Main lepidopteran pest species from an eucalyptus plantation in Minas Gerais, Brazil

Abstract

Lepidoptera species were monitored in a plantation of Eucalyptus grandis in the Municipality of Bom Despacho, State of Minas Gerais, Brazil from March 1987 to February 1992. A total of 547 species were collected and divided in: primary pests: 13; secondary pests: 20; species without defined importance to eucalyptus: 79; and non-identified species: 435. These four groups had a mean of 5231.29; 338.18; 438.16 and 2222.87 individuals with a total of 8229.87 individuals collected per trap. The number of species without defined importance to eucalyptus, and non-identified species, increased during the collecting period of five years while those of primary and secondary pests showed similar numbers in all years. The most collected primary pests Thyrinteina arnobia Stoll and Stenalcidia sp. (Geometridae) showed higher frequencies during the driest and coldest periods of the year, whereas Psorocampa denticulata Schaus (Notodontidae) was most frequent during periods of higher rainfall. Species of groups III and IV increased in diversity with eucalyptus age. This area has a high probability of outbreaks of eucalyptus defoliating caterpillars, especially T. arnobia. For this reason, lepidopteran pests should be monitored in this plantation during the driest and coldest periods of the year, when they can reach population peaks. Rev. Biol. Trop. 54(2): 553-560. Epub 2006 Jun 01.

Population Dynamics of Lepidoptera Pests in Eucalyptus urophylla Plantations in the Brazilian Amazonia

“…The population peaks of group I pests were similar to those of the other areas of Brazil, usually during the drier months and with warmer temperatures when the plants may exhibit stress mainly due to water deficit [6,7,11,12,20]. Stress in the eucalyptus trees may favor the establishment of insect pests, due to lowered plant defenses [7,21].…”

“…Species of primary and secondary pests included 48.52% of the total number of individuals, which was only 4.72% of the total species, showing their adaptation to the eucalyptus plantations [7,9,11,12,17]. Species of the native vegetation may migrate to the eucalypts due to the abundant food supply where they can become pests in several regions of Brazil [8,12].…”

“…Psorocampa denticulata showed low abundance of occurrence. It did not occur in most years, and showed reduced frequency in the total number of individuals; however, it is one of the most frequent in other Brazilian regions [6,11,12,16] during periods of rainfall [11]. This species exhibits diapause in the pre-pupal stage and requires periods of low and high humidity to complete the cycle.…”

“…The lepidopteran specimens collected were divided into groups I, II, and III, representing the primary pests, secondary pests, and species without defined importance to eucalyptus, respectively [11].…”

Insect pests in tropical forestry

“…LEPIDOPTERAN DEFOLIATORS -BRAZIL The increasing pest problems in Eucalyptus monocultures in Brazil led to the establishment of survey programmes in the late 1980s and early 1990s that aimed to identify and recognize the relative importance of the various eucalypt insect pests (Zanuncio et al, 2001). The main pests in these plantations were found to be defoliating insects, par ticularly caterpillars of moths such as Thyrinteina arnobia (see Chapters 5 and 10), Stenalcidia grosica and Glena unipennaria (Geometridae), Eupseudosoma aberrans (Arctiidae) and Psorocampa denticulata (Notodontidae) (Zanuncio et al, 2001(Zanuncio et al, , 2003(Zanuncio et al, , 2006de Freitas et al, 2005). The moths of most of the lepidopteran defoliators are night active and their populations have been moni tored with light traps equipped with black-light tubes and 12-V batteries placed 2 m above ground level (Pereira et al, 2001;Zanuncio et al, 2006).…”