Influence of fruit age of the Brazilian Green Dwarf coconut on the relationship between Aceria guerreronis population density and percentage of fruit damage.

The coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae), is one of the main coconut pests in the American, African and parts of the Asian continents, reaching densities of several thousand mites per fruit. Diagrammatic scales have been developed to standardize the estimation of the population densities of A. guerreronis according to the estimated percentage of damage, but these have not taken into account the possible effect of fruit age, although previous studies have already reported the variation in mite numbers with fruit age. The objective of this study was to re-construct the relation between damage and mite density at different fruit ages collected in an urban coconut plantation containing the green dwarf variety ranging from the beginning to nearly the end of the infestation, as regularly seen under field conditions in northeast Brazil, in order to improve future estimates with diagrammatic scales. The percentage of damage was estimated with two diagrammatic scales on a total of 470 fruits from 1 to 5 months old, from a field at Ilhéus, Bahia, Brazil, determining the respective number of mites on each fruit. The results suggested that in estimates with diagrammatic scales: (1) fruit age has a major effect on the estimation of A. guerreronis densities, (2) fruits of different ages should be analyzed separately, and (3) regular evaluation of infestation levels should be done preferably on fruits of about 3-4 months old, which show the highest densities.

Phytoseiid mites (Acari: Phytoseiidae) associated with tropical ornamental plants, with a checklist and a key to the species of Bahia, Brazil.

Twenty-four papers refer to phytoseiid mites from different plant species in the state of Bahia, northeastern Brazil, but none of those refer to taxonomic surveys on ornamental plants. The aim of this study was to determine phytoseiids from tropical ornamentals in the southern coastal region of Bahia state, as well as to present a checklist and an identification key to the species recorded in that state. Samples were collected at eight localities of five municipalities. A total of seventeen species in nine genera was found on fifteen plant species of the families Costaceae, Heliconiaceae, Musaceae and Zingiberaceae. The most frequent and abundant phytoseiid species were Iphiseiodes metapodalis (El-Banhawy), Amblyseius operculatus De Leon and Iphiseiodes zuluagai Denmark & Muma, respectively. The checklist and the identification key to the Phytoseiidae species of Bahia were prepared based on the published literature.

Three new species of phytoseiid mites (Acari: Phytoseiidae) from Bahia State, Brazil.

During a survey of predatory mites on cocoa cropping areas in Bahia State, north-eastern Brazil, three undescribed species of Phytoseiidae were collected on natural vegetation associated with crops. Typhlodromips baculiductus n. sp., Graminaseius bahiensis n. sp. and Typhlodromalus annulatus n. sp. are described and diagnosed. Comments on the boundary between the genera Amblydromalus Chant & McMurtry and Typhlodromalus Muma are also included.

Comparative toxicity of pesticides in three phytoseiid mites with different life-style occurring in citrus: Euseius stipulatus, Neoseiulus californicus and Phytoseiulus persimilis.

Conservation and augmentative biological control strategies have been developed to take full advantage of the natural enemies that occur in Spanish citrus orchards. Among them, the predatory mites Euseius stipulatus, Neoseiulus californicus and Phytoseiulus persimilis play an important role in the biological control of tetranychid mites. However, these predatory mites are often affected by pesticides and information about the side-effects of these products against these beneficial arthropods is essential to guarantee their efficacy. The side-effects of some pesticides remain unknown and the primary aim of this study was to fill this gap. We have further used this information and that collected from other sources to compare the response of these three mite species to pesticides. Based on this information, E. stipulatus has the most tolerant species, followed by N. californicus and P. persimilis. Therefore, using E. stipulatus as an indicator species in citrus may have led to the paradox of selecting presumed selective pesticides resulting in excessive impact on N. californicus and, especially on P. persimilis. Because these two latter species are considered key for the biological control of T. urticae in citrus, especially clementines, in Spain, we propose to use P. persimilis as the relevant indicator of such effects on predacious mites occurring in citrus instead of E. stipulatus. This change could have a dramatic impact on the satisfactory control of tetranychid mites in citrus in the near future.