Combining lacewings and parasitoids for biological control of foxglove aphids in sweet pepper

The role of natural enemy diversity in biological pest control has been debated in many studies, and understanding how interactions amongst predators and parasitoids affect herbivore populations is crucial for pest management. In this study, we assessed the individual and combined use of two species of natural enemies, the parasitoid Aphidius ervi Haliday, and the predatory brown lacewing Micromus variegatus (Fabricius), on their shared prey, the foxglove aphid, Aulacorthum solani (Kaltenbach), on sweet pepper. We hypothesized that the presence of intraguild predation (IGP) and predator facilitation (through induced aphid dropping behaviour) might have both negative and positive effects on aphid control, respectively. Our greenhouse trial showed that overall, the greatest suppression of aphids occurred in the treatment with both the parasitoid and the lacewing. While the combination of lacewings and parasitoids significantly increased aphid control compared to the use of parasitoids alone, the effect was not significantly different to the treatment with only predators, although there was a clear trend of enhanced suppression. Thus, the combined effects of both species of natural enemies were between additive and non-additive, suggesting that the combination is neither positive nor negative for aphid control. High levels of IGP, as proven in the laboratory, were probably compensated for by the strong aphid suppression provided by the lacewings, whether or not supplemented with some level of predator facilitation. For aphid management over a longer time scale, it might still be useful to combine lacewings and parasitoids to ensure stable and resilient aphid control.Fil: Rocca, Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Messelink, Gerben J.. University of Agriculture Wageningen; Países Bajo

Sampling plans for aphids and their parasitoids in blueberry fields in Argentina

Fil: Rocca, Margarita. Centro de Estudios en Parasitología y Vectores (CEPAVE). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Greco, Nancy Mabel. Centro de Estudios en Parasitología y Vectores (CEPAVE). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin

Primeros registros de Chrysomelidae (Insecta, Coleoptera) sobre arándanos en Argentina: nuevas asociaciones entre crisomélidos nativos y un cultivo exótico

The blueberry, Vaccinium corymbosum L. (Ericaceae), is a shrub native to the northern Hemisphere introduced in Argentina, where it occupies small cultivated areas mainly in the provinces of Buenos Aires, Entre Ríos and Tucumán. At present, little is known about insects associated with this crop in Argentina. The aim of this study was to identify the species of Chrysomelidae present in blueberry crops in different regions of Argentina, and to present new chrysomelids-blueberry associations. Identification diagnosis, geographical distribution, association with other plants and aspects of their biology is given for each species. Seven species of crop-damaging Chrysomelidae were recorded in blueberry crops of Buenos Aires and Entre Rios. They belong to the subfamilies Galerucinae: Diabrotica speciosa (Germar), Disonychodes exclamationis (Boheman), Caeporisstigmula Germar, and Cacoscelis melanoptera Germar; Eumolpinae: Percolaspis varia (Lefèvre), and Spintherophyta semiaurata (Klug); and Cryptocephalinae: Lexiphanes coenobita Suffrian.El arándano, Vaccinium corymbosum L. (Ericaceae), es un arbusto nativo del hemisferio Norte, que fue introducido en la Argentina donde ocupa pequeñas áreas cultivadas, principalmente en las provincias de Buenos Aires, Entre Ríos y Tucumán. Hasta la actualidad, se conoce poco sobre los insectos asociados con este cultivo. El objetivo de este trabajo es relevar las especies de crisomélidos presentes en los cultivos de arándano de diferentes regiones, y aportar nuevas asociaciones crisomélidos-arándano para la Argentina. Para cada especie registrada, se brinda la diagnosis para su reconocimiento, su distribución geográfica, la asociación con otras plantas y algunos aspectos de su biología. Se registraron siete especies de Chrysomelidae que utilizan el arándano como recurso alimenticio en las provincias de Buenos Aires y Entre Ríos: subfamilia Galerucinae: Diabrotica speciosa (Germar), Disonychodes exclamationis (Boheman), Caeporis stigmula Germar, Cacoscelis melanoptera Germar; subfamilia Eumolpinae: Percolaspis varia (Lefèvre) y Spintherophyta semiaurata (Klug); y subfamilia Cryptocephalinae: Lexiphanes coenobita Suffrian.Fil: Cabrera, Nora Clara. Universidad Nacional de la Plata. Facultad de Cs.naturales y Museo. Area Zoologia; ArgentinaFil: Rocca, Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Estudios Parasitológicos y de Vectores (i); Argentin

Combining lacewings and parasitoids for biological control of foxglove aphids in sweet pepper

The role of natural enemy diversity in biological pest control has been debated in many studies, and understanding how interactions amongst predators and parasitoids affect herbivore populations is crucial for pest management. In this study, we assessed the individual and combined use of two species of natural enemies, the parasitoid Aphidius ervi Haliday, and the predatory brown lacewing Micromus variegatus (Fabricius), on their shared prey, the foxglove aphid, Aulacorthum solani (Kaltenbach), on sweet pepper. We hypothesized that the presence of intraguild predation (IGP) and predator facilitation (through induced aphid dropping behaviour) might have both negative and positive effects on aphid control, respectively. Our greenhouse trial showed that overall, the greatest suppression of aphids occurred in the treatment with both the parasitoid and the lacewing. While the combination of lacewings and parasitoids significantly increased aphid control compared to the use of parasitoids alone, the effect was not significantly different to the treatment with only predators, although there was a clear trend of enhanced suppression. Thus, the combined effects of both species of natural enemies were between additive and non-additive, suggesting that the combination is neither positive nor negative for aphid control. High levels of IGP, as proven in the laboratory, were probably compensated for by the strong aphid suppression provided by the lacewings, whether or not supplemented with some level of predator facilitation. For aphid management over a longer time scale, it might still be useful to combine lacewings and parasitoids to ensure stable and resilient aphid control.Centro de Estudios Parasitológicos y de Vectore

Primeros registros de Chrysomelidae (Insecta, Coleoptera) sobre arándanos en Argentina: nuevas asociaciones entre crisomélidos nativos y un cultivo exótico

The blueberry, Vaccinium corymbosum L. (Ericaceae), is a shrub native to the northern Hemisphere introduced in Argentina, where it occupies small cultivated areas mainly in the provinces of Buenos Aires, Entre Ríos and Tucumán. At present, little is known about insects associated with this crop in Argentina. The aim of this study was to identify the species of Chrysomelidae present in blueberry crops in different regions of Argentina, and to present new chrysomelids-blueberry associations. Identification diagnosis, geographical distribution, association with other plants and aspects of their biology is given for each species. Seven species of crop-damaging Chrysomelidae were recorded in blueberry crops of Buenos Aires and Entre Rios. They belong to the subfamilies Galerucinae: Diabrotica speciosa (Germar), Disonychodes exclamationis (Boheman), Caeporisstigmula Germar, and Cacoscelis melanoptera Germar; Eumolpinae: Percolaspis varia (Lefèvre), and Spintherophyta semiaurata (Klug); and Cryptocephalinae: Lexiphanes coenobita Suffrian.El arándano, Vaccinium corymbosum L. (Ericaceae), es un arbusto nativo del hemisferio Norte, que fue introducido en la Argentina donde ocupa pequeñas áreas cultivadas, principalmente en las provincias de Buenos Aires, Entre Ríos y Tucumán. Hasta la actualidad, se conoce poco sobre los insectos asociados con este cultivo. El objetivo de este trabajo es relevar las especies de crisomélidos presentes en los cultivos de arándano de diferentes regiones, y aportar nuevas asociaciones crisomélidos-arándano para la Argentina. Para cada especie registrada, se brinda la diagnosis para su reconocimiento, su distribución geográfica, la asociación con otras plantas y algunos aspectos de su biología. Se registraron siete especies de Chrysomelidae que utilizan el arándano como recurso alimenticio en las provincias de Buenos Aires y Entre Ríos: subfamilia Galerucinae: Diabrotica speciosa (Germar), Disonychodes exclamationis (Boheman), Caeporis stigmula Germar, Cacoscelis melanoptera Germar; subfamilia Eumolpinae: Percolaspis varia (Lefèvre) y Spintherophyta semiaurata (Klug); y subfamilia Cryptocephalinae: Lexiphanes coenobita Suffrian.Facultad de Ciencias Naturales y MuseoCentro de Estudios Parasitológicos y de Vectore

Diversidad de los artrópodos fitófagos del cultivo de arándano [Vaccinium corymbosum] en la Argentina

Tesis presentada para optar al Grado de Doctor en Ciencias NaturalesFil: Rocca, Margarita. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentin

Primer registro de Syncharina lineiceps (Hemiptera: Cicadellidae) en la Argentina: clave para el reconocimiento de las especies del género

We report for the first time in Argentina the presence of Syncharina lineiceps (Spinola) and it is cited as new record for blueberries crops. For each species of the genus Syncharina Young we provide updated information referred to geographic distribution and plants hosts. A key to identify the species of the genus is presented.Se cita por primera vez para la Argentina la especie Syncharina lineiceps (Spinola) y se da a conocer como nuevo registro para los cultivos de arándanos. Para cada especie del género Syncharina Young, se proporciona información actualizada referida a la distribución geográfica y las plantas huéspedes. Se propone una clave para identificar las especies del género

Larval interactions between two aphidophagous coccinellids in sweet pepper

Antagonistic interactions among predators have the potential to dampen top-down impacts on a shared pest. Strong cannibalism by adults and larvae on eggs along with a stronger intraguild predation by Eriopis connexa on Cycloneda sanguinea (Coccinellidae) than vice versa had been documented. The intensity and direction of these interactions could vary with the larval instar. We calculated aggressiveness, attack, and predation rates between larvae in the laboratory and studied both larval mortality and within-plant distribution in plants. Despite high attack rates, larvae of both species usually escaped from predation, except for the fourth vs. second–instar combinations, where the smaller larvae were more vulnerable to predation than the larger. Successful predation by E. connexa fourth-instars on C. sanguinea second-instars frequently occurred. All interactions between larvae became relaxed when extraguild prey were present. The larval mortality within the plants was influenced by the availability of extraguild prey only. Larvae of both species promptly dispersed outside the plant when prey became unavailable. With the extraguild prey present, the larvae of both species initially preferred the plant upper stratum in both combinations, but then dispersed. This study suggests that the defensive capability and larval dispersal could prevent cannibalism and intraguild-predation interactions.Fil: Rocca, Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Rizzo, Maria Estefania. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Greco, Nancy Mabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; Argentin

Combining lacewings and parasitoids for biological control of foxglove aphids in sweet pepper

The role of natural enemy diversity in biological pest control has been debated in many studies, and understanding how interactions amongst predators and parasitoids affect herbivore populations is crucial for pest management. In this study, we assessed the individual and combined use of two species of natural enemies, the parasitoid Aphidius ervi Haliday, and the predatory brown lacewing Micromus variegatus (Fabricius), on their shared prey, the foxglove aphid, Aulacorthum solani (Kaltenbach), on sweet pepper. We hypothesized that the presence of intraguild predation (IGP) and predator facilitation (through induced aphid dropping behaviour) might have both negative and positive effects on aphid control, respectively. Our greenhouse trial showed that overall, the greatest suppression of aphids occurred in the treatment with both the parasitoid and the lacewing. While the combination of lacewings and parasitoids significantly increased aphid control compared to the use of parasitoids alone, the effect was not significantly different to the treatment with only predators, although there was a clear trend of enhanced suppression. Thus, the combined effects of both species of natural enemies were between additive and non-additive, suggesting that the combination is neither positive nor negative for aphid control. High levels of IGP, as proven in the laboratory, were probably compensated for by the strong aphid suppression provided by the lacewings, whether or not supplemented with some level of predator facilitation. For aphid management over a longer time scale, it might still be useful to combine lacewings and parasitoids to ensure stable and resilient aphid control.Centro de Estudios Parasitológicos y de Vectore

Intra- and interspecific interactions between aphidophagous ladybirds: the role of prey in predator coexistence

Cannibalism (CANN) and intraguild predation (IGP)may provide energy and nutrients to individuals and eliminate potential competitors. These negative competitive interactions could also affect the coexistence of predatory species. The co-occurrence of aphidophagous ladybird species in crops creates opportunities for CANN and IGP, especially when aphids become scarce. The Lotka–Volterra model predicts the coexistence of two species if intraspecific competition is stronger than interspecific interference interactions. Cycloneda sanguinea L. and Eriopis connexa (Germar) (both Coleoptera: Coccinellidae) coexist in sweet pepper crops in La Plata (Argentina) consuming mainly Myzus persicae (Sulzer) (Hemiptera: Aphididae). The present study used laboratory experiments to estimate levels of CANN and IGP by adults and larvae on eggs, and by adults on larvae, in both the presence and absence of prey (i.e., M. persicae), to explain the effect of prey on coexistence of these two predators. Levels of CANN by C. sanguinea and E. connexa were high in the absence of aphids, and decreased when prey was present. Intraguild predation was bidirectional and asymmetric. Adults and larvae of E. connexa were more voracious IG predators of C. sanguinea than vice versa, the former being the stronger IG predator and interference competitor. Eriopis connexa always won when larvae of the same instar were compared, whereas the larger larva always won when larvae were of different instars, regardless of species. In the presence of prey, CANN by both species decreased, but IGP by E. connexa on C. sanguinea remained high, suggesting that E. connexa could displace C. sanguinea via interspecific interference competition. Other factors potentially affecting the coexistence of C. sanguinea and E. connexa in sweet pepper crops are discussed.Facultad de Ciencias Naturales y MuseoCentro de Estudios Parasitológicos y de Vectore