Agriculture Reference
In-Depth Information
on the host body and penetrate the cuticle, killing the pest in 3 to 5 days.
The infected bodies produce more spores that can infect additional pests.
Beauveria bassiana
products work best in cool, cloudy, moist conditions
at temperatures below about 80°F (27°C). They are likely to be of more use
to growers in moderate climates than in warmer regions. Apply the product
only when the pest is present, and target young pests early in an infesta-
tion. The effectiveness of
B. bassiana
products has been variable, with more
research studies showing poor pest control than showing fair or good con-
trol.
Beauveria bassiana
does not discriminate against pests and beneficials.
Avoid spraying
B. bassiana
products when pollinators are active in your fruit
crops.
Spinosad
Spinosad is a patented product that is derived from the fermentation of the
very rare actinomycete bacterium
Saccharopolysora spinosa
. This product is
a broad-spectrum pesticide that is useful against many insects. The mater-
ial works mostly as an ingested poison, although insects directly contacted
by the spray can also be affected. Essentially, the toxin causes the nervous
system to maintain a high state of agitation until the insect dies from ex-
haustion.
Spinosad has very low levels of toxicity for mammals, is slightly toxic to
birds, and is highly toxic to bees. Spinosad persists for several days on leaf
and fruit surfaces and is most effective against caterpillars and beetles that
feed on the leaves. Its control of aphids, whiteflies, and thrips has been mixed.
Beneficials are generally not affected much by the material once the spray
has dried.
Spinosad can persist for months in water and soil that is not exposed to
sunlight. It is moderately toxic to fish and aquatic invertebrates and should
not be allowed to contaminate surface waters. While spinosad is a break-
through for controlling leaf rollers and other orchard caterpillars and plant-
eating beetles, it is not a silver bullet. Resistance can build up when the ma-
terial is overused, so make it part of an integrated program, and rotate it with
