During collections carried out in Guerrero, Mexico in 2001, Euoniticellus intermedius (Reiche 1849), a scarab not previously known from Guerrero was captured. In addition, Eurysternus magnus Castelnau 1840 was collected in Acahuizotla on September 4, 2001 at an altitude of 650 m, a range extension for this native species.
Euoniticellus intermedius (Reiche 1849) was introduced into Texas in the 1970s. The first record from Mexico was from the Reservation of the Biosphere “La Michilía”, in the state of Durano by Montes de Oca et al. (1994). Three years later, Montes de Oca & Halffter (1997) reported it from Baja California Sur, Guanajuato, Michoacán, Chihuahua, Tamaulipas, Hildago, and Veracruz. Deloya (2000) recorded it from the south of the state of Morelos. In monthly collections carried out in the Sierra Madre del Sur between 1,400-1,670 between January and June, 2001 at Ocotito (17°14'17” N, 99°30'43” W), Guerrero, a female specimen of E. intermedius was collected. It is the first record for the state of Guerrero. The specimen is labelled “MEXICO: Guerrero, Chilpancingo, Ocotito, 30-III-2001, altitude 680 m, bovine excrement, 12:30 pm, E. Ramírez, col. (1)”. It is deposited in the entomological collection of the Instituto de Ecología, A.C. (IEXA). The locality is a Pinus-Quercus forest with annual precipitation of 1650 mm and annual half temperature of 24°C.
The native scarab Eurysternus magnus has a wide distribution between Panama and Mexico in montane rain forest between the 900 and 2,200 m (Howden & Young 1981; Jessop 1985; Morón 1994). In Mexico, it has been reported from Chiapas, Guerrero Hidalgo, Oaxaca, Querétaro, Tamaulipas, and Veracruz. In the Sierra Madre del Sur, E. magnus had been recorded from Juquila, Oaxaca to 1,550 m (Bates 1888) and from the Sierra del Alquitrán, Guerrero, in a Quercus-Pinus forest between 1,400 and 1,670 m (Delgado 1997).
Delgado Castillo (1989) carried out a study between 1985 and 1987 on the Scarabaeoidea fauna of Acahuizotla, between 650-850 m altitude. He mentions Pseudocanthon Bates, Deltochilum Eschscholtz, Canthon Hoffmansegg, Coprophanaeus Olsoufieff, Phanaeus MacLeay, Copris Müller, Dichotomius Hope, Canthidium Erichson, Ateuchus Weber, Scatimus Erichson, Uroxys Westwood, and Onthophagus Latreille. In that study, intensive sampling with pitfall traps baited with carrion, bovine dung, and equine dung failed to reveal the presence of Eurysternus.
A specimen of Eurysternus now deposited in the entomological collection of the Instituto de Ecología, A.C. (IEXA), is labelled MEXICO: Guerrero, Achauizotla, 650 m msm, 4-IX-2001, Juarez Pineda, A.J. col. (1).” This specimen was collected at substantially lower altitude (650m) than specimens reported by previous collectors, who collected at 1400-1670 m.
This communication is a contribution to the project “Systematic and ecology of insects phytophagous and saprophagous” of the Departamento Entomología (912-044), Instituto de Ecología, A.C.
Euoniticellus intermedius (Reiche) is reported for the first time from the State of Guerrero, Mexico, with a female specimen captured at Ocotito on 30 March 2001. The altitudinal range of Eurysternus magnus Castelnau in the Sierra Madre del Sur (1,400-1,670 m), is greatly extended with a male specimen captured at 650 m at Acahuizotla, Guerrero, on September 4, 2001.