Wireworm Flashcards
Wire worm the larvae of?
The click beetle
Where do wireworm live
Soil dwelling and are robust and adaptable
What are wireworms a pest of
Potato and seen in cereals and other root veg
What are the 3 main species of click beetle ?
- Lined click beetle
- Common click beetle
- Agriotes click beetle
Where is the lined click beetle dominant
Midlands and southwest
Where is the common click beetle most dominant
North and west
Where is the agriotes click beetle most dominant
Midlands, southwest and east
How do you differentiate the species
By the wireworm
Other wireworm species ?
Can impact on potato production but their economic importance is minor
3 reasons of importance
- Not allowed to use persistent soil insecticides.
- Zero damage tolerance in potato industry
- Difficult to monitor and predict damage- invest energy into wireworm and not OWBM
What damage is caused in potatoes ?
Larvae burrow on, even low populations can cause significant reductions in crop marketability for potatoes and root veg
What damage is caused in cereals
Stunted growth and limited water and nutrient uptake
What’s the problem with damage in potatoes
The marketability to consumers- strict regulations on how potatoes should look for retail
Identification of wireworm
Newly hatched are transparent to white, then go browny orange
Identification of click beetle
Adults are dark brown to black
Example of prevention ?
Site characteristics e.g. field aspect- south facing fields tend to have higher populations because it’s warmer- they’re ectotherms so development is dictated by climate temps
3 examples of detection
Soil sampling,
Bait trapping
Pheromone trapping
Info on soil samples
20 soil corers for every 4-10ha
Samples washed at lab
Labour intensive- expensive
Could miss worse affected areas- sample in W shape
Bait trapping info
Only effective in reasonable temperatures (above freezing), must be active, check after 10-14 days, attracted to co2
Problems with bait trapping
Must have no other food source- not going to be effective in potato field
Pheromone traps info
Check traps weekly from April-august -labour intensive, set traps away from field margins, 1 trap per species as it’s species specific- expensive
Pheromone trapping problems
Not directly measuring the population but correlating adults to larvae, attract adults from other fields, so could over estimate
Action thresholds
Total season long catch:
Below 50 some damage
50-150 significant damage
Above 150 severe damage
Actual population size if 50-150 is found ?
150 thousand per hectare
Actual population size for above 150?
250 thousand plus per hectare
Plant for soil/ bait sampling
Do not grow potatoes if even one is detected
5 examples of control
Cultivation,
Early harvest
Control grass weeds
Chemical control
Biological control biofumigation
How does cultivation help control
Consolidated seedbed helps restrict movement and keeps them localised to limit input and expenses
How does controlling grass weeds help control
Restricts alternative food sources
How does early harvest help control
Grow early harvested potatoes to avoid worst damage as you progress through the season you get worse damage- earlier harvest avoids it
How does chemical control help
Nemathorin - applied at 15kg/ha with a 17 week harvest interval.
But monitoring must be evident to justify the treatments for assured product schemes so cultivation is the main method used
Biological control
Entomopathogenic fungi combined with pheromone trapping, lures and kills but not yet commercially available for wireworm
Biofumigation
Masserate mustard crops into the soil helps control PCN and wireworm
