Fruit Fly (Diptera: Tephritidae) Diversity and Host Relationships in Diverse Environments Estimated with Two Sampling Methods.

Knowledge of the diversity of fruit flies is essential for understanding aspects of their community ecology. However, the effectiveness of sampling methods in representing species diversity and relationships with hosts in a diverse environment has not been adequately assessed. This study aimed to determine the optimum method to represent the diversity of fruit flies and assess their relationships with host fruits. Species of Anastrepha sampled with both traps and fruits in the same area were comprehensively analyzed. Data were analyzed by Hill's numbers (species diversity in both sampling methods), heat map graph (interaction of species with methods), and rank clocks (population fluctuations of the most abundant species). We also measured the interaction strength of the species. Our results showed that estimated parameters of species diversity in an area may differ when sampled with traps or fruits. However, the most abundant species appeared to interact similarly in both methods. Fruits of members of the families Myrtaceae and Anacardiaceae contributed highly to the presence of Anastrepha. The optimum strategy to represent Anastrepha diversity in an area is the combined use of both sampling methods.

Influence of different sterilization processes on the properties of commercial poly(lactic acid).

This study aims at analyzing the modifications in the morphological, physical, chemical and thermal properties of commercial poly(lactic acid) (PLA) films after exposure to five different sterilization processes. Films were obtained by compression molding, hygienized and sterilized by ethylene oxide (SEtO), hydrogen peroxide plasma (SH2O2), saturated steam (SSS), electron beam radiation (SEB) and gamma radiation (SGR). The samples of PLASEtO, PLASH2O2, PLASEB and PLASGR exhibited thermal and physical changes after being submitted to sterilization processes. PLASSS showed morphological, chemical, thermal and physical changes. It is concluded that processes by SEtO, SH2O2, SEB and EGR can be applied for the sterilization of PLA films and the SSS process is not recommended in view of the data obtained and test conditions reported in this study for PLA films.

Population Growth and Damage Caused by Rhopalosiphum padi (L.) (Hemiptera, Aphididae) on Different Cultivars and Phenological Stages of Wheat.

Among the aphids associated with wheat and other winter cereals, Rhopalosiphum padi (L.) is currently the predominant species in the wheat growing region of southern Brazil. The damage caused by this aphid occurs by direct feeding and/or by the transmission of pathogenic viruses, such as the Barley/Cereal yellow dwarf virus. In order to estimate the direct damage caused by R. padi on wheat, we evaluated the population growth of this aphid during the tillering and elongation stages and its effects on grain yield components. The experiment was conducted in a screenhouse with three wheat cultivars (BRS Guabiju, BRS Timbaúva, and Embrapa 16). The effect of a period of 16 days, starting from an infestation of 40 aviruliferous aphids/plant, was evaluated and compared to non-infested plants. In both stages, the population growth of R. padi was lower on the BRS Timbaúva. Although infestation caused a reduction in the grain yield of the three cultivars, this effect was lower for BRS Timbaúva. The cultivar Embrapa 16 supported higher infestations and was more tolerant to damage than the BRS Guabiju.