Remarkably efficient production of a highly insecticidal Chrysodeixis chalcites nucleopolyhedrovirus (ChchNPV) isolate in its homologous host

A Chrysodeixis chalcites nucleopolyhedrovirus from the Canary Islands (ChchNPV‐TF1) has proved to be effective for control of Chrysodeixis chalcites on banana crops. Commercialization of this virus as a bioinsecticide requires an efficient production system.

The sixth instar (L6) was the most suitable for virus production, producing 1.80 × 1011 occlusion bodies (OB)/larva and showed a lower prevalence of cannibalism (5.4%) than fourth (L4) or fifth (L5) instars. Inoculation of L6 at 24 h post molting produced six times more OB (5.72 × 1011 OB/larva) than recently molted L6 larvae (1.00 × 1011 OB/larva). No significant differences were recorded in mean time to death (165–175 h) or OB production per larva (3.75 × 1011 to 5.97 × 1011) or per mg larval weight (1.30 × 1011 to 2.11 × 109), in larvae inoculated with a range of inoculum concentrations (LC50–LC90). Groups of infected L6 larvae reared at a density of 150 larvae/container produced a greater total number of OBs (8.07 × 1013 OB/container) than lower densities (25, 50 and 100 OB/container), and a similar number to containers with 200 inoculated larvae (8.43 × 1013 OB/container).

The processes described here allow efficient production of sufficient OBs to treat ∼ 40 ha of banana crops using the insects from a single container. © 2018 Society of Chemical Industry

This study received financial support from the Instituto Nacional de Investigaciones Agrarias (Project RTA2010‐00016‐C02‐02 and RTA2013‐00114‐C02‐02) and the Programa Nacional Español de I + D + I (Projects AGL2008‐05456‐CO3‐01 and AGL2011‐30352‐CO2‐01).

Peer reviewed