and no pollen application plots. This study demonstrates the potential of K. aberrans to effectively control T. urticae at ratios of 1:5 and 1:15 within three weeks, especially at a ratio of 1:5 when the pollen was added. Furthermore, releasing K. aberrans at the appropriate time and ratio enabled more successful control of T. urticae populations and plant damage, and subsequently kept the mites at low levels.

Phytoseiid mites under different vineyard managements in the subregions of Lima and Cávado of the Vinho Verde region in Portugal

Knowledge about phytoseiid species associated with vines is a preliminary step in the development and implementation of integrated management strategies against phytophagous mites such as Panonychus ulmi. The aim of this study was to perform a comparative survey of phytoseiids present in abandoned, organically managed, and conventionally managed vineyards, as well as to compare ecological indices in these production systems. Samplings were conducted between July and September 2017 in vineyards situated in the Subregions of Lima and Cávado, the Vinho Verde region. A total of 50 leaves/vineyard were collected from 12 vineyards, kept in containers at low temperature and taken to Escola Superior Agrária-Instituto Politécnico Viana do Castelo to be screened under a stereoscope microscope. A total of 3.153 phytoseiid mites were sampled, belonging to eight species distributed across the vineyards analyzed. The most common species were Typhlodromus (Typhlodromus) pyri (45.7%), Kampimodromus aberrans (39%), and Phytoseius macropilis (8.7%). Higher richness occurred in abandoned vineyards, with seven species, and the most abundant were K. aberrans (46.5%) and T. (T.) pyri (28.9%). Only two predatory species were present (in similar proportions) in organically managed vineyards, T. (T.) pyri and K. aberrans, while T. (T.) pyri predominated in conventionally managed vineyards (93.8%). Kampimodromus aberrans, P. macropilis, and T. (T.) pyri were eudominant in abandoned vineyards while K. aberrans and T. (T.) pyri were eudominant in organic vineyards. Typhlodromus (T.) pyri was eudominant and T. (T.) exhilaratus was dominant in conventionally managed vineyards. Therefore, we might conclude that phytoseiid abundance significantly differs among vineyard management types, with higher ecological indices in abandoned vineyards, and lower indices in conventional managed vineyards in the northern region of Portugal.

To the species composition of Phytoseiid mites (Parasitiformes, Phytoseiidae) of the National Nature Park "Ichnyansky"(Chernigiv Region, Ukraine)

New data on the species composition and distribution of phytoseiid mites (Parasitiformes, Phytoseiidae) in plant associations of the National Nature Park “Ichnyansky” were obtained. Twenty species from 9 genera of the family Phytoseiidae are recorded: Amblyseius andersoni, Amblyseius herbarius, Amblyseius obtusus, Amblyseius rademacheri, Neoseiulus danilevskyi, Neoseiulus reductus, Neoseiulus zwoelferi, Euseius finlandicus, Kampimodromus aberrans, Kampimodromu corylosus, Dubininellus echinus, Dubininellus juvenis, Typhloctonus tiliarum, Amlydromella halinae, Amlydromella pirianykae, Amlydromella rhenana, Amlydromella clavata, Amlydromella verrucosa, Typhlodromus laurae, Galendromus longipilus. The calculation of the occurrence index (P1, %) of the identified species of phytoseiid showed that its maximum value is observed in E. finlandicus. This species is also the most numerous in the total number of collected specimens in the sample. Kampimodromus aberrans, D. juvenis, G. longipilus, K. corylosus, N. danilevskyi, N. zwoelferi and T. tiliarum should be considered as the most rarely encountered species with index of occurrence of 1.3%. The remaining species have intermediate values of this index. The analysis of literature data on the occurrence of phytoseiid species with the highest value of the index of occurrence (E. finlandicus, A. pirianykae and A. andersoni) in the plant associations of adjacent zones (Polesie and Steppe Zone) allowed us to reveal some regularities. In Polesie, E. finlandicus (Kolodochka, 2011) is the most common species. In the Steppe zone, E. finlandicus also has a high index of occurrence and is the third most common species of predatory phytoseiid mites. Such a high occurrence of this species is caused by a wide range of its potential victims. Euseius finlandicus is an euribiont, however more adapted to shrub vegetation. The decrease in the occurrence index of this species from Polesie to the Steppe Zone is explained by changes in the moisture content of biocenoses, as well as due to the gradual replacement of tree-shrub vegetation of grass. Amlydromella pirianykae and Amblyseius andersoni are found mainly on herbs. The detection of these species on trees and shrubs should be considered as incidental finds. The characteristic biocenoses for these species are the wet bayrachnye forests, floodplains of rivers, meadows. When choosing a biocenosis for habitat, humidity plays a key role. The analysis of the phytoseiid mites species complex in the plant associations of the Ichnyansky National Natural Park showed the presence of one dominant species, one subdominant, five types of first order subdominant and 13 minor community members in the community.

Phytoseiid mites from Basilicata region (Southern Italy): species diversity, redescription of Typhloseiulus arzakanicus Arutunjan and a dichotomic key of the genus Typhloseiulus Chant and McMurtry 1994 (Parasitiformes, Phytoseiidae)

A survey of phytoseiid mites was carried out in the Basilicata region (Southern Italy) between 1976 and 2014 on wild and cultivated plants. A total of 38 species belonging to eleven genera and two subgenera were found on 59 plant species. The most common species was Euseius finlandicus (Oudemans) (39%) followed by Typhlodromus (Typhlodromus) exhilaratus Ragusa (32.2%), Kampimodromus aberrans (Oudemans) (27.1%), Typhlodromus (Anthoseius) cryptus (Athias-Henriot) (23.7%). Typhloseiulus arzakanicus (Arutunjan), found for first time in Italy, is redescribed here, while the male of this species is described for the first time. A dichotomic key of the species belonging to the genus Typhloseiulus is also given.