PLANT PROTECTION 1 – Pests, Diseases and Weeds

PLANT PROTECTION 1 – Pests, Diseases and Weeds
Pest cycle
There is no metamorphosis (eggs, 5-6 nymphal
stages, adult) with several (3-4) generations each
year. Adults continue to grow and alternate
between a stage that usually does not feed, but can
reproduce, and one that cannot reproduce but does
most of the feeding. Each generation takes about 3-
5 weeks. The female springtail lays minute semispherical
eggs in small groups in the soil or among
organic matter where adults may be feeding. The
eggs hatch into young which resemble the adult in
general form and grow by a series of moults.
‘Overwintering’
Probably as eggs in soil among organic matter but
they may occur all year round if moisture is
present and it is not too hot or cold.
Spread
By floating on water in drainage channels, pots,
streams.
Movement of decaying vegetable matter or soil
containing such.
Movement of turf sod, containers, etc.
Conditions favoring
Favoured by prolonged cool, damp or wet
weather in autumn and spring.
Common following rain or heavy watering.
Springtails float on the surface of drainage water.
Stagnant water.
Decaying moist organic matter, eg compost
heaps, leaf mould.
Numbers decrease during warm summer months
when soils are drier.
Management (IPM)
Are you a commercial grower or home gardener?
1.Obtain/prepare a plan if necessary, that fits
your situation.
2.Crop, region. Remember springtails may be
generally beneficial and only occasionally damage
some crops, eg mushrooms, seedlings.
3.Identification of pest must be confirmed. Do not
confuse with thrips (page 130). Consult a diagnostic
service if necessary (page xiv).
4.Monitor populations of springtails and beneficials
especially during cool, damp weather, where there is
stagnant water and they are known to be a problem.
Remember you need to know when, where, what
and how to monitor (page 39). Record findings.
5.Threshold. How much damage can you accept?
Have any thresholds been established? If so, what are
they, eg economic, aesthetic or environmental? Do
you need to calculate your own threshold?
6.Action. You may need to reduce irrigation, improve
drainage and encourage natural enemies by
minimizing insecticide use. It is not necessary to use
insecticides in the home garden.
7.Evaluation. Review the IPM program. Adjust
control strategies if required.
Control methods
Cultural methods. Reduce moisture. If
planting seedlings in soil heavily infested with
springtails, liming and frequent turning over of the
earth before planting will reduce their numbers and
the risk of injury to plants. Reduce irrigation,
improve drainage.
Biological control. Natural enemies include
ants, beetles, bugs, mites and probably spiders.
Birds will feed on them.
Insecticides. In a home garden situation
pesticides are not recommended. In commercial
crops insecticides may be applied to soil or plants
only if monitoring indicates there is likely to be
there is to be economic injury to seeds or seedlings.
Table 39. Springtails – Some insecticides.
What to use?
SPRAYS, eg
Commercial crops only, eg
Group 1B, eg Lorsban , various (chlorpyrifos) is registered
to control springtails in young cotton plants.
Insecticides are not necessary in the home garden.
When and how to apply?
Springtails occasionally may require control in some
commercial crops, eg cotton, mushrooms, turf, vegetables.
It may be necessary to add a wetting agent.
Insecticides should only be applied:
After springtails have been identified, and numbers
indicate damage is likely to occur.
When cultural control methods such as reduced moisture
do not bring about a quick reduction in numbers and
If seeds or seedlings of commercial crops are likely to
continue to be injured.
198 Insects and allied pests - Springtails (Collembola)