Working Group on Iberian Lucanidae (GTLI)

Justification and objectives
Lucanidae larvae are melolonthiform and feed on decaying wood. They are not strictly xylophagous, but saproxylophagous (Dajoz, 1974). All Lucanidae have three larval instars. Duration of larval life is variable, between one and five years depending on the species (Paulian, 1988). This slow development is due to the low nitritive quality of decayed wood (low nitrogen content). Because larval period makes the most of Lucanidae life cycle, due to this slow development, it is needed to know th details of this phase if a better understanding of the ecology and conservation of this group is to be got. Unfortunately, almost all information available about larval diet is merely anecdotic. The influence of temperature, humidity, tree species or nutritive quality on the larval development is unknown. No study has been carried out about, e.g. preference for certain tree species or the quality of different tree species as larval food (Hanks et al., 1993).

GTLI is especially interested in larval biology of Lucanidae. Because insect growing is a popular activity among amateur entomologists, it should be possible to take advantege of this hobby to get a very valuable scientific information:

• duration of each larval instar,
• pupation behaviour,
• food intake rates foreach larval instar,
• growth rates between and within instars,
• variation of the growth as a function of wood kind (tree species and decaying level),
• variation of adult body size as a function of feeding larval conditions (Moczek, 1998).

How to collaborate
Follow the instructions for the scientific study of larval development in Lucanidae (only in Spanish). There two basic projects can be found which address the objectives above.

References

Dajoz, R. 1974. Les insectes xylophages et leur rôle dans la dégradation du bois mort. En P. Pesson (ed.) Écologie forestière. La fôret: son climat, son sol, ses arbres, sa faune: 257-307. Gauthier-Villars, París.

Hanks, L. M.; Paine, T. D. & Millar, J. G. 1993. Host species preference and larval performance in the wood-boring beetle Phoracantha semipunctata F. Oecologia 95: 22-29.

Moczek, A. P. 1998. Horn polyphenism in the beetle Onthophagus taurus: larval diet quality and plasticity in parental investment determine adult body size and male horn morphology. Behav. Ecol. 9: 636-641.

Paulian, R. 1988. Biologie des coléoptères. Lechevalier, París.