Seasonal adaptations of the fall webworm Hyphantria cunea (Drury) (Lepidoptera: Arctiidae) following its invasion of Japan

Abstract

The fall webworm, Hyphantria cunea (Drury) (Lepidoptera: Arctiidae), invaded Japan from North America about 60 years ago. Immediately after its invasion -and for the first three decades -its life cycle was bivoltine, two generations per year throughout its entire distribution in Japan. Thereafter, its life cycle shifted to trivoltine in the southwestern areas of Japan. In the present study we examined the life-history traits proposed to be implicated in this event with the aim of clarifying the mechanism of this life-cycle shift. The critical photoperiod for diapause induction, as defined by the photoperiod at which 50% of individuals enter diapause, was shorter in the trivoltine populations than in their bivoltine counterparts. The temperature sensitivity of the photoperiodic response, as defined by the difference in the critical photoperiod between 20 and 25°C, was greater in the trivoltine populations than in the bivoltine ones. The geographic variation in larval and pupal periods was positively correlated to the latitude of the original localities of the populations. The change in the number of larval instars would be one of the main factors accounting for the regional differences in the developmental period. These results suggest that some life-history traits of H. cunea have changed following its invasion of Japan as an adaptive response to local climates.

Population dependent effects of photoperiod on diapause related physiological traits in an invasive beetle (Leptinotarsa decemlineata)

“…While there are some examples of rapid photoperiodic adaptation (e.g. , Gomi 2007, Dalin et al 2010, Urbanski et al 2012, the actual molecular and physiological mechanisms of photoperiodic adaptation are still largely unclear (Bradshaw & Holzapfel 2007, Kostal 2011). There is a demand for more research in this area since it is becoming increasingly clear that photoperiodic adaptation is an important driver during range expansion since it allows species to re-synchronize lifehistory and stress tolerance related traits with novel phenology (Tauber et al 1986, Nelson et al 2010.…”

Northerly shift in voltinism watershed in Hyphantria cunea (Drury) (Lepidoptera: Arctiidae) along the Japan Sea coast: Evidence of global warming?

“…and Liquidambar styraciflua L. in 2006 and2007 in Takaoka (36°45ЈN, 137°01ЈE) and in 2007 and2008 in Kanazawa (36°34ЈN, 136°39ЈE). The collection sites were the same in both years in each city.…”

“…The northern limit of the trivoltine area lies in localities at around 36°N (Gomi, 1996a(Gomi, , 1997(Gomi, , 2000. Some life-history traits differ between bivoltine and trivoltine populations (Gomi, 1996b(Gomi, , 1997(Gomi, , 2007Gomi and Takeda, 1996). These shifts in the life cycle and life-history traits have occurred in relation to expansion of the distribution range in Japan.…”

Review of forests, wood products and wood biotechnology of Iran and Germany - Part III

“…The more invasive black-headed species is the one that has spread through central Europe, eastern Asia, New Zealand, and Japan (Kean & Kumarasinghe, 2007). In the last country bivoltine and trivoltine populations of the blackheaded race were described (Gomi, 2007). …”

“…In Japan, a bivoltine life cycle prevailed throughout the distribution area, but trivoltine populations are recoded in the south-western areas (Masaki, 1975;Gomi, 2007). In central Europe there are usually two generations per year as well as in the Iranian Caspian areas (Rezaei et al, 2006).…”