Quality Control Guidelines for Biocontrol Agents 281Predator efficiency/ 25 M. euphorbiae or 50 M. persicae should be consumed within
searching capability 4 days by a second-instar larva; n = 10; an annual test.
WHEN SHIPPED IN SECOND LARVAL STAGE
Quantity Number of live predators as specified on the package; a weekly test.
Predator quality 65% of second-instar larvae have to develop to third-instar larvae
within 5 days using aphids as prey; to be conducted once a year or
when the rearing system is changed.
Predator efficiency/ 25 M. euphorbiae or 50 M. persicae should be consumed within
searching capability 4 days by a second-instar larva; n = 10; an annual test.
Description of testing methods
Preparation of agar- Use a round Petri dish (13.5 cm diameter and 2 cm height) that can
leaf for testing be closed very tightly; a nylon mesh is incorporated into the lid to
predator quality and facilitate air exchange. Trays are filled with agar solution (1.5%) to a
predation capacity depth of 5 mm; just before the agar solidifies a leaf is placed with its
upper surface on agar; then transfer 30 adult aphids with a toothpick
on to the leaf; close the Petri-dish tray and turn it upside down. All
aphid adults are removed 24 h later and the offspring are counted
(offspring should be 100). Three species of aphids can be used as
prey items: A. gossypii on cucumber, M. euphorbiae on strawberry or
potato, or M. persicae on sweet pepper.
FORCHRYSOPERLASHIPPED AS EGGS
Predator quality Offer individual, freshly emerged larvae at least 50 prey items on a
leaf on agar as described above; n = 30.
Predator efficiency As described for larvae, see below.
Searching capacity As described for larvae, see below.
FORCHRYSOPERLASHIPPED AS LARVAE
Predator quality Offer individual, freshly emerged second-instar larvae about 100
aphids on a leaf on agar as described above; n = 30.
Predator efficiency Prepare agar–leaf set-up as described above; introduce second-instar
larva into Petri dish and count number of aphids consumed after 4
days.
Searching capability This test is carried out on a plant (i.e. on sweet pepper in the ‘ten-leaf
stage’ or on potato) put into a transparent plastic cylinder (20 cm
diameter and 50 cm high) with nylon mesh on the top for air
exchange and pressed on to a container filled with vermiculite to pre-
vent escape of larvae. Take a leaf with the offspring of 30 adult
aphids, count the aphids and cut the leaf in equal pieces, then dis-
tribute these pieces all over the plant to get an even distribution. Half
a day later the aphids have moved on to the plant; then transfer a
second Chrysoperlainstar on each plant. Count the remaining aphids
4 days later.
Initial design: M.G. Tommasini and R. Mayer.
Coordinator: M. Mosti (provisional test).