Page 3 - Berni_1997

A brief contribution to the history of the genus Bacillus in Sicily
Simone Berni, 17 Loc. Le More di Cuna, 53014 Monteroni d'Arbia (Sn, Italy.

Abstract
Some short notes on the presence of the genus Bacillus (lnsecta, Phasmatodea, Bacillidae) in the ltalian peninsula and
particularly in Sicily. The present paper recounts the vicissitudes that led to the discovery of ne w taxa in the 1980s;
provides an outline of their distribution, with notes on the relationships between the different species and a further
account of their reproduction modes. Finally, excursions to the lblean region (south-eastern Sicily) and Marettimo
Island (Egadi Archipelago) are described, and future trips and study projects are suggested.

Key words
Bacillus, Sicily, lblean region, Amphigonic, Hybrid, Parthenogenesis, Hybridogenesis, Gynogenesis, Androgenesis,
Species, Endemie, Extinction, Rearing, Biodiversity.

lntroduction
Up to the 1960s, only one amphigonic (sexually reproducing) population of Bacillus rossius
(Rossi, 1788) in the ltalian peninsula was recorded in the literature (Montalenti & Fratini,
1959) and was located in Campania. ltalian researchers subsequently noted some further
findings in Liguria and Tuscany (Marina di Pisa), where both amphigonic and parthenogenetic
populations were living. With regard to B. rossius, some authors noted various sub-species
defined on electrophoretic and ootaxonomic bases; two of these are recorded in Italy (see
Figure 1). B. rossius rossius is located along the Tirrenic coasts (the coastlines of Liguria,
Tuscany, Sardinia, Campania and Lazio), andina small area at the river Po delta, while B.
rossius redtenbacheri lives along the entire length of the Adriatic and lonic basins and at the
ti p of the Italian peninsula (Calabria, Apulia, Basilicata), including Sicily, the Eolie Islands
and a small area in southem Sardinia (see Figure 2 fora view of the ltalian Districts).

Recently described taxa in Sicily
Prior to 1980 only B. rossius and Clonopsis gallica (Charpentier, 1825) were known from
ltaly and there was a considerable amount of confusion among dealers and breeders of
insects. When the efforts of researchers concentrated on southem ltaly (and in particular on
Sicily) in search of bisexual stocks of B. rossius, they soon found themselves confronted with
some new species of stick insects. Within a short time period, in the Iblean region of south-
eastem Sicily, Bacillus grandii (Nascetti & Bullini, 1982), Bacillus whitei (Nascetti & Bullini,
1982) and Bacillus lynceorum (Bullini, Nascetti & Bianchi Bullini, 1984) were described.
Holotypes of new Sicilian stick insects are kept a t N atural History Museum "Giacomo
Doria", Genoa, Italy. The fust species immediately aroused interest because it was bisexual,
in the same manner as B. rossius. The others two species were hybrids and the interest of
the researchers was stimulated by their reproductive mechanisms, because it was clear they
were genetically free from the progenitor taxa (species which ha ve originated the hybrids).
Parthenogenesis, the embryonal development in the egg without the participation ofthe
male, was first noted in Bacillus as far back as the beginning of the 1930s, thanks to
observations made by a group of French researchers that included Cappe de Baillon, de
Vichet and Favrelle (Benazzi, 1946). These authors carried out a series of experiments by
crossing females of B. rossius, which in France is a parthenogenetic species only because
males are very rare (de Vichet, 1944), with males of the same species collected from the
Algerian coasts in bisexual populations (Favrelle & de Vichet, 1937). So-called "geographic
parthenogenesis" was presumed to take piace in regions with cold climates. Later, this
assumption was contradicted by the discovery of parthenogenetic populations in areas, such
as the Iblean region, where the climate would seem to favour amphigonic populations. From
the 1960s onwards, the ltalian zoologists and cytogenetists Mario Benazzi (initially) and

Phasmid Studies. 6(1 ): l