Cristian Montalva

The cypress aphid in Chile: A review of the current situation and preliminary data of the biological control

El pulgon del cipres, Cinara cupressi, es considerado una de las plagas invasoras mas importantes del mundo y en Chile se encuentra presente en todo el territorio continental nacional. Afecta a las especies forestales nativas cipres de la cordillera (Austrocedrus chilensis) y alerce (Fitzroya cupressoides), como tambien a especies exoticas que se utilizan ornamentalmente en el area urbana. El sector forestal de Chile ha potenciado y privilegiado el uso de controladores biologicos como parte del manejo integrado de plagas. Es por esto que se ha utilizado Pauesia juniperorum para el control de C. cupressi. Sin embargo, se han detectado bajos niveles de parasitismo. En este trabajo se analizan y discuten aspectos de la biologia y comportamiento de C. cupressi y de los controladores biologicos detectados en el pais, asi como tambien las medidas implementadas por el gobierno considerando que esta fue la primera deteccion de una plaga exotica de importancia asociada a especies del bosque nativo. Se propone a futuro evaluar la sincronia y el nivel de parasitismo del controlador biologico P. juniperorum, con el fin de determinar si el parasitoide se ha establecido en todo el territorio nacional o es necesario complementarlo con otros agentes como Lecanicillium lecanii u otros biocontroladores como Xenostigmus bifasciatus. Este ultimo puede ser una alternativa a evaluarse para alcanzar un mejor control, de tal manera de disminuir las poblaciones del afido que amenaza especies forestales de gran valor para el patrimonio nacional y a especies usadas como arboles ornamentales.

Metarhizium alvesii sp. nov.: A new member of the Metarhizium anisopliae species complex

A strain within the Metarhizium anisopliae species complex was isolated in 2009 from a soil sample in a banana plantation in the municipality of Quixeré, Northeastern region of Brazil. Previous studies showed that this insect-pathogenic strain does not fit with any current taxon within the M. anisopliae species complex, as determined by both genomic and by mass spectrometric analyses. In the present study, CG1123 (=ARSEF 13308) is shown to be morphologically indistinguishable from most species in this cosmopolitan species complex, whereas multilocus phylogeny confirmed its uniqueness and supports its recognition as a new species, Metarhizium alvesii, in honor of Sérgio Batista Alves, one of the founders of insect pathology in Brazil.

Transcriptomic insight into pathogenicity-associated factors of Conidiobolus obscurus, an obligate aphid-pathogenic fungus belonging to Entomopthoromycota: Transcriptomic analysis of C. obscurus

BACKGROUND Conidiobolus obscurus is a widespread fungal entomopathogen with aphid biocontrol potential. This study focused on a de novo transcriptomic analysis of C. obscurus. RESULTS A number of pathogenicity-associated factors were annotated for the first time from the assembled 17 231 fungal unigenes, including those encoding subtilisin-like proteolytic enzymes (Pr1s), trypsin-like proteases, metalloproteases, carboxypeptidases and endochitinases. Many of these genes were transcriptionally up-regulated by at least twofold in mycotized cadavers compared with the in vitro fungal cultures. The resultant transcriptomic database was validated by the transcript levels of three selected pathogenicity-related genes quantified from different in vivo and in vitro material in real-time quantitative polymerase chain reaction (PCR). The involvement of multiple Pr1 proteases in the first stage of fungal infection was also suggested. Interestingly, a unique cytolytic (Cyt)-like δ-endotoxin gene was highly expressed in both mycotized cadavers and fungal cultures, and was more or less distinct from its homologues in bacteria and other fungi. CONCLUSION Our findings provide the first global insight into various pathogenicity-related genes in this obligate aphid pathogen and may help to develop novel biocontrol strategy against aphid pests.

Hirsutella sp. (Hypocreales: Ophiocordycipitaceae) affecting the invasive social wasp Vespula vulgaris (Hymenoptera: Vespidae) in southern Chile

Summary In Chile, the invasive and noxious pest Vespula vulgaris (L.) (Hymenoptera: Vespidae) was first reported in 2011 in the Araucanía region and is currently distributed between Araucanía and Magallanes regions. In Mar 2015 (autumn), during an ongoing monitoring of funnel traps by the Servicio Agrícola y Ganadero, a fungus-infected individual was collected. The fungus was identified morphologically as a species of Hirsutella (Hypocreales: Ophiocordycipitaceae). This is the first report of any Hirsutella species on V. vulgaris in Chile. No in vitro cultures were successfully established from the infected insect.

The spatial–temporal dynamics of bamboo aphid dispersal flight along with their natural enemies: biocontrol implication

Bamboo is widely planted in forestlands and farmlands in tropical and subtropical areas. Bamboo biomass and production are threatened by cohorts of aphid pests. Understanding spatial–temporal dispersal trends of alates and interactions with their natural enemies might help regulate aphid population dynamics in the field. This study performed air capture of bamboo aphids by yellow-cloth-and-plant trap. A total of 3577 alates were captured during April to July 2014. Many of the trapped alates tended to short-distance horizontal flight, while half of Takecallis taiwanus (Takahashi) displayed upper-air flight trend. The temporal dynamics of trapped alates varied between species. The dispersal of Takecallis arundinariae (Essig) peaked mid-May, followed by T. taiwanus, and Metamacropodaphis bambusisucta (Zhang). Post-flight survival and fecundity of the trapped alates supported successful colonization. A total of 247 alates died from fungal pathogen infection (68.0%), parasitoids (25.5%), and Allothrombium ectoparasites (6.5%). Up to 97.6% of the mycosis was attributed to Neozygites linanensis (Zhou and Montalva). The Alate-borne parasitoid and ectoparasite species were consistent with those in local farming areas. It implied that aphid species in bamboo-inclusive agroforestry system might be in the interaction of apparent competition by shared arthropod natural enemies. These results highlight the dispersal pattern of bamboo aphid alates and the transport of natural enemies, providing initial insight to aphid biocontrol in bamboo stand.