The pine processionary (Thaumetopoea pityocampa) and pine tree lappet (Dendrolimus pini) are moths of the families Thaumetopoeidae and Lasiocampidae. They are abundant species found in pine woods in north, central and southern Europe. Because their larvae, or caterpillars, feed on the needles of pine trees and some other conifer tree species, these species are considered to be a pest. Moreover, caterpillars represent a public health hazard because they have thousands of hairs which contain a urticating allergenic protein called thaumetopoein.
In the larval phase, the caterpillars are full of microscopic urticating hairs that are able to penetrate the epidermis and mucous membranes. The most frequent clinical manifestations are cutaneous allergic reactions, although cases of eye irritation, rhinitis and even respiratory conditions and anaphylaxis have been reported. These effects can be particularly problematic when the caterpillar moves from the tree to the ground. A huge number of cases of intoxication or allergic reactions occur every year, most of them requiring a visit to a medical centre or hospital.
Fumigants and synthetic pesticides can be used to control these pests, but they are often not suitable for urban places with a limited number of pines (parks, school yards, recreational forest, etc.) due to their potential to cause an allergic or toxic reaction in people, pets and urban wildlife.
The LIFE PISA projects main objective was to demonstrate an alternative approach to controlling the target pests. Activities were planned in four countries (Greece, Italy, Spain and UK) and would focus on improving the effectiveness of trapping systems that can be used in a range of urban situations.
An updated review of environmental and health problems would be initially carried out, as well as associated EU legislation on the control of metropolitan pine pest problems. Results would inform the design and manufacture of new trap system prototypes, including:
In addition, the project would design and produce prototype versions of a mating disruption (MD) system that interferes with the males ability to find a female, resulting in reduced mating and egg-laying.
The LIFE PISA project demonstrated the viability of combining several techniques currently used to control pine processionary (Thaumetopoea pityocampa) and pine-tree lappet (Dendrolimus pini). These techniques were applied in different urban and recreational areas, where air or massive fumigation is not possible. The avoidance of chemical pesticides resulted in a decrease of the target species in these areas by at least 30%. They therefore led to a significant reduction of injures and allergic reactions in pets (mainly dogs), children and adults, while also reducing the amount of dead or defoliated trees. These mate disruption techniques were shown to be particularly effective for use in urban areas.
Furthermore, the project team was able to make some improvements to the existing control techniques. They improved the design and efficiency of the pheromone trap and optimised the trunk barrier device, making it easier to mount and dismount, and adaptable to different size pines. The cost of producing traps was also reduced to 33-40 per device, with trunk traps costing 25 per trap. The traps were designed to be inconspicuous and to leave other forest fauna undisturbed. Moreover, the project showed that recyclable bioplastics, such as PLA (polylactic acid), could be used in their construction, offering added value to manufacturers and contributing to the circular economy.
Knowledge gained during the project was transferred to forest pest control authorities, city council, neighbourhood associations and other relevant stakeholders, while a high number of companies interested in the project results contacted the project partners. The replication of the developed methods would help to minimise the problems related to the target species across Europe, and a market penetration of this technology of around 10% over the next couple of years is foreseeable.
Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).