Biologia de Agistemus floridanus Gonzalez (Acari, Stigmaeidae)

<abstract language="eng">The rubber tree (Hevea brasiliensis Muell. Arg.) (Euphorbiaceae) is attacked by various species of phytophagous mites in Brazil. Studies conducted in the State of Mato Grosso showed the presence of Agistemus floridanus Gonzalez, 1965 (Stigmaeidae) on rubber trees, associated with the mite Tenuipalpus heveae Baker, 1945. The aim of this work was to study the biology of that predator in the laboratory, when fed with T. heveae as prey. The study was started with 22 eggs, which resulted in 15 females reaching adult hood. To determine the effect of mating on oviposition, 30 females were used; half of those were maintained isolated and the remaining were maintained then with males during the whole adult stage. The stage of egg was the longest, with a duration of more than 4.0 days. The total duration of the immature phase was 10.2 days. Each female oviposited an average of 38.4 eggs, with a daily oviposition rate of 2.3 eggs per female. The duration of each adult phase, the daily oviposition rate and the longevity were different between the mated females and non-mated females. All eggs produced by non-mated originated males, characterizing, in this way, the development through arrhenothokous parthenogenesis. The results showed that A. floridanus has an innate increase capacity of 13.2 times in each generation, that the average duration of one generation is 19.2 days, that the intrinsic rate of increase (rm) is about 0.16 female per female per day and that the number of females added daily to the population is 1.1

Mite diversity (Arthropoda: Acari) on Euphorbiaceous plants in three localities in the state of S\ue3o Paulo

Patches of natural vegetation have been reported to play an important role in the preservation of diversity of natural enemies of pest arthropods. Euphorbiaceous plants are common in natural and regenerated ecosystems in the State of São Paulo. Those plants may act as reservoirs of phytophagous mites and their respective natural enemies, both of which are also found on cultivated plants of the same family. The objective of the work reported in this paper was to study the diversity of mite species on euphorbiaceous plants in three regions of the State of São Paulo, and to compare the similarities between those regions in relation to the composition of the mite fauna they harbor. A total of 31,603 mites belonging to 105 species in 74 genera and 16 families were collected. Twenty one of those species belong to families composed essentially of phytophages (Diptilomiopidae, Eriophyidae, Tenuipalpidae and Tetranychidae) and 43, to families composed essentially of predaceous organisms (Ameroseiidae, Ascidae, Cheyletidae, Cunaxidae, Eupalopsellidae, Stigmaeidae and Phytoseiidae). The remaining species belong to families composed of species with diverse or inadequately known feeding habits, which are here categorized as "generalists" (Acaridae, Eupodidae, Tarsonemidae, Tydeidae and Winterschmidtiidae). The plants considered in the study were classified in two groups according to the mite fauna they harbor. Plants of the Group 1 had on the average higher diversity, uniformity and species richness than the Group 2. The only species commonly exploited commercially that was considered in this study, the rubber tree, had high similarity with the remaining plants of the same locality in which they were found, indicating a flux of mites between the plants considered in the study. None of the most important mite pests of rubber trees was found on other euphorbiaceous plants considered in this study. The result of this study may help in the selection of prospective predaceous mites to be tested in applied biological control projects for the control of the major mite pests on rubber tree