Annals of Applied Biology ISSN 0003-4746 REVIEW ARTICLE In the light of new greenhouse technologies: 2. Direct effects of artificial lighting on arthropods and integrated pest management in greenhouse crops N.S. Johansen 1 , I. V ¨ anninen 2 , D.M. Pinto 2 , A.I. Nissinen 2 & L. Shipp 3 1 Bioforsk Plantehelse, Norwegian Institute of Agricultural and Environmental Research, Hoegskoleveien, Norway 2 MTT Agrifood Research Finland, Plant Production Research, Jokioinen, Finland 3 Agriculture and Agri-Food Canada, Greenhouse and Processing Crops Research Centre Harrow, ON, Canada Keywords Behaviour; biology; insects; light intensity; mites; photobiology; photoperiod; photoreceptors; plant protection; visual ecology; wavelength distribution. Correspondence N.S. Johansen, Bioforsk Plantehelse, Norwegian Institute of Agricultural and Environmental Research, Hoegskoleveien 7, N-1432 ˚ As, Norway. Email: nina.johansen@bioforsk.no Received: 28 January 2011; revised version accepted: 20 April 2011. doi:10.1111/j.1744-7348.2011.00483.x Abstract Novel lighting technology offers the possibility of improved arthropod inte- grated pest management (IPM) in artificially lighted crops. This review compiles the current knowledge on how greenhouse pest and beneficial arthropods are directly affected by light, with the focus on whiteflies. The effect of ultravio- let depletion on orientation and colour-coded phototaxis are to some extent studied and utilised for control of the flying adult stage of some pest species, but far less is known about the visual ecology of commercially used biological control agents and pollinators, and about how light affects arthropod biology in different life stages. Four approaches for utilisation of artificial light in IPM of whiteflies are suggested: (a) use of attractive visual stimuli incorporated into traps for monitoring and direct control, (b) use of visual stimuli that disrupt the host-detection process, (c) radiation with harmful or inhibitory wavelengths to kill or suppress pest populations and (d) use of time cues to manipulate daily rhythms and photoperiodic responses. Knowledge gaps are identified to design a road map for research on IPM in crops lighted with high-pressure sodium lamps, light-emitting diodes (LEDs) and photoselective films. LEDs are concluded to offer possibilities for behavioural manipulation of arthropods, but the extent of such possibilities depends in practice on which wavelength combinations are determined to be optimal for plant production. Furthermore, the direct effects of artificial lighting on IPM must be studied in the context of plant-mediated effects of artificial light on arthropods, as both types of manipulations are possible, particularly with LEDs. Introduction In recent years, great effort has been put into the research and development of new greenhouse lighting technol- ogy in order to optimise plant production and quality and to save energy (V¨ anninen et al., 2010 and references therein). Manipulation of light intensity and photoperiod by broad-spectrum high-pressure sodium lamps (HPSLs) is the dominating lighting strategy in the boreal and temperate zones at the moment (Moe et al., 2006), but increasing interest is being focussed on different types of less energy-demanding narrow spectrum lamps and in photoselective covers and screens, and greenhouse panes which combine high light transmission and insu- lation values (Morrow, 2008; V ¨ anninen et al., 2010). The light environment created by a combination of luminaries and natural daylight, or by films or panes with different spectral properties, deviates from the natural light envi- ronment in spectral composition, light intensity, and in the case of artificially lighted greenhouses, in photoperiod duration. This artificial light environment can influence herbivore pest and beneficial insects and mites living in the crop indirectly via light-mediated changes in the Ann Appl Biol 159 (2011) 1–27 © 2011 The Authors 1 Annals of Applied Biology © 2011 Association of Applied Biologists