Effects of photoperiod and temperature on adult oligopause of Aphelinus asychis and larval diapause of A. albipodus (Hymenoptera: Aphelinidae)

Abstract

The effects of photoperiod and temperature on the dormancy of two aphid parasitoids in Japan, Aphelinus asychis and A. albipodus, were studied in the laboratory. Adult (reproductive) dormancy was induced in A. asychis under 10L : 14D at moderate temperatures and under 15L : 9D at low temperatures. Dormant adults started oviposition 6-17 d after emergence under 10L : 14D at 15 and 18°C. Transferring newly emerged adults from 10L : 14D at 15 and 18°C to 15L : 9D at 20°C caused an apparent reversal of dormancy induction within 1-2 d. It was believed that adult dormancy in A. asychis conforms to "oligopause" rather than "diapause" sensu Mansingh (1971). Adults of A. asychis showed an apparent variation in abdominal coloration from yellowish brown to black. The proportion of females with dark abdominal coloration was higher under 10L : 14D than under 15L : 9D and high at lower temperatures. We regarded this polyphenism as a part of the "diapause syndrome" because oligopause and abdominal coloration were controlled by the same environmental factors. Aphelinus albipodus entered diapause as last instar larvae. The critical photoperiod for diapause induction was 11-12 h at 18°C, and diapause was terminated within six weeks by cold treatment (10L : 14D, 5°C).

Development and Parasitism byAphelinus certus(Hymenoptera: Aphelinidae), a Parasitoid ofAphis glycines(Hemiptera: Aphididae)

“…Other Aphelinus spp. overwinter as lastinstar larvae (Bernal et al 2001, Tatsumi andTakada 2005), within mummies (Prinsloo and du Plessis 2000), or as free living adults (Hamilton 1973). Overwintering strategy affects the ability of the parasitoid to develop early in the season.…”

The Effect of Temperatures on the Biological Characteristics of Two Aphid Parasitoids Aphelinus asychis (Walker) and Aphelinus varipes (Förster) (Hymenoptera: Aphelinidae) on Two Aphid Hosts

“…진딧물 방제에 있어 농약의 저항성 및 교차저항성의 발달 (Song et al, 1993;Song and Motoyama, 1996;Choi et al, 2001;Seo et al, 2008 and (Elliott et al, 1999), 기주곤충에 따른 생물학적 특성 조사를 통한 방제인자로서의 가능성 탐색 (Tatsumi and Takada, 2005a), 기능반응연구 (Byeon et al, 2011), 콩진딧물(Acyrthosiphon pisum)의 발육단계가 진디면충좀벌의 산란능력에 미치는 영향 (Gerling et al, 1990), 기주, 식물, 기주-식물의 상호작용으로 발생되는 화학물질에 대한 진디면충좀벌의 반응 (Rao et al, 1999), 진디면충좀벌 성충의 휴면에 미치는 광주기, 온도의 영 향 (Tatsumi and Takada, 2005b (Borgemeister and Poehling, 1988;Höller, 1989;Höller et al, 1993;Weniger, 1994), 목화면충좀 벌에 대한 연구는 형태학적 특성 (Weniger, 1994), 계통별 분자 생물학적 특성 조사 (Strong, 1993 (Force and Messenger, 1964;Tang and Yokomi, 1995;Rӧhne, 2002) 나타났을 가능성이 있는 것으로 생각된다.…”

Overwintering of the aphid parasitoids Aphelinus asychis and A. albipodus (Hymenoptera: Aphelinidae) under natural conditions in Kyoto, Japan

“…It is important to know the dormancy characteristics of the parasitoids to understand their effectiveness as biological control agents. Previously, we examined the effects of photoperiod and temperature on dormancy induction and termination of a Kyoto population of A. asychis and Kyoto and Kobe populations of A. albipodus (Tatsumi and Takada, 2005b). The results showed that they had different dormancy characteristics.…”

“…The results showed that they had different dormancy characteristics. A. asychis entered weak diapause, strictly oligopause sensu Mansingh (1971), as adults under short days at moderate temperatures or under long days at lower temperatures, whereas A. albipodus entered diapause as last instar larvae under short days at 18°C (Tatsumi and Takada, 2005b). Oligopausing female adults of A. asychis resumed reproductive activity rapidly upon transfer to 15L : 9D at 20°C, whereas adults of A. albipodus did not emerge for about 2 mo when diapausing larvae were transferred to 15L :9 D at 20°C without cold treatment (Tatsumi and Takada, 2005b).…”