Microhabitat Variation in Egg Diapause Incidence in Summer Within a Local Population: An Adaptation to Decline in Host-Plant Suitability in Trigonotylus caelestialium (Hemiptera: Miridae)
| Autor: | Keisuke Nagamine, Yoshinori Shintani |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
Poales Photoperiod Zoology Diapause Diapause Insect 01 natural sciences Animals Poaceae Ecology Evolution Behavior and Systematics Ovum photoperiodism Ecology biology Host (biology) Incidence Voltinism food and beverages biology.organism_classification Miridae 010601 ecology 010602 entomology Alopecurus aequalis Insect Science Female Seasons |
| Zdroj: | Environmental Entomology. 49:912-917 |
| ISSN: | 1938-2936 0046-225X |
| Popis: | Diapause induction in multivoltine insects is an ecophysiological event that is generally triggered by seasonal cues such as photoperiod and temperature. The rice leaf bug, Trigonotylus caelestialium (Kirkaldy), feeds on various Poaceae grasses and produces several generations a year. Previous studies have shown that adults produce diapause and nondiapause eggs under short-day and long-day conditions, respectively. However, there is a distinct mid-summer peak in diapause incidence before an autumnal increase in diapause incidence in the field, which cannot be explained by the laboratory results. The present study was performed to examine the environmental factors affecting the diapause incidence in mid-summer and the adaptive significance of this phenomenon. Seasonal trends in diapause incidence differed significantly among three sites located 150–400 m apart from each other and with different host plants. The suitability of host plants differs depending on species and seasonally. Therefore, the microhabitat difference in diapause trend is believed to be due to the difference in host plants. When field-collected female adults laying diapause eggs in late June were fed a seasonally deteriorating host (the orange foxtail, Alopecurus aequalis Sobol. [Poales: Poaceae]), they kept laying diapause eggs, whereas when fed a suitable host (the wheat, Triticum aestivum L. [Poales: Poaceae]) for 5 d, they changed oviposition mode to lay nondiapause eggs. These results indicate that host-plant suitability affects the oviposition mode of T. caelestialium. Diapause-egg oviposition in mid-summer in T. caelestialium has adaptive significance as a bet-hedging strategy against unpredictable dietary conditions. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|