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

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P.F. ROVERSI ET AL.
forestry productions and other human activities, including aspects related to
environmental hygiene. To this instance are referred those species whose larvae,
during specific developmental stages, bear urticating hairs, i.e. tegumentary
appendages, connected to special glands, capable of eliciting adverse reactions in
humans rangin from dermatitis and conjunctivitis to Ig-E mediated anaphylactic
reactions (Wirtz, 1984; Arlian, 2002).
In this chapter recent advance on these issues are discussed, with particular
attention to environment-friendly methods based on biological control agents,
including the G+ bacterium Bacillus thuringiensis and the technologies developed to
treat large park and forest areas in wild as well as urban environments.
2. URTICATING LEPIDOPTERA
The larval hairs, which act as defence mechanisms, are very small (about one tenth
of mm) and are generally harpoon-shaped. Their dissemination in the environment
raises serious implications for the public hygiene. When hairs penetrate the skin and
mucosal tissues of man or other warm-blooded organisms, they cause severe
irritations due to both the physical action of penetration (favoured by their shape)
and the chemical activity of a soluble protein released by the accidental breaking of
the hairs. These structures are set up on the larval body in particular areas called
“mirrors”, whose morphology and distribution are characteristic for each species.
The “mirrors” are produced at every moult, reaching their maximum breadth in last-age
larvae that can present from hundred–thousand to, sometimes, million urticating
hairs (Fig. 1b, c).
The effects produced on man by urticating hairs present a remarkable interest in
health-care, either for epidermic reactions, more or less persistent, aroused on the
majority of victims or for other consequences, sometimes observed in individuals
particularly responsive or sensitized, owing to reiterated contacts. Some worthmentioning
effects are those related to mucous tissues and sensory organs, mainly
eyes. Inflammatory reactions can be particularly dangerous for main airways when
massive inhalation occurs, due to unsafe operations performed during pest control
by workers not adequately protected (Lamy, Novak, Duboscq, Ducombs, &
Maleville, 1988).
Thanks to their tiny size, urticating hairs are easily carried away by air currents.
For this reason, during intense and widespread outbreaks, remarkable drawbacks
may occur not only close or within areas stricken by the disease, but also in
locations considerably far. In recent years, when monitoring the diffusion of this and
other structures or arthropods parts, these phenomena were referred as “Animal
Atmospheric Pollution”. At the same time, monitoring operations of pollen and other
allergenic structures transported by air are performed on this kind of organic
materials (Lamy, 1990; Werno & Lamy, 1990; Gottschling & Meyer, 2006).
Lepidopteran larvae bearing urticating hairs with a defence function are known
among many species of temperate and tropical regions within the following families:
Thaumetopoeidae, Lymantriidae, Saturniidae, Nymphalidae, Lasiocampidae,
Bombycidae, Arctiidae, Noctuidae, Anthelidae, Eupterotidae, Limacodidae and
Megalopygidae.