scholarly journals Cross-tolerance to Desiccation and Cold in Khapra Beetle (Coleoptera: Dermestidae)

2019 ◽  
Vol 113 (2) ◽  
pp. 695-699
Author(s):  
Sunil Shivananjappa ◽  
Robert A Laird ◽  
Kevin D Floate ◽  
Paul G Fields
Keyword(s):  
Cold Tolerance ◽  
Low Temperatures ◽  
Insect Pests ◽  
Indian Subcontinent ◽  
Cross Tolerance ◽  
Physiological Mechanisms ◽  
Ecological Stress ◽  
Khapra Beetle ◽  
Lethal Time ◽  
Cold Hardy

Abstract Khapra beetle, Trogoderma granarium Everts, is unusual in two key respects. First, they are among the most cold hardy of stored-product insect pests even though they originate in hot and dry regions of the Indian subcontinent. Second, their larvae can enter into diapause to survive harsh environmental conditions. In the present study, we examined whether these two phenomena are related, i.e., due to cross-tolerance. Cross-tolerance is the tolerance to one ecological stress when induced by a separate stress. To investigate this, khapra beetle larvae were reared at different relative humidities (3, 28, 49, and 79%) in either nondiapausing or diapausing conditions. Then the cold tolerance of larvae was estimated by measuring mortality after different durations at −10°C. For nondiapausing larvae, relative humidity had little effect on cold tolerance with the lethal time to 50% mortality (LT50) occurring between 2 and 4 d. For diapausing larvae, cold tolerance increased with greater desiccation stress with LT50’s of 5, 7, 10, and 18 d at 79, 49, 28, and 3% RH, respectively. This suggests that the physiological mechanisms that protect diapausing larvae from desiccation may also increase cold tolerance, even though these insects may rarely be exposed to low temperatures.

The effect of diapause and cold acclimation on the cold-hardiness of the warehouse beetle, Trogoderma variabile (Coleoptera: Dermestidae)

2014 ◽  
Vol 147 (2) ◽  
pp. 158-168 ◽  
Author(s):  
Ahmed Y. Abdelghany ◽  
Duangsamorn Suthisut ◽  
Paul G. Fields
Keyword(s):  
Cold Acclimation ◽  
Cold Tolerance ◽  
Low Temperatures ◽  
Cold Hardiness ◽  
Supercooling Point ◽  
Stored Product Pest ◽  
Trogoderma Variabile ◽  
Lethal Time ◽  
Cold Hardy

AbstractThe warehouse beetle, Trogoderma variabile Ballion (Coleoptera: Dermestidae), is a stored-product pest with scant information on its cold tolerance. Ninety-two per cent of larvae reared in isolation at 30 °C went into diapause in the seventh instar, the remaining 8% emerged as adults in 50 days. Diapausing larvae died after 142 days in the 10th instar. The cold tolerance at 0 °C from highest to lowest was; old larvae>pupae>adult=young larvae>eggs. The LT50 (lethal time for 50% of the population) for grouped (non-diapause) non-acclimated old larvae at 0 °C, −5 °C, −10 °C, −16 °C, and −19 °C were; 20, 11, 5, 1, and 1 day, the LT95 were; 38, 15, 10, 5, and 1 days, respectively. The LT50 for isolated (diapausing), cold-acclimated old larvae at the same temperatures were; 275, 125, 74, 26, and 18 days, and the LT95 were; 500, 160, 100, 45, 20 days, respectively. The supercooling point (SCP) of different stages of non-acclimated insects ranged from −25.3 °C (eggs) to −16.1 °C (young larvae). The most cold hardy stage, isolated and acclimated old larvae, had a SCP of −24.9 °C. The potential of using low temperatures to control T. variabile is discussed.

scholarly journals Gene Characterization and Enzymatic Activities Related to Trehalose Metabolism of In Vitro Reared Trichogramma dendrolimi Matsumura (Hymenoptera: Trichogrammatidae) under Sustained Cold Stress

Insects ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 767
Author(s):  
Xin Lü ◽  
Shi-chou Han ◽  
Zhi-gang Li ◽  
Li-ying Li ◽  
Jun Li
Keyword(s):  
Cold Tolerance ◽  
Enzyme Activities ◽  
Low Temperatures ◽  
Insect Pests ◽  
Egg Parasitoid ◽  
Threshold Temperature ◽  
Gene Expressions ◽  
Gene Characterization ◽  
Trichogramma Dendrolimi

Trichogramma spp. is an important egg parasitoid wasp for biocontrol of agriculture and forestry insect pests. Trehalose serves as an energy source or stress protectant for insects. To study the potential role of trehalose in cold resistance on an egg parasitoid, cDNA for trehalose-6-phosphate synthase (TPS) and soluble trehalase (TRE) from Trichogramma dendrolimi were cloned and characterized. Gene expressions and enzyme activities of TdTPS and TdTRE were determined in larvae, prepupae, pupae, and adults at sustained low temperatures, 13 °C and 16 °C. TdTPS and TdTRE expressions had similar patterns with higher levels in prepupae at 13 °C and 16 °C. TdTPS enzyme activities increased with a decrease of temperature, and TdTRE activity in prepupae decreased sharply at these two low temperatures. In vitro reared T. dendrolimi could complete entire development above 13 °C, and the development period was prolonged without cold injury. Results indicated trehalose might regulate growth and the metabolic process of cold tolerance. Moreover, 13 °C is the cold tolerance threshold temperature and the prepupal stage is a critical developmental period for in vitro reared T. dendrolimi. These findings identify a low cost, prolonged development rearing method, and the cold tolerance for T. dendrolimi, which will facilitate improved mass rearing methods for biocontrol.

Flower cold hardiness: a potential determinant of the flowering sequence exhibited by bog ericads

1979 ◽  
Vol 57 (9) ◽  
pp. 997-999 ◽  
Author(s):  
R. J. Reader
Keyword(s):  
Low Temperatures ◽  
Cold Hardiness ◽  
Vaccinium Macrocarpon ◽  
Southern Ontario ◽  
Air Temperatures ◽  
Insect Pollinators ◽  
Cold Hardy ◽  
Vaccinium Myrtilloides ◽  
Potential Determinant ◽  
Ledum Groenlandicum

In laboratory freezing trials, cold hardiness of six types of bog ericad flowers differed significantly (i.e., Chamaedaphne calyculata > Andromeda glaucophylla > Kalmia polifolia > Vaccinium myrtilloides > Ledum groenlandicum > Vaccinium macrocarpon) at air temperatures between −4 and −10 °C but not at temperatures above −2 °C. At the Luther Marsh bog in southern Ontario, low temperatures (−3 to −7 °C) would select against May flowering by the least cold hardy ericads. Availability of pollinators, on the other hand, would encourage May flowering by the most cold hardy species. Presumably, competition for insect pollinators has promoted the diversification of bog ericad flowering peaks, while air temperature, in conjunction with flower cold hardiness, determined the order in which flowering peaks were reached.

Cold-Hardiness, Habitat and Winter Survival of Some Orchard Arthropods in Nova Scotia

1964 ◽  
Vol 96 (4) ◽  
pp. 617-625 ◽  
Author(s):  
A. W. MacPhee
Keyword(s):  
Nova Scotia ◽  
Air Temperature ◽  
Low Temperatures ◽  
Cold Hardiness ◽  
Winter Survival ◽  
Kings County ◽  
Winter Conditions ◽  
Cold Hardy

AbstractIn Kings County, Nova Scotia, low temperatures in the coldest nights of winter can differ by as much as 10°F. from one area to another. This has an important bearing on winter survival of some arthropods. Overwintering sites of orchard arthropods range from exposed situations which remain at air temperature to well protected ones on the ground where temperatures rarely go below 20°F. The cold-hardiness of each of 24 species of arthropods was measured: seven were sufficiently cold-hardy to survive any winter conditions in Nova Scotia, five were less cold-hardy but overwinter in well protected sites and twelve had marginal cold-hardiness, their mortality varying with the winter and the locality.

Molecular coding of olfactory specificity

1975 ◽  
Vol 53 (9) ◽  
pp. 1247-1253 ◽  
Author(s):  
R. H. Wright ◽  
R. E. Burgess
Keyword(s):  
Organic Compounds ◽  
Molecular Basis ◽  
Insect Pests ◽  
Low Frequency ◽  
Olfactory Stimulation ◽  
Primary Process ◽  
Vibrational Modes ◽  
Physiological Mechanisms ◽  
Practical Applications

An analysis of the low-frequency vibrational modes of organic compounds in 19 odor categories indicates that the primary process of olfactory stimulation is common to both vertebrates and insects. Understanding the molecular basis of olfactory specificity may provide a clue to the physiological mechanisms and has immediate practical applications in the control of insect pests.

Parasites and low temperatures

Parasitology ◽  
1999 ◽  
Vol 119 (S1) ◽  
pp. S7-S17 ◽  
Author(s):  
D. A. Wharton
Keyword(s):  
Life Cycle ◽  
Cold Tolerance ◽  
Low Temperatures ◽  
Cold Hardiness ◽  
Free Living ◽  
Rate Of Growth ◽  
Subzero Temperatures ◽  
Growth Development ◽  
Epidemiological Significance

SUMMARYLow temperatures affect the rate of growth, development and metabolism of parasites and when temperatures fall below 0°C may expose the parasite to the potentially lethal risk of freezing. Some parasites have mechanisms, such as diapause, which synchronise their life cycle with favourable seasons and the availability of hosts. Parasites of endothermic hosts are protected from low temperatures by the thermoregulatory abilities of their host. Free-living and off-host stages, however, may be exposed to subzero temperatures and both freezing-tolerant and freeze-avoiding strategies of cold hardiness are found. Parasites of ectothermic hosts may be exposed to subzero temperatures within their hosts. They can rely on the cold tolerance adaptations of their host or they may develop their own mechanisms. Exposure to low temperatures may occur within the carcass of the host and this may be of epidemiological significance if the parasite can be transmitted via the consumption of the carcass.

Nonparallel Geographic Patterns for Tolerance to Cold and Desiccation in Drosophila-Melanogaster and Drosophila-Simulans

1990 ◽  
Vol 38 (2) ◽  
pp. 155 ◽  
Author(s):  
JK Davidson
Keyword(s):  
Cold Tolerance ◽  
Desiccation Tolerance ◽  
A Priori ◽  
Strong Association ◽  
Temperate Climate ◽  
Physiological Mechanisms ◽  
Parallel Patterns ◽  
Climatic Extremes ◽  
Geographic Patterns ◽  
The Tropics

D. melanogaster populations from the fluctuating temperate climate of Melbourne (38�S) and in the tropics at Townsville (19�S) were investigated for differentiation in cold tolerance and desiccation tolerance, and were found to differ as predicted a priori from climatic considerations. Flies from the former locality were more tolerant to both of these environmental stresses. In comparable D. simulans populations, there was no significant differentiation between populations for cold tolerance or desiccation tolerance. In both species, there was genetic variation within each population. It is hypothesised that the non-parallel patterns in these sibling species may be due to different genetic strategies in temporal variation for tolerance to the stresses associated with climatic extremes. For D. melanogaster and D. simulans, there was no strong association between cold tolerance and desiccation tolerance in either the Melbourne and Townsville populations. Correlations between the stresses over the 15 strains were calculated for the sexes, generations, localities and species separately and were all non-significant. Cold tolerance and desiccation tolerance thus involve different physiological mechanisms.

POPULATION DENSITY AND SEX RATIO DYNAMICS OF OVERWINTERING MAIZE WEEVILS (COLEOPTERA: CURCULIONIDAE) INFESTING FIELD CORN

1986 ◽  
Vol 21 (4) ◽  
pp. 368-375 ◽  
Author(s):  
D. E. Dix ◽  
J. N. All
Keyword(s):  
Population Density ◽  
Sex Ratio ◽  
Cold Tolerance ◽  
Sitophilus Zeamais ◽  
Winter Mortality ◽  
Weather Extremes ◽  
Maize Weevil ◽  
Monthly Basis ◽  
Field Corn ◽  
Cold Hardy

Natural infestations of the maize weevil, Sitophilus zeamais (Motschulsky) were monitored in selected corn fields located in each of five major climatic or edaphic environments of Georgia. The population density and sex ratio of each population was recorded on a monthly basis during the fall and winters of 1982–83–84. Females suffered higher winter mortality than males, resulting in increasingly male-skewed sex ratios (from 0.8/1.0 to 1.6/1.0) as winter progressed. The degree of male-skewedness was positively correlated with the amount of subzero weather experienced by each population. Surviving weevil populations decreased in size as winter progressed, with the greatest reductions at the higher latitudes. No weevils survived through spring north of 33° 57′N where winter weather extremes of −15°C occurred. No true diapausing stage was found; however, cold tolerance tests indicated that winter-collected weevils were significantly more cold hardy than laboratory-reared weevils.

Association of qLTG3-1 with germination stage cold tolerance in diverse rice germplasm from the Indian subcontinent

2013 ◽  
Vol 11 (3) ◽  
pp. 206-211 ◽  
Author(s):  
Clarissa Challam ◽  
Gayle Alisha Kharshing ◽  
Julia S. Yumnam ◽  
Mayank Rai ◽  
Wricha Tyagi
Keyword(s):  
Low Temperature ◽  
Cold Stress ◽  
Cold Tolerance ◽  
Indian Subcontinent ◽  
Crop Productivity ◽  
Climatic Conditions ◽  
Superior Performance ◽  
Rice Germplasm ◽  
Potential Marker ◽  
Rice Genotypes

Low temperature is a major constraint for crop productivity. To cope with this challenge, plants have developed several mechanisms to adapt to low temperature. Developing breeding strategies to enhance cold stress tolerance in crops requires an understanding of the mechanisms by which plants perceive and transmit cold stress-related signals to their cellular machinery, thereby activating adaptive responses. Only one quantitative trait locus for tolerance to low-temperature germination, qLTG3-1, has been narrowed down to the gene level in rice. A 71 bp indel that can be used to distinguish between tolerant and susceptible parents has been identified. We tested the 71 bp indel on 65 diverse rice genotypes including those adapted to colder climates of North and Northeastern India to find evidence of the tolerant allele (insertion) and to see whether it is associated with low-temperature germinability in these genotypes. Our results show that 48% of the rice genotypes tested carried the tolerant allele. The insertion was found to be significantly associated with cold tolerance during germination. Moreover, several landraces/improved varieties known for their superior performance in other abiotic stress conditions such as drought and high salinity conditions, and which were previously never exposed to low temperature, carry the beneficial allele for qLTG3-1, suggesting an additional role of this allele in adverse climatic conditions. This study enhances current understanding of the distribution of the tolerant allele qLTG3-1 in rice germplasm, which could help in the identification of suitable donors for potential marker-assisted breeding programmes.

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