October 2021 - 32

RESEARCH
Product Handling
Effect of
and Distribution
on Biologicals' Success
This article examines the quality assessment of shipments of the parasitoid Eretmocerus
eremicus received from two biological control suppliers.
BY NATHAN J. HERRICK AND RAYMOND A. CLOYD
Q
uality assessment of purchased biological control agents is
important when implementing a biological control program.
Before release into greenhouse production systems, greenhouse
producers should determine if biological
control agents including parasitoids,
predators, and/or entompathogenic
nematodes received from a biological
control distributor or supplier are alive
and functional. If biological control
agents of inferior quality are released,
then insect and mite pest populations
will cause unexpected levels of plant
damage leading to a false assumption
that biological control is not effective.
The success of a biological control
program depends on the quality of
the biological control agents released.
Furthermore, suppliers (i.e., companies
that ship biological control agents
to greenhouse producers directly or
through a distributor) and distributors
(i.e., companies that receive shipments of
biological control agents from suppliers
and then ship to greenhouse producers)
need to ensure proper product packaging
of biological control agents. Proper
packaging will minimize exposure to
extremes in temperature and/or relative
humidity that can be encountered during
shipping.
Figure 1.
the supplier, time of year, and formulation or packaging of products from
suppliers. Therefore, greenhouse producers should assess the quality of
purchased biological control agents before releasing or applying them into
the greenhouse to ensure suppression of
insect or mite pest populations and prevent
plant damage.
The quality of the same biological
control agent and the numbers provided
may differ depending on the commercial
supplier. However, few studies have
assessed the quality of biological control
agents from suppliers. Therefore, the
objective of the following preliminary
study was to determine emergence of the
whitefly parasitoid, Eretmocerus eremicus,
adults from parasitized pupae received
from shipments provided by two different
biological control suppliers.
Biological control agent quality may
not be exclusively associated with the
supplier or distributor, but can be due to
the shipping process, which is beyond
the control of the distributor or supplier.
For instance, exposure to extremes in temperature and/or relative
humidity can compromise biological control agent quality, leading to
biological control agents arriving dead or in such poor condition that they
cannot regulate insect or mite pest populations.
In fact, the quality of biological control agents can vary depending on
32 OCTOBER 2021 GPNMAG.COM
Figure 2.
MATERIALS AND METHODS
The following study was conducted in
our laboratory at Kansas State University
and the laboratory of a biological control
distributor in 2018. Two shipments of
sweet potato whitefly, Bemisa tabaci, pupae
parasitized by the parasitoid, Eretmocerus
eremicus, which were adhered/glued to
release cards were received from two
biological control suppliers (Supplier A
and Supplier B). Both shipments from the
suppliers were initially sent to the biological
control distributor. The biological control
distributor evaluated five release cards
from each supplier associated with each
shipment. In addition, five release cards
from each supplier were sent from the biological control distributor to our
laboratory at Kansas State University for evaluation.
Upon receipt of the shipments from the suppliers, each release card
from the five received from each supplier (Supplier A and B) was placed
into a 500 mL Mason jar and a 2x2-inch section of a yellow sticky card was
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October 2021

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