Noeli Juarez Ferla

Ácaros (Arachnida, Acari) da seringueira (Hevea brasiliensis Muell. Arg.) no Estado do Mato Grosso, Brasil

Mites started to be considered economically important on rubber tree since the early 1990s, when they were considered responsible for damages caused to this crop and by the consequent yield reduction. The aim of this work was to determine the mites present on this crop in the State of Mato Grosso and to elaborate a key for the separation of the species found. This study was conducted in fields of Plantacoes Edouard Michelin Ltda., in Itiquira, and Triângulo Agro-Industrial S/A. in Pontes e Lacerda. Samplings were conducted monthly in six different clones: PB 260, PR 255, IAN 713, IAN 873, FX 3864 and RRIM 600. Clones PB 260 and IAN 873 were sampled between August 1998 and July 2000; other clones were sampled between August 1999 and July 2000. In the season 1998/1999 samples consisted of 15 leaves of each of 10 plants taken randomly and in the season 1999/2000, 5 leaves of the median stratum of each of 15 plants taken randomly were sampled. A total of 4270 mites were found, belonging to 11 families. Nearly 77,2% of the mites collected belonged to the families Eriophyidae. Tarsone-midae. Tcnuipalpidae and Tetranychidae. composed predominantly by phytophagous species. Phytoseiidae was the most diverse family, with 15 species, followed by the families Tetranychidae and Eriophydae, with five species, and Tydeidae, with four species.

Ácaros predadores (Acari) em plantas nativas e cultivadas do Estado do Rio Grande do Sul, Brasil

This research was carried out in twenty counties of the following regions in the state of Rio Grande do Sul: Plain, Central Depression, Plateau and Coast Plain to find out the diversity of mite predators in these places. Forty-six vegetable species were sampled, thirty species of miles of the families Anystidae, Ascidae, Cheyletidae, Cunaxidae, Phyloseiidae and Stigmaeidae were mel. The Phytoseiidae were the mite that presented the greatest diversity, being present in the majority of the sample plants. Most of the Phytoseiidae that were met belong to five species of the Euseius Wainstein, 1962 genus, the second genus of this family was Iphiseiodes DeLeon, 1966, with just one species. The Stigmaeidae come up as second family in number but fewer than Phytoseiidae. In this family, the most common mite belong to the Agistemus Sumers, 1960 genus. The biggest of the mites species (13 species), was met in Morus spp. (Moraceae) and Tabebuia spp. (Bignoniaceae); Phaseolus vulgaris (Papilionaceae); only one species of the mite was met in Campomanesia spp. (Myrtaceae), Phaseolus vulgaris (Papilionaceae) and Rosa spp. (Rosaceae). In Alamanda spp.(Apocinaceae), Ficus spp. (Moraceae), Jacaranda mimosifolia (Bignoniaceae) and Solanum spp. (Solanaceae) were met mites predators. A dichotomic key is presented to separate the families, genus and species of the mites.

Ácaros predadores (Acari) associados à cultura do morango (Fragaria sp., Rosaceae) e plantas próximas no Estado do Rio Grande do Sul

Ferla, N.J., Marchetti, M.M. & Goncalves, D. Predatory mites (Acari) associated with strawberry and neighboring plants in the State of Rio Grande do Sul. Biota Neotrop. May/Aug 2007 vol. 7, no. 2 http://www.biotaneotropica.org.br/v7n2/pt/abstract?article+bn01807022007 ISSN 1676-0603. The aim of this study was to determine the species predatory mites on strawberry crop and associated plants in the State of Rio Grande do Sul. It was conducted in Bom Principio, Capitao and Lajeado counties, in crops of strawberry Oso Grande variety in low tunnels. The evaluations were done monthly between August 2002 and March 2004. In the plants of strawberry, the samples were constituted of three leaves collected in each of 15 plants taken randomly, totaling 45 leaves/field. In the associated plants, the sampling effort was of one hour for each plant evaluated. Mites of the families Ascidae, Parasitidae, Phytoseiidae, Cunaxidae, Erythraeidae, Stigmaeidae and Tydeidae were observed associated with the two-spotted spider mite, Tetranychus urticae Koch, 1836, important pest of this crop in the region where the study was conducted. Twenty species were identified, 14 of which belong to the family Phytoseiidae. Phytoseiulus macropilis (Banks, 1905) and Neoseiulus californicus (McGregor, 1954) were the most common species. On associated plants, the highest diversity of predatory mites was found on Richardia sp. (six mite species), Agerantum conyzoides L. (four mite species) and Sonchus oleraceus L., Bidens pilosa L. and Rumex sp. (three mite species). A dichotomous key is presented for the separation of the species collected.

Oviposição dos ácaros predadores Agistemus floridanus Gonzalez, Euseius concordis (Chant) e Neoseiulus anonymus (Chant & Baker) (Acari) em resposta a diferentes tipos de alimento

Phytoseiidae and Sigmaeidae are the most common predatory mites on rubber tree leaves in the State of Mato Grosso, associated with phytophagous mites of the families Eriophyidae, Tenuipalpidae and Tetranychidae. The aim of this work was to compare the effect of different kinds of food, including different species of mites commonly found on the rubber tree in Mato Grosso, and one kind of pollen, on the oviposition of the predators Agistemus floridanus Gonzalez, 1965 (Stigmaeidae), Euseius concordis (Chant, 1959) and Neoseiulus anonymus (Chant & Baker, 1965), both Phytoseiidae. Those predators are common on rubber tree leaves in Mato Grosso. For the tests with A. floridanus, discs of 2 cm in diameter of rubber tree leaves were used as substrate. Food provided to the predators were the mites Calacarus heveae Feres, 1992, Oligonychus gossypii (Zacher, 1921), Polyphagotarsonemus latus (Banks, 1904), Tenuipalpus heveae Baker, 1945 and Tetranychus mexicanus (McGregor, 1950), and pollen of Typha angustifolia L. Agistemus floridanus accepted a larger variety of foodthan other predators. This was the only predator with high oviposition rate when fed C. heveae and T. heveae, the phytophagous mites considered most important on rubber trees. Euseius concordis and A. floridanus had nearly the same oviposition rates when fed pollen of T. angustifolia (ca. one egg per female per day). Neoseiulus anonymus had the highest oviposition rate than other predators when fed O. gossypii and T. mexicanus. Polyphagotarsonemus latus was the least suitable food for the predators studied.

Biologia de Agistemus floridanus Gonzalez (Acari, Stigmaeidae)

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.

Mitefauna (Arachnida: Acari) associated to grapevine, Vitis vinifera L. (Vitaceae), in the municipalities of Bento Gonçalves and Candiota, Rio Grande do Sul, Brazil

The mitefauna associated to Merlot and Chardonnay grapevine cultivars and associated plants in the municipalities of Bento Goncalves and Candiota, Rio Grande do Sul was investigated. The study was developed between October 2006 and September 2007, where 20 grapevine plants were randomly chosen from each municipality and monthly sampled. Three leaves of each plant were taken. A total of 11,598 mites belonging to 14 families and to 52 species were found. Fifty-nine percent of the total specimens were collected in Candiota, being 93% associated to the Merlot cultivar. Higher species richness was observed on associated plants. Phytoseiidae showed the highest species richness, with ten species, and Eriophyidae showed the highest abundance, with 8,675 specimens. Calepitrimerus vitis (Nalepa, 1905) and Polyphagotarsonemus latus (Banks, 1904) were the most common phytophagous mites, while Neoseiulus californicus (McGregor, 1954) and Pronematus anconai (Baker ,1943) were the most common predators.

Flutuação populacional e sintomas de dano por ácaros (Acari) em seringueira no Estado do Mato Grosso, Brasil

Despite the importance of rubber trees (Hevea brasiliensis Muell. Arg.) to Brazil, little is known about mite population fluctuation on this crop. The aim of this work was to study the fluctuation of the mite population on rubber trees in the state of Mato Grosso and to observe the evolution of the symptoms caused by their attack. This study was conducted in rubber tree fields at Itiquira and Pontes e Lacerda in the state of Mato Grosso with six clones: FX 3864, RRIM 600, IAN 873, IAN 713, PB 260 and PR 255. Samplings were conducted between August 1998 and July 2000. The 1998/1999 samples consisted of 150 leaves of each of the basal, median and apical strata of 10 plants, randomly taken. The 1999/2000 sampling methodology was changed due the results for the previous partial for five leaves of the median stratum of each of 15 plants randomly taken. Calacarus heveae Feres was the most frequent species in Itiquira and Phyllocoptruta serigueirae Feres in Pontes e Lacerda. Early leaf drop was observed only in Itiquira

Ciclo biológico de Calacarus heveae Feres, 1992 (Acari, Eriophyidae)

Calacarus heveae Feres, 1992 is an Eriophyidae mite described from rubber tree (Hevea brasiliensis Muell. Arg.) in the northwest region of the State of Sao Paulo. This mite prefers the adaxial face of the folioles and it can reduce the brightness of the leaves, turning them progressively yellow and brownish, and consequently premature fall. The aim of this work was to study the biology of C. heveae in laboratory, on detached rubber tree folioles. The study was conducted at 28±1 oC in the photophase (12h), 25±1 oC in the dark phase (12h), and 90±5% relative humidity. The study was initiated with a total of 59 eggs. The average duration of egg, larva and nymph stages was 5.8, 2.0 and 1.4 days, respectively. The period from egg to adult lasted 9.3 days, and the average periods of pre-oviposition, oviposition and post-oviposition, 1.8, 6.1 and 1.2 days, respectively. The average longevity of the adult male was ca. 4.0 days, while the longevity adult female was about 8.4 days. The average daily oviposition rate was 2.3 egg per female while the average fecundity was 16.2 eggs per female.

Mites fluctuation population on peach tree (Prunus persica (L.) Batsch) and in associated plants

, NOELI JUAREZ FERLAABSTRACT - Despite the importance of peach (Prunus persica (L.) Batsch) in Rio Grande do Sul, little is known about mites fluctuation population considered important to this crop. The objective of this study was to know the population diversity and fluctuation of mite species associated with Premier and Eldorado varieties in Roca Sales and Venâncio Aires counties, Rio Grande do Sul. The study was conducted from July 2008 to June 2009 when 15 plants were randomly chosen in each area. The plants were divided in quadrants and from each one a branch was chosen from which three leaves were removed: one collected in the apical region, another in the medium and the other in the basal region, totalizing 180 leaves/area. Five of the most abundant associated plants were collected monthly in enough amounts for the screening under the stereoscopic microscope during an hour. A total of 1,124 mites were found belonging to 14 families and 28 species. Tetranychus ludeni Zacher, 1913, Panonychus ulmi (Koch, 1836) and Mononychellus planki (McGregor, 1950) were the most abundant phytophagous mites, whereas Typhlodromalus aripo Deleon, 1967 and Phytoseiulus macropilis (Banks, 1904) the most common predatory mites. The period of one hour under stereoscopic microscope was enough to get a representative sample. In both places evaluated the ecologic indices were low, but little higherin Premier (H’ 0.56; EqJ: 0.43) when compared to Eldorado (H’ 0.53; EqJ 0.40). In Premier constant species were not observed and accessory only Brevipalpus phoenicis (Geijskes, 1939), T. ludeni and T. aripo. Higher abundance was observed in December and January and bigger amount in April. Already in Eldorado, T. ludeni and P. ulmi were constants. Greater abundance was observed in November and December, whereas grater richness in December and January. In both orchards were not found mites in buds. Tetranychus ludeni is the most abundant phytophagous mites with outbreak population in November, December and January and high predator diversity was observed on associated plants and on peach plants, indicating the existence of species mobility in peach orchard.Index terms: Acari, biological control, Panonychus ulmi, Tetranychus ludeni, Typhlodromalus aripo.

Functional response of Phytoseiulus macropilis under different Tetranychus urticae (Acari: Phytoseiidae, Tetranychidae) population density in laboratory

We tested the functional response of the phytoseiid predator Phytoseiulus macropilis (Banks, 1904) to different population densities of Tetranychus urticae Koch, 1836 (the two-spotted spider mite - TSSM) in the laboratory. We evaluated the curve that best fits the data obtained, based on the reduced X2. The predators were obtained from leaves of Oso Grande strawberries at the municipality of Bom Principio, state of Rio Grande do Sul, Brazil. Fifteen seemingly healthy females of P. macropilis were randomly chosen and individualized in each of the arenas with different TSSM densities. The following prey densities were tested: 1, 2, 3, 5, 10, 20, 30, 35, 45, 55, 70 and 125 females. The tests were performed in a germination chamber with photoperiod of 12 hours at 28 ± 1oC per day and 22 ± 1oC at night and 80 ± 5% relative humidity. In all tests with up to three prey items, P. macropilis showed low functional response, whereas higher rates were observed when more prey items were offered. There was a strong positive correlation between increased prey numbers and daily prey consumption (r = 0.84 and p = 0.0006). A significant correlation was found between prey consumption and total oviposition (r = 0.70, p = 0.01). The daily oviposition rate was lower when few prey items were offered, increasing significantly with increased prey availability. The results showed a positive correlation between the number of prey items offered to the predator and its oviposition rate (r = 0.66, p = 0.01). Nevertheless, a strong correlation was observed between the daily consumption of prey and eggs/female/day (r = 0.92, p < 0.0001). A shorter oviposition period was reported when up to three prey items were offered. The oviposition period and the increase in prey numbers were positively correlated (r = 0.30, p = 0.34), but the difference was not statistically significant. Nevertheless, the longer the egg-laying period, the greater the oviposition rate (r = 0.90, p < 0.0001). The curve that best fits the data obtained in each case was also calculated, based on the least square method.