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We examined the faunal composition and abundance of phytoseiid mites (Acari: Phytoseiidae) in apple orchards under different pest management systems in Hungary. A total of 30 apple orchards were surveyed, including abandoned and organic orchards and orchards where integrated pest management (IPM) or broad spectrum insecticides (conventional pest management) were applied. A total of 18 phytoseiid species were found in the canopy of apple trees. Species richness was greatest in the organic orchards (mean: 3.3 species/400 leaves) and the least in the conventional orchards (1.4), with IPM (2.1) and abandoned (2.7) orchards showing intermediate values. The phytoseiid community's Rényi diversity displayed a similar pattern. However, the total phytoseiid abundance in the orchards with different pest management systems did not differ, with abundance varying between 1.8 and 2.6 phytoseiids/10 leaves. Amblyseius andersoni, Euseius finlandicus, and Typhlodromus pyri were the three most common species. The relative abundance of A. andersoni increased with the pesticide load of the orchards whereas the relative abundance of E. finlandicus decreased. The abundance of T. pyri did not change in the apple orchards under different pest management strategies; regardless of the type of applied treatment, they only displayed greater abundance in five of the orchards. The remaining 15 phytoseiid species only occurred in small numbers, mostly from the abandoned and organic orchards. We identified a negative correlation between the abundance of T. pyri and the other phytoseiids in the abandoned and organic orchards. However, we did not find any similar link between the abundance of A. andersoni and E. finlandicus.

Abstract. The use of phytoseiid species in biological plant protection is widespread. However, the techniques used to release them differ. The possible release of Amblyseius andersoni (Chant, 1959) using a new method was tested. High numbers of this mite overwinter in the ground litter in Hungarian orchards. By transferring such ground litter to plots in young orchards, the population density was found to be significantly increased in the release compared to control plots; A. andersoni became the dominant phytoseiid species in the new orchard. Due to the rate at which it spreads, this species was also recorded in the control plots towards the end of the growing season (Aug., Sept.), at which time there was no significant difference in the numbers of this species in the treated and control plots. In the winter following release, A. andersoni was found in the ground litter of the orchard.

This paper analyzes South Africa's Free Basic Water Policy, under which households receive a free water allowance equal to the World Health Organization's recommended minimum. I estimate residential water demand, evaluate the welfare effects of free water, and provide optimal price schedules derived from a social planner's problem. I use a data set of monthly metered billing data for 60,000 households for 2002–2009 from a particularly disadvantaged suburb of Pretoria, with rich price variation across 20 different nonlinear tariff schedules. I find that the free allowance acts as a lump‐sum subsidy, without large effects on water consumption. However, it is possible to reallocate the current subsidy to form an optimal tariff without a free allowance, which would increase welfare while leaving the water provider's profit unchanged. This optimal tariff would also reduce the number of households consuming low quantities of water, a desirable policy goal according to the WHO.

A faunal survey was carried out in Hungary between 2011 and 2014 in order to monitor the occurrence of tydeoid species in 139 vineyards located in five distinctive wine regions. Twenty four tydeoid species belonging to the families Tydeidae, Iolinidae and Triophtydeidae have been identified, of which Tydeus californicus (Banks) was the most dominant species. The following thirteen species, viz. Tydeus reticoxus Ueckermann, T. spathulatus Oudemans, Brachytydeus falsa (Livshitz), B. latiuscula (Kuznetzov), B. longiuscula (Kuznetzov), B. matura (Livshitz), B. opima (Kuznetzov & Zapletina), B. tuttlei (Baker), Metalorryia palpsetosa (Karg), Nudilorryia paraferula Kaźmierski, N. mariae Kaźmierski, Pseudolorryia striata Momen & Lundqvist, and Neopronematus neglectus (Kuznetzov) were added to Hungarian fauna. Of the identified species, 18 were collected for the first time in vineyards, and this was also the first record of seven species since their original description.

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In the present study, we conducted field surveys to detect the population density of the most important invasive weed species and their associated virus vectoring aphids in crops grown under high input field (HIF) vs. low-input field (LIF) conditions, with and without fertilizers and pesticides. The most frequent invasive weed species were annual fleabane, Erigeron annua (L.), Canadian horseweed, Erigeron canadensis (L.) and Canadian goldenrod, Solidago canadensis (L.). These species were predominantly hosts of the aphids Brachycaudus helichrysi and Aulacorthum solani under both management systems. The 13% higher coverage of E. annua under LIF conditions resulted in a 30% higher B. helichrysi abundance and ∼85% higher A. solani abundance compared with HIF conditions. To reveal the incidence of virus infection in crop plants and invasive weeds, high-throughput sequencing of small RNAs was performed. Bioinformatics analysis combined with independent validation methods revealed the presence of six viruses, but with strikingly different patterns under LIF and HIF conditions. Their presence without symptoms in invasive weeds and crop plants supports the necessity of employing new approaches to those currently employed in invasive weed management. These findings also suggest that invasive weeds could serve as hosts for local aphid species and reservoirs for plant pathogenic viruses, both under low and high input management systems. In this light, as here demonstrated, viruses transmitted by local aphid species were found to differ between the management systems; hence, the importance of B. helichrysi and A. solani as virus vectors in particular clearly needs to be re-evaluated. Altogether, we accept that the present study is a pilot one and individual virus vectoring of aphids still needs to be directly tested. Even so, it represents one of the first contributions to this particular area, and thereby paves the way for further similar applied research in the future.

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