SURVIVAL OF PUPAE OF HELIOTHIS VIRESCENS AND HELIOTHIS ZEA (LEPIDOPTERA: NOCTUIDAE) AT LOW TEMPERATURES

1982 ◽  
Vol 114 (4) ◽  
pp. 289-301 ◽  
Author(s):  
Joseph E. Eger ◽  
John A. Witz ◽  
Albert W. Hartstack ◽  
Winfield L. Sterling
Keyword(s):  
Low Temperature ◽  
Exposure Time ◽  
Predictive Models ◽  
Low Temperatures ◽  
Heliothis Virescens ◽  
Cold Hardiness ◽  
Heliothis Zea ◽  
Geographic Locations ◽  
Lepidoptera Noctuidae

AbstractMortality of diapausing and non-diapausing pupae of Heliothis virescens (Fabricius) and H. zea (Boddie) at low temperatures was assessed in the laboratory. Comparison of the exposure time necessary to induce 50% mortality (LT50) indicated that survival of diapausing pupae was significantly higher than that of non-diapausing pupae. Similar comparisons showed no consistent significant differences in mortality of pupae from different geographic locations within Texas or in pupae preconditioned in several different ways. One exception was the response of pupae of H. virescens preconditioned to varying temperatures. This type of preconditioning appeared to increase the cold-hardiness of pupae at subfreezing temperatures. Contact moisture significantly decreased LT50 values of pupae of both species at sub-zero temperatures. Predictive models for low temperature mortality were developed for dry, diapausing pupae.

COMPARATIVE RESPONSES OF FERAL AND LABORATORY TRICHOGRAMMA SPP. (HYMENOPTERA: TRICHOGRAMMATIDAE) TO HELIOTHIS SPP. (LEPIDOPTERA: NOCTUIDAE) MOTH SCALES AND INERT PARTICLES

1988 ◽  
Vol 23 (3) ◽  
pp. 245-250 ◽  
Author(s):  
M. S. Thomson ◽  
R. E. Stinner
Keyword(s):  
Heliothis Virescens ◽  
Heliothis Zea ◽  
Physiological Status ◽  
Naturally Occurring ◽  
Scale Response ◽  
Small Glass ◽  
Heliothis Spp ◽  
Moth Scales ◽  
Lepidoptera Noctuidae ◽  
Laboratory Assay

A laboratory assay of the klinokinetic response of Trichogramma spp. to scales of Heliothis virescens (F.) and Heliothis zea (Boddie) was investigated. The assay indicated significant behavioral response to materials similar in size to lepidopteran scales (small glass beads, cotton fibers); however, response to these materials was significantly less than response to H. virescens scales. The assay did not distinguish any difference in response to H. zea scales betewen naturally occurring and laboratory-bred Trichogramma exiguum Pinto and Platner. Physiological status (freshly emerged, virgin vs. 3–4 day-old, mated) of the H. zea moths from which scales originated affected scale response, but anatomical origin (abdominal tip vs. abdominal venter vs. wing) of host scales did not.

scholarly journals The Interaction of Photoperiod and Temperature on Cold Hardiness and the Accumulation of Soluble Sugars in Two Cultivars of Southern Magnolia (Magnolia grandiflora L.)

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 848F-848
Author(s):  
C.L. Haynes ◽  
O.M. Lindstrom ◽  
M.A. Dirr
Keyword(s):  
Low Temperature ◽  
Cold Acclimation ◽  
Low Temperatures ◽  
Cold Hardiness ◽  
Sugar Content ◽  
Soluble Sugar ◽  
Soluble Sugars ◽  
Total Soluble Sugars ◽  
Magnolia Grandiflora ◽  
Temperature Interaction

Decreasing photoperiods and decreasing temperatures induce cold acclimation and the accumulation of soluble sugars in many plants. Two cultivars of southern magnolia differing in cold hardiness and acclimation patterns, were monitored to determine photoperiod × temperature interaction on cold hardiness and soluble sugar content. Cold hardiness increased with low temperatures and short photoperiods. Total soluble sugars, sucrose, and raffinose consistently increased in the leaves and stems of both cultivars in response primarily to low temperature. `Little Gem' was less responsive to photoperiod than `Claudia Wannamaker'

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