Mealybug poses a serious economic threat to warm greenhouse ornamentals (mainly cut flowers and indoor plants), a sector with 277 companies (90% full) and a production value of € 194 million in Flanders. This persistent pest is at an early stage difficult to detect and extremely difficult to fully control. This project aims to these growers to provide a sustainable solution to combat mealybugs with minimal impact on the existing integrated control system (IPM).
Management of mealybugs in ornamental plant production within an IPM system
This project ran in collaboration with the Research Center for Ornamental Plants (PCS, Destelbergen, Belgium) and had as main objective to inventorize the major mealybus species in ornamentals in Flanders, Belgium, and to optimize their integrated management. Molecular makers (based on the 28S rDNA and ITS2 genes) were developed to allow a reliable identification of the most prevalent mealybug species. In samples collected at Flemish production facilities the following species were recorded: long-tailed mealybug (Pseudococcus longispinus ), citrus mealybug (Planococcus citri ), obscure mealybug (Pseudococcus viburni ), bamboo mealybug (Trionymus bambusae), cotton mealybug (Phenacoccus solenopsis) and citrophilus mealybug (Pseudococcus calceolariae). Development and reproduction of the three major species in Flemish ornamentals (P. longispinus, P. citri en P. viburni) were studied as a function of constant and alternating temperatures. The further focus at Ghent University was on the biological control of mealybug pests using the predatory coccinellid Cryptolaemus montrouzieri and the lacewing Chrysoperla carnea, the predation capacity of which on different life stages of P. citri en P. longispinus was compared in the laboratory. Finally, laboratory experiments were carried out to investigate the intraguild interactions among these two predators.