In:
Applied and Environmental Microbiology, American Society for Microbiology, Vol. 58, No. 9 ( 1992-09), p. 2711-2716
Abstract:
The majority of overwintering insects avoid lethal freezing by lowering the temperature at which ice spontaneously nucleates within their body fluids. We examined the effect of ice-nucleating-active bacteria on the cold-hardiness of the lady beetle, Hippodamia convergens , a freeze-intolerant species that overwinters by supercooling to ca. −16°C. Topical application of the ice-nucleating-active bacteria Pseudomonas syringae increased the supercooling point to temperatures as high as −3°C. This decrease in cold tolerance was maintained for at least 3 days after treatment. Various treatment doses (10 8 , 10 6 , and 10 4 bacteria per ml) and modes of action (bacterial ingestion and topical application) were also compared. At the highest concentration of topically applied P. syringae , 50% of the beetles froze between −2 and −4°C. After topical application at the lowest concentration, 50% of the individuals froze by −11°C. In contrast, beetles fed bacteria at this concentration did not begin to freeze until −10°C, and 50% were frozen only at temperatures of −13°C or less. In addition to reducing the supercooling capacity in H. convergens , ice-nucleating-active bacteria also significantly reduced the cold-hardiness of four additional insects. These data demonstrate that ice-nucleating-active bacteria can be used to elevate the supercooling point and thereby decrease insect cold tolerance. The results of this study support the proposition that ice-nucleating-active bacteria may be used as a biological insecticide for the control of insect pests during the winter.
Type of Medium:
Online Resource
ISSN:
0099-2240
,
1098-5336
DOI:
10.1128/aem.58.9.2711-2716.1992
Language:
English
Publisher:
American Society for Microbiology
Publication Date:
1992
detail.hit.zdb_id:
223011-2
detail.hit.zdb_id:
1478346-0
SSG:
12
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