Ecological theory predicts that herbivory should be weaker on islands than on mainland based on the assumption that islands have lower herbivore abundance and diversity. However, empirical tests of this prediction are rare, especially for insect herbivores, and those few tests often fail to address the mechanisms behind island-mainland divergence in herbivory. In particular, past studies have not addressed the relative contribution of top-down (i.e. predator-driven) and bottom-up (i.e. plant-driven) factors to these dynamics. To address this, we experimentally excluded insectivorous vertebrate predators (e.g. birds, bats) and measured leaf traits associated with herbivory in 52 populations of 12 oak (Quercus) species in three island-mainland sites: The Channel Islands of California vs. mainland California, Balearic Islands vs. mainland Spain, and the island Bornholm vs. mainland Sweden (N = 204 trees). In each site, at the end of the growing season, we measured leaf damage by insect herbivores on control vs. predator-excluded branches and measured leaf traits, namely: phenolic compounds, specific leaf area, and nitrogen and phosphorous content. In addition, we obtained climatic and soil data for island and mainland populations using global databases. Specifically, we tested for island-mainland differences in herbivory, and whether differences in vertebrate predator effects or leaf traits between islands and mainland contributed to explaining the observed herbivory patterns. Supporting predictions, herbivory was lower on islands than on mainland, but only in the case of Mediterranean sites (California and Spain). We found no evidence for vertebrate predator effects on herbivory on either islands or mainland in any study site. In addition, while insularity affected leaf traits in some of the study sites (Sweden-Bornholm and California), these effects were seemingly unrelated to differences in herbivory. Synthesis. Our results suggest that vertebrate predation and the studied leaf traits did not contribute to island-mainland variation patterns in herbivory, calling for more nuanced and comprehensive investigations of predator and plant trait effects, including measurements of other plant traits and assessments of predation by different groups of natural enemies. La teor & iacute;a ecol & oacute;gica predice que la herbivor & iacute;a ha de ser m & aacute;s d & eacute;bil en las islas que en el continente, ya que las islas tienen una menor abundancia y diversidad de herb & iacute;voros. Sin embargo, todav & iacute;a no contamos con suficiente evidencia emp & iacute;rica que apoye estas predicciones, especialmente en lo que se refiere a la herbivor & iacute;a por insectos, y los pocos estudios que existen a menudo no abordan los mecanismos que generan estos patrones de divergencia entre islas y continente en los niveles de herbivor & iacute;a. En particular, las investigaciones previas no han examinado la contribuci & oacute;n relativa de las fuerzas top-down (es decir, efectos mediados por los depredadores) y bottom-up (es decir, efectos mediados por los rasgos funcionales de las plantas) en estas din & aacute;micas. En este trabajo, excluimos experimentalmente a depredadores insect & iacute;voros vertebrados (p. ej., aves, murci & eacute;lagos) y medimos rasgos foliares asociados con la herbivor & iacute;a en 52 poblaciones de 12 especies de robles (Quercus) en tres sitios insulares y continentales: las Islas del Canal de California vs. California continental, las Islas Baleares vs. Espa & ntilde;a continental, y la isla de Bornholm vs. Suecia continental (N = 204 & aacute;rboles). En cada sitio, al final de la & eacute;poca de crecimiento, medimos el da & ntilde;o foliar causado por insectos herb & iacute;voros en ramas control vs. ramas con exclusi & oacute;n de depredadores, y medimos diferentes rasgos foliares, en particular, la concentraci & oacute;n de compuestos fen & oacute;licos, el & aacute;rea foliar espec & iacute;fica y el contenido de nitr & oacute;geno y f & oacute;sforo. Adem & aacute;s, obtuvimos datos clim & aacute;ticos y de suelo de las poblaciones insulares y continentales utilizando bases de datos globales. Espec & iacute;ficamente, evaluamos los efectos de la insularidad sobre la herbivor & iacute;a y si exist & iacute;an patrones contrastados de los efectos de depredaci & oacute;n y expresi & oacute;n de rasgos foliares entre islas y continentes que contribuyesen a explicar los patrones observados en la herbivor & iacute;a. De acuerdo con la teor & iacute;a ecol & oacute;gica, la herbivor & iacute;a fue menor en las islas en comparaci & oacute;n con el continente, pero solo en el caso de los sitios mediterr & aacute;neos (California y Espa & ntilde;a). No encontramos evidencia de efectos de los depredadores sobre la herbivor & iacute;a en ninguno de los sitios de estudio, ya sea en las islas o en el continente. Adem & aacute;s, aunque la insularidad afect & oacute; a la expresi & oacute;n de rasgos foliares en algunos de los sitios de estudio (Suecia-Bornholm y California), estos efectos no estuvieron aparentemente relacionados con las diferencias observadas en la herbivor & iacute;a. S & iacute;ntesis. Nuestros resultados sugieren que la depredaci & oacute;n por vertebrados y los rasgos foliares estudiados no contribuyeron a los patrones de variaci & oacute;n entre islas y continente observados en los niveles de herbivor & iacute;a, lo que plantea la necesidad de investigaciones m & aacute;s exhaustivas que incluyan la evaluaci & oacute;n de otros rasgos funcionales y evaluaciones de la depredaci & oacute;n por otros grupos de enemigos naturales de los herb & iacute;voros.

Melanaphis sorghi is a pest that is native to Africa but is now distributed worldwide. In 2013, its destructive capacity was demonstrated when it devastated sorghum crops in the United States and Mexico, making it a new pest of economic importance in North America. At the time, the phytosanitary authorities of both countries recommended the use of pesticides to control the outbreak, and biological control products for the management of this pest were not known. In response to the outbreak of M. sorghi in North America, several field studies have been performed in the last decade on sorghum crops in the USA and Mexico. Works have focused on assessing resistant sorghum hybrids, pesticide use, and recruitment of associated aphid predators and entomopathogens for natural control of M. sorghi populations. The objective of this review is to compile the information that has been generated in the past decade about indigenous enemies affecting M. sorghi naturally in the field, as well as the search for biological control alternatives and evaluations of interactive effects of resistant sorghum hybrids, pesticides, and natural enemies. To date, different predators, parasitoids, fungi, and bacteria have been evaluated and in many cases found to affect M. sorghi populations in sorghum agroecosystems or laboratory bioassays, and the use of resistant sorghum varieties and pesticides did not have clear toxic effects on natural enemy populations. Many of the macroorganisms and microorganisms that have been evaluated as potential biological controls have shown potential as alternatives to synthetic pesticides for keeping M. sorghi population densities below economic damage thresholds and are compatible with integrated management of sorghum aphids. While most tests of these biological alternatives have shown that they have aphidicidal potential against sorghum aphids, it is crucial to take into account that their effectiveness in the field depends on a number of abiotic and biotic factors, including soil texture, temperature, humidity, and natural enemies.

The distribution of wild boar (Sus scrofa L.) on almost all continents brings with it a number of negative impacts, the intensity of which depend on the local population density. One of these impacts is the rooting of the soil surface as part of their foraging behavior, which represents an ecologically valuable disturbance to the forest ecosystem. In this study, conducted in 2022 and 2023, we placed 50 pitfall traps across 10 plots at 10 model sites to compare epigeic arthropod communities in areas affected by wild boar rooting with those unaffected by rooting activity. Our findings demonstrate the presence or absence of rooting is a highly significant factor in shaping arthropod epigeic community assemblies. Rooted plots predominantly hosted species from the taxons Araneae, Carabidae, Elateridae, and Diplopoda, whereas plots without rooting were significantly associated with the taxons Tenebrionidae, Opiliones, Gryllidae, and Geotrupidae. Diptera, and Staphylinidae were not affected by wild boar rooting activity. Throughout the study, a decreasing trend in species diversity was observed. Wild boar rooting notably impacted the composition of epigeic assemblages.

In fact, less than 1% of applied pesticides reach their target pests, while the remainder pollute the neighboring environment and adversely impact human health as well as non-target organisms in agricultural ecosystem. Pesticides can contribute to the loss of agrobiodiversity, which are essential to maintaining the agro-ecosystem's structure and functioning in order to produce and secure enough food. This review article examines the negative effects of pesticides on non-target invertebrates including earthworms, honeybees, predators, and parasitoids. It also highlights areas where further research is needed to address unresolved issues related to pesticide exposure, aiming to improve conservation efforts for these crucial species. These organisms play crucial roles in ecosystem functioning, such as soil health, pollination, and pest control. Both lethal and sub-lethal effects of pesticides on the selected non-target invertebrates were discussed. Pesticides affect DNA integrity, enzyme activity, growth, behavior, and reproduction of earthworms even at low concentrations. Pesticides could also induce a reduction in individual survival, disruption in learning performance and memory, as well as a change in the foraging behavior of honeybees. Additionally, pesticides adversely affect population growth indices, reproduction, development, longevity, and consumption of predators and parasitoids. As a result, pesticides must pass adequate ecotoxicological risk assessment to be enlisted by regulatory authorities. Therefore, it is important to adopt integrated pest management (IPM) strategies that minimize pesticide use and promote the conservation of beneficial organisms in order to maintain agrobiodiversity and sustainable agricultural systems. Furthermore, adopting precision agriculture and organic farming lessen these negative effects as well.less than