Stator limbatus, (HORN, 1873)

Garlet, Juliana, Costa, Ervandil C., Boscardin, Jardel, Murari, Augusto B. & Machado, Dayanna N., 2011, Damage byStator limbatus (Horn, 1873) (Coleoptera: Chrysomelidae: Bruchinae) to Seeds ofAcacia podalyriifoliaA. Cunningham ex G. Don. (Fabaceae: Mimosoideae), The Coleopterists Bulletin 65 (4), pp. 432-433 : 432-433

DAMAGE BY STATOR LIMBATUS (HORN, 1873) ( COLEOPTERA : CHRYSOMELIDAE : BRUCHINAE ) TO SEEDS OF ACACIA PODALYRIIFOLIA A. CUNNINGHAM EX G. DON . ( FABACEAE : MIMOSOIDEAE )

JULIANA GARLET, ERVANDIL C. COSTA, JARDEL BOSCARDIN, AUGUSTO B. MURARI, AND DAYANNA N. MACHADO Departamento de Defesa Fitossanitária, Universidade Federal de Santa Maria Av. Roraiama, n° 1000, prédio 42, Bairro Camobi, Santa Maria, Rio Grande do Sul, BRAZIL [e-mail]

Plants in the genus Acacia Miller ( Fabaceae : Mimosoideae ) are widely cultivated in Brazil. Some species, such as Acacia mearnsii de Wild. and Acacia mangium Willd. which are planted in the southern and northern parts of the country, respectively, are used in the production of cellulose, charcoal, and tannin. Acacia podalyriifolia A. Cunningham ex G. Don is an important ornamental plant for the purpose of landscaping in parks, gardens, and streets because of the small size of its canopy that varies between five and seven meters. The leaves of this ornamental plant are very decorative due to their colors. Thus, they can be used in flower arrangements and bouquets ( Lorenzi et al. 2003).

The production of quality seedlings of Acacia is difficult because the seeds are frequently attacked by pest insects. Of these, beetles of the chrysomelid subfamily Bruchinae are the most dominant pest insects (Romero and Johnson 2004). The damage caused by bruchines can hinder acquiring seeds to propagate the forest species. In addition, this damage can also facilitate fungal infection and the appearance of other pathogenic agents ( Soave and Wetzel 1987). The damage is normally in the maturation process, and it is hard to control the pest at this stage. After the egg hatches, the larva enters the seed and grows within. Near the time of physiological maturation, the adult emerges from the damaged seed ( Santos et al. 1991, 1994). The present study reports the occurrence of damage to A. podalyriifolia seeds by Stator limbatus (Horn, 1873) .

In December 2009, damage was observed in A. podalyriifolia seeds by insects in Santa Maria, Rio Grande do Sul, Brazil. The following year, seeds were collected from September to December 2010; the period of seed maturation is from November to December. The pods were taken directly from the canopy of five trees, from which 3,652 seeds were collected .

Adult emergence from the seeds occurred at the beginning of December 2010. Two thousand five hundred seeds (70%) were attacked and from them 2,598 adult beetles emerged. One to three emergence holes were found per seed ( Fig. 1 ). Thus, up to three adults emerged from some seeds. The beetles were identified as S. limbatus by comparison with identified individuals in the Laboratory of Forest Entomology at the University Federal of Santa Maria. Adult S. limbatus have a dark colored head, elytra with orange spots and dark borders, and broad hind femora ( Fig. 2 ). The adults vary between 1.6 and 2.7 mm in length ( Pereira et al. 2004). Bruchines may have several generations per year depending on temperature and humidity (Howe and Currie 1964), so probably after the outbreak of the seeds of A. podalyriifolia , the insect sought another host for reproduction.

This is the first report of A. podalyriifolia seeds attacked by S. limbatus in Brazil. Morse and Farrell (2005) affirmed that S. limbatus is the most generalist species of the genus, attacking the seeds of 59 plant species in 18 genera. Johnson (1995) reported 74 hosts for S. limbatus in Latin America, among which 30 are in the genus Acacia . In Brazil, there are reports of S. limbatus attacking A. mangium in Roraima ( Pereira et al. 2004) and A. mearnsii in Rio Grande do Sul. The above mentioned observation suggests that this pest insect is distributed throughout the Brazilian territory (Oliveira and Costa 2009).

Figures

Fig. 1. Acacia podalyriifolia seed (8 mm long) attacked by Stator limbatus.

Fig. 2. Stator limbatus, dorsal view (2.42 mm long).