A Mechanism for the Decrease in Developmental Period of a Trivoltine Population of Hyphantria cunea (Lepidoptera: Arctiidae)

概要

論文の詳細を見る
The life cycle of the fall webworm, Hyphantria cunea, has differentiated from bivoltine to trivoltine since the early 1970's in the southwestern areas of Japan. Previous studies showed differentiation in developmental period as well: development was shorter in the trivoltine populations. In the present study, the precise mechanisms of this change were investigated by comparing developmental characteristics between bivoltine (Akita) and trivoltine (Urawa) populations. The theoretical lower threshold temperatures for larval and pupal development were not different between the two populations. The thermal constant for larval development was smaller in the trivoltine population than in the bivoltine population, but that for pupal development was almost identical for the two populations. Most individuals passed six larval instars, and some passed seven in both populations. The incidence of seven-instar larvae was significantly higher in the bivoltine population than in the trivoltine population. The larval period was significantly longer in the seven-instar type than in the six-instar type. Larvae of the six-instar type grew at similar rates in the two populations. Head width of last instar larvae was larger in the seven-instar type than in the six-instar type, but pupal weight was not statistically different between the two types. These results suggest that the reduction in developmental period in the trivoltine population can be attributed to a reduction in the thermal constant, especially than during the larval stage. A lower incidence of seven-instar larvae appears to be the major mechanism for reducing the thermal constant in the trivoltine population.
日本応用動物昆虫学会の論文
1996-05-25

A Mechanism for the Decrease in Developmental Period of a Trivoltine Population of Hyphantria cunea (Lepidoptera: Arctiidae)

スポンサーリンク

概要

著者

関連論文

スポンサーリンク