Within-Tree Distribution and Survival of the Eucalyptus Longhorned Borer Phoracantha semipunctata (Coleoptera: Cerambycidae) in a Mediterranean-Type Ecosystem

The attack patterns, infestation success and larval development of woodborers within living trees are complex and are largely shaped by host tree characteristics. Following a severe drought in a native eucalypt forest where outbreak densities of a native Australian beetle, the eucalyptus longhorned borer (Phoracantha semipunctata), occurred, a tree dissection study was conducted in Australia. This involved felling 40 trees each of jarrah (Eucalyptus marginata) and marri (Corymbia calophylla) that were cut into 1-m sections and neonate larval galleries, larvae in pupal cells and adult borer emergence were measured and added to give total numbers per tree to determine the within-tree distribution and survival of P. semipunctata. There was a significant impact on larval survival in both species, in contrast, pupal survival remained high. Within-tree distribution of P. semipunctata was directional with borer emergence and incidence of larval galleries both negatively associated with tree section height above the ground and positively associated with section diameter and bark thickness, reaching a maximum towards the base of trees. High incidence and survival in lower thicker tree sections indicate a more conducive environment for larval development, in contrast to poor larval survival in smaller thinner sections at the top of trees. The dependence of larval survival on tree characteristics controlling the within-tree distribution of borer emergence is emphasized, and needs to be considered when estimating the spread of borer populations during outbreaks.

LEVANTAMENTO DA ENTOMOFAUNA EM PLANTIOS DE Eucalyptus spp. POR MEIO DE ARMADILHA LUMINOSA EM SÃO FRANCISCO DE ASSIS - RS

A cultura do eucalipto tornou-se uma importante atividade econômica no Brasil, no entanto, com o aumento das áreas de plantio, os problemas entomológicos tendem a aumentar nas mesmas proporções. Neste sentido, torna-se necessário o constante monitoramento dos insetos associados a esses sistemas de plantio homogêneos, buscando o desenvolvimento de programas de manejo integrado de pragas. Assim, o objetivo deste trabalho foi o levantamento populacional da entomofauna associada a plantios de Eucalyptus spp., em São Francisco de Assis - RS. As coletas foram realizadas por meio de armadilhas luminosas no período de julho de 2008 a agosto de 2009, em talhões de três anos de idade, com as espécies: Eucalyptus dunnii, Eucalyptus grandis e Eucalyptus grandis x Eucalyptus urophylla. Os insetos coletados foram analisados através dos índices de frequência, abundância, constância e diversidade. Realizou-se ainda a correlação entre as espécies-praga identificadas e as variáveis meteorológicas do período. Foram coletados 3.623 indivíduos distribuídos em oito ordens (Blattodea, Coleoptera, Dermaptera, Hemiptera, Hymenoptera, Lepidoptera, Mantodea e Odonata), identificando-se três espécies e três gêneros de lepidópteros desfolhadores considerados de importância econômica: Automeris illustris, Eupseudosoma sp., Sabulodes sp., Sarsina sp., Thyrinteina arnobia e Agrotis ipsilon. e a coleobroca Phoracantha semipunctata. Pelos resultados obtidos, pode-se concluir que existem espécies-praga importantes da cultura de Eucalyptus já estabelecidas na região, necessitando, portanto, de monitoramento constante para que estas espécies não ocasionem danos aos plantios.

Phoracantha semipunctata. [Distribution map].

A new distribution map is provided for Phoracantha semipunctata (Fabricius). Coleoptera: Cerambycidae. Hosts: Eucalyptus spp. Information is given on the geographical distribution in Europe (Cyprus, France, Corsica, Mainland France, Italy, Mainland Italy, Sardinia, Sicily, Malta, Netherlands, Portugal, Mainland Portugal, Spain, Canary Islands, Mainland Spain, Sweden, Switzerland), Asia (Israel, Lebanon, Turkey), Africa (Algeria, Egypt, Lesotho, Libya, Malawi, Mauritius, Morocco, Mozambique, Reunion, Rodrigues Island, South Africa, Tunisia, Zambia, Zimbabwe), North America (USA, California), South America (Argentina, Bolivia, Brazil, Bahia, Espirito Santo, Minas Gerais, Parana, Rio Grande do Sul, Sao Paulo, Chile, Peru, Uruguay), and Oceania (Australia, New South Wales, Northern Territory, Queensland, South Australia, Tasmania, Victoria, Western Australia, New Zealand, Papua New Guinea).

The immature stages of Phoracantha recurva Newman, 1842 and Phoracantha semipunctata Fabricius, 1775 (Coleoptera, Cerambycidae) and a key to larvae of these species

The description of the last instar larva and pupa of Phoracantha recurva Newman, 1842 and the redescription of the immature stages of Phoracantha semipunctata Fabricius, 1775 showing new characters of possible diagnostic value are presented in this work. A key of identification of both species based on these characters is also given.