ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

First instar mortalities of three New Zealand leafroller species (Lepidoptera: Tortricidae) exposed to controlled atmosphere treatments.

Whiting, D. C.; O'Connor, G. M.; Maindonald, J. H.;

Postharvest Biology and Technology Year: 1996 Vol: 8 Issue: 3 Pages: 229-236 Ref: 18 ref.

1996

บทคัดย่อ

Postharvest disinfestation treatments are being developed against leafroller species which are pests of kiwifruits in response to reduced preharvest chemical control strategies which have been adopted in order to reduce pesticide residues at harvest. Mortality-responses of first instar Cnephasia jactatana, Ctenopseustis obliquana and Planotortrix octo reared on artificial diets to various controlled atmospheres at different temperatures were determined. At 20 deg C, reducing the O2 concentration from 3.85 to 0.4% greatly reduced the mean estimated time for 99% mortality (LT99). An O2 concentration of 0.4% combined with a CO2 concentration of 5% resulted in the lowest LT99 for each of the species (18.8, 31.5 and 31.6 h, respectively). At this temperature, C. jactatana was more susceptible to atmospheres with more than or equal to 1% O2 than C. obliquana and P. octo. Although LT99s were greatly decreased by the same reduction of O2 concentration at 30 deg C, the mortality responses to atmospheres

with concentrations less than or equal to 1% O2 were similar. Changing the CO2 concentration of the atmosphere between 1 and 20% had a minor effect on the mortality responses of the 3 species at both 20 and 30 deg C. When treatments were applied at 40 deg C, the LT99s were short (less than or equal to 4.6 h) and comparatively homogeneous regardless of either the O2 or the CO2 composition of the atmosphere.