Summary1. The role of generalist predators in pest control has been neglected because generalists are not able to track pest populations. Generalist predators are suggested to be important in spring before specialist predators become active. 2. Here, we show that some generalist predators are important even during winter, when the majority of arthropod pests and their enemies are dormant. We quantified the role of winteractive generalist predators on the suppression of pear psylla during winter using a discrete nonlinear model of an intraguild predation system. 3. To parameterize our model, we conducted a series of experiments on (i) functional responses, (ii) prey preferences and (iii) ontogenetic development and made observations on the population densities of spiders and potential prey. We ran the model for different winter scenarios, that is, for very cold and very warm winters. 4. Synthesis and applications. We found that winter-active predators considerably suppressed the pear psylla population. Predators exerted a stronger effect in a warmer winter than in a colder one. Orchard growers thus should avoid use of non-selective pesticides during this period and instead aim to support the community of generalist predators. Our results suggest more attention should be given to encouraging generalist predator populations in other systems, even in periods when crops are not producing.

No abstract

Geographical surveys of plant feeders on weeds are essential for finding species which can be studied as classical biological control agents of alien plants. Four eriophyoid species have been collected on well-known weeds surveyed on the Italian territory. A new species, Aceria verbenacae sp. nov., was found on leaf and stem deformations of Salvia verbenaca L. (Lamiaceae) and is described and illustrated. Two Phyllocoptinae species were found for the first time in Italy: Aculus mosoniensis (Ripka & Érsek) comb. nov. and Metaculus rapistri Carmona. Aculus mosoniensis was collected on leaf deformations of Ailanthus altissima (Mill.) Swingle (Simaroubaceae), whereas M. rapistri was collected on leaf and stem deformations of Isatis tinctoria L. (Brassicaceae). Finally, Aceria drabae (Nalepa) was found on deformed leaves and stems of Lepidium draba L. (Brassicaceae) in central Italy. Its previous record in Friuli Venezia Giulia was based only on symptoms observed on the host plants. Three last species are described and illustrated in details to allow morphological comparisons along with previous reports.

BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.

Habitat networks can help to make habitats more resilient and assist species survival in a fragmented landscape and changing climate. Butterflies are one of the main indicators of diversity due to their high sensitivity to environmental changes. In the context of sudden and unpredictable environmental changes, protection strategies for butterflies at risk of extinction should consider the exact distribution of these species, as well as the various threats to which each of them is subjected. About 290 species of butterflies are reported in Italian fauna, and 120 of them are recorded in Apulia (Southern Italy). In the Alta Murgia National Park (AMNP) (Apulia Region, Italy), screening was performed to study the relationships between area/landscape composition and diurnal butterfly community structure. Representative semi-natural habitats of Alta Murgia buffering productive crops were selected to set up transects/paths along dry grasslands, oak forests and pine forests. Monthly samplings were performed for one year. During the survey, 909 specimens from 53 species were collected. The highest values of butterfly’s abundance and richness were recorded in dry grasslands. A strong positive correlation between butterfly abundance and air temperature was registered (Pearson correlation: r = 0.8; p < 0.001). Melanargia arge, endemic in central-southern Italy and considered threatened in Europe (Annexes II and IV—Habitats Directive), was registered in each habitat. The biodiversity indices (Chao 1, Shannon and Simpson) for each habitat were high and similar to those in protected areas of Sicily. The connected landscape is important for generalist or open-habitat specialists, and large remnants are key for disturbance-sensitive and threatened taxa. The presented evidence can provide useful information on butterfly conservation in the AMNP and for the management and conservation of characteristic landscapes of Alta Murgia.

Information regarding Pentatomoidea is scarce in Southern Italy, and in particular concering the Apulia region (Sourthern Italy), an area of high biodiversity potential. We conducted an extensive survey of Pentatomoidea fauna in the Alta Murgia National Park, a Site of Community Importance, and neighbouring areas located in central part of Apulia region. The survey was carried out in 2016, 2017 and 2020, sampling different habitat types. We found 55 species, with five new records for Apulia: Solenosthedium bilunatum, Acrosternum millierei, Sciocoris homalonotus, Cyphostethus tristriatus and Holcogaster fibulata. The polyphagous pest Halyomorpha halys was found only in urban areas, whereas Ventocoris falcatus, Ellipsocoris kalashiani and Tholagmus flavolineatus, considered rare species, were collected in dry grasslands, confirming the crucial role of natural habitat for biodiversity conservation.