title: New opportunities for the integration of microorganisms into biological pest control systems in greenhouse crops.
abstract: Biological pest control with mass-produced arthropod natural enemies is well developed in greenhouse crops and has often resulted in the evolution of complex ecosystems with persistent populations of multiple arthropod natural enemy species. However, there are cases where arthropod natural enemies are either not effective enough, not available, or their use is rather costly. For these reasons, biological control based on microorganisms, also referred to as 'microbials', represents a complementary strategy for further development. Although commercially available microbials have been around for quite some time, research on and the applied use of combinations of arthropod natural enemies and microbials have remained relatively under explored. Here, we review current uses of entomopathogenic fungi, bacteria and viruses, and their possible direct and indirect effects on arthropod natural enemies in European greenhouses. We discuss how microbials might be combined with arthropod natural enemies in the light of new methodologies and technologies such as conservation biological control, greenhouse climate management, and formulation and delivery. Furthermore, we explore the possibilities of using other microorganisms for biological control, such as endophytes, and the need to understand the effect of insect-associated microorganisms, or symbionts, on the success of biological control. Finally, we suggest future research directions to optimize the combined use of microbials and arthropod natural enemies in greenhouse production.
authors.affiliation: Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Växtskyddsvägen 3, P.O. Box 23053, Alnarp, Sweden.
authors.forename: Francisco
authors.initials: F
authors.lastname: Gonzalez
authors.affiliation: Department of Plant Protection and Breeding, Siedlce University of Natural Sciences and Humanities, Prusa 14 Street, 08-110 Siedlce, Poland.
authors.forename: Cezary
authors.initials: C
authors.lastname: Tkaczuk
authors.affiliation: Research-Development Institute for Plant Protection, Bd. Ion Ionescu de la Brad nr. 8, Sector 1, P.O. Box 013813, Bucharest, Romania.
authors.forename: Mihaela Monica
authors.initials: MM
authors.lastname: Dinu
authors.affiliation: Department of Biological Control, Institute of Plant Protection - NRI, Władysława Węgorka 20 Street, 60-318 Poznań, Poland.
authors.forename: Żaneta
authors.initials: Ż
authors.lastname: Fiedler
authors.affiliation: Department of Crop Sciences, Agricultural Entomology, Georg-August-University, Grisebachstrasse 6, 37077 Goettingen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Vidal
authors.affiliation: Department of Entomology, NeweYa'ar Research Center, P.O. Box 1021, 30095 Ramat Yishay, Israel.
authors.forename: Einat
authors.initials: E
authors.lastname: Zchori-Fein
authors.affiliation: Wageningen UR Greenhouse Horticulture, PO Box 20, 2265 ZG Bleiswijk, The Netherlands.
authors.forename: Gerben J
authors.identifier: 0000-0002-5196-1229
authors.initials: GJ
authors.lastname: Messelink
keywords: Arthropod natural enemies; Endophytes; Entomopathogens; Microbials; Symbionts