Thermal resilience of Prostephanus truncatus (Horn): Can we derive optimum temperature-time combinations for commodity treatment?

Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae), is a wood-boring, destructive quarantine insect pest of stored cereal grains and tuber crops. Current disinfestation methods against this pest mainly include fumigants, whose usage in some countries has been contested and discontinued owing t...

Full description

Saved in:
Bibliographic Details
Main Authors: Machekano, Honest, Mutamiswa, Reyard, Singano, Charles, Joseph, Virgil, Chidawanyika, Frank, Nyamukondiwa, Casper
Format: Article
Language:English
Published: Elsevier 2022
Subjects:
Online Access:https://doi.org/10.1016/j.jspr.2020.101568
http://hdl.handle.net/11408/4946
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1779905207792041984
author Machekano, Honest
Mutamiswa, Reyard
Singano, Charles
Joseph, Virgil
Chidawanyika, Frank
Nyamukondiwa, Casper
author_facet Machekano, Honest
Mutamiswa, Reyard
Singano, Charles
Joseph, Virgil
Chidawanyika, Frank
Nyamukondiwa, Casper
author_sort Machekano, Honest
collection DSpace
description Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae), is a wood-boring, destructive quarantine insect pest of stored cereal grains and tuber crops. Current disinfestation methods against this pest mainly include fumigants, whose usage in some countries has been contested and discontinued owing to increasing pesticide resistance, public health risks and environmental hazards. Grain temperature treatments thus, offer a sustainable non-chemical and near universally acceptable form of disinfestation for international commodity movement. Currently, blanket temperature treatments are applied regardless of as-yet-unknown P. truncatus developmental stage thermal mortality thresholds that simultaneously optimise grain quality. Here, we used established static and dynamic protocols to determine the low and high thermal profile of P. truncatus larvae and adults measured as critical thermal minima (CTmin), lower lethal temperatures (LLT0), chill coma recovery time (CCRT), supercooling points (SCPs), critical thermal maxima (CTmax), upper lethal temperatures (ULT0) and heat knock-down time (HKDT). We tested the adult ULT-time matrices on maize and sorghum grain quality (germination %) to determine the most effective temperature-time combination(s) retaining optimum grain germination quality. Our results showed adults had higher basal heat (CTmax and HKDT), cold (CTmin, CCRT and SCP) and potential thermal plasticity than larvae (P < 0.05). The LLTs and ULTs ranged −1 to −15 °C and 41–49 °C respectively. Using LLT0 and ULT0, our results showed that for heat treatment, moderate temperature × long duration matrix; i.e. either 45.5 °C × 4 h or 47 °C × 2 h were more efficacious while retaining commodity quality. Similarly, for cold treatment; −9 °C × 4 h, −11 °C × 2 h, −13 °C × 1 h and −15 °C × 0.5 h were effective for complete mortality. These temperature-time combinations may be a sustainable alternative to fumigants in phytosanitary grain disinfestation against P. truncatus or related pests. Such pest- and commodity -specific thermal profiling is critical for development of effective standardised grain disinfestation protocols.
format Article
id ir-11408-4946
institution My University
language English
publishDate 2022
publisher Elsevier
record_format dspace
spelling ir-11408-49462022-07-07T13:03:23Z Thermal resilience of Prostephanus truncatus (Horn): Can we derive optimum temperature-time combinations for commodity treatment? Machekano, Honest Mutamiswa, Reyard Singano, Charles Joseph, Virgil Chidawanyika, Frank Nyamukondiwa, Casper Critical thermal limits Lethal temperatures Grain temperature treatment Commodity quality Postharvest pests Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae), is a wood-boring, destructive quarantine insect pest of stored cereal grains and tuber crops. Current disinfestation methods against this pest mainly include fumigants, whose usage in some countries has been contested and discontinued owing to increasing pesticide resistance, public health risks and environmental hazards. Grain temperature treatments thus, offer a sustainable non-chemical and near universally acceptable form of disinfestation for international commodity movement. Currently, blanket temperature treatments are applied regardless of as-yet-unknown P. truncatus developmental stage thermal mortality thresholds that simultaneously optimise grain quality. Here, we used established static and dynamic protocols to determine the low and high thermal profile of P. truncatus larvae and adults measured as critical thermal minima (CTmin), lower lethal temperatures (LLT0), chill coma recovery time (CCRT), supercooling points (SCPs), critical thermal maxima (CTmax), upper lethal temperatures (ULT0) and heat knock-down time (HKDT). We tested the adult ULT-time matrices on maize and sorghum grain quality (germination %) to determine the most effective temperature-time combination(s) retaining optimum grain germination quality. Our results showed adults had higher basal heat (CTmax and HKDT), cold (CTmin, CCRT and SCP) and potential thermal plasticity than larvae (P < 0.05). The LLTs and ULTs ranged −1 to −15 °C and 41–49 °C respectively. Using LLT0 and ULT0, our results showed that for heat treatment, moderate temperature × long duration matrix; i.e. either 45.5 °C × 4 h or 47 °C × 2 h were more efficacious while retaining commodity quality. Similarly, for cold treatment; −9 °C × 4 h, −11 °C × 2 h, −13 °C × 1 h and −15 °C × 0.5 h were effective for complete mortality. These temperature-time combinations may be a sustainable alternative to fumigants in phytosanitary grain disinfestation against P. truncatus or related pests. Such pest- and commodity -specific thermal profiling is critical for development of effective standardised grain disinfestation protocols. 2022-07-07T13:03:23Z 2022-07-07T13:03:23Z 2020 Article 0022-474X https://doi.org/10.1016/j.jspr.2020.101568 http://hdl.handle.net/11408/4946 en Journal of Stored Products Research;Volume 86, 101568 open Elsevier
spellingShingle Critical thermal limits
Lethal temperatures
Grain temperature treatment
Commodity quality
Postharvest pests
Machekano, Honest
Mutamiswa, Reyard
Singano, Charles
Joseph, Virgil
Chidawanyika, Frank
Nyamukondiwa, Casper
Thermal resilience of Prostephanus truncatus (Horn): Can we derive optimum temperature-time combinations for commodity treatment?
title Thermal resilience of Prostephanus truncatus (Horn): Can we derive optimum temperature-time combinations for commodity treatment?
title_full Thermal resilience of Prostephanus truncatus (Horn): Can we derive optimum temperature-time combinations for commodity treatment?
title_fullStr Thermal resilience of Prostephanus truncatus (Horn): Can we derive optimum temperature-time combinations for commodity treatment?
title_full_unstemmed Thermal resilience of Prostephanus truncatus (Horn): Can we derive optimum temperature-time combinations for commodity treatment?
title_short Thermal resilience of Prostephanus truncatus (Horn): Can we derive optimum temperature-time combinations for commodity treatment?
title_sort thermal resilience of prostephanus truncatus (horn): can we derive optimum temperature-time combinations for commodity treatment?
topic Critical thermal limits
Lethal temperatures
Grain temperature treatment
Commodity quality
Postharvest pests
url https://doi.org/10.1016/j.jspr.2020.101568
http://hdl.handle.net/11408/4946
work_keys_str_mv AT machekanohonest thermalresilienceofprostephanustruncatushorncanwederiveoptimumtemperaturetimecombinationsforcommoditytreatment
AT mutamiswareyard thermalresilienceofprostephanustruncatushorncanwederiveoptimumtemperaturetimecombinationsforcommoditytreatment
AT singanocharles thermalresilienceofprostephanustruncatushorncanwederiveoptimumtemperaturetimecombinationsforcommoditytreatment
AT josephvirgil thermalresilienceofprostephanustruncatushorncanwederiveoptimumtemperaturetimecombinationsforcommoditytreatment
AT chidawanyikafrank thermalresilienceofprostephanustruncatushorncanwederiveoptimumtemperaturetimecombinationsforcommoditytreatment
AT nyamukondiwacasper thermalresilienceofprostephanustruncatushorncanwederiveoptimumtemperaturetimecombinationsforcommoditytreatment