Born in Rivello (PZ) on 5.7.1937. In 1960 graduate in Agricultural Sciences at University of Naples, Faculty of Agriculture, in Portici (NA).

1975-1981. Coordinator of  the Italian research center group “Integrated Control”.

1977. Full member of the Italian Academy of Entomology.

1978-2009. Full professor of Biological and Integrated Control, University of Naples.

1981-1988. Member  of the advisory commitee for the Agricultural Sciences.

1984. Italian delegate in the International Organization of Biological control – Section West Palaearctic.

1984-1987. Director of the Institute of Agricultural Entomology, University of Naples.

1987-1989. Director of the Department of Entomology and Agrcultural Zoology.

1989-1994. Coordinator of  the research group “Biological  Control” (Ministry of Agriculture).

1996-2003. Director of the Italian research center “Tecniques of Biological Control”.

1994-2003. Coordinator of the doctorate course “Agricultural Entomology” at the University of Naples “Federico II”.

The researches carried out concern  subject matters of  agricultural entomology, biological and integrated control, taxonomy and biology of entonophagous insects, mainly Hymenoptera Chalcidoidea.
1986. Awarded gold medal from the “Filippo Silvestri” Foundation for significant researches in biological control.

Doutt R. L., Viggiani G. 1968. The classification of the Trichogrammatidae (Hym. Trichogrammatidae). Proc. Cal. Ac. Sc. 35 (fourth ser.): 477-586.

Viggiani G. 1971. Studio morfologico comparativo dell’armatura genitale esterna maschile dei Trichogrammatidae. Ricerche sugli Hymenoptera Chalcidoidea. XXVIII. Boll. Lab. Ent. agr. “Filippo Silvestri” 29: 181-222.

Viggiani G., Mazzone P. 1978. Morfologia, biologia e utilizzazione di Prospaltella lahorensis How. (Hym. Aphelinidae), parassita esotico introdotto in Italia per la lotta biologica al Dialeurodes citri (Ashm.). Ricerche sugli Hymenoptera Chalcidoidea. LX. Boll. Lab. Ent. agr. “Filippo Silvestri” 35: 99-160.

Viggiani G. 2019. New genera, species, and records of Trichogrammatidae (Hymenoptera: Chalcidoidea). Fragmenta entomologica 51 (2): 161-186.

Viggiani G. 2020.  The complex of parasitoids of Asphondylia spp. (Diptera Cecidomyiidae), flower gall midges of Lamiaceae, with description of a new species of Baryscapus (Hymenoptera Eulophidae). Bulletin of Insectology 73 (1): 45-52.