Adalton Raga

Abamectin resistance in Tetranychus urticae Koch (Acari: Tetranychidae): selection, cross-resistance and stability of resistance

Studies on artificial laboratory selections with abamectin, cross-resistance relationships, and stability of resistance were carried out with Tetranychus urticae Koch to provide basic information for an abamectin resistance management program. Selections for resistance and susceptibility to abamectin were performed in a population of T. urticae, collected from a commercial strawberry field in the State of Sao Paulo, Brazil. After five selections for resistance and five selections for susceptibility, susceptible (S) and resistant (R) strains of T. urticae to abamectin were obtained. The resistance ratio (R/S) at the LC50 reached 342-fold values. The toxicity of eight acaricides was evaluated in the R and S strains, observing significant differences (at LC50) between R and S strains for milbemectin, fenpropathrin and chlorfenapyr. Significant correlation was detected between the LC50s of abamectin and milbemectin, indicating cross-resistance between these acaricides. No cross-resistance was detected for the acaricides fenpyroximate, cyhexatin, propargite and dimethoate. The stability of abamectin resistance was also studied under laboratory conditions. Abamectin resistance was unstable in the absence of selection pressure. For all studied populations (with 75, 50 and 25% of initial frequency of resistant mites), the percentage of resistant mites decreased to levels equal or lower than 15% in six months. The results indicate that milbemectin should be avoided for managing abamectin resistance in T. urticae.

Toxicidade Diferencial de Agroquímicos a Neoseiulus californicus (McGregor) (Acari: Phytoseiidae) e Tetranychus urticae Koch (Acari: Tetranychidae) em Morangueiro

This work aimed to evaluate the differential toxicity of pesticides to populations of the mite species Neoseiulus californicus (McGregor) and Tetranychus urticae Koch collected from commercial crops of strawberry (Fragaria sp.) in Atibaia county, State of Sao Paulo, Brazil. In the test of acute toxicity of pesticides, adult females of N. californicus received the pesticide treatment under Potter spray tower. The predaceous mite N. californicus showed the same or higher tolerance than T. urticae to various pesticides in laboratory. The highest difference was observed to the acaricide propargite, for which the predaceous mite was 25.1 times more tolerant than the two-spotted spider mite. This phytoseiid was also 4.7, 2.9 and 2.5 times more tolerant than T. urticae to chlorfenapyr, fenpyroximate, and cyhexatin, respectively. In the test of residual toxicity of pesticides, the chemicals were sprayed on plants of strawberry in the field. Leaves were collected after different periods from the treatment and artificially infested with adult females of N. californicus. The mortality was assessed 48h or 72h after treatment. Fenpyroximate, fenpropathrin, dimethoate, propargite, sulphur, and benomyl were innocuous to N. californicus. Chlorfenapyr, cyhexatin, and abamectin were significantly harmful to the predaceous mite causing initial mortality rates between 37.5% and 57.5%. The use of predaceous mites like of this population of N. californicus, which presents low susceptibility to various pesticides can be very useful for programs of management of T. urticae on strawberry in Brazil.

Diversity and seasonality of fruit flies (Diptera: Tephritidae and Lonchaeidae) and their parasitoids (Hymenoptera: Braconidae and Figitidae) in orchards of guava, loquat and peach.

This work was carried out in orchards of guava progenies, and loquat and peach cultivars, in Monte Alegre do Sul, SP, Brazil, in 2002 and 2003. Guavas and loquats were bagged and unbagged bi-weekly and weekly, respectively, for assessment of the infestation period. Peach was only bagged weekly. The assays started when the fruits were at the beginning of development, but still green. Ripe fruits were taken to the laboratory and placed individually into plastic cups. McPhail plastic traps containing torula yeast were hung from January 2002 to January 2004 to assess the fruit fly population in each orchard, but only the Ceratitis capitata population is here discussed. Five tephritid species were reared from the fruits: Anastrepha bistrigata Bezzi, A. fraterculus (Wiedemann), A. obliqua (Macquart), A. sororcula Zucchi, and C. capitata, in addition to six lonchaeid species: Neosilba certa (Walker), N. glaberrima (Wiedemann), N. pendula (Bezzi), N. zadolicha McAlpine and Steyskal, Neosilba sp. 4, and Neosilba sp. 10 (both species are in the process of being described by P. C. Strikis), as well as some unidentified Neosilba species. Ten parasitoid species were obtained from fruit fly puparia, of which five were braconids: Asobara anastrephae (Muesebeck), Doryctobracon areolatus (Szépligeti), D. brasiliensis (Szépligeti), Opius bellus Gahan, and Utetes anastrephae (Viereck), and five figitids: Aganaspis pelleranoi (Brèthes), Dicerataspis grenadensis Ashmead, Lopheucoila anastrephae (Rhower), Leptopilina boulardi (Barbotin, Carlton and Kelner-Pillaut), and Trybliographa infuscata Diaz, Gallardo and Uchôa. Ceratitis capitata showed a seasonal behavior with population density peaking at the second semester of each year. Anastrepha and Neosilba species remained in the orchards throughout both years.

Eficácia de atrativos alimentares na captura de moscas-das-frutas em pomar de citros

ABSTRACT ATTRACTIVENESS OF FOOD BAITS TO THE FRUIT FLIES IN CITRUS ORCHARD Fruit flies (Diptera: Tephritoidea) are key pests in citrus production in the State of Sao Paulo,Brazil, mainly Anastrepha fraterculus (Wied.) and Ceratitis capitata (Wied.). The objective of this study wasto evaluate food baits to monitor fruit fly population in citrus orchard. The experimental design usedwas randomized block, with five treatments and five replications. The experiment was set in 30 September,2003 and evaluated for nine weeks. The attractants tested were the hydrolysate proteins Bio Anastrepha,Isca Mosca and Aumax®, all diluted in 5% water, sugar cane syrup (7%) alone and added to natural orangejuice (10%). Weekly 400 mL aqueous attractants were used into plastic McPhail traps hunged within atree of ´Pera Rio‘ orange. At the time of sampling, flies were removed and conducted to the laboratoryfor counting, sexing and identification. It was captured 1,821 adults of Tephritoidea, from which 892 of

Effect of spinosad bait against Ceratitis capitata (Wied.) and Anastrepha fraterculus (Wied.) (Diptera: Tephritidae) in laboratory

Laboratory studies were conducted to determine the mortalities caused by spinosad in Ceratitis capitata (Wied.) and Anastrepha fraterculus (Wied.). Spinosad formulated bait, diluted in water, was compared with baits of malathion, trichlorfon, fenthion and deltamethrin. The lethal time increased for C. capitata (medfly) adults fed in lower concentrations of spinosad. The LT50 values for C. capitata were estimated in 106, 126 and 154 min for 80, 8 and 4 ppm, respectively. No differences at LT50 were observed for different ages, 2-3d, 3-5d and 5-7d old C. capitata exposed to 80 ppm. Both fruit fly species presented similar pattern of survival when treated with spinosad at 80 ppm. In general, fenthion and trichlorfon showed LT50 values lower than spinosad for different ages of medfly. After 180 min from initial exposure to spinosad bait, the mortality rates of 2-3d and 3-5d old C. capitata were similar to that by fenthion. The LT50 for A. fraterculus was estimated in 85.9 min, slightly shorter than for C. capitata when both species were exposed to 8 ppm of spinosad. Medfly adults exposed to concentrations equal or inferior to 0.4 ppm of spinosad showed LT50s longer than 12 h. Leaves treated and kept in the field with baits of spinosad, malathion, fenthion and deltamethrin, caused high mortalities of medfly adults until two days after treatment.

Diversidade de ácaros (Arachnida: Acari) em Coffea arabica L. cv. Mundo Novo, nos municípios de Jeriquara e Garça, Estado de São Paulo

The objective of this study was to characterize the diversity of mites on coffee plants of the Mundo Novo cultivar in two important coffee producing areas (Jeriquara and Garca) in the state of Sao Paulo. Samples of leaves, branches and fruits were fortnightly collected, from April 2001 to June 2003, from the middle third of 10 plants randomly taken from each field. Twelve leaves (each leaf from the third or forth pair from the distal part of each branch), 12 branches (apical 25 cm) and 100 fruits. A total of 13,052 specimens were collected in the two studied places, 7,155 in Jeriquara and 5,897 in Garca. From a total of 108 mite species collected from coffee plants in this study, forty five species were collected in both studied fields, which presented 56% of similarity. The number of species found exclusively in Jeriquara (47) was approximately three times higher than the number of species observed only in Garca (16). For Jeriquara, the diversity of mites on surface of leaves, as well as in domatia, and on branches and fruits was higher than for Garca. In both studied areas, Brevipalpus phoenicis (Geijskes, 1939) and Oligonychus ilicis (McGregor 1919) were the most abundant and frequent phytophagous mite species. Stigmaeids and phytoseiids were the most abundant and frequent predaceous mites in both localities. The most abundant and frequent predaceous species were Agistemus brasiliensis Matioli, Ueckermann & Oliveira, 2002, Zetzellia malvinae Matioli, Ueckermann & Oliveira, 2002, Euseius citrifolius Denmark & Muma, 1970, and Euseius concordis (Chant 1959) in Jeriquara; and Z. malvinae, E. citrifolius and E. concordis in Garca.

Dinâmica populacional e incidência de moscas-das-frutas e parasitoides em cultivares de pessegueiros (Prunus Persica L. Batsch) no município de presidente prudente-sp

ABSTRACT - The objectives of this research were evaluate the population dynamic and diversity of fruit flies (Diptera: Tephritoidea) on peach cultivars Tropical, Talisma, Aurora 2, Aurora 1, Dourado 2 and Docura 2, under the rootstocks ‘Okinawa’ and Ume, in Presidente Prudente, Sao Paulo, Brazil. The dynamic popula-tion of fruit flies was correlated with temperature and precipitation. The fruit fly infestation was correlated with chemical characteristics of fruits. During July 2004 to December 2006, the fruit fly population was monitored weekly using McPhail traps. The natural infestation was estimated from 30 fruits of each cultivar collected per year. The experiment was conducted under randomized design with five replications. Ceratitis capitata was dominant on peach cultivars for the both rootstocks. No significant correlations were detected between the fruit fly densities and the temperature and precipitation, and the variables soluble solids and titratable acidity. Among peach cultivars, Aurora 2 presented the highest infestation by C. capitata, reach-ing 22% and 23%, in 2004 and 2006, respectively. Neosilba spp. (Lonchaeidae) was also recovered from peaches. Doryctobracon areolatus (Braconidae), Tetrastichus giffardianus (Eulophidae) and Pachycrepoideus vindemmiae (Pteromalidae) were recovered from Tephritidae pulparium.Index-terms: peach, rootstocks, population dynamic, Tephritidae, Lonchaeidae.

Effect of Insecticides and Fungicides on the Interaction between Members of the Mite Families Phytoseiidae and Stigmaeidae on Citrus

The study was carried out to evaluate the effect of some insecticides and fungicides on the interaction between predacious mites of the families Phytoseiidae and Stigmaeidae on citrus. Euseius citrifolius Denmark and Muma, Euseius concordis (Chant) (Phytoseiidae), and Agistemus aff. bakeri (Stigmaeidae) were the most abundant species of predacious mites. No significant reduction of the population of stigmaeids was detected following the pesticide treatment. On the contrary, the population of those mites increased after the application of methidathion, petroleum oil, deltamethrin, cupric oxychloride and cuprous oxide, as compared to the population of those mites in the control plots. The chemicals promoting increased stigmaeid populations are some of those that promoted reduction of phytoseiid populations. A significant negative correlation was found between the numbers of phytoseiids and stigmaeids on citrus leaves immediately before treatments, and 33, 50, 83 and 105 days after treatment. A clear negative linear correlation between the number of predacious mites from both families was detected for benomyl, cupric oxychloride, cuprous oxide, thiophanate methyl, and control. Phytoseiid–stigmaeid interaction on citrus orchard is discussed.

Diversity and seasonality of fruit flies (Diptera: Tephritidae and Lonchaeidae) and their parasitoids (Hymenoptera: Braconidae and Figitidae) in orchards of guava, loquat and peach

This work was carried out in orchards of guava progenies, and loquat and peach cultivars, in Monte Alegre do Sul, SP, Brazil, in 2002 and 2003. Guavas and loquats were bagged and unbagged bi-weekly and weekly, respectively, for assessment of the infestation period. Peach was only bagged weekly. The assays started when the fruits were at the beginning of development, but still green. Ripe fruits were taken to the laboratory and placed individually into plastic cups. McPhail plastic traps containing torula yeast were hung from January 2002 to January 2004 to assess the fruit fly population in each orchard, but only the Ceratitis capitata population is here discussed. Five tephritid species were reared from the fruits: Anastrepha bistrigata Bezzi, A. fraterculus (Wiedemann), A. obliqua (Macquart), A. sororcula Zucchi, and C. capitata, in addition to six lonchaeid species: Neosilba certa (Walker), N. glaberrima (Wiedemann), N. pendula (Bezzi), N. zadolicha McAlpine and Steyskal, Neosilba sp. 4, and Neosilba sp. 10 (both species are in the process of being described by P. C. Strikis), as well as some unidentified Neosilba species. Ten parasitoid species were obtained from fruit fly puparia, of which five were braconids: Asobara anastrephae (Muesebeck), Doryctobracon areolatus (Szépligeti), D. brasiliensis (Szépligeti), Opius bellus Gahan, and Utetes anastrephae (Viereck), and five figitids: Aganaspis pelleranoi (Brèthes), Dicerataspis grenadensis Ashmead, Lopheucoila anastrephae (Rhower), Leptopilina boulardi (Barbotin, Carlton and Kelner-Pillaut), and Trybliographa infuscata Diaz, Gallardo and Uchôa. Ceratitis capitata showed a seasonal behavior with population density peaking at the second semester of each year. Anastrepha and Neosilba species remained in the orchards throughout both years.

Parasitóides (Hymenoptera: Braconidae) de moscas-das-frutas (Diptera: Tephritidae) no Estado de São Paulo: plantas associadas e parasitismo

A total of 3,008 braconid parasitoids in 26 species of fruit fly host plants were collected in 33 localities of São Paulo State. The majority of the braconids (96.2%) belonged to four Opiinae species, Doryctobracon areolatus (Szépligeti), Doryctobracon brasiliensis (Szépligeti), Opius bellus (Gahan) and Utetes anastrephae (Viereck), and the remaining 3.8%, a single species of Alysiinae, Asobara anastrephae (Muesebeck). Doryctobracon areolatus was collected on Anastrepha fraterculus (Wied), A. obliqua (Macquart) and A. amita Zucchi, and was found associated with the largest number of fruit fly host plant species (26), being recorded for the first time in fruits of Clausena lansium and Cryptocarya aschersoniana. This species was the most common, occurring in most of the sampled localities, totaling 77.5% of all parasitoids collected. Doryctobracon brasiliensis was associated only with A. fraterculus and recorded, for the first time, in Japanese plum (Prunus salicina). It was not possible to associate the remaining braconids to the fruit fly species. Opius bellus was also reared from larvae in C. aschersoniana. The natural parasitism percentage ranged from <1% to 40%.