[Edited_by_A._Ciancio,_C.N.R.,_Bari,_Italy_and_K.(Bookos.org)

AERIAL BT TREATMENTS
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The main species of urticating Lepidoptera, responsible of severe infestations
among countries around the Mediterranean see, belong to the genus Thaumetopoea
(Fam. Thaumetopoeidae) and Euproctis (Fam. Lymantridae) (Roversi, 2006). In the
Palaearctic region, the members of the Thaumetopoeidae family form a small group
of species that represents a formidable menace in wide areas even because of the
progressive expansion of their distribution range. The increase in their distribution
area is the consequence of both general climatic trends, characterized by milder
winter temperatures, and anomalous climatic events allowing colonization of new
territories, either at higher altitudes as well as in areas northern than those reached
until a few years ago.
The two main species known for the negative effects of their infestations are the
Pine Processionary Moth (PPM), Thaumetopoea pityocampa (Den. et Schiff.) and
the Oak Processionary Moth (OPM), T. processioneae (L.). Proceeding towards
northern territories other species are worth mention, such as T. pinivora (Treitschke)
whose colonies are reported to have increased their extension in areas of North
Europe completely undamaged until recent times.
The individuals of the three species exhibit a sub-social behaviour, their larvae
living in groups throughout their development. Moreover, the first two species
sometimes build nests of remarkable dimensions, so that a huge amount of urticating
hairs can be present inside the nests for a long time.
PPM is a lepidopteran with a wide distribution range in the Mediterranean area
and Middle-East Europe. It is considered the most important insect pest of pines in
southern Europe and North Africa, affecting many indigenous and exotic pines, as
well as other Pinaceae (in order of preference, Pinus nigra austriaca, P. sylvestris,
P. laricio, P. pinea, P. halepensis, P. pinaster, P. canariensis, Cedrus spp. and Larix
decidua) (OEPP/EPPO, 2004). Within its range of distribution, T. pityocampa is
common in extremely diversified habitats, varying from coastal formations to
mountain woods at altitudes higher than 2,000 m. Particularly severe problems are
reported at the end of winter, when long processions of mature larvae abandon pines
in a line, as they come down from trees to deepen themselves into the ground, where
pupation will take place (Fig. 1a). In this last phase, contacts with people and
animals are very frequent.
OPM is an univoltine forest defoliator of deciduous oaks, widely distributed in
central, western and southern Europe (Agenjo, 1941). The larvae are equipped, from
the third instar, with urticating hairs and are active in spring–summer. They exhibit a
gregarious behaviour throughout their life, constructing sack-shaped nests on the
stem or axis of large branches, in which they pupate in a papery cartoon. This pest
can completely defoliate oak stands but it is also found on isolated trees in avenues
and parks. Since the 1990s, heavy attacks by OPM have become increasingly
frequent throughout very large areas in various European countries (Flemming,
1997; Tomiczek & Krehan, 2003; Lövgren & Dalsved, 2005; Wulf & Pehl, 2005),
including Holland, where outbreaks had not been reported for a century (Bosma &
Jans, 1998; Stigter & Romeijn, 1992; Stigter, Geraedts, & Spikers, 1996).
In recent years, OPM became a problem even in United Kingdom (Townsend,
2007). In southern Europe heavy and extensive infestations occurred both in Middle
European oak environments and forests, and in sub-Mediterranean inhabited mainly