In order to investigate aspects of the predator–prey relationship
between A. swirskii and O. insidiosus, a laboratory bioassay
was performed. Experimental arenas consisted of a 10 cm length
of plastic tubing (1-cm diam) that was closed at one end with a
filter. A piece of pepper leaf (1.0 10.0 cm) removed from a muscadine
variety was placed inside the tube and the open end of the
tube fitted with a 200 ll pipette tip. The other (filter) end of the
tube was attached to a vacuum pump to enable arthropods to be
aspirated directly inside the arenas, following which the pipette
opening was closed with Parafilm. The following treatment combinations
were evaluated; (1) single predator releases consisting
of 15 adult chilli thrips plus 3 A. swirskii or 3 O. insidiosus (2)
combination predator releases consisting of 20 adult chilli thrips
plus 2 A. swirskii and 2 O. insidiosus per test tube and (3) no predator
controls. There were 3 replicates per treatment. To look for
host stage effects, the experiment was repeated using thrips larvae.
Tubes were incubated at 25 C and evaluated daily for numbers
of live and dead thrips and predators until all the thrips in at
least one tube were killed.