Senna multijuga (Rich.) H. S. Irwin & Barneby (Caesalpinaceae) is a native ornamental tree common in southeastern Brazil and susceptible to seed damage due to bruchines. To identify seed predators and determine their population cycles, fruits from five trees were collected in 2000 and 2001 and stored in a green house until adult emerged. Seed beetles were then identified as Sennius crudelis Ribeiro-Costa & Reynaud, 1998, S. puncticollis (Fåhraeus, 1839) and S. nappi Ribeiro-Costa & Reynaud, 1998. Sennius crudelis was the most abundant species in 2000 followed by S. puncticollis and S. nappi. In 2001, Sennius crudelis was followed by S. nappi and S. puncticollis. Differences were observed among trees relating to fruiting period which reflected in the oviposition. Adult emergence begins in July in the green house and in the field. These results show that bruchine beetles have complex population dynamics, and understanding those dynamics is important to answer other ecological questions of the group.
Bruchinae; population dynamics; seed predators; Sennius
