Practical placement improves the performance of slow release sachets of Neoseiulus cucumeris

• Published in: Biocontrol science and technology 2014-10, Vol.24 (10), p.1153-1166
• Main Authors: Buitenhuis, Rosemarije, Glemser, Erik, Brommit, Angela
• Format: Article
• Language: English
• Subjects: Acari; dispersal; environmental conditions; floriculture; greenhouse; Phytoseiidae
• ISSN: 0958-3157; 1360-0478
• DOI: 10.1080/09583157.2014.930726

This research investigated factors that affect the performance of Neoseiulus cucumeris (Oudemans) (Acari: Phytoseiidae) slow release sachets, focusing on dispersal in environments with non-continuous canopies and high exposure to greenhouse environmental conditions. When released from a central plant in a tray, the distribution of N. cucumeris across all other plants was uneven with the majority of mites recovered at the release point. Shading by a plant canopy reduced the mean internal temperature of the sachets, temperature peaks were less pronounced and the relative humidity was higher than in exposed sachets. Most N. cucumeris left the exposed sachets in the first week, followed by reduced emergence and no signs of breeding were observed in the sachets. Sachets in a plant canopy had low emergence during the first week, increasing thereafter. Overall, plant canopy sachets released more N. cucumeris than exposed sachets. Emergence patterns of N. cucumeris from sachets under greenhouse and ideal conditions were variable, with sachets generally performing better under ideal conditions. Even under constant ideal conditions, the number of N. cucumeris released from sachets varied among batches and some produced a suboptimal number of predators. Results demonstrate that exposed greenhouse conditions can seriously affect the performance of N. cucumeris sachets and that good coverage is needed to compensate for limited dispersal in non-continuous plant canopies.