Novel biopesticide based on Erinnyis ello betabaculovirus: characterization and preliminary field evaluation to control Erinnyis ello in rubber plantations.

BACKGROUND: The hornworn Erinnyis ello is the major pest of natural rubber crops in Colombia, mainly controlled using toxic chemical insecticides. The use of E. ello Betabaculovirus is an environmentally sustainable alternative for its control. The aim of the present work was to characterize a prototype biopesticide formulation and evaluate its efficacy under different conditions. RESULTS: Quality control evaluations of formulated biopesticide revealed that all the parameters evaluated were under the permissible level. The lethal concentrations LC50 and LC90 of the biopesticide were 4.3 × 103 and 5.5 × 104 occlusion bodies (OBs) mL-1 , respectively. Biopesticide efficacies against second and fourth instar larvae under greenhouse conditions were higher than 80%. Evaluation of two application rates in a clonal garden resulted in 84% and 88% efficacy, comparable to that obtained with the chemical. The biopesticide in a commercial plantation showed efficacies between 74% and 82%. Biopesticide post-application persistence was estimated at least in 1 week under field natural conditions. Results allowed selection of the lowest evaluated dose (1 × 1011 OBs ha-1 ) as the basis for further field evaluations. CONCLUSION: Formulated ErelGV showed high efficacy to control the hornworm in rubber crops and high potential to be included in integrated pest management programs, thus it could be an interesting alternative to replace agrochemicals. © 2018 Society of Chemical Industry.

The complete sequence of the first Spodoptera frugiperda Betabaculovirus genome: a natural multiple recombinant virus.

Spodoptera frugiperda (Lepidoptera: Noctuidae) is a major pest in maize crops in Colombia, and affects several regions in America. A granulovirus isolated from S. frugiperda (SfGV VG008) has potential as an enhancer of insecticidal activity of previously described nucleopolyhedrovirus from the same insect species (SfMNPV). The SfGV VG008 genome was sequenced and analyzed showing circular double stranded DNA of 140,913 bp encoding 146 putative ORFs that include 37 Baculoviridae core genes, 88 shared with betabaculoviruses, two shared only with betabaculoviruses from Noctuide insects, two shared with alphabaculoviruses, three copies of own genes (paralogs) and the other 14 corresponding to unique genes without representation in the other baculovirus species. Particularly, the genome encodes for important virulence factors such as 4 chitinases and 2 enhancins. The sequence analysis revealed the existence of eight homologous regions (hrs) and also suggests processes of gene acquisition by horizontal transfer including the SfGV VG008 ORFs 046/047 (paralogs), 059, 089 and 099. The bioinformatics evidence indicates that the genome donors of mentioned genes could be alpha- and/or betabaculovirus species. The previous reported ability of SfGV VG008 to naturally co-infect the same host with other virus show a possible mechanism to capture genes and thus improve its fitness.