Sitotroga cerealella (Olivier) resilience to extreme temperature and desiccation may explain its increasing pest status in changing climates

The mechanisms underlying Sitotroga cerealella survival under variable and increasing mean thermal and desiccation environments typical under global change is currently unknown. To understand how S. cerealella survives extreme abiotic stressors typical of stored-grain environments, we measured S. ce...

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Main Authors: Machekano, Honest, Mvumi, Brighton M., Nyamukondiwa, Casper
Format: Article
Language:deu
Published: Julius Kühn-Institut 2018-11-01
Series:Julius-Kühn-Archiv
Subjects:
Online Access:https://www.openagrar.de/receive/openagrar_mods_00078235
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author Machekano, Honest
Mvumi, Brighton M.
Nyamukondiwa, Casper
author_facet Machekano, Honest
Mvumi, Brighton M.
Nyamukondiwa, Casper
author_sort Machekano, Honest
collection DOAJ
description The mechanisms underlying Sitotroga cerealella survival under variable and increasing mean thermal and desiccation environments typical under global change is currently unknown. To understand how S. cerealella survives extreme abiotic stressors typical of stored-grain environments, we measured S. cerealella tolerance temperature and desiccation. The results showed that to survive desiccating grain storage environments, S. cerealella relied more on high body water content (BWC) (70.2 ± 3.72%) compared to lipid reserves (9.8± 0.81%). In desiccating environment, S. cerealella showed a reduced water loss rate (0.056mg/h) (equivalent of 1.81% of body water/hour) which would require 19.31 h to reduce the insect body water to its critical minimum (35.23% body water content at death), which is 50.20% of normal initial body water. Similarly S. cerealella exhibited high basal heat tolerance with critical thermal maximum of 46.09 ± 1.042°C and a heat knockdown time of 7.97 ± 1.64 minutes. Basal cold tolerance was relatively compromised (critical thermal minima of 4.52 ± 1.06°C and chill coma recovery time of 5.80 ±1.17 minutes), following 1h at 0°C. We found no significant correlation (P > 0.001) between BWC and the measured thermal tolerance traits. Low water loss rates reported here may be an evolutionary resistance mechanism for desiccation tolerance. Observed abiotic stress tolerance may explain the ubiquitous distribution of S. cerealella in Africa which is likely to enhance its survival and increase its pest status under global change.
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spelling doaj.art-7fabfd95a5894465864d3fbce577adce2023-11-30T06:29:01ZdeuJulius Kühn-InstitutJulius-Kühn-Archiv1868-98922199-921X2018-11-01463116517110.5073/jka.2018.463.040Sitotroga cerealella (Olivier) resilience to extreme temperature and desiccation may explain its increasing pest status in changing climatesMachekano, Honest0Mvumi, Brighton M.1Nyamukondiwa, Casper2Department of Biological Sciences and Biotechnology, Faculty of Science, Botswana International University of Science and Technology, Palapye, BotswanaDepartment of Biological Sciences and Biotechnology, Faculty of Science, Botswana International University of Science and Technology, Palapye, BotswanaDepartment of Biological Sciences and Biotechnology, Faculty of Science, Botswana International University of Science and Technology, Palapye, BotswanaThe mechanisms underlying Sitotroga cerealella survival under variable and increasing mean thermal and desiccation environments typical under global change is currently unknown. To understand how S. cerealella survives extreme abiotic stressors typical of stored-grain environments, we measured S. cerealella tolerance temperature and desiccation. The results showed that to survive desiccating grain storage environments, S. cerealella relied more on high body water content (BWC) (70.2 ± 3.72%) compared to lipid reserves (9.8± 0.81%). In desiccating environment, S. cerealella showed a reduced water loss rate (0.056mg/h) (equivalent of 1.81% of body water/hour) which would require 19.31 h to reduce the insect body water to its critical minimum (35.23% body water content at death), which is 50.20% of normal initial body water. Similarly S. cerealella exhibited high basal heat tolerance with critical thermal maximum of 46.09 ± 1.042°C and a heat knockdown time of 7.97 ± 1.64 minutes. Basal cold tolerance was relatively compromised (critical thermal minima of 4.52 ± 1.06°C and chill coma recovery time of 5.80 ±1.17 minutes), following 1h at 0°C. We found no significant correlation (P > 0.001) between BWC and the measured thermal tolerance traits. Low water loss rates reported here may be an evolutionary resistance mechanism for desiccation tolerance. Observed abiotic stress tolerance may explain the ubiquitous distribution of S. cerealella in Africa which is likely to enhance its survival and increase its pest status under global change.https://www.openagrar.de/receive/openagrar_mods_00078235storage insect pestsabiotic stressthermal tolerancedesiccation tolerancestored cereal grainstress tolerance mechanisms
spellingShingle Machekano, Honest
Mvumi, Brighton M.
Nyamukondiwa, Casper
Sitotroga cerealella (Olivier) resilience to extreme temperature and desiccation may explain its increasing pest status in changing climates
Julius-Kühn-Archiv
storage insect pests
abiotic stress
thermal tolerance
desiccation tolerance
stored cereal grain
stress tolerance mechanisms
title Sitotroga cerealella (Olivier) resilience to extreme temperature and desiccation may explain its increasing pest status in changing climates
title_full Sitotroga cerealella (Olivier) resilience to extreme temperature and desiccation may explain its increasing pest status in changing climates
title_fullStr Sitotroga cerealella (Olivier) resilience to extreme temperature and desiccation may explain its increasing pest status in changing climates
title_full_unstemmed Sitotroga cerealella (Olivier) resilience to extreme temperature and desiccation may explain its increasing pest status in changing climates
title_short Sitotroga cerealella (Olivier) resilience to extreme temperature and desiccation may explain its increasing pest status in changing climates
title_sort sitotroga cerealella olivier resilience to extreme temperature and desiccation may explain its increasing pest status in changing climates
topic storage insect pests
abiotic stress
thermal tolerance
desiccation tolerance
stored cereal grain
stress tolerance mechanisms
url https://www.openagrar.de/receive/openagrar_mods_00078235
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AT mvumibrightonm sitotrogacerealellaolivierresiliencetoextremetemperatureanddesiccationmayexplainitsincreasingpeststatusinchangingclimates
AT nyamukondiwacasper sitotrogacerealellaolivierresiliencetoextremetemperatureanddesiccationmayexplainitsincreasingpeststatusinchangingclimates