Pine processionary caterpillar

Elia Hermoso de MendozaAsier LabacaIbai SagarnaArrate Echeveste3ºITA (HF)

Introduction

• Scots pine (Pinus sylvestris L.) has a wide distribution in Europe and Asia.

• Important in economic and ecological terms.

• In the study:– They Investigate the impact of PPC on natural

populations of Scots pine in southern Spain

• Objective:– Evaluate the consequences for forest regeneration

and thereby prescribe appropriate guidelines to prevent the potential devastation of the pest.

Biological cycle of Scots pines

Flowering and pollination

April (year 0). year 1

Female strobili arefertilized

year 2

May of year 1 to January

seed dispersion22 months

Cones develop

Biological cycle of processionary

Cycle univoltine

Adult flight

in mid-summer.45 daysSeptember

Eggs laid and hatchin the canopy of the trees

autumn and winter

larvae developIn the nest ---protected cold

2.- METHODS

Study realized

In Trevenque area

National Park of Sierra Nevada

Why??

Grow native Pinus Silvestris nevadensis

In 98´- 99´had a heavy defoliation by PPC(pine processionary caterpiller)

Studying Biological cycle

of Scots pine (1)

PPC (2)

2.1.- Damages

Defoliation January and March

Larvae are in a mature state.

2.2.- Sampling

They observed the survival of the Scot pine

How??

- Estimating of porcentage of defoliation suffered during the period of plague activity.

- And divide the new growth by initial growth.

2.2.1.- On juvenile Scot pine

2.2.3. On adult Scot pine

Observed parts of the pine as:

First:

Two process:

1) Estimated the percentage of damage suffered during the period of plague.

2) Choose 10 pines completily defoliated and 10 with low or no defoliation. They measured

Measured of diametre, lengh and the number of seeds and the average weight.

cones,

flowers

seeds.

Results and discussions

• PPC drastically reduces the growth and the reproduction of Scots pine.

• Juvenile defoliated trees: – Grow 50% less than other trees– Have 50% fewer seeds – Have 40% lighter seeds

• Scots pine have lower rate of growth in southern Spain, so the PPC afection is more important.

• Also the global warming is reducing the days with frost so larval survival of PPC is bigger.

Conclusion and guidelines

• The effect of global warming on Scots pines because of the PPC will have a negative effect in southern Spain. necessary to control.

• Biological controls have limited effect and are expensivemethods based on self-perpetuating characteristics of the system.

• Short term the increased tree diversity and community complexity in adjacent reforested pine stands could greatly reduce the spread of PPC.

• Long-term reforestation programmes helping both the spread towards adjacent areas as well as the migration of Scots pine in altitude will be valuable for preventing attack by PPC.

• This task may be achieved with techniques already developed in situ using shrubs as nurse plants to increase seedling survival

minimizing the ecological impact of reforestation on these protected high-mountain ecosystems.