Nomadacris septemfasciata is a true locust species and exhibits phase polymorphism, which can potentially lead to outbreaks and plagues. In a recent outbreak of acridids in sugarcane in South Africa, swarms of N. septemfasciata were observed at increasing densities and displaying colouration indicative of the gregarious phase. The aim of this study was to determine the density-dependant phase polyphenism of populations of N. septemfasciata occurring in sugarcane study sites, based on traditional and geometric morphometric measurements, eye stripes and field observations of hopper colour specimens of N. septemfasciata were collected at three locations from May 2012 to May 2013. Three body characters (length measurements) were measured on 594 individuals and the number of dark vertical stripes on the eyes were counted. Lastly, 100 specimens from two locations (25 males and 25 females from each location) were analysed using geometric morphometrics, based on landmarks on wings. Significant differences in E/F ratios were found between locations and seasons, while wing shape also indicated a significant difference between locations (although small) and wing size (centroid size) showed no significant differences. There was a highly significant difference between wing shape of males and females, and the more gregarious males also exhibited higher E/F ratios in many instances. Eye stripes did not appear to be a reliable character and seemed to contradict the E/F ratio values. To our knowledge, this is the first report of using geometric morphometrics, traditional morphometrics and the number of eye stripes to assess phase polyphenism in adult locusts.

Este estudo objetivou verificar a ocorrência de insetos em reflorestamentos experimentais com paricá, Schizolobium parahyba var. amazonicum (Fabaceae); acácia, Racosperma mangium (Fabaceae) e teca, Tectona grandis (Lamiaceae), na região de Pau d'Arco, PA, associando os efeitos sazonais e ontogenéticos nos plantios. O estudo foi conduzido entre os meses de maio de 2006 a junho de 2007 e constou de levantamentos mensais de insetos associados a plantios com idades de três a 16 meses. Houve associação positiva entre a ocorrência de insetos e suas respectivas injúrias com a sazonalidade e o desenvolvimento das plantas. Ao menos um pico populacional de insetos desfolhadores, sugadores e/ou polinizadores foi observado nas três espécies florestais. A análise de agrupamento confirmou a associação entre ocorrência de insetos, período chuvoso e idade da planta, destacando-se (a) lepidópteros em T. grandis, (b) coleópteros desfolhadores em S. parahyba; (c) acridídeos e lepidópteros em R. mangium; (d) cicadelídeos em S. parahyba e T. grandis; e (e) apídeos em R. mangium.

This study aimed to verify the occurrence of insects in experimental reforestation with Schizolobium parahyba var. amazonicum (Fabaceae) known as paricá, Racosperma mangium (Fabaceae) known as acacia and Tectona grandis (Lamiaceae) known as teca in the region of Pau d'Arco, Pará State, Brazil associating the seasonal and ontogenetic effects in plantations. The study was conducted from May 2006 to June 2007 and consisted of monthly surveys of insects associated with plantations aging 3 to 16 months. There was a positive association between the occurrence of insects and their injuries with seasonality and plant development. At least one population peak of defoliators, sucking and / or pollinators were observed in three tree species. Cluster analysis confirmed the association between the occurrence of insects, rainy season and plant age, especially (a) lepidopteran in T. grandis, (b) defoliators beetles in S. parahyba, (c) acridids and lepidopteran in R. mangium (d) cicadellids in S. parahyba and T. grandis, and (e) apids in R. mangium.

Resumo Os centros de dispersão da fauna acridiana arbórea da Amazônia são definidos com base no estudo das Subfamílias Bactrophorinae e Proctolabinae. Foram revelados quatro centros de dispersão, os quais correspondem aos principais centros propostos por Müller (1973) e Haffer (1979). As características ecológicas de suas faunas e as relações entre os centros são abordadas provisoriamente através do estudo de alguns padrões de distribuição policêntrica (Ommatolampinae, Proctolabinae), assim como através de relações mais restritas entre os centros amazônicos e a Mata Atlântica.

Abstract The dispersal centers of the Amazonian acridid arboreal fauna are defined on the basis of the study of the subfamilies Bactrophorinae and Proctolabinae. Four dispersal centers are revealed which correspond to the main centers proposed by Müller (1973) and Haffer (1979). The ecological characteristics of their fauna and the relations between the centers are tentatively approached through the study of some polycentric distribution patterns (Ommatolampinae, Proctolabinae) as well as through the more restricted relations between the Amazonian centers and the Atlantic Forest.