Gilberto J. de Moraes

Revision of the lifestyles of phytoseiid mites (Acari: Phytoseiidae) and implications for biological control strategies

ABSTRACT A new classification of lifestyles of phytoseiid mites is proposed based on the findings and suggestions from many studies conducted in the fifteen years since the publication of the lifestyle system by McMurtry & Croft (1997). In this newly proposed classification, Type I (Specialized mite predators) is divided into three subtypes to highlight mite prey specificity: subtype I-a—Specialized predators of Tetranychus species (Tetranychidae); subtype I-b—Specialized predators of web-nest producing mites (Tetranychidae); subtype I-c—Specialized predators of tydeoids (Tydeoidea). Type II (Selective predators of tetranychid mites) remains essentially the same. Type III (Generalist predators) is a huge and diverse group of general feeders; predators in this category are now grouped into five subtypes based on the microhabitat occupied and morphology: subtype III-a—Generalist predators living on pubescent leaves; subtype III-b—Generalist predators living on glabrous leaves; III-c—Generalist predators living in confined spaces on dicotyledonous plants; III-d—Generalist predators living in confined spaces on monocotyledonous plants; III-e—Generalist predators from soil/litter habitats. Type IV (Pollen feeding generalist predators) also remains essentially the same. Two possible additional lifestyles include phytoseiids living on aquatic plants and phytoseiids able to pierce leaf cells. Behavioral and biological information is updated and implications for biological control strategies are discussed.

Seletividade de agroquímicos ao ácaro predador Iphiseiodes zuluagai Denmark & Muma (Acari: Phytoseiidae)

The side-effects of agrochemical to Iphiseiodes zuluagai Denmark & Muma (Acari: Phytoseiidae) were studied in laboratory using the residual contact spray method in glass surface. Forty-two plant protection products, used in Brazilian citrus orchards, were tested. Mite mortality and fecundity were evaluated for eight days. Tested products were ranked in toxicity classes, according to IOBC/WPRS system, by the total effect (combination of mortality and reproduction effect). The results showed that ca. 26% of the tested products were harmless (captan, clofentezine, fenbutatin oxide, fosetyl, hexythiazox, copper hydroxide, naled, copper oxychloride, cuprous oxide and tetradifon), 14% slightly harmful (abamectin, chlorothalonil, copper sulphate, thiophanate-methyl (PM) and ziram), 7% moderately harmful (sulfur, parathion-methyl and thiophanate-methyl (SC)) and 52% harmful to the mite (acrinathrin, amitraz, azinphos-ethyl, azocyclotin, benomyl, bifenthrin, bromopropylate, carbaryl, carbosulfan, chlorfenapyr, cyhexatin, dicofol, fenpropathrin, fenpyroximate, mancozeb, mineral and vegetable oils, phosmet, propargite, quinomethionate, triazophos and vamidothion).

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.

Population dynamics of Aceria guerreronis Keifer (Acari: Eriophyidae) and associated predators on coconut fruits in Northeastern Brazil

Aceria guerreronis Keifer can cause severe damage to coconuts in several countries around the world. Rare studies have been conducted to determine the predatory mites associated with A. guerreronis in Brazil. The study evaluated the prevalence of A. guerreronis and associated predators on the bracts and on the surface of the fruits underneath the bracts, for 12 months, on coconut palms grown along the coast of the States of Alagoas, Paraíba and Pernambuco, Northeastern Brazil. Mites of 10 families were found, but by far the most abundant species was A. guerreronis, corresponding to 99.5% of the mites collected. The prevailing species amongst the predators were the Phytoseiidae mites Neoseiulus baraki (Athias-Henriot) and Neoseiulus paspalivorus (De Leon). These are flat mites that have short limbs, characteristics that allow them to invade the main habitat occupied by A. guerreronis. Other predators were found, but in low numbers, due mainly to their difficulty in reaching the fruit areas most inhabited by A. guerreronis. However, these mites could prey on that pest when it leaves its preferred habitat to disperse. No significant correlations were observed between the levels of abiotic factors and the population levels of A. guerreronis or of the phytoseiids associated with it. This probably occurred due to the simultaneous and conflicting effects of those factors on the mites in the field, or to significant differences between the climatic factors measured in the environment and those prevailing in the habitat occupied by A. guerreronis.

Review of the invasion of Tetranychus evansi : biology, colonization pathways, potential expansion and prospects for biological control

In the last two decades the subtropical red tomato spider mite, Tetranychus evansi, has expanded its geographical distribution and emerged as a major invasive agricultural pest. The mite is considered to be native to South America. Since its first report from north-eastern Brazil in 1952, it has been reported from different continents. This paper reviews literature on several aspects of the biology of T. evansi related to its status as an invasive species. It addresses taxonomical issues, occurrences, life history traits, host-plant interactions, genetic diversity of geographical isolates and worldwide colonisation pathways. It also presents updated data which allowed the assessment of the actual worldwide distribution of this species, from its discovery to the latest reports. As T. evansi is considered an emerging agricultural pest, we also present data based on modelling of the potential of T. evansi to colonize new geographical areas. In addition, this review presents past and current research on natural enemies of T. evansi potentially useful for its biological control. While summarizing the knowledge on T. evansi, the review emphasizes research possibilities that are worth pursuing, mainly concerning the ability of T. evansi to establish new populations and to detect new promising natural enemies.

Diet-dependent life history, feeding preference and thermal requirements of the predatory mite Neoseiulus baraki (Acari: Phytoseiidae).

Neoseiulus baraki Athias-Henriot (Acari: Phytoseiidae) has been reported from the Americas, Africa and Asia, often in association with Aceria guerreronis Keifer (Acari: Eriophyidae), one of the most important pests of coconut (Cocos nucifera L.) in different parts of the world. That phytoseiid has been considered one of the most common predators associated with A. guerreronis in Brazil. The objective of this study was to evaluate the feeding preference and the effect of food items commonly present on coconut fruits and several temperature regimes on the life history of a Brazilian population of N. baraki. Completion of immature development was possible when N. baraki was fed A. guerreronis, Steneotarsonemus concavuscutum Lofego and Gondim Jr., and Tyrophagus putrescentiae (Schrank). Fecundity was highest on T. putrescentiae (39.4 eggs), followed by A. guerreronis (24.8 eggs). In choice tests, irrespective of the food on which N. baraki was reared, a larger number of adults of this predator chose leaf discs containing A. guerreronis than discs containing other food items, demonstrating a preference of the former for the latter as food. Egg to adult thermal developmental time was calculated as 84.2 degree-days, above a threshold of 15.8°C. This lower developmental threshold is higher than previously published for phytoseiid species from higher latitudes. Neoseiulusbaraki was shown to have higher biotic potential at 30°C (rm 0.29). The results suggest N. baraki to be a promising biological control agent of A. guerreronis, well adapted to survive and develop in areas with relatively high temperatures, where that pest prevails.

Predatory mites associated with Tetranychus evansi Baker & Pritchard (Acari: Tetranychidae) on native solanaceous plants of coastal Pernambuco State, Brazil

The occurrence of the tomato red spider mite (Tetranychus evansi Baker & Pritchard) and predatory mites on four of the most abundant native solanaceous plants in coastal Pernambuco, Brazil, was evaluated. Monthly samples were collected from mid September 2002 to late May 2003 in Alianca, Carpina, Camaragibe, Goiana, Igarassu and Recife. A total of 5,485 mites of more than 27 species were found, of which the most common were the phytophagous species T. evansi and Brevipalpus phoenicis (Geijskes) (Tenuipalpidae), and the predaceous species Asca sp. (Ascidae), Phytoseius guianensis De Leon and Paraphytoseius orientalis (Narayanan, Kaur & Ghai) (both Phytoseiidae). Negative indexes of association were determined between T. evansi and each of four species of predaceous phytoseiids [i.e., the three most numerous species found in this study as well as Phytoseiulus macropilis (Banks)]. Laboratory tests were also conducted to evaluate the acceptability of Tetranychus urticae Koch and T. evansi as prey by the four predatory species. Only P. macropilis survived and oviposited well when fed T. urticae. Although they were able to remain alive for some days when fed T. evansi, the reproduction levels of the four predator species were very low. These results suggest that despite being commonly found on solanaceous plants in the field, these predators feed very little or do not feed at all on T. evansi in nature.

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.

Search for effective natural enemies of Tetranychus evansi in south and southeast Brazil

Tetranychus evansi Baker & Pritchard is an important pest of Solanaceae in several countries. Introduced accidentally to Africa, it presently occurs in many countries of that continent. In some of them, it is considered a key pest. The suspected area of origin of this mite is South America. The objective of the present study was to identify phytoseiid mites on solanaceous plants in association with T. evansi in south and southeast Brazil for introduction in the African continent for use in a classic biological control program. Almost 1,400 predatory mites of the family Phytoseiidae were collected, on 22 solanaceous species. The Amblyseiinae were the most diverse group in this study. Twenty-three of the species found belong to this subfamily, while only three belong to the Typhlodrominae and two to the Phytoseiinae. The most abundant and most frequent phytoseiid species were Phytoseius guianensis De Leon and Galendromus annectens (De Leon) of the Phytoseiinae and Typhlodrominae, respectively. The most frequent and abundant species of Amblyseiinae was Neoseiulus tunus (De Leon). Phytoseius guianensis and N. tunus were never found in association with T. evansi and G. annectens was found only once in association with it. Two factors suggested Phytoseiulus longipes Evans as the most promising predator found in this study. It could walk very well on tomato leaves infested by T. evansi, without being hampered by the profuse webbing produced by the prey and by the trichomes. In addition, several specimens of both sexes including eggs and nymphs of the predator were found associated with T. evansi on three different plant species and in two different periods of the year, when T. evansi was the only arthropod present on the leaves.