TWO NEW HOST ANTS OF THE MYRMECOPHILOUS BEETLE SPECIES THORICTUS BUIGASI ESCALERA, 1923 (COLEOPTERA: DERMESTIDAE: THORICTINAE) FROM MOROCCO

Introduction [Up]

Thorictus buigasi Escalera, 1923 is a myrmecophilous phoretic species (‍Kistner, 1979). Till now, its only known host ant species was Cataglyphis viatica, to which antennae it attaches with its mandibles (‍Háva et al., 2012). This species was already known in Morocco in two localities, Essaouira in the Atlantic coast (‍John 1965; ‍Kocher 1969), and Marrakech in the High Atlas (‍Háva et al., 2012; ‍Lenoir, 2013).

The study of some twenty colonies of different species of Cataglyphis collected during myrmecological prospections by the first author in Morocco has allowed the discovery for the first time from Morocco of Cataglyphis otini Santschi, 1929 and C. cubica (Forel, 1903) as new host ants for the myrmecophilous beetle species Thorictus buigasi.

Material and methods[Up]

During myrmecological prospections in Morocco, between April and June, we were able to excavate a number of colonies of Cataglyphis of different species. The presence of T. buigasi was verified at body level on collected workers (especially at the antennae) as well as in the compartments and the dumps of the nests.

Ants and beetle specimens were studied under a Nikon SMZ745 stereomicroscope and identified using a key for Cataglyphis (‍Cagniant, 2009) and the dermestidae.wz.cz website (‍Háva, 2012). All specimens are deposited in the faunistic collection of the Faculty of Sciences of El Jadida.

Results[Up]

Cataglyphis otini and C. cubica are reported for the first time in Morocco as two new host ants of Thorictus buigasi. Regarding C. cubica, the specimen of T. buigasi was collected from the head of a worker (Tangier province), like in the example of C. viatica (‍Háva et al., 2012). However, in the case of C. otini, five specimens of T. buigasi were found freely walking in the nest dump in Benslimane province. In the same locality, seven specimens of the beetle were captured by sifting organic remains from C. viatica nest dumps (Figs 1-2).

Fig. 1.— New distribution of T. buigasi in Morocco: old citations associated with C. viatica are in blue circles, new ones are in red (square with C. cubica, triangle with C. otini and circle with C. viatica).

Fig. 1.– Nueva distribución de T. buigasi en Marruecos: las citas antiguas asociadas a C. viatica figuran en círculos azules, las nuevas en rojo (cuadrado con C. cubica, triángulo con C. otini y círculo con C. viatica).

Fig. 2.— (a) Thorictus buigasi on the head of Cataglyphis cubica (new record), (b) Thorictus buigasi on the head of Cataglyphis viatica (photo: Fernando Amor in Háva et al., 2012).

Fig. 2.– (a) Thorictus buigasi sobre la cabeza de Cataglyphis cubica (nuevo registro), (b) Thorictus buigasi sobre la cabeza de Cataglyphis viatica (foto: Fernando Amor en ‍Háva et al., 2012).

Discussion [Up]

Thorictus buigasi shows a wide geographical distribution in Morocco (Rif: Tangier, Central Plateau: Benslimane, Coastal Atlantic: Essaouira and High Atlas: Marrakech) and also displays variability regarding their ant host species. In fact, it does not attach in a specific way to C. viatica, but it can be hosted by other species at least belonging to the same genus (C. cubica and C. otini). This variation has also been reported in several taxa in the castaneus species group, such as: Thorictus castaneus castaneus Germar, 1834, T. foreli Wasmann, 1894, T. foveicollis Reitter, 1880, and T. gibbosus Zhantiev, 2010 (‍Háva et al., 2012).

Moroccan T. buigasi records (‍John, 1965; ‍Kocher, 1969; ‍Háva et al., 2012) were described as clinging to the antennae of C. viatica with their mandibles. During our surveys, specimens located in Benslimane province were detected free in the nest dump. However, the specimen detected in Tangier was found hooked to the head of a C. cubica worker.

The discovery of T. buigasi both free in the nest dump and attached to ant antennae suggests that this species leads a free life inside the nest, and uses its host to move when necessary, since they are detritivorous (‍Sánchez-Piñero & Gómez, 1995). It is not surprising that its preferred habitat is the dump because of the presence of an abundant amount of organic matter accumulated by its host.