Biological impact of ultraviolet-B radiation on spider mites and its application in integrated pest management

Abstract

Many plant-dwelling mites reside on lower leaf surfaces. The biological impact of solar ultraviolet-B (UV-B) radiation on spider mites has been demonstrated over the last decade. Due to the serious problem of acaricide resistance in spider mites, the development of alternative control methods and establishment of an integrated pest management (IPM) strategy are urgently needed, especially for greenhouse horticultural crops such as strawberries. A physical control method for spider mites using UV-B lamps (UV-B method) has been established. Using the UV-B method, simultaneous control of spider mites and powdery mildew, a major disease, is possible, making it is a favorable IPM strategy. Here, I introduce general findings regarding the biological impact of UV radiation on spider mites and phytoseiid mites, useful natural enemies for biological control, over the last decade, including dose response, effective wavelengths, and photoreactivation. Moreover, I introduce the application of UV-B to spider mite control in strawberry greenhouses, including the possibility of concurrent use with biological control via phytoseiid mites, and discuss its possible contributions to IPM.

Acaricidal Activity of UV-C irradiation on Tetranychus urticae and eggs using pulsed krypton fluoride excimer laser

“…Information on the effects of UV radiation on T. urticae are scarce. While biological impact of UV-B (280-315 nm) radiation on spider-mite populations was recently reviewed [32], the use of UV-C was not considered. Nevertheless, this review commented on the sensitivity of spider mites to UV-radiation, underlying that T. urticae individuals remain mostly on the lower leaf surfaces as UV-protection mechanism, excepted during diapause when they seemed to be more protected by the synthesis of ketocarotenoid, and notably astaxanthin.…”

Current Situation of Tetranychus urticae (Acari: Tetranychidae) in Northern Africa: The Sustainable Control Methods and Priorities for Future Research

“…The eggs and larvae of T. urticae are more vulnerable to UVB radiation than adult females, and mortality is directly proportional to the cumulative UVB irradiance [123]. Additionally, using the ultraviolet-B method control of spider mites showed excellent results, especially for greenhouse horticultural crops such as strawberries; performing it is a favorable IPM strategy [124]. Conversely, the enhanced UV-B radiation increases the deleterious effects on insect behavior and health and affects their interactions with plants via induction of defensive material products and photomorphogenic variations.…”

Adult female exposure to mild ultraviolet radiation reduces longevity but not egg load in two parasitoid wasps

“…In contrast, the general assumption that mature individuals are well‐protected against photodamage, having completed their development and acquired a more sclerotized, pigmented exoskeleton (Paul & Gwynn‐Jones, 2003; Potter & Woods, 2013), is not strongly supported by experimental evidence. Mechanisms of adult UV tolerance and vulnerability have been described in several phytophagous and predatory mite species (reviewed in Osakabe, 2021), but in insects, evidence is scarce and concerns a small number of pest species.…”

“…In contrast, the general assumption that mature individuals are well-protected against photodamage, having completed their development and acquired a more sclerotized, pigmented exoskeleton (Paul & Gwynn-Jones, 2003;Potter & Woods, 2013), is not strongly supported by experimental evidence. Mechanisms of adult UV tolerance and vulnerability have been described in several phytophagous and predatory mite species (reviewed in Osakabe, 2021), but in insects, evidence is scarce and concerns a small number of pest species. Adult insect short-term exposure (i.e., minutes to hours) to UV-A (315-400 nm), the most prevalent and least energetic type of UV radiation that reaches the surface of the Earth, has been shown to increase oxidative stress levels (moths: Meng et al, 2009) and stress-related gene expression (flour beetles: Sang et al, 2012;fruit flies: Zhou et al, 2013).…”