Estudo da atividade acaricida de ésteres de sacarose em ácaros (Acari) de Hevea brasiliensis Mull. Arg. (Euphorbiaceae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Dinâmica populacional e controle do ácaro Aceria litchii Keifer (Prostigmata: Eriophyidae) em plantas de lichia

Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV

Biological control of Bradysia matogrossensis (Diptera : Sciaridae) in mushroom cultivation with predatory mites

Larvae of Sciaridae flies (Diptera) cause considerable damage to the mushroom Agaricus blazei (Murrill) ss. Heinemann in Brazil. Brazilian growers have had considerable difficulties in controlling this pest. The objective of this work was to test the effect of the predatory Laelapidae mite Stratiolaelaps scimitus (Womersley) as a control agent of Bradysia matogrossensis (Lane) in cultures of A. blazei. The work corresponded to an evaluation of the efficiency of that predator when released in boxes containing each about 15 L of commercial mushroom compost naturally infested with the pest. The results showed a significant effect of that predator on the population of B. matogrossensis. The release of either 665 or 1330 S. scimitus per box significantly reduced the pest population to levels that, according to grower's experience, apparently could not cause considerable damage. The positive results obtained warrant the conduction of complementary studies to determine the lowest rates of the predator that could still produce acceptable levels of control.

Acaricides used in conventional and organic citrus orchard: leprosis and phytoseiid mites population control

The citrus leprosis control in São Paulo state is performed exclusively by acaricides to control the vector mite, Brevipalpus phoenicis, which increases the production costs and may affect the beneficial organism's population. Therefore, the aim of this trial was to evaluate during four seasons, the effects of acaricides recommended to control the mite B. phoenicis in conventional and organic citrus over evolution of citrus leprosis and over phytoseiids' population. The experiment was installed in October of 2003 in a citrus orchard in Reginopolis city, state of São Paulo. The experimental design used randomized blocks, the dosages was expressed as mL c.p./100L of water and the treatments were the following: spirodiclofen (20 mL); cyhexatin (50 mL) (used in rotation), lime sulfur (4,000 mL) and control (without pesticide application). However, the rotation between spirodiclofen and cyhexatin began in September 2006. Prior to that time, only spirodiclofen had been used. Surveys were conducted every 15 days on the B. phoenicis, Iphiseioides zuluagai, and Euseius populations. The control level adopted by the B. phoenicis was 8.3%, and the pesticide applications were conducted using tractor-sprayers. During the 2007-08 seasons, 10 infected fallen fruits per plot were collected and the number of leprosis lesions was quantified by each fruit. By the end of the 2007-08 seasons, the productivity, harvest losses, the disease incidence and severity were evaluated. It was found that the lesions' location over the fruit is more important in determining its drop than the lesions' number. The more intense the mite infestation, the greater is the number of lesions, resulting in increased premature fruit drop. A strategy using acaricides spirodiclofen and cyhexatin in rotation promoted more efficient control of B. phoenicis compared to lime sulfur, resulting in greater productivity, lower fruit losses and severity levels. The lime sulfur applications reduced the mite population incidence below the control level; however it did not prevent the lesions' occurrence. The acaricides applicarevented adverse effects on phytoseiid population because there was a reduction of their density.

Taxonomic studies of laelapid mites (Acari: Mesostigmata: Laelapidae) and their use in combination with entomopathogenic nematodes (Rhabditida: Steinernematidae, Heterorhabditidae) to control Frankliniella occidentalis (Thysanoptera: Thripidae)

Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV

Mites of public health importance and their control /

Mode of access: Internet.

Morphological variation and reproductive incompatibility of three coconut-mite-associated populations of predatory mites identified as Neoseiulus paspalivorus (Acari: Phytoseiidae)

Predatory mites identified as Neoseiulus paspalivorus DeLeon (Phytoseiidae) have been considered as agents for classical biological control of the coconut mite, Aceria guerreronis Keifer (Eriophyidae), in Africa and elsewhere. Preliminary identification of geographically distinct populations as belonging to the same species (N. paspalivorus) was based on their morphological similarity. However, laboratory studies recently conducted have shown large differences in feeding behaviors and biological characteristics among individuals collected from three geographic origins: Brazil (South America), Benin and Ghana (West Africa). As morphologically similar specimens do not necessarily belong to the same species, we evaluated under laboratory conditions, reproductive compatibility between the specimens from three geographic locations to ascertain their conspecificity. Morphological measurements were also made to determine whether there is a means of discriminating between them. Inter-population crosses showed complete reproductive isolation between the three geographic populations, but interpopulation discontinuities in morphometric characters were absent. These results indicate that the tested specimens are distinct biological entities despite morphological similarity. Further molecular genetic studies are therefore proposed, including screening for endosymbionts and assessment of genetic differentiation, to determine the cause of reproductive incompatibility and to clarify the taxonomic relationship between those populations.

Fungal pathogens as classical biological control agents against arthropods

Fungal entomopathogens have been used more frequently than other types of pathogens for classical biological control. Among 136 programs using different groups of arthropod pathogens, 49.3% have introduced fungal pathogens (including both the traditional fungi and microsporidia). The most commonly introduced species was Metarhizium anisopliae (Metschnikoff) Sorokin, with 13 introductions, followed by Entomophaga maimaiga Humber, Shimazu & Soper, which was released seven times. The majority of introduction programs have focused on controlling invasive species of insects or mites (70.7%) rather than on native hosts (29.4%). Almost half of the introductions of traditional fungi targeted species of Hemiptera and 75% of the microsporidia introduced have been introduced against lepidopteran species. The United States was the country where most introductions of fungi took place (n = 24). From 1993 to 2007, no arthropod pathogens were released in the US due to the rigorous regulatory structure, but in 2008 two species of microsporidia were introduced against the gypsy moth, Lymantria dispar (L.). Establishment of entomopathogenic fungi in programs introducing traditional fungi was 32.1% and establishment was 50.0% for programs introducing microsporidia. In some programs, releases have resulted in permanent successful establishment with no non-target effects. In summary, classical biological control using fungal entomopathogens can provide a successful and environmentally friendly avenue for controlling arthropod pests, including the increasing numbers of invasive non-native species.

Role of entomopathogenic fungi in the control of Tetranychus evansi and Tetranychus urticae (Acari: Tetranychidae), pests of horticultural crops

The spider mites Tetranychus urticae Koch and Tetranychus evansi Baker and Pritchard are important pests of horticultural crops. They are infected by entomopathogenic fungi naturally or experimentally. Fungal pathogens known to cause high infection in spider mite populations belong to the order Entomophthorales and include Neozygites spp. Studies are being carried out to develop some of these fungi as mycoacaricides, as standalone control measures in an inundative strategy to replace the synthetic acaricides currently in use or as a component of integrated mite management. Although emphasis has been put on inundative releases, entomopathogenic fungi can also be used in classical, conservation and augmentative biological control. Permanent establishment of an exotic agent in a new area of introduction may be possible in the case of spider mites. Conservation biological control can be achieved by identifying strategies to promote any natural enemies already present within crop ecosystems, based on a thorough understanding of their biology, ecology and behaviour. Further research should focus on development of efficient mass production systems, formulation, and delivery systems of fungal pathogens.

Phytoseiid mites of the tribe Typhlodromini (Acari: Phytoseiidae) from sub-Saharan Africa

This is the ninth publication in a series on the taxonomy of phytoseiid mites of sub-Saharan Africa. Sixty-five phytoseiid species of the tribe Typhlodromini Wainstein, all of which are in the genus Typhlodromus Scheuten are reported in this paper (62 in the subgenus Anthoseius DeLeon and 3 in the subgenus Typhlodromus Scheuten). They refer to all species of this tribe known to occur in sub-Saharan Africa. Fifteen new species are described and 41 species are redescribed. Most of the reported species were collected in various habitats in southern Africa and in cassava habitats in tropical Africa. A key is included for the separation of these species.

Phytoseiid mites (Acari : Phytoseiidae) of the subfamilies Phytoseiinae Berlese and Typhlodrominae Wainstein from Peru, with descriptions of two new species

This paper reports the mites of the subfamilies Phytoseiinae and Typhlodrominae (Phytoseiidae) from Peru, providing descriptions of 2 new species, Phytoseius ortegae Guanilo and Moraes, n. sp. and Phytoseius poripherus Guanilo and Moraes, n. sp., and a taxonomic key to separate the species reported.

Phytoseiid mites of the tribe Paraseiulini Wainstein (Acari : Phytoseiidae) from sub-Saharan Africa

This is the eighth publication of a series on the determination of phytoseiid mites of sub-Saharan Africa. Twenty-three phytoseiid species of the tribe Paraseiulini Wainstein are reported in this paper. They refer to all species of this tribe known to occur in sub-Saharan Africa. Six of these species are described for the first time and 13 species are redescribed. Most of the reported species were collected in cassava habitats in tropical Africa and in other habitats in South Africa. A key is included to help in the separation of the species treated in this paper.

First record of the mite Hirstiella diolii Baker (Prostigmata : Pterygosomatidae) from Australia, with a review of mites found on Australian lizards

We report the First occurrence in Australia of an exotic mite parasite of lizards, Hirstiella diolii Baker (Prostigmata, Pterygosomatidae), and its association with iguanas at the Taronga Zoo in Sydney. We also report on the spread of the exotic snake mite Ophionyssus natricis (Gervais) to native populations of skinks, provide a key to the mites associated with Australian lizards and review how to distinguish chiggers from pterygosomatid mites.

Of mites and bees: A review of mite-bee associations in Australia and a revision of Raymentia Womersley (Acari : Mesostigmata : Laelapidae), with the description of two new species of mites from Lasioglossum (Parasphecodes) spp. (Hymenoptera : Halictidae)

Social bees have a diverse fauna of symbiotic mesostigmatic mites, including highly pathogenic parasites of the honeybee, but there are few reports of Mesostigmata phoretic on or inhabiting the nests of solitary or communal, ground-nesting bees. In south-eastern Australia, however, native bees in the family Halictidae carry what appears to be a substantial radiation of host-specific mesostigmatans in the family Laelapidae. Herein, we redescribe the obscure genus Raymentia , associated with Lasioglossum (Parasphecodes ) spp. bees (Halictidae) and describe two new species, R. eickwortiana from L. lacthium (Smith) and R. walkeriana from L. atronitens (Cockerell). The type species, R. anomala Womersley, is associated with L. altichum (Smith). In addition, we review the mites known to be associated with Australian bees, provide a key to differentiate them, and describe and illustrate acarinaria of the Halictinae. We also report on the first occurrences in Australia of the genera Trochometridium Cross (Heterostigmata: Trochometridiidae), from L. eremaean Walker (Halictidae), and Cheletophyes Oudemans (Prostigmata: Cheyletidae) from Xylocopa Latreille (Xylocopinae), and on the previously unknown association between a Neocypholaelaps Vitzthum (Mesostigmata: Ameroseiidae) and Lipotriches tomentifera (Friese) (Halictidae).

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

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.