Diapositive 1

1
Integrated Pest Management for WESTERN CORN
ROOTWORM -WCR (Diabrotica virgifera virgifera
LeConte) in Central and Eastern Europe
MODULE C13
2
Background

• First detection of WCR (damage by larvae) in
• Europe in 1992
• Rapid spread of the pest in Europe
• Jumping-spread movement beyond the
• actual spread line
• Multiple transatlantic introductions of WCR.

3
Morphology of WCR

• Eggs 0,5 mm whitish-yellow 15-20cm in the
  soil
• Larvae 3 larval stages 1,2 mm (L1)- 1,5 cm
  (L3) whitish-yellow, black head capsule soil,
  maize roots
• Pupae (pupa libera) 7,5 mm whitish-yellow non
  moving stage in the soil
• Adults 7,5 mm yellow, with three black strips
  difference between males and females active on
  plants.

4
Life cycle of WCR
Eggs overwinter in the soil
L1
Adults die
V
VIII - IX
L2
VI
L3
VII-VIII
Oviposition
VI-VII
VII-VIII
Pupae
Emergence of adults
Source S. Toepfer
5
Damage by WCR larvae

• Successful development of larvae (almost) only
  on maize roots
• Maize root system damaged, plants will lodge
  (goose-neck symptom)
• WCR larval damage evaluation Iowa 1-6 scale,
  node injury scale.

6
Damage by WCR adults

• WCR adults are feeding on several plant species,
• Feed on pollen of different crops
• Feed on maize leaves, silks and pollen
• Economic damage on maize plants due to silk
  clipping
• Less fertilized ears and yield loss (quantity and
  quality of kernels).

7
Monitoring of WCR adults

• Purpose
• Evaluation of the
• - presence of WCR adult population
• - potential for silk clipping
• - risk for next year larval damage (if not
  rotated).
• Tools/methods
• - Csalomon pheromone traps
• - yellow sticky traps (e.g. Pherocon AM)
• - whole plant count.

8
IPM for WCR

• Cultural practices
• - Feeding and oviposition of females in maize,
• successful larval development in
  subsequent year maize
• CROP ROTATION
• - Field size/margins/surrounding of the field
• - Soil type, tillage system/weeds
• - Planting time/hybrid selection BT maize (?)
• - Production inputs (fertilizer, water, green
  manure).
• LATE PLANTING escape from taching period of the
  larvae where temperature and rainfall allow
• EARLY PLANTING to allow root system development
  as soon as possible where temperature and
  rainfall allow

Crop rotation field test plots for WCR management
(EU 5th Framework project Hungary, 2000-2004)
9
IPM for WCR

• Biological methods
• - There are several antagonists and parasitoids
  (entomopathogenic fungi, Nematodes, Diptera spp.)
  and predators (praying mantis, ground beetles,
  spiders, frogs and some birds) that parasite or
  prey on WCR
• - It is still not defined to what extent these
  predators are able to regulate the WCR
  population.

FAO/ P. HOFFMANN
FAO/ S. TOEPFER
10
IPM for WCR

• Chemical control
• Larvae to prevent/decrease larval damage in
  given year
• - seed treatment
• - soil insecticide application at planting
• Adults to prevent damage by silk clipping or to
  reduce egg
• laying and next year larval damage
• - foliar insecticide application
• - high clearence ground sprayer
• - aircraft/helicopter
• - attract and kill (reduced insecticide
  ratefeeding
• arrestant)
• Innovative control option
• Bt (rootworm resistant) maize hybrids
• - widespread in USA
• - under approval in Europe

11
Farmers perspective?
FARMERS AIM is to be able to MANAGE the pest on
their fields, but Management of the WCR on one
field is not effective enough so COMMUNITY ACTION
is needed, based on COMMON UNDERSTANDING.