ABSTRACT Perennial ryegrass is one of the most important food sources in animal production. However, several pests affect this crop, and one of the primary control strategies is the symbiotic relationships between ryegrass endophyte fungi. This fungus produces alkaloids that exhibit toxic activity against arthropods. Furthermore, the effect of fungi may extend to higher trophic levels, including predators (spiders and/or insects), decreasing their abundance and diversity. Given the importance of spiders and insects as predators, whether the symbiotic interaction between perennial ryegrass and endophyte fungus reduces the abundance and diversity of predators pose an important question. To address this question, natural enemies in perennial ryegrass were collected and analyzed over a year, and the percentage of endophyte fungus was evaluated by the presence of hyphae from two ryegrass cultivars, Jumbo (E-) and Alto AR1 (E+). We observed an 80% endophyte infection rate for (E+) and 0% for (E-). Moreover, 222 individual spiders corresponding to 10 families were identified in both perennial ryegrasses, including 209 individuals for (E-) and 13 for (E+). The most abundant spider family was Lycosidae, representing 71.17% of the total spiders. In addition, 65 insects were collected, corresponding to 6 families, with Carabidae being the most abundant. Furthermore, the Simpson index indicated the dominance of the family Lycosidae. Overall, spider and insect abundance and diversity were reduced in (E+), suggesting a negative effect of the endophyte on predator populations.

The Argentine stem weevil, Listronotus bonariensis, is an important pest in pastures, especially ryegrass (Lolium sp.), compromising grassland persistence and productivity. Both, adult and specially larvae cause severe damage, action that generate the death of the tiller and reducing forage production. Chemical control has limited effectiveness in adult’s insect and negative effects on the environmental and toxicity to pollinators when applied close to the flowering period is observed. Therefore, the main currently strategy is based on the use of cultivars of Lolium endophyte fungus-infected with Neothypodium genus. However, over a decade that there are no reports on the presence of this weevil in southern Chile. Hence, the aim of this research was report the actual incidence of L. bonariensis in ryegrass pastures. The results of two years of prospecting showed that this weevil is currently causing damage to the ryegrass pastures indicating that the effectiveness of species infected with the fungus must be evaluated.

Plant domestication is a process in which plants’ chemical defenses that help them cope with herbivores might decline. Consequences of this process could be reflected in an increase in insect pests. Therefore, we carried out a survey to contrast the diversity, damage indexes and insect assemblages between cultivated and wild "Murtilla" (Ugni molinae) plants. The main scientific question put forward in this paper is as follows: Is there a decrease in diversity and an increase in both insect assemblages and damage indexes associated with the domestication process in U. molinae plants? The objective of this report was to compare the structure of a taxonomic assemblage collected in both wild and cultivated plants and their temporal variation over the year. Seven ecotypes and their respective wild populations were selected for these studies. The results showed higher insect assemblages in wild parents (77.35%) vs. cultivated (22.7%). The damage indexes were also higher in wild plants (0.23). The diversity indexes according to Margalef (12.98), the Shannon index (5.15) and the Simpson index (19.04) were higher in wild plants. Moreover, approximately 60 species were determínate. We detected changes in insect assemblages, damage and diversity indexes that could suggest that murtilla domestication has altered insect assemblages.

M. Chacón-Fuentes, M. Lizama, L. Parra, I Seguel y A. Quiroz. 2016. Diversidad, composición de la comunidad de insectos e índice de daño, en murtillas silvestres y cultivadas. Cien. Inv. Agr. 43(1):57-67. La domesticación vegetal es un proceso en el cual las plantas pueden disminuir su nivel de defensas químicas para combatir herbívoros. Algunas de las posibles consecuencias podrían reflejarse en un incremento en el número y en la diversidad de insectos. Por lo tanto, se realizó un "survey" para comparar el índice de daño y la diversidad de insectos en plantas cultivadas y silvestres de murtilla (Ugni molinae). La principal interrogante de este trabajo fue: ¿La domesticación en plantas de murtilla, disminuirá la diversidad e incrementará el índice de daño y la comunidad de insectos? El objetivo de esta investigación fue comparar la población de insectos asociada a plantas silvestres y cultivadas además de analizar su variación durante el año. Siete ecotipos y sus correspondientes contrapartes silvestres fueron seleccionadas para este estudio. Los resultados mostraron un mayor número de insectos en plantas silvestres (77,35%) vs. (22,7%) cultivadas. El índice de daño fue mayor en plantas silvestres (0,23) comparada con plantas cultivadas. El índice de Margalef mostró la mayor riqueza de insectos en plantas cultivadas. Sin embargo, el índice de Shannon fue mayor (5.15) en plantas silvestres. Además, cerca de 60 especies de insectos fueron determinadas. Se detectaron cambios en la comunidad de insectos, índices de daño y diversidad que podrían sugerir que la domesticación en murtilla ha alterado la comunidad de insectos.