Notes on the biology of Italian taxa

Genus Nyctophila

Nyctophila reichii larva. Credits: Ferran Pestaña.
Nyctophila reichii adult female.

In Italy genus Nyctophila includes three species. According to the European Check List Project, Nyctophila reichii is quite common both in Spain and France, but it is not recorded  in Italy. Anyway, it has to be noted that for one of them (N. reichei) the project “Fauna d’Italia” reports“possible presence along western borders of Italy” while two species are endemic that is N. calabriae solely recorded in Calabria and Nyctophila bonvouloirii to be found only in Sicily (Audisio et al., 1995).

Adults males and females are significantly different. The adult male anatomy is the one typical of Coleoptera: the fore wings are transformed in elyptrae protecting the hind wings used for flying. Adult females are neotenic and unable to fly. Black larvae are predators feeding on slugs and snails. Unfortunately, little scientific knowledge about the biology of the species belonging to this genus is recorded in Italy.

Genus Lampyris

Lampyris noctiluca adult female. Credits: David Evans.

Eight species of Italian fireflies belong to genus LampyrisL.noctiluca can be easily found in Europe and in Great Britain. The distribution of four of the endemic species (L. ambigena, L. brutia, L. lareynii and L. fuscata) is limited to the southern regions of Italy, while L. sardiniae is an insular endemism (De Cock & Geisthardt, 2007). 

Like in the genus Nyctophila, sexes are dimorphic. Adult females are neotenic and larger than males; they emit a constant, green light while lying on the ground or herbs, whereas males are not visible when flying in darkness in search for females, since their bioluminescence is limited to spots under the abdomen. In Italy L. noctiluca’s flight season is longer than the one of Luciola sp.,  spanning from May to September, if summer drought is not severe.

Lampyris larva (dorsal vision). Credits: Tito Sacchi.

Larvae can emit light, too. Their life cycle needs two/three years to be completed, while their feeding behavior resembles the ones of Nyctophila larvae, which means they prey on small soil invertebrates like snails and slugs. First, preys are bitten and then a digestive fluid is injected in their body; as a result the prey is first paralyzed and then liquefied.

Habitat mainly includes meadows, hedgerows, ditches.

Genus Lamprohiza

Lamprohiza splendidula adult female. Credits: Francisco Walter Schultes.

Four species belonging to this genus are known in Italy. The distribution of one of them (L. foliacea) has an endemic nature (Sardinia). L. splendidula is more common than other species recorded in Italy.

Adult females have got a whitish abdomen; they cannot fly. Through photogen organs located in their whitish abdomen, they  emit a green light which can be seen even on the dorsal section of their body. Adult males, which are smaller than females,  glow when flying thanks to the luminous bands located in their last ventral segments. Larvae are flat, dorsally brownish and ventrally yellowish. Their light organs lie in the abdomen and shine dorsally through the cuticle; they usually glow only when disturbed.

Genus Phosphaenus

Lamprohiza splendidula and Phosphaenus hemipterus.

The only species belonging to this genus is P.hemipterus. Male adults are provided with incomplete wings, while females are wingless. Adults are dark brown, and females are bigger than males. Larvae resemble the ones of Lampyris, but they lack the bilateral series of reddish dots on the abdomen and are smaller and darker.

Their distribution is very wide: from the Mediterranean area to Central Europe, from West near the Atlantic Ocean to North to the edge of Scandinavia and in England. Moreover, this species was introduced in North America. 

Habitat includes meadows, forest edges, but more commonly males can be observed in sites containing pavements, brickwork or stonework, such as parks or gardens (De Cock, 2004; Tyler, 2002). Females can be rarely observed, as they usually use as a shelter ground cracks.

Genus Luciola

Luciola lusitanica (male, dorsal vision). Credits: TIto Sacchi.
Luciola lusitanica (male, ventral vision). Credits: Tito Sacchi.
Ventral vision of Luciola lusitanica male and female adults (l: photogenic area).

Two Luciola species can be recorded in Italy: L.italica and L.lusitanica (Audisio et al.,1995; Brunelli et al., 1997). The taxonomy of European species belonging to Luciola is under review; however, a molecular taxonomy research has revealed the existence of five different clades, but in Italy the separation between populations of L.italica and L.lusitanica is not always clear (Day et al.,2014). While waiting for the results of the ongoing revision, the discrimination between those species can base on morphology, first of all on size, since both adult males and females of L.lusitanica are bigger than Luciola italica (Mikšić, 1969).

In the Po floodplain  L. lusitanica nuptial flights can be usually observed from May to July, from nightfall to midnight. Males’ flight activity usually peaks in June. The length of the flight season is affected by rainfall, since abundant rainfall can extend the flight season (unpublished data). Another important ecological factor is temperature: in the Apennines, due to the effect of altitude on temperatures, males’ flight season tends to be delayed in comparison to the one in the plain. Differently from males, females do not fly, but they glow to attract males while resting on herbs or on the soil. Courtship signals were studied by Papi (1969). After mating, females lay their eggs on the soil, where larvae will develop by preying upon snails, slugs and other small invertebrates.