The Old World genus Bruchidius Schilsky, 1905 (Coleoptera: Chrysomelidae: Bruchinae), comprises about 300 species of seed beetles (Kingsolver 2004). Bruchine chrysomelids are economically important pests of agricultural and stored products. Larval host plants of most Bruchidius species are legumes (Fabaceae), as well as species of Apiaceae and Asteraceae (Borowiec 1987). Albizia julibrissin Durazz, and Cercis siliquastrum L. (Fabales: Fabaceae) are native to Turkey and planted as ornamental trees. We studied the seed beetles Bruchidius terrenus (Sharp) and B. siliquastri Delobel, which infest the seeds of A. julibrissin and C. siliquastrum, respectively, and their parasitoids.

MATERIAL AND METHODS

Seed pods of Albizia julibrissin (Mimosa) were collected in 2011 and 2012 on the Istanbul University Forestry Faculty Campus and at the Atatürk Arboretum. Cercis siliquastrum (Judas tree) seed pods were collected at the same locations in 2012. Pods were held in the laboratory in plastic boxes until the emergence of adult beetles and parasitoids.

RESULTS AND DISCUSSION

Seeds of A. julibrissin collected on the Istanbul University Forestry Faculty campus and at the Atatürk Arboretum were infested (Table 1) with Bruchidius terrenus (Fig. 1). In 2011 the rate of infestation of A. julibrissin seeds with this bruchid was 71.01% from the Forestry Faculty Campus and 59.07% from the Atatürk Arboretum. The corresponding rates in 2012 were 78.05% and 52.23%. Dinarmus acutus (Thomson) (Hymenoptera: Pteromalidae: Pteromalinae) parasitized B. terrenus at both locations.

Hoebeke et al. (2009) reported about 90% of seeds of some A. julibrissin trees in USA were infested with B. terrenus. We found seeds of this plant species heavily infested with B. terrenus (Table 1), an Asian seed specialist of A. julibrissin that occurs widely in the eastern Palearctic Region, North America, Bulgaria (Moritomo 1990; Hua 2002; Hoebeke et al. 2009; Stojanova et al. 2011). According to Stojanova (2010) the presence of its host plant, an appropriate climate, and the absence of natural enemies are conditions favorable for fast and successful invasion by B. terrenus in new territories outside its native range.

Fig. 1.

Bruchidius terrenus, a) adult, b) larvae in seed, and c) exit hole on seed d) male genitalia e) female genitalia.

TABLE 1.

EMERGENCE OF THE SEED BEETLE BRUCHIDIUS TERRENUS FROM SEEDS OF ALBIZIA JULIBRISSIN AND EMERGENCE OF A PTEROMALID PARASITOID FROM B. TERRENUS .

TABLE 2.

EMERGENCE OF THE SEED BEETLE BRUCHIDIUS SILIQUASTRI FROM SEEDS OF CERCIS SILIQUASTRUM AND EMERGENCE OF A PTEROMALID PARASITOID FROM B. SILIQUASTRI .

Fig. 2.

Bruchidius siliquastri, a) male, b) female, c) male pygidium, d) female pygidium showing foveae, e) male venter I, showing the large setiferous patch, f) female venter I. g) male genitalia h) female genitalia.

Seeds of the C. siliquastrum collected on the Istanbul University Forestry Faculty Campus and at the Atatürk Arboretum were infested (Table 2). The infestation rate of Cercis siliquastrum seeds by B. siliquastri (Fig. 2) on the Forestry Faculty campus was 81.85% and 75.61% at the Atatürk Arboretum. Also D. acutus was a parasitoid of Bruchidius siliquastri at the 2 locations. Bruchidius siliquastri was newly recorded in France as a seed beetle of C. siliquastrum (Kergoat et al. 2007), and subsequently in China, Hungary, Spain, Belgium, Slovakia, Czech Republic and Bulgaria (Stojanova et al. 2011; Šefrová 2010; Yus Ramos 2009a,b,c).

In this study we recognized that these seed beetle species are very specialized to their host plants, because we did not find Bruchidius siliquastri in Albizia julibrissin seeds nor B. terrenus in Cercis siliquastrum seeds.

Bruchidius terrenus and B. siliquastri, Delobel 2007 are recorded for the first time from Turkey in our study.