Seasonal development and ecology of anthocorids (Heteroptera, Anthocoridae)

Abstract

Seasonal development and ecology of Anthocoridae are reviewed. Most of 500–600 species in the family are predacious or zoo-phytophagous, and a few other species are exclusively phytophagous or myrmecophilous. Some anthocorids are (and many others can potentially be) used as biological control agents in the Integrated Pest Management (IPM). Overwintering at the adult stage is typical of anthocorid bugs from the temperate zone (especially for the subfamily Anthocorinae). The known exceptions are the embryonic diapause in Tetraphleps abdulghanii, Temnostethus pusillus, and T. gracilis (Anthocorinae) and continuous development through all seasons (a homodynamic seasonal cycle) in Lyctocoris campestris and some species of Xylocoris (Lyctocorinae). In a number of species, especially in the genera Anthocoris and Orius, copulation occurs before overwintering and only females survive winter, a feature very unusual for Heteroptera and insects in general. Many anthocorid species are multivoltine in the temperate zone, producing several (up to 8 in some cases) generations per year. The number of generations typically decreases to 1 per year towards the north. Seasonal development of multivoltine species is chiefly controlled by daylength and temperature. All multivoltine anthocorids of the temperate zone studied to date have photoperiodic response of a long-day type: the females reproduce under the long-day conditions, but enter diapause under the short-day conditions. Towards the south, the photoperiodic response gradually becomes weaker: some populations do not enter diapause even under the short-day conditions, especially at higher temperatures. Termination of diapause is poorly understood in anthocorids, but a number of species require low-temperature treatment for a few weeks prior to the start of oviposition. Alary and color polymorphism are rare in the family, and they have never been shown to be seasonal or environmentally controlled. Pronounced seasonal migrations and aggregation behavior also have never been reported in Anthocoridae. Summer diapause appears to be very unusual for the family, having been reported only in Tetraphleps abdulghanii. The seasonal change of host plants, known in some populations of Anthocoris nemorum and A. nemoralis, is also a seasonal adaptation unusual for Heteroptera. Seasonality of tropical and subtropical species is poorly studied, but anthocorids developing without winter diapause are considered promising agents for the biological control of arthropod pests. Further studies of ecophysiology of Anthocoridae will optimize application and mass rearing of these predators in IPM programs.