Sequential sampling plan for Ceratitis capitata (Diptera: Tephritidae) in guava orchards.

This study aimed to elaborate a sequential sampling plan for C. capitata in commercial orchards of guava. 90 McPhail traps were randomly installed in three guava orchards in a transverse direction for 23 weeks. The data were submitted to sequential probability ratio test. Adopted the average of 0.3 C. capitata for the level of security and 0.7 for the control action. In this sequential sampling plan was defined the average number of 0.40 adults of C. capitata for each trap McPhail (sample). The sequential plan generated is unprecedented and will contribute to the rapid and safe decision making in the control of C. capitata population in guava farming.

Impacts of Exotic Pasture Establishment on Dung Beetle Assemblages (Coleoptera: Scarabaeidae: Scarabaeinae) in the Brazilian Cerrado.

The Brazilian Cerrado is the second largest Neotropical biome and an important hotspot of biodiversity. However, land use change in this ecosystem is producing landscapes with modified natural environments and anthropogenic environments, such as exotic pastures. In this study, we evaluated how conversion of native Cerrado vegetation to exotic pastures affects the dung beetle assemblages (Coleoptera: Scarabaeidae: Scarabaeinae). We sampled dung beetles in four areas of Cerrado (sensu stricto) and in four areas of exotic pastures (Urochloa spp.) in Aquidauana, Mato Grosso do Sul, Brazil. In all, 7,544 individuals from 43 species of dung beetles were collected, and 19 species were found in both the Cerrado and exotic pastures. The abundance and species richness of dung beetles were higher in Cerrado remnants. Species composition differed between Cerrado and exotic pastures, where 11 species were classified as specialists of Cerrado, 10 species were considered specialists of exotic pastures, and 6 species were habitat generalists. Roller beetles were most negatively affected by exotic pasture establishment. We demonstrated that exotic pasture establishment has a negative impact on dung beetle assemblages in Brazilian Cerrado. The decline in abundance and richness of roller beetles has important implications for the understanding of ecosystem functioning because it can reduce the ecological functions performed by dung beetle assemblages in exotic pastures. Finally, the high number of dung beetle species shared between Cerrado and exotic pastures suggests that the Cerrado remnants is a fundamental requirement for the conservation of biodiversity of dung beetles in exotic pastures in the Brazilian Cerrado.

Spatial distribution and control levels of Anastrepha spp. (Diptera: Tephritidae) in guava orchards.

This study aimed to know the patterns of spatial distribution of Anastrepha spp. and establish a criterion for determining the appropriate time for pest control. For this, 90 McPhail traps were used as Sampling Units (SU) divided into three commercial orchards of Novo Milênio guava with a total area of 14 ha. Traps were interspersed between the rows of plants, systematically in the orchards, hung and baited with 5% hydrolyzed corn protein with weekly collections. We caught 8,170 Anastrepha spp. in 840 SU. The mean infestation index was compared to the three types of distribution: random, uniform, aggregate, and fit by the theoretical frequency distributions of Poisson, negative binomial and positive binomial. The populations of Anastrepha presented aggregate distribution according to the mean variance method (I), tested by distance from randomness. The economic damage risk potential of Anastrepha spp. was associated with the aggregate distribution behavior. The most appropriate moment for the use of control techniques is when reaching 20 flies by the negative binomial. On the other hand, number of fruit fly adults per trap per day (FTD), underestimates population index, which will allow population growth, leading to risk of crop production loss.

Sequential sampling plan for fruit fly species of the Genus Anastrepha (Diptera: Tephritidae) in guava orchards.

This study aimed to elaborate a sequential sampling plan for Anastrepha species in commercial orchards of guava Psidium guajava Novo Milênio cultivar. Samplings were carried out in three orchards in the State of Mato Grosso do Sul. Fruit flies were sampled for 23 weeks. Data were subjected to the sequential probability ratio test. We adopted the mean of 0.3 Anastrepha individuals for the safety level and 0.7 for the control level and the observed frequency was adjusted to the negative binomial expected frequency (Bn) for the equation of the line. The condition of adopting a control method recommended by S1 = 6.5554 + 0.5362n was observed in the upper line. In turn, the lower line, which does not require the use of a control method, is defined by So = -2.8229 + 0.5362n. The sequential sampling plan predicted the expected maximum number of 37 sampling units to decide whether or not to use control method(s). This sequential plan was defined with mean number of 0.54 adults for each McPhail trap unit (sample). The sequential plan generated is unprecedented and will contribute to the rapid and safe decision making in the control of Anastrepha species of economic importance in guava farming.

Optimising Methods for Dung Beetle (Coleoptera: Scarabaeidae) Sampling in Brazilian Pastures.

Dung beetles are globally used in ecological research and are useful for assessing the effects of anthropic and natural changes in environment on biodiversity. Here we investigate how the choice of baits (human feces, cattle dung, carrion or a combination of all three) and sampling season influence the taxonomic and functional diversity of insects captured in traps in Brazilian pastures. We sampled dung beetles in July 2011 (dry season) and January 2012 (rainy season) in eight areas: four pastures with native grasses (e.g., Andropogon spp. and Axonopus spp.) and four pastures with introduced grasses (Urochloa spp.) in Aquidauana, Mato Grosso do Sul, Brazil. To collect the insects, we used pitfall traps baited with carrion, cattle dung and human feces. A total of 7,086 dung beetles of 32 species were captured. In both pasture types, only traps baited with human feces captured similar abundance, species richness, and functional diversity compared with the sum total of beetles captured by the three bait types. The species richness and functional diversity were higher in the rainy season in both pasture types. Our results demonstrate that using human feces alone as bait and sampling dung beetles in the rainy season are potentially sufficient to ensure the greatest number of functional traits, species, and individuals in both pasture types. Thus, the best sampling method observed in this study may be useful for studies focused on dung beetle fauna survey and rigorous comparison among studies on these insects in Brazilian pastures.