Natural enemies of armored scales (Hemiptera: Diaspididae) and soft scales (Hemiptera: Coccoidae) in Chile: molecular and morphological identification.

Scale insects (Hemiptera: Sternorrhyncha: Coccomorpha) are key pests of agricultural crops and ornamental plants worldwide. Their populations are difficult to control, even with insecticides, due to their cryptic habits. Moreover, there is growing concern over the use of synthetic pesticides for their control, due to deleterious environmental effects and the emergence of resistant populations of target pests. In this context, biological control may be an effective and sustainable approach. Hymenoptera Chalcidoidea includes natural enemies of scale insects that have been successfully used in many biological control programs. However, the correct identification of pest scale species and their natural enemies is particularly challenging because these insects are very small and highly specialized. Integrative taxonomy, coupling DNA barcoding and morphological analysis, has been successfully used to characterize pests and natural enemy species. In this study, we performed a survey of parasitoids and predators of armored and soft scales in Chile, based on 28S and COI barcodes. Fifty-three populations of Diaspididae and 79 populations of Coccidae were sampled over the entire length of the country, from Arica (18˚S) to Frutillar (41˚S), between January 2015 and February 2016. The phylogenetic relationships obtained by Bayesian inference from multilocus haplotypes revealed 41 putative species of Chalcidoidea, five Coccinellidae and three Neuroptera. Species delimitation was confirmed using ABGD, GMYC and PTP model. In Chalcidoidea, 23 species were identified morphologically, resulting in new COI barcodes for 12 species and new 28S barcodes for 14 species. Two predator species (Rhyzobius lophantae and Coccidophilus transandinus) were identified morphologically, and two parasitoid species, Chartocerus niger and Signiphora bifasciata, were recorded for the first time in Chile

Mechanisms affecting population density in fragmented habitat

We conducted a factorial simulation experiment to analyze the relative importance of movement pattern, boundary-crossing probability, and mortality in habitat and matrix on population density, and its dependency on habitat fragmentation, as well as inter-patch distance. We also examined how the initial response of a species to a fragmentation event may affect our observations of population density in post-fragmentation experiments. We found that the boundary-crossing probability from habitat to matrix, which partly determines the emigration rate, is the most important determinant for population density within habitat patches. The probability of crossing a boundary from matrix to habitat had a weaker, but positive, effect on population density. Movement behavior in habitat had a stronger effect on population density than movement behavior in matrix. Habitat fragmentation and inter-patch distance may have a positive or negative effect on population density. The direction of both effects depends on two factors. First, when the boundary-crossing probability from habitat to matrix is high, population density may decline with increasing habitat fragmentation. Conversely, for species with a high matrix-to-habitat boundary-crossing probability, population density may increase with increasing habitat fragmentation. Second, the initial distribution of individuals across the landscape: we found that habitat fragmentation and inter-patch distance were positively correlated with population density when individuals were distributed across matrix and habitat at the beginning of our simulation experiments. The direction of these relationships changed to negative when individuals were initially distributed across habitat only. Our findings imply that the speed of the initial response of organisms to habitat fragmentation events may determine the direction of observed relationships between habitat fragmentation and population density. The time scale of post-fragmentation studies must, therefore, be adjusted to match the pace of post-fragmentation movement responses

Development of microsatellite markers and detection of genetic variation between Goniozus wasp populations

Molecular genetic markers reveal differences between genotypes according to the presence of alleles (the same or different) at target loci. Microsatellite markers are especially useful codominant markers that have been used in a wide range of studies to elucidate the population structure and dynamics of a range of organisms, including agriculturally beneficial insects such as parasitic wasps (parasitoids). In the present study, twelve primer pairs were designed for the south Asian , Goniozus nephantidis (Muesebeck) (Hymenoptera: Bethylidae), and 24 for its New World congener, Goniozus legneri Gordh, parasitoids of the larvae of the lepidopteran coconut pest Opisina arenosella Walker (Lepidoptera: Crytophasidae) and other lepidopteran pests, respectively, in order to investigate polymorphism within and between populations. The wasps fingerprinted were a total of 85 G. nephantidis and G. legneri, including individuals belonging to three putatively different strains of G. legneri. Annealing gradient tests (50–65°C) were conducted to study the quality of the PCR amplification across an annealing temperature gradient using a mixed genotype DNA template from each species separately. Seven primer pairs, which amplified clear products of approximately the expected size of G. nephantidis and 18 of G. legneri, were then selected for capillary analysis for fragment size determination on a Beckmann CEQ 8000. Neither G. nephantidis nor G. legneri were polymorphic within populations. However, there were six primer pairs that did show polymorphism between G. legneri populations that originated from different geographical areas within South America (Uruguay and Chile). Furthermore, one primer pair revealed diversity between the two strains collected within Chile. One of the markers was subsequently used to provide unbiased assessment of primary sex ratio in G. legneri

The Effects of Host-Feeding on Synovigenic Egg Development in An Endoparasitic Wasp, Itoplectis naranyae

Many adult parasitoids feed on host insects, a behavior known as host-feeding. Feeding on hosts is essential to maximizing female fecundity, but its contribution to reproduction varies from species to species. The relationship between fecundity and host-feeding was examined in the solitary endoparasitoid wasp Itoplectis naranyae Ashmead, (Hymenoptera: Ichneumonidae) to assess the significance of host-feeding in female reproduction. Adult female wasps did not respond to hosts when they were 0–1 days old, but subsequently increased their oviposition and host-feeding activities with increasing female age. While newly emerging females had no mature eggs in their ovary, the number of mature eggs increased rapidly thereafter, a process termed synovigeny. Female wasps were capable of maturing eggs without host-feeding, and this suggested that they produced a certain portion of eggs from nutritional reserves that had been stored during the larval stage. Behavioral observations revealed that I. naranyae was a destructive host-feeder as the host was damaged during feeding. Female fecundity was greater in females that had previously fed on hosts than those did not, indicating that host-feeding was involved in egg production. There was a time-delayed relation between host-feeding events and additional egg production; at least 3 days were required to mature eggs from nutrients gained via feeding on hosts. The significance of host-feeding in I. naranyae reproduction is discussed in the context of its life history traits

Efectividad de Bandas en Base a Aceites y Polibuteno en el Control del Burrito de la Vid Naupactus xanthographus (Coleoptera: Curculionidae)

El burrito (Naupactus xanthographus) (Coleoptera: Curculionidae) es una plaga de importancia económica en vid. Su ciclo larvario subterráneo dificulta el control químico, pero dado que el adulto no vuela, en frutales se ha manejado exitosamente usando bandas con una mezcla oleosa más insecticida, sin embargo esto no es aceptado en producción orgánica. En este trabajo se evaluaron en condiciones de laboratorio e invernadero bandas de polietileno con productos aceptados en producción orgánica (mezcla aceitosa, azadirachtina y polibuteno) en comparación con alternativas de uso actual (azinfosmetil y Banda INIA) y testigo. Las bandas fueron engrapadas a postes de pino y luego los burritos fueron colocados en la base, observando su comportamiento, habilidad para cruzar la banda y la mortalidad a las 24 y 96 h luego de contactar la banda. Los postes fueron dejados a la intemperie y se repitió el experimento a los 20 y 40 días. Un experimento similar se realizó en bandas dispuestas horizontalmente. Los tratamientos influenciaron el comportamiento y mortalidad de los individuos (?2; P < 0,05). Los tratamientos con azinfosmetil y Banda INIA tuvieron un marcado efecto de repelencia el día 0, seguido de azadirachtina (?2 ; P < 0,05), sin embargo esto disminuyó en el tiempo, hasta no diferenciarse del testigo el día 40 (P = 0,34). Todos los tratamientos presentaron una acción como barrera física mayor al testigo (?2; P < 0,05), con 100% de efectividad del polibuteno. La mayor mortalidad se presentó en los tratamientos con azinfosmetil y Banda INIA, aún 40 días después de aplicadas las mezclas. Los tratamientos azadirachtina, polibuteno y pasta base presentaron una mortalidad inicialmente superior al testigo, con azadirachtina similar a los tradicionales (?2; P < 0,05), sin embargo esta diferencia no se mantuvo hasta los 40 días

Dinámica Temporal de Coleópteros Asociados a Alfalfa

La alfalfa es un cultivo que aloja una gran diversidad de insectos. Estos pueden variar en composición y abundancia según la época del año de acuerdo a la fenología del cultivo y, además, en función del régimen de corte de la alfalfa. En este trabajo se describe la composición y la dinámica temporal del ensamble de coleópteros asociados a un cultivo de alfalfa de dos años de edad ubicado en Santiago. Una vez al mes, entre noviembre del 2001 y febrero de 2002, se muestrearon estos insectos en alfalfa segada permanentemente y en alfalfa sin segar, a través de redes entomológicas y trampas Barber. Se colectaron un total de 2166 coleópteros de 73 especies. De ellas, 36 fueron colectadas sólo en trampas Barber, 13 sólo en redes y 24 mediante ambos métodos. Sólo 15 especies se colectaron durante los cuatro meses y 29 aparecen sólo en una fecha de muestreo, lo que indica un ensamble muy dinámico. La mayor parte de las especies fueron, en alguno de sus estados de vida, depredadoras. En Barber, la mayor abundancia y riqueza de especies se obtuvo en enero y en redes la abundancia tiende a ser mayor en enero y febrero, en cambio la riqueza fue similar todos los meses. La abundancia de coleópteros varíó según la familia, siendo en Barber más abundantes Anthicidae y Tenebrionidae, y en redes, Lathridiidae y Coccinellidae. Sin embargo, la abundancia relativa de ellas respecto a las otras familias varió en el tiempo. Los coleópteros más abundantes fueron depredadores y saprófagos. En relación al régimen de corte, solamente en enero los coleópteros en alfalfa segada fueron más abundantes y tendieron a ser más diversos. Lo anterior corroboró la variabilidad de la fauna de coleópteros asociados a alfalfa en función del tiempo y del crecimiento de esta

Potential spatial interaction of the invasive species Harmonia axyridis (pallas) with native and endemic coccinellids

Biological invasions represent a serious menace to local species assemblages, mainly due to interspecific relationships such as competition and predation. One important invasive species worldwide is Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), which has invaded many regions of the world, threatening the native and endemic coccinellid assemblages due to negative interspecific interactions. These interactions have been widely studied at a local scale, but have been less studied at regional scales. Our aim was to estimate and analyse the potential spatial interaction associated with the co-occurrence of H.axyridis with native and endemic species in Chile, considering bioclimatic and land cover variables. First, we created species distribution models (SDM) for H.axyridis, native and endemic coccinellids and six representative coccinellid species using maximum entropy technique. Then, we overlapped each SDM with land cover types to estimate the bioclimatic suitability within each land cover type. Finally, we identified the co-occurrences of organisms according to the SDM and the land cover types, estimating in what land covers H.axyridis and the other coccinellids are more likely to co-occur. Our results show that the suitable area for H.axyridis occurs from 30 degrees to 42 degrees S in Chile, while for native and endemic species this area is greater. The six selected species are mainly concentrated in central Chile, but differ in their potential suitable areas; Adalia angulifera Mulsant and Scymnus bicolor (Germain) have the largest range, and Mimoscymnus macula (Germain) has the most restricted one. The highest level of potential spatial interactions with H.axyridis occurs in central Chile, specifically in croplands and scrublands, and the lowest in primary native forest for all the species. Our results provide a spatially explicit baseline for coccinellid conservation and management of this invasive species.FONDECYT 114066

Primer registro de Goniozus legneri (Hymenoptera: Bethylidae) para Chile

Codling (Cydia pomonella) and carob moths (Ectomyelois ceratoniae) are important pests of apples and walnuts in Chile.During fruit samplings, a parasitoid was found attacking the larvae of these species. Because there was no previous information on larval parasitoids of them in Chile, a study was conducted with the objectives of identifying the parasitoid species found, to gain information on its biology and to determine how widespread itwas in central Chile. Fruits from apple and walnut trees were sampled in different localities of central Chile, from the Metropolitan to the VII Region. The species found in the fruits attacking the larvae of the codling and carob moths was Goniozus legneri. The mean parasitism observed in laboratory conditions was 50 and 33% in C. pomonella and E. ceratoniae, respectively. The number of eggs laid per host in C. pomonella was 10.8 ± 3.8 and in E. ceratoniae was 8.3 ± 3.8. This is the fi rst report of this parasitoid species in ChileLa polilla de la manzana (Cydia pomonella) y del algarrobo (Ectomyelois ceratoniae) son plagas importantes de manzanos y nogales en Chile. Durante monitoreos de fruta se encontró un betílido atacando larvas de estas especies. Como no existía conocimiento previo de parasitoides de larvas de estas especies en Chile, se realizó un estudio para determinar la especie, estudiar su biología y establecer su dispersión en Chile central. Con este propósito se muestrearon frutos de nogales y manzanos provenientes de árboles con y sin aplicaciones de pesticidas, en distintas localidades ubicadas entre la Región Metropolitana y la VII Región, donde se encontró Goniozus legneri atacando a larvas de polilla de la manzana y polilla del algarrobo. El parasitismo promedio observado en laboratorio fue de 33 y 50% en E. ceratoniae y en C. pomonella respectivamente. El número de huevos por larva de C. pomonella fue de 10.8 ± 3.8 y en E. ceratoniae fue 8.3 ± 3.8. Este constituye el primer reporte de esta especie parasotoide para Chil