PLANT PROTECTION 1 – Pests, Diseases and Weeds

PLANT PROTECTION 1 – Pests, Diseases and Weeds
Spread
By nymphs and adults crawling, adults have
wings but seldom use them. They may slowly
spread from around houses and sheds through
gardens into neighboring properties.
Mainly spread by human activity, eg
– Transport of hay, machinery, soil in nursery stock,
ornamental plants, bulbs, pot plants, also on
contaminated seeds and cardboard boxes.
– Infestations in caravan parks infest caravans and
tents are transported to other parks.
Conditions favoring
Cool moist weather. Most active during spring
and autumn and rarely troublesome during very
cold or hot weather. Heavier soil.
Intensive cropping and stubble retention practices
improve the habitat for earwigs. Large populations
can build up in stubble from relatively undamaged
crops to damage subsequent emerging crops, eg build
up in lupin stubble, to devastate later emerging crops
of canola. It may be necessary to reseed some crops.
Use of mulching material and groundcovers.
Also damage mature crops. After harvest they
migrate to windrows where they feed on pods
when windrows are put through the harvester to
extract seed, the harvester is contaminated and
may require cleaning.
Management (IPM)
Are you a commercial grower or home gardener?
1. Plan in advance. IPM programs are available for
some other earwigs, eg black field earwigs on various
crops, eg sweetcorn, providing information on
monitoring, thresholds and action levels.
2. Crop, region. Obtain information on local pest
species and their control.
3. Identification of species must be confirmed. Earwigs
are only a problem if numbers are large. Distinguish
between local pest and beneficial species. Consult a
diagnostic service if necessary (page xiv).
4. Monitor earwigs and/or damage weekly early in the
season if they were a pest the previous season, record
results. For vegetable crops, lightly scrape soil and
sieve to detect adults and nymphs prior to planting, use
germinating seed baits, etc. For grapevines, knock vines
sharply to dislodge any sheltering earwigs, band with
corrugated cardboard and examine soil around trunks.
5. Thresholds have been established for some crops.
How much damage can you accept? If so, what are
they, eg economic, aesthetic, environmental? Do you
need to calculate your own thresholds?
6. Action. Take appropriate action when decided
threshold is reached. Home gardeners usually settle on
non-chemical methods eg sanitation, traps.
7. Evaluate procedures to see how well they worked.
Recommend improvements if required
Control methods
Sanitation. Removal of rubbish, decaying plant
material and other debris, where earwigs might
breed and shelter during the day, assist control.
See also Plant quarantine below.
Biological control. No biological control
agents are available for purchase or been released.
Birds are well known predators of earwigs.
They may be parasitized by some insects and a
nematode. The offensive fluid they eject may
repel some predators and parasites.
Plant quarantine.
State/regional quarantine. The European
earwig was discovered a few years ago in WA.
The Industry Resource Protection Program,
Agriculture WA, is surveying the extent of
infestation. Occurrences in WA should be
reported to Agricultural Protection Board in
your district, so their spread can be restricted.
Ensure that all machinery, vehicles and
equipment arriving on your property has been
cleaned. Also ensure that you minimize the risk
of spreading them in WA.
Pest-tested planting material.
Check seed and plant material for live earwigs
before bringing them onto your property. Only
plant earwig-free material.
Physical & mechanical methods.
Indoors. Earwigs can be swept up and destroyed
as found. They breed outdoors and invade houses.
Put in plastic bag and leave in sun for a day.
Crops. Burning stubble has shown some success but is
not a preferred option because of the risk of wind
erosion and environmental pollution.
Garden traps. Earwigs hide during the day and
can be attracted to shelter traps placed in areas
where they are a problem.
– Rolled newspapers or rolled corrugated cardboard.
– Upturned flower pots filled loosely with straw or
crumpled or torn paper.
– Examine traps twice per week and destroy earwigs
by shaking into a bucket of soapy water. Paper rolls
could be destroyed directly by burning if permitted.
Insecticides. Control with contact insecticides
is difficult because earwigs shelter under mulch, bark,
organic matter, in fence posts and other inconspicuous
places. Baits are used in some crops (Table 38).
Table 38. European earwig - Some insecticides.
What to use?
OUTDOORS
Group 1A, eg various (carbaryl) – some residual activity
Group 1B, eg various (chlorpyrifos) - baits
Group 22A, eg Avatar (indoxacarb)
Various home garden products, eg pyrethrins; Beat-A-
Bug Insect Spray (chilli/garlic/pyrethrins);
Baythroid (cyfluthrin)
When and how to apply?
Home gardeners should not need to use insecticides.
Commercially, grain baits containing insecticide, seed
dressings and sprays offer some protection. Baits may
be more effective if earwigs are present on the ground.
No insecticides may be registered for your crop.
Seek advice for spray/bait recommendations
for your region and your crop.
SEED TREATMENT
Group 4A, eg.Picus Seed Treatment Insecticide (imidacloprid) is Only apply to healthy seed.
used to control black field earwigs in certain crops
INDOORS
Remember earwigs breed outside. Shovel up earwigs
found inside and if necessary control earwigs outside.
Insects and allied pests - Dermaptera (earwigs) 189