Test for Beneficial Insects
By Jim Core
May 23, 2003
A new test that determines the health of
beneficial insects raised on artificial diets has been developed by
Agricultural Research Service scientists
in Gainesville, Fla.
Beneficial insects that are mass reared commercially are important because
they are used to suppress field and greenhouse pests. Producers need to be able
to assess the quality of beneficial insects raised on artificial diets. One
measure of quality is the rate of egg production, but determining that rate is
a difficult and time-consuming process with very small insects.
Now ARS research entomologists Jeffrey P. Shapiro and Stephen M. Ferkovich
have found a way to measure egg production. They've developed enzyme-linked
immunosorbent assays (ELISAs) that measure yolk proteins in an insect's blood
(hemolymph) or body to predict how many eggs the insects will lay while feeding
on artificial or natural diets.
Shapiro and Ferkovich used monoclonal antibodies in ELISAs to measure minute
quantities of yolk proteins in insects during studies at the
Biocontrol Research Unit at the ARS Center for Medical, Agricultural and
Veterinary Entomology in Gainesville. This is the first time an ELISA has
been used to predict the reproductive fitness of mass-reared insect predators
In commercial mass-rearing facilities, beneficial insects are fed a range of
artificial diets. Such diets have advantages over natural feeding prey,
especially if costs can be reduced and the quality of the resulting insects can
be maintained. The proper nutrients must be included in the artificial diets to
stimulate the insect's normal life cycle. Before sale or release, producers
must determine the amount of offspring the colony's females are capable of
producing. This assures the quality of adult insects produced by an insectary.
The monoclonal antibodies used in the ELISAs specifically tag yolk proteins
of the spined soldier bug, Podisus maculiventris and the minute pirate
bug, Orius insidiosus. These predators are widely used beneficial
insects that prey on caterpillars, thrips, insect eggs, aphids, mites and other
ARS is negotiating a license for cloned hybrid cells and associated
antibodies used in the ELISAs, even though they will not be patented. The
licensee should have a commercial test available within one year.
ARS is the chief scientific research agency of the
U.S. Department of Agriculture.