Biomonitoring of biocontrol across the full annual cycle in temperate climates: Post-harvest, winter and early-season interaction data and methodological considerations for its collection

Conservation biocontrol, the regulation of crop pests by naturally-occurring biocontrol agents (e.g., predators and parasitoids), is predominantly monitored throughout periods of primary crop growth when pests exert the most observable impact on yields. Pest-focused agricultural biomonitoring often overlooks post-harvest, winter and even early-season biocontrol, despite the significant predator-pest interactions during these periods that profoundly affect pest abundance and, consequently, crop yields. Rapid advances in biomonitoring, particularly in the detection of predator-pest interactions that underpin biocontrol, provide an opportunity to reconsider how and when we monitor these interactions. Advances in agricultural biomonitoring must transcend methodological innovation and encompass conceptual changes in monitoring of agricultural systems. Here, we assess existing evidence supporting the importance of periods beyond primary crop growth for biocontrol, and how predator-pest interactions are likely to evolve during these periods, subsequently influencing pest population dynamics during the primary crop growth period. We advocate for a greater concerted effort to establish continuous monitoring of biocontrol interactions, particularly beyond primary crop growth periods in temperate climates. To facilitate this, we also summarise the methodological approaches that can make it possible, and explore how extending sampling across the full annual cycle might impact the practicalities and outcomes of these approaches. Year-round monitoring of biocontrol interactions, both in crops and adjacent semi-natural habitats, will provide a previously intractable understanding of predator-pest dynamics, offering significant potential to enhance our ability to optimise and manipulate these systems. This would manifest in reduced crop yield losses, pest infestation rates and disease transmission, with concomitant long-term financial, environmental and land-use benefits

Extent and persistence of soil water repellency induced by pines in different geographic regions

This work was supported by the Slovak Scientific Grant Agency VEGA Project Nos. 2/0054/14 and 2/0009/2015, the Slovak Research and Development Agency Project No. APVV-15-0160, and it results from the project implementation of the “Centre of excellence for integrated flood protection of land” (ITMS 26240120004).Peer reviewedPublisher PD

Global Patterns of Guild Composition and Functional Diversity of Spiders

The objectives of this work are: (1) to define spider guilds for all extant families worldwide; (2) test if guilds defined at family level are good surrogates of species guilds; (3) compare the taxonomic and guild composition of spider assemblages from different parts of the world; (4) compare the taxonomic and functional diversity of spider assemblages and; (5) relate functional diversity with habitat structure. Data on foraging strategy, prey range, vertical stratification and circadian activity was collected for 108 families. Spider guilds were defined by hierarchical clustering. We searched for inconsistencies between family guild placement and the known guild of each species. Richness and abundance per guild before and after correcting guild placement were compared, as were the proportions of each guild and family between all possible pairs of sites. Functional diversity per site was calculated based on hierarchical clustering. Eight guilds were discriminated: (1) sensing, (2) sheet, (3) space, and (4) orb web weavers; (5) specialists; (6) ambush, (7) ground, and (8) other hunters. Sixteen percent of the species richness corresponding to 11% of all captured individuals was incorrectly attributed to a guild by family surrogacy; however, the correlation of uncorrected vs. corrected guilds was invariably high. The correlation of guild richness or abundances was generally higher than the correlation of family richness or abundances. Functional diversity was not always higher in the tropics than in temperate regions. Families may potentially serve as ecological surrogates for species. Different families may present similar roles in the ecosystems, with replacement of some taxa by other within the same guild. Spiders in tropical regions seem to have higher redundancy of functional roles and/or finer resource partitioning than in temperate regions. Although species and family diversity were higher in the tropics, functional diversity seems to be also influenced by altitude and habitat structure

The diet of the black widow spider Latrodectus mirabilis (Theridiidae) in two cereal crops of central Argentina

The spider Latrodectus mirabilis (Holmberg, 1876) is commonly found in cereals crops of central Argentina. We studied its diet composition at the field and capture rate on leaf-cutting ants based on laboratory experiments. This study comprises the first approach that documents the diet of L. mirabilis in wheat and oat fields of central Argentina. We identified 1,004 prey items collected from its webs during the last phenological stages of both cereal crops. The prey composition was variable but the spiders prey mainly on ants (Formicidae, Hymenoptera), who represented more than 86% of the total. Meanwhile, in the capture rate experiences we registered a high proportion of ants captured by spiders at the beginning of experiences, capturing the half of the ants from total in the first four hours. Summarizing, we reported a polyphagous diet of this spider species in wheat and oat fields. Ants were the most important prey item of this spider, as found in other Latrodectus spiders around the world