The five points below follow the outline of
"The Five Features of IPM" set forth by Everett J. (Deke) Dietrick in 1969.
Examples are given of how all five features — avoid disruptive pesticides, build
beneficial refuge, monitor insects, develop cultural practices, and release beneficial
organisms — favor the development of cost effective pest control.
1 -- Avoid use of disruptive pesticides Food drives
these systems, when you kill pests, you are killing the food or host of beneficial
insects. Even seemingly safe pesticides may kill fungi on leaves that is a secondary food
for some beneficials. Spray only if there is a pest problem! Repeated use of all classes
of chemical poisons on your farm results in pest resistance to the poisons. The natural
enemies of pests are also killed, or are starved away from the fields, and, therefore, do
not have an equal chance to develop resistance as do the pests. Predators and parasites do
not leave completely, but their numbers are significantly reduced compared to pest
numbers. It sometimes takes several generations of beneficials to grow back the natural
balance.
Certain dosages of conventional pesticides and
insecticidal soaps and oils selectively kill pests and are less disruptive to biological
controls. Our beneficials are compatible with "soft pesticides" like microbial
insecticides, sterile male releases and pheromone mating disruption. The use of
pyrethroids and broad spectrum pesticides is recommended only in extreme cases, as these
kill many beneficials as well as pests.
2 -- Build beneficial refuges Strip or trap cover
crops that are never sprayed offer a field insectary and winter refuge for beneficial
insects without harm to market products. Parasites live several times longer and destroy
more pests when there are weeds or other plants to provide pollen, nectar and refuge.
Think of giving up 1% of your field for pest control. Much of this 1% can come from
roadsides, borders, box ends and row ends. Sunflower and sorghum borders are particularly
good habitats for growing lacewing and other natural enemies on the farm. Corn and alfalfa
borders and interplantings of flowering plants can also increase Trichogramma parasitism
of moth eggs in the crop. You can use trap crops to draw pests from your crop and raise
beneficials on them. Corn is more attractive than cotton for corn earworm (=cotton
bollworm) so interplant corn with a cotton crop. Trichogramma released on the corn can be
found racing up and down silks parasitizing corn earworm eggs.
3 -- Monitor Insect Ecology Whatever is done in any
field situation is always founded, as far as possible, upon the full knowledge of the
interactions and ratios of the pests and their natural enemies. Therefore, monitoring
should involve thorough sampling and observation of relative numbers of pests and all
beneficials. Develop a system for scouting and assessing general trends in the change of
pests and generalist predators in a given field as a guide for treatment or no treatment.
You don’t have to count all the insects, just observe the ratio of pests to
beneficials. One of the most important tools for monitoring is the D-Vac vacuum insect
net. [Editors note: Everett helped invent the D-Vac and has produced them for forty years.
He uses it to show farmers the progress of biological control, especially the tiny forms.]
Keeping track of the beneficials and seeing the ratios of good and bad bugs makes it
possible to predict damage thresholds in time to keep the yields optimum. D-Vac samples
placed in alcohol and examined under a dissecting microscope show the progress of the
entire natural enemy complex and is practical for decision-making.
4 -- Develop cultural practices Slight changes in
farming to take advantage of the known behaviors of both the pests and the beneficials
that attack them can avoid the pest flare-ups taken for granted under conventional
chemical farming. Techniques of crop rotation, hedging and refuge management can make a
difference. Strip cutting (harvesting alternate strips or fields of alfalfa or cover crops
when they begin to bloom), for example, forces a steady migration of beneficials into
nearby row crops yielding many times the natural enemies of uniformly cut hay fields or
cover crops.
5 -- Release beneficial organisms: Rincon-Vitova
distributes many biological control organisms; predators, parasites, pathogens and
antagonists. These organisms attack different pests, sometimes target specific life
stages, and often attack during a particular season. Ideally, releases are started as
early in the season as possible, when the first pests enter fields. While each farm and
season is unique, growers and pest control advisors can draw on Rincon-Vitova's reviews of
published findings of biocontrol entomologists and experience to build a program tailored
to their situation.
The primary purpose of following the five features
above is to conserve natural enemies. IPM emphasizes beneficials and seeks to suppress
particular pest levels so that rather than pest numbers rising explosively, they stay
within tolerable damage levels with minimum loss of beneficials. 100% mortality of all
pests is not required to prevent economic losses to the market crop. The IPM method gets
easier each year, as a reservoir of natural enemies becomes established.
