Influence of soil hydric parameters on the winter cold hardiness of a burrowing beetle, Leptinotarsa decemlineata (Say) |
| |
Authors: | J P Costanzo J B Moore R E Lee Jr P E Kaufman J A Wyman |
| |
Institution: | (1) Department of Zoology, Miami University, Oxford, OH 45056, USA, Tel.: +1-513/529-3173, Fax: +1-513/529-6900, e-mail: costanzo@msmail.muohio.edu, US;(2) Department of Entomology, University of Wisconsin-Madison, Madison, WI 53706, USA, US |
| |
Abstract: | This investigation examined the influence of soil moisture and associated parameters on the cold hardiness of the Colorado
potato beetle (Leptinotarsa decemlineata Say), a temperate-zone species that overwinters in terrestrial burrows. The body mass and water content of adult beetles
kept in sand at 4 °C varied over a 16-week period of diapause according to the substratum's moisture content. Changes in body
water content, in turn, influenced the crystallization temperature (range −3.3 to −18.4 °C; n = 417), indicating that environmental moisture indirectly determined supercooling capacity, a measure of physiological cold
hardiness. Beetles held in dry sand readily tolerated a 24-h exposure to temperatures ranging from 0° to −5 °C, but those
chilled in sand containing as little as 1.7% water (dry mass) had elevated mortality. Thus, burrowing in dry soils not only
promotes supercooling via its effect on water balance, but may also inhibit inoculative freezing. Mortality of beetles exposed
to −5 °C for 24 h was lower in substrates composed of sand, clay and/or peat (36–52%) than in pure silica sand (78%) having
an identical water content (17.0% dry mass). In addition to moisture, the texture, structure, water potential, and other physico-chemical
attributes of soil may strongly influence the cold hardiness and overwintering survival of burrowing insects.
Accepted: 10 September 1996 |
| |
Keywords: | Cold hardiness Inoculative freezing Insect overwintering Microenvironment Moisture relations |
本文献已被 SpringerLink 等数据库收录! |
|