THE POTENTIAL FOR ESTABLISHMENT OF THE EGG PARASITE OOENCYRTUS KUWANAI IN ONTARIO POPULATIONS OF THE GYPSY MOTH

1978 ◽  
Vol 110 (6) ◽  
pp. 633-638 ◽  
Author(s):  
K.J. Griffiths ◽  
C.R. Sullivan

AbstractThe overwintering adult of Ooencyrtus kuwanai (How.) is susceptible to freezing. Male adults from New Jersey have a mean supercooling point of −9.6 ± 0.37°C, significantly higher than those from Maine (−12.3 ± 1.08°). Neither group had its cold hardiness increased by exposure to sublethal temperatures. Female adults from New Jersey had a mean supercooling point of −10.8 ± 0.69° when tested after rearing at 22°C, again significantly higher than that of similarly treated female adults from Maine (−15.4 ± 0.90°). Exposure of New Jersey females to sublethal temperatures decreased their supercooling point significantly, to −14.5 ± 1.59°. Maine female adults were not tested after that treatment. No adults survived continuous exposure to 0°C for 30 days. Hence this parasite is apparently incapable of surviving in the current range of the gypsy moth in Canada.

1977 ◽  
Vol 109 (2) ◽  
pp. 215-220 ◽  
Author(s):  
C. R. Sullivan ◽  
K. J. Griffiths ◽  
D. R. Wallace

AbstractThe overwintering mature larva of the parasite Anastatus disparis Ruschka within the intact gypsy moth, Lymantria (= Porthetria) dispar L., egg chorion is susceptible to freezing and has a mean supercooling point of −28.8±0.14°C. This level of cold hardiness is not increased by exposure to sublethal low temperatures. Over 85% of larvae survived 10 months at 0°C and 4 days at −12° or −18°C, both followed by an additional 2–3 months at 0°C, but over half of the survivors went into prolonged diapause which was not fulfilled by subsequent rearing at room temperature. The parasite is apparently capable of surviving winter conditions over the same geographic area in Canada as the gypsy moth, and the introduction of A. disparts into locations in Canada where gypsy moth is now present is recommended.


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.


Entomophaga ◽  
1993 ◽  
Vol 38 (2) ◽  
pp. 257-266 ◽  
Author(s):  
D. W. Williams ◽  
R. W. Fuester ◽  
W. W. Metterhouse ◽  
R. J. Balaam ◽  
R. H. Bullock ◽  
...  

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.


1994 ◽  
Vol 4 (1) ◽  
pp. 34-40 ◽  
Author(s):  
Kenneth R. Tourjee ◽  
James Harding ◽  
Thomas G. Byrne

The development of gerbera (Gerbera jamesonii H. Bolus ex. Hooker) as a floricultural crop is traced from its collection as a botanical novelty in South Africa to its establishment as a commercial crop in the 1930s. The origin of the cultivated germplasm, G. jamesonii and G. viridifolia (DC) Schultz- Bipontinus, is discussed, as well as breeding work that occurred in Europe and the United States. The contributions of the two species to the cultivated germplasm is unknown. Early breeding in Europe was conducted by RI. Lynch at the Cambridge Botanic Gardens in England, R. Adnet at La Rosarie in Antibes, France; and by C. Sprenger in Italy. In the United States, early work was done at estates in New Jersey by Herrington and Atkins, and by the commercial growers Jaenicke and the J.L. Childs' Seed Co. Establishing the cold hardiness of the crop for temperate climates was an early goal of horticulturists and breeders. Much of the cultivated germplasm can be traced to material that passed through Cambridge and Antibes.


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.


PLoS ONE ◽  
2014 ◽  
Vol 9 (8) ◽  
pp. e102531 ◽  
Author(s):  
Alec M. Kretchun ◽  
Robert M. Scheller ◽  
Melissa S. Lucash ◽  
Kenneth L. Clark ◽  
John Hom ◽  
...  

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.


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