Impact of eucalyptus plantations in different regions of Brazil on the distribution and abundance of defoliating caterpillars

Eucalyptus species are cultivated in homogeneous plantations in Brazil, mainly to supply wood for the cellulose and steel industries, which favors the establishment of insect pests. The objective was to determine the geographical distribution and structure abundance of Lepidoptera defoliators of eucalypt. Primary pest species of eucalypt of the order Lepidoptera were found in all areas sampled and their populations were correlated with the age of the eucalypt plants, rainfall, and monthly average temperature. They presented population peaks between February and July [Tres Marias and Niquelandia] and July to November [Monte Dourado] during periods of lower rainfall. The highest population peaks of these species were recorded when the eucalypt plants were three to six years old. The area of Guanhaes presented better stability and fewer possibilities for the occurrence of eucalyptus Lepidoptera primary pests

Ecological observations and germination of Sterculia chicha seeds colonized by Anastrepha bezzii

Anastrepha bezzii [Diptera: Tephritidae] larvae are common inside fruits of Sterculia chicha [Malvaceae] in Minas Gerais State, Brazil. The seed dormancy and attack by A. bezzii of the native species S. chicha can be detrimental to seed germination and thus the natural spread of this plant. The objectives of the current study were to compare ecological observations of A. bezzii and S. chicha in the field and laboratory, and to assess the germination of S. chicha colonized by A. bezzii. A total of five seeds that were either intact or punctured by A. bezzii larvae were removed per S. chicha fruit. The seeds were subjected to a germination test performed using one of four treatments: intact seeds without scarification [T1]; intact seeds scarified for 3 min with sandpaper number 40 on one side of each seed [T2]; drilled seeds without scarification [T3]; and drilled seeds scarified for 3 min with sandpaper number 40 on one side of each seed [T4]. The germination of S. chicha seeds was highest in the T2 group [72.6%], intermediate in the T1 [51.7%] and T4 groups [33.1%], and lowest in the T3 group [11.2%]. The attack by A. bezzii of the fruits and seeds of S. chicha can be detrimental to seed germination and thus the further establishment of this native species in the field. The scarification of intact seeds of S. chicha for 3 min with sandpaper number 40 on one side of each seed can overcome the dormancy for its production in nurseries