Diapause response of Lygus hesperus (Hemiptera: Miridae) at different temperatures

Authors: Spurgeon, Dale

Submitted to: Journal of Entomological Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/16/2019
Publication Date: 1/3/2020
Citation: Spurgeon, D.W. 2020. Diapause response of Lygus hesperus (Hemiptera: Miridae) at different temperatures. Journal of Entomological Science. 55(1):126-129. https://doi.org/10.18474/0749-8004-55.1.126.
DOI: https://doi.org/10.18474/0749-8004-55.1.126

Interpretive Summary: The western tarnished plant bug (Lygus) is an important pest of many crops in the western U.S. This pest is known to survive the initial portion of the non-cropping winter period as adults in a short-duration dormancy known as diapause. This dormancy is induced by exposure of the insects to short day lengths. A previous report indicated the incidence of diapause was not enhanced by low temperatures, but the diapause response was diminished by high temperatures. However, the influence of temperature was examined using a day length that was shorter than that required for the maximal diapause response. When Lygus were reared from egg to adulthood under a 12-h day length at three temperatures (70, 80, and 85 degrees F), rearing temperature failed to markedly influence the diapause response. The observed incidences of diapause were less than the estimated maximum for this population of Lygus, therefore the day length used was not so short as to preclude a response to temperature. These results indicate the diapause response of Lygus is largely temperature-insensitive over the range of conditions typical of early- to late-fall in Central Arizona.

Technical Abstract: The western tarnished plant bug, Lygus hesperus Knight, is an important pest of many crops in the western U.S. This pest is known to survive the initial portion of the non-cropping winter period as adults in a relatively short diapause. A previous report indicated the incidence of diapause was not enhanced by low temperatures, but the diapause response was diminished by high temperatures. However, the influence of temperature was examined at a photophase that was shorter than that required for the maximal diapause response. When L. hesperus were reared from egg to adulthood under a 12:12 (L:D) h photoperiod at three temperatures (21.1, 26.7, and 29.4 degrees C), rearing temperature failed to markedly influence the diapause response. The observed incidences of diapause were less than the estimated maximum for this population of L. hesperus, therefore the photophase used was not so short as to preclude a response to temperature. These results indicate the photoperiodic diapause response of L. hesperus is largely temperature-insensitive over the range of thermal conditions typical of early- to late-fall in Central Arizona.