Photoperiodic and temperature control of nymphal development and induction of reproductive diapause in two predatory Orius bugs: interspecific and geographic differences

Abstract

The effects of day-length and temperature on pre-adult growth and induction of reproductive diapause are studied in Orius sauteri and Orius minutus (Heteroptera: Anthocoridae) from northern (43.0°N, 141.4°E) and central (36.1°N, 140.1°E) Japan. In the north, at 20 °C, pre-adult growth is slower under an LD 14 : 10 h photoperiod than under shorter or longer photophases. At 24 and 28 °C, the longer photophases result in shorter pre-adult periods. Acceleration of nymphal growth by short days in autumn appears to be adaptive. In the central region, this response is less pronounced, suggesting that timing of adult emergence is less critical than in the north. Day length also influences the thermal requirements for pre-adult development. The slope of the regression line representing temperature dependence of pre-adult development is significantly smaller and the lower development threshold (LDT) is significantly lower under an LD 12 : 12 h photoperiod than under long-day conditions. The weaker dependence of nymphal growth on temperature and the lower LDT in autumn might be adaptive. In the north, increased temperature shifts the critical day length of diapause induction and suppresses the photoperiodic response in O. sauteri but not in O. minutus . Further south, the incidence of diapause in both species is low even under short-day conditions but the same interspecific difference is observed (i.e. increase of temperature affects the response in O. sauteri but not in O. minutus ). This suggests seasonally earlier diapause induction with weaker temperature dependence in O. minutus than in O. sauteri .

Thermal Biology of the Predatory BugsOrius thripoborusandO. naivashae(Hemiptera: Anthocoridae)

“…Moreover, t 0 -values of local overwintering populations may even be lower than those estimated in this laboratory study under long day conditions and with insects directly taken from rearing stocks. Musolin and Ito (2008) found that in O. sauteri, temperature dependence of preadult development was smaller and a lower development threshold was estimated under a photoperiod of 12:12 (L:D) h than under long-day conditions. The current study may provide useful information to understand the potential role of these predators in augmentation and conservation biological control programs in southern Africa: 1) 25ЊC appears to be the optimal rearing temperature for both studied species.…”

Optimization of Orius majusculus release: photoperiodic sensitivity at different temperatures and storage of diapausing adults

“…Unlike some other Orius species (van den Meirecker, 1994;Musolin et al, 2004;Musolin and Ito, 2008), its response remained the same in terms of diapause incidence, which was 100% at full exposure, under a wide range of constant temperatures (18-30 °C) in the present study. It is obvious that increasing the day length is the only way to avoid diapause in O. majusculus from Antalya.…”

“…Available data on the photoperiodic sensitivity of different life stages in Orius were obtained using single temperature regimes only (van den Meiracker, 1994;Ruberson et al, 2000;Cho et al, 2005). Since temperature was demonstrated to have an impact on the photoperiodic response of Orius species (Musolin et al, 2004;Musolin and Ito, 2008), photoperiodic sensitivity of different life stages was detected using both constant and fluctuating temperature regimes in the present study.…”

Ovarian Development in Predacious Orius pumilio: Relationship to Diet, Mating, and Juvenile Hormone

“…It has expedited the testing of hypotheses regarding genetic interactions (Shapiro et al 2010) between closely related species such as O. pumilio and O. insidiosus, which reside in closely related ecological niches (Shapiro et al 2009b). As accomplished with other anthocorid species, the limited sympatry of the tropical and subtropical O. pumilio with the ubiquitous O. insidiosus can now be assessed in the context of climatic dynamics, genetics (Hinomoto et al 2004, Honda et al 1998, mating behavior and biology (Horton et al 2005a,b), and diapause and biogeography (Horton et al 1998, Ito and Nakata 1998, Kakimoto et al 2003, Musolin et al 2004, Musolin and Ito 2008.…”