Study on the physiology of diapause, cold hardiness and supercooling point of overwintering pupae of the pistachio fruit hull borer, Arimania comaroffi

2012 ◽  
Vol 58 (7) ◽  
pp. 897-902 ◽  
Author(s):  
Marjan Bemani ◽  
Hamzeh Izadi ◽  
Kamran Mahdian ◽  
Abbas Khani ◽  
Mohammad Amin samih
1974 ◽  
Vol 52 (5) ◽  
pp. 629-637 ◽  
Author(s):  
Ajai Mansingh

Studies were conducted on the relationship between levels of glycerol and carbohydrates, supercooling points, and the relative abilities of diapausing and developing eggs and of larval instars of Malacosoma americanum to withstand various periods of chilling at 5° and −15 °C.Diapause in the mature embryos was associated with very high glycerol content (112 mg/g), low carbohydrate level (13 mg/g), and the ability to supercool to −35 °C. During diapause termination, the glycerol level was reduced lo 11 mg/g with a slight rise only in carbohydrate level while the supercooling point was raised to −14 °C. When quiescence was induced in the larvae by chilling them at 5 °C for 1 to 7 weeks, their wet weights and carbohydrate and glycerol contents decreased gradually. However, the supercooling point remained constant around −14 °C.Diapausing embryos could survive several weeks of chilling at −15° and 5 °C. However, only a few weeks of exposure to 5 °C was fatal to quiescent larvae.It is concluded that there is a direct relationship between glycerol content, supercooling points, and the relative abilities of developing and diapausing stages of the tent caterpillar to withstand low temperatures. The developing stages were naturally "cold-tolerant" with the ability to supercool to −14 °C and survive a few weeks of quiescence at 5 °C, which is well below their range of physiological adaptation. Induction of diapause enhanced the supercooling ability and increased cold-hardiness in the mature embryos.


1993 ◽  
Vol 71 (4) ◽  
pp. 759-764 ◽  
Author(s):  
Thierry Hance ◽  
Guy Boivin

The cold hardiness of egg parasitoids is critical to their survival in winter because these organisms have little control in the choice of their overwintering site. The supercooling points of Listronotus oregonensis eggs increased from −24.9 to −22.1 °C as eggs matured. When these eggs were parasitized by Anaphes sp., their supercooling point remained stable at −22.9 °C throughout the development of the parasitoid. Anaphes sp. maintained its cold hardiness by increasing its levels of glycerol and fructose. When the parental generation was exposed to a combination of low temperature and short photoperiod, the supercooling point of the daughter generation (F1) was significantly decreased. A further decrease in the supercooling point was observed when F1 individuals were stored at 3 °C for 14 or 20 days. These data show that local extinction of populations overwintering in nonsheltered habitats is probably common in southwestern Quebec.


2015 ◽  
Author(s):  
Stefanos S Andreadis ◽  
Yianna Poulia ◽  
Sofia Noukari ◽  
Barbara Aslanidou ◽  
Matilda Savopoulou-Soultani

The potato tuberworm, Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae), is a worldwide pest of solanaceous crops especially devastating to potatoes. In the present study we investigated the cold hardiness profile of short-term acclimated and non-acclimated immature and adult stages of a field population of P. operculella. Late instars displayed the lowest mean supercooling point, for both short-term acclimated and non-acclimated individuals, however, no significant differences were observed among developmental stages. Unlike supercooling capacity, acclimation at 5 oC for 5 days enhanced the ability to survive at subzero temperatures after a 2 h exposure. Mean lethal temperature (LTemp50) of all developmental stages (egg, late instar, pupa and adult) decreased after short-term acclimation, however only adults displayed a significant difference among acclimated and non-acclimated individuals concerning their LTemp50 (-11.1 and -8.3 oC, respectively). Generally, pupae were the most cold tolerant developmental stage followed in decreasing order by the eggs and adults, while interestingly late instars were the least ones. Non-freezing injury above the supercooling point was well documented for all developmental stages indicating a pre-freeze mortality and suggesting that P. operculella is considered to be chill tolerant rather than freeze intolerant. Nevertheless, given its high degree of cold hardiness, winter mortality of P. operculella due to low temperatures is not likely to occur and potential pest outbreak can take place following a mild winter.


2020 ◽  
Vol 113 (3) ◽  
pp. 1254-1261
Author(s):  
Jiahe Pei ◽  
Chengcheng Li ◽  
Lili Ren ◽  
Shixiang Zong

Abstract Streltzoviella insularis (Staudinger) (Lepidoptera: Cossidae) is a woodboring pest that severely damages urban and plain afforestation trees in northern China. Cold hardiness is an important strategy for the insect to survived during low winter temperatures. Understanding the strategy of S. insularis might provide insights for pest management approaches. To assess the key factors affecting cold hardiness, we measured the supercooling point, freezing point, total water content, total fat content, glycogen content, and total protein content of overwintering larvae. The relationships between supercooling points, temperature, body size, and nutrients were analyzed. The results showed that the supercooling point and freezing point of the larvae decreased first, reached the lowest point in January, and then increased during the rest of the overwintering period. The supercooling point positively correlated with the daily average temperature and the daily minimum temperature. Total lipid content negatively correlated with the supercooling point, while glycogen content had a significant positive correlation with the supercooling point. The temperature may have a major impact on cold hardiness, whereas individual body size may have no significant influence over cold tolerance. During the overwintering process, glycogen and total lipid contents may directly affect cold hardiness. Therefore, the lipid and carbohydrate metabolism may play a role in the cold tolerance of S. insularis larvae. This study provides a physiological and biochemical basis for future metabolic studies on S. insularis larva and the research of overwintering strategies.


2012 ◽  
Vol 57 (1) ◽  
Author(s):  
Angela Ploomi ◽  
Irja Kivimägi ◽  
Eha Kruus ◽  
Ivar Sibul ◽  
Katrin Jõgar ◽  
...  

Abstract Cold-hardiness can be measured by supercooling points – the temperature at which spontaneous freezing occurs. Seasonal changes in supercooling point were assessed in field-collected predacious carabid beetle species: Carabus granulatus L., Pterostichus oblongopunctatus L. and Platynus assimilis Payk. (Coleoptera: Carabidae). Supercooling ability of these beetles changed seasonally. The tested carabid beetles proved to belong to freeze-avoiding cryotype.


1995 ◽  
Vol 127 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Paul Fields ◽  
Stéphan Pouleur ◽  
Claude Richard

AbstractCold treatment is used to control the rusty grain beetle (Cryptolestes ferrugineus) (Coleoptera: Cucujidae), the predominant insect pest of stored grain in Canada. However, because it is difficult to cool the grain enough to control C. ferrugineus quickly, we have examined ways to reduce the cold-tolerance of adult C. ferrugineus, the most cold-hardy stage. We compared the efficacy of two ice nucleators, Pseudomonas syringae and Fusarium avenaceum, to decrease cold-tolerance of this insect, as well as their thermal stability. Ice nuclei from the bacteria P. syringae raised C. ferrugineus supercooling point from −17 to −6 °C, and increased mortality at −9°C for 24 h from 11 to 100%. Pseudomonas syringae held at 30°C for 16 weeks showed only a slight decline in its ability to reduce C. ferrugineus cold-tolerance. The fungus F. avenaceum raised the supercooling point of C. ferrugineus from −17 to −9°C, but only increased the mortality at −9°C for 24 h from 10 to 33%. Wheat treated with F. avenaceum and held at 30°C for 4 weeks reduced the cold-hardiness of C. ferrugineus, but had no effect after 8 weeks at 30°C. One reason for the difference between the two nucleators is that P. syringae had approximately 1000 times more ice nuclei per gram than did F. avenaceum. These results suggest that P. syringae is stable enough to reduce C. ferrugineus cold-tolerance after several weeks on warm grain. We discuss possible ways to increase the ice-nucleating activity of F. avenaceum.


1990 ◽  
Vol 148 (1) ◽  
pp. 245-254 ◽  
Author(s):  
M. C. Czajka ◽  
R. E. Lee

In studies of insect cold-hardiness, the supercooling point (SCP) is defined as the temperature at which spontaneous nucleation of body fluids occurs. Despite having an SCP of −20 degrees C, adults of Drosophila melanogaster did not survive exposure to −5 degrees C, which suggests that cold shock causes lethal injury that is not associated with freezing. If, however, flies were chilled at 5 degrees C, for as little as 30 min, approximately 50% of the flies survived exposure to −5 degrees C for 2h. This capacity to cold-harden rapidly was greatest in 3- and 5-day-old adults. The rapid cold-hardening response was also observed in larvae and pupae: no larvae survived 2 h of exposure to −5 degrees C, whereas 63% pupariated if chilled at 5 degrees C before subzero exposure. Similarly, although exposure of pupae to −8 degrees C was lethal, if pre-chilled at 5 degrees C 22% eclosed. This extremely rapid cold-hardening response may function to allow insects to enhance cold-tolerance in response to diurnal or unexpected seasonal decreases in environmental temperature.


1990 ◽  
Vol 68 (5) ◽  
pp. 830-835 ◽  
Author(s):  
W. J. Turnock ◽  
P. M. Reader ◽  
G. K. Bracken

The Canadian population of Delia radicum is more cold hardy than the English population in that the supercooling point is slightly lower and overwintering pupae are less sensitive to lower temperatures and longer exposure times. However, the Canadian population is slightly less cold hardy at higher temperatures within the cold injury zone. Female D. radicum were more susceptible to cold-induced mortality than males among the Canadian population, but this sex difference was not significant in the English population. The proportion of malformed adults and the rate of postdiapause development were not related to cold injury in either population. The bounds of the cold injury zone for species or populations of freezing susceptible, diapausing insects plus the sensitivity of the species to cold injury within this zone can provide an ecologically sound method of describing cold hardiness. Sensitivity, measured by the slope of a regression describing the relationship between survival and the duration of exposure at a low temperature, can also be used to calculate the rate at which cold injury occurs at any temperature within the cold injury zone. This slope may reflect the overwintering conditions of a species or population because Canadian populations of both D. radicum and Mamestra configurata (Noctuidae) have similar coefficients, but these are very different from the coefficient of the English population of D. radicum. The supercooling point did not provide a useful indication of the susceptibility of these cold-hardy diapausing insects to cold injury.


1993 ◽  
Vol 71 (9) ◽  
pp. 1710-1714 ◽  
Author(s):  
W. J. Turnock

The pupae of Lacanobia atlantica (Grt.) overwinter in the soil and are susceptible to freezing. Cold injury and death occur at temperatures above the supercooling point (SCP) of −26.4 °C, and below ca. −12.6 °C. Mortality increases as temperature decreases and as exposure lengthens. These results are compared with those for Mamestra configurata Wlk., Delia radicum (L.), and Athrycia cinerea Coq., which have similar overwintering habits. Their mean SCPs (−27.3 to −20.3 °C) differ less than do the values representing the highest temperature at which cold injury occurs (≈−12.6 to ≈4 °C). Response curves of three of the species were similar for changes in temperature and duration of exposure, and similarly in a plot of the time to 50% survival (LT50) against temperature. They differed only in their relative cold-hardiness. In contrast, A. cinerea was less sensitive to changes in temperature and duration of exposure. A single parameter (e.g., the mean SCP) is not adequate to describe the cold-hardiness of these species because they vary not only in the upper and lower bounds of their cold-injury zones but also in their response to temperature and duration of exposure within this zone.


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