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022			_a0022-0493
022			_a1938-291X (Online)
024			_2https://doi.org/10.1093/jee/49.1.19
040			_aMX-TxCIM
041			_aeng
090			_aREP-722
100	1		_aBarnes, D. _99876
245	1	0	_aLow temperature tolerance of the European corn borer in relation to winter survival in Minnesota
260			_c1956. _aUnited Kingdom : _bOxford University Press,
340			_aPrinted
500			_aPeer-review: Yes - Open Access: Yes|http://science.thomsonreuters.com/cgi-bin/jrnlst/jlresults.cgi?PC=MASTER&ISSN=0022-0493
520			_aSince the European corn borer has moved rapidly northward from population centers to the south and east into all the corn-producing areas of Minnesota, the effect of winter temperatures in that state on the ability of the borer to continue to survive and to maintain a population level of economic importance has been questioned. One may postulate that the corn borer has become established in the newly invaded areas either because the hibernating larvae are well protected from severe cold by insulation, or because they are sufficiently cold-hardy to withstand the low temperatures of Minnesota winters even in unprotected situations. It has been established by field surveys that there is usually a good survival over winter, even above the snow, in standing corn stalks. However, in the spring of 1948 a high percentage of the borers in the stalks were dead. Thus, we are certain that under some conditions a large proportion of the larvae are unable to overwinter successfully in Minnesota. Insects may be classified into four general categories on the basis of their tolerance to cold. These are: 1) insects which are able to survive freezing and are killed only by long exposure to low temperatures or by one or more sudden changes in temperature; 2) insects that can remain dormant in an undercooled state but do not survive freezing at temperatures below the undercooling point; 3) insects which exhibit very little undereooling and are killed by temperatures near the true freezing point; 4) non-hardy, non-hibernating insects killed by temperatures above freezing. The purpose of this study is to determine whieh of the above categories characterizes the corn borer and consequently the nature of the cold hardiness of this species; and further, to establish the time during the dormant period when natural mortality is most likely to occur. Most of the emphasis has been placed on a study of the importance of the "intensity factor of cold" as indicated by determining the undercooling point and freezing of larvae collected periodically from the field, and of larvae exposed to experimental conditions in the laboratory. Dittman (1943), states that the undercooling of living insects behaves in the same manner as water in a finely divided state. Water particles in this condition, in the absence of ice crystals or other solid particles that may act as nuclei for crystallization in the absence of shock or movement, may be undercooled to a considerable degree.
546			_aText in English
595			_aRPC
650		7	_2AGROVOC _915734 _aCold
650		7	_2AGROVOC _91173 _aMaize
650		7	_2AGROVOC _95800 _aInsecta
651		7	_2AGROVOC _930554 _aMinnesota
700	1		_aHodson, A.C. _930555
773	0		_tJournal of Economic Entomology _gv. 49, no. 1, p. 19-24 _dProlessor 01 Entomology, University of Minnesota, 1956. _wG444522 _x0022-0493
942			_cJA _2ddc
999			_c21117 _d21117