Mites (Acari: Mesostigmata, Sarcoptiformes and Trombidiformes) associated to soybean in Brazil, including new records from the cerrado areas

In Brazil, soybean Glycine max (L.) Merril crops are subjected to incidence of several pests, which are mainly insect species. However, the occurrences of other pest species are growing. In this context, outbreaks of phytophagous mites are becoming more frequent. Nevertheless, records of mites in such crop are available only for Maranhao, Mato Grosso, Minas Gerais and Rio Grande do Sul states. Thus, this work gathers all information published about the diversity of mites found in soybean in Brazil, and also new records of mite species made on samplings taken from the central Cerrado area. In the whole, occurrence of 44 species of plant mites in soybean has been recorded in Brazil. Data from prior studies and the results of this work present the tetranychid Mononychellus planki (McGregor) as the mite species most frequently occurring in the Brazilian soybean crops. A large portion of Phytoseiidae species has occurred in crops from Rio Grande do Sul state. In addition, spontaneous soybean has hosted almost half of the phytoseiid species sampled in Cerrado region. High diversity of Tarsonemidae has been found in the cultivated soybean. More studies about soybean mites are needed to clarify the damage potential of phytophagous mites and the biological role of predatory mites in this crop.

Acquired resistance of horses to Amblyomma cajennense (Fabricius, 1787) ticks

Acquired immunity of horses to larvae, nymphs and adults of the Amblyomma cajennense tick was evaluated through three consecutive experimental infestations of tick-bite naive hosts. Data from these infestations were compared to those from field-sensitized horses and donkeys. It was observed that tick-bite naive horses developed a low level of resistance after two infestations as shown by a significant decrease in larval yield and a tendency for lower engorged weight of nymphs during third infestation. Ticks fed on field-sensitized horses had a similar biological performance to that observed on the third infestation of tick-bite naive horses but the mean engorged nymph weight was significantly lower than that of the first infestation from tick-bite naive horses. Donkeys presented the strongest resistance with significantly lower engorged weights of all instars and of the egg mass compared to the first infestation of tick-bite naive horses. Donkeys also displayed a significantly higher resistance than field-sensitized horses as demonstrated by significantly lower egg mass weights. Overall these results indicate that donkeys but not horses maintain a strong resistance to A. cajennense ticks. The importance of these findings in relation to vectoring of tick-borne diseases is discussed. (C) 2003 Elsevier B.V. All rights reserved.

Mites (Mesostigmata, Prostigmata, Astigmatina) associated with weeds among physic nut crops (Jatropha curcas L.: Euphorbiaceae) in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Predation potential and biology of Protogamasellopsis posnaniensis Wisniewski & Hirschmann (Acari: Rhodacaridae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Prevalência de Demodex folliculorum e Demodex brevis em uma amostra da população de Botucatu, São Paulo, Brasil.

A survey was conducted to determine the prevalence of D. folliculorum and D. brevis for the first time in Brazil. In this study, association between the presence of mites and host factors (age, sex and race) were analysed. Samples were obtained from 100 individuals submitted to a facial cleaning in an aesthetic clinic in Botucatu city. All the samples were mounted in Berlese's medium and examined by dark-field phase microscopy. From 100 studied individuals, 72 were positive, among the positive cases, 51% showed D. folliculorum, 2% showed D. brevis and 19% both species. The parasite distribution in relation to sex was not taken in account because the sex ratio favoured females (90%). According to age, prevalence was high in all age groups. The factors influencing this distribution could be due. 1. the examination of extensive skin areas, 2. the group examined composed of individuals in treatment in an anaesthetic clinic could be more infested than a normal population, 3. the fact that in tropics, the prevalence is often high in all ages.

Effect of fungicides on the mite fauna of prunus persica L. cultivars in Presidente Prudente, SP, Brazil

The objective of this study was to characterize the diversity of phytophagous and predatory mites on peach cultivars either with or without fungicide treatment, in the city of Presidente Prudente, State of São Paulo, Brazil. In order to evaluate the effect of fungicides, leaf samples were colleted at random from treated and untreated plants of the Tropical, Aurora 1 and Aurora 2 cultivars, from June 2004 to February 2006. From the results obtained it can be concluded that: plants with or without treatment showed high populations of predatory mites, indicating that the treatments were innocuous on the mite populations. A diversified composition of the mite community was observed. The Phytoseiidae family had the highest richness in numbers and species of mites. Euseius citrifolius and E. concordis were the most abundant species. Plants with or without treatment had high abundances of predatory mites, with a predominance of E. citrifolius.

Mite (Acari; Arachnida) diversity of two native plants in fragments of a semideciduous seasonal forest in Brazil

Studies to determine mite species richness in natural environments are still scarce, and have been conducted mainly in tropical ecosystems. The aim of this study was to determine the species richness of mites on two common native plants in fragments of the semideciduous seasonal forest in the Northwest of São Paulo State, Brazil. In each of eight fragments, 10 specimens of Actinostemon communis (Euphorbiaceae) and 10 of Trichilia casaretti (Meliaceae) were selected and marked. In total, 124 species of mites belonging to 21 families were found on the two plants. Tarsonemidae had the highest diversity (34 species), followed by Phytoseiidae (31), Tetranychidae (9) and Tenuipalpidae (8). Species accumulation curves for the two sampled plants did not reach an asymptote, even with the large sampling effort. Hence, it is estimated that a greater sampling effort may lead to an increase in species richness compared with what was found in this study. The richness of this mite fauna suggests that preservation of these plant species is important to maintain the mite diversity in these forest fragments. © 2013 Taylor & Francis Group, LLC.

Ocorrência sazonal da acarofauna em videira no município de Jales-SP e avaliação de resistência de variedades a Tetranychus urticae Koch (acari: tetranychidae)

Pós-graduação em Agronomia - FEIS

Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) in cotton: vertical distribution of egg masses, effects of adult density and plant age on oviposition behavior

O trabalho teve por objetivo determinar, em casa-de-vegetação, a densidade adequada de adultos, a idade ideal das plantas e a distribuição vertical de ovos nas diferentes partes da planta, visando à realização de estudos de resistência e à melhoria das práticas de manejo de Spodoptera frugiperda em algodoeiro. Os experimentos de oviposição de S. frugiperda em relação à densidade de adultos, relação entre plantas de algodoeiro e oviposição de S. frugiperda e não preferência para oviposição de S. frugiperda em variedades de algodoeiro foram realizados com plantas da variedade de algodoeiro BRS Ita 90. A não preferência (antixenose) para oviposição foi acompanhada nas variedades FiberMax 966, FiberMax 977, DeltaOpal, DeltaPenta, Acala 90, Coodetec 408, Coodetec 409, Coodetec 410, BRS Cedro, BRS Ipê, BRS Aroeira, IPR 96, IPR 20, BRS Araçá, IAC 24 e BRS Ita 90. Concluiu-se que S. frugiperda prefere ovipositar em plantas com cerca de 60 dias de idade, na superfície inferior das folhas situadas no terço superior dos testes de plantas sob condições de estufa. Uma densidade de, pelo menos, três pares de adultos S. frugiperda por planta foi suficiente para realizar testes de não preferência para oviposição em casa de vegetação. As variedades Coodetec 408, BRS Aroeira, BRS Araçá, BRS Ita 90 e DeltaPenta apresentaram resistência do tipo não preferência para oviposição de S. frugiperda. Em regiões com altas infestações de S. frugiperda, seria prudente para o cultivo utilizar a variedade de algodão BRS Ita 90.

Population dynamics of Aceodromus convolvuli (Acari: Mesostigmata: Blattisociidae) on spontaneous plants associated with Jatropha curcas in central Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Distribuição espacial e determinação da depreciação quantitativa e qualitativa causada por Tetranychus ogmophallos (Acari: Tetranychidae) ao amendoinzeiro

Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV

Evaluation of growth and foraging in laboratory colonies of Coptotermes gestroi (Isoptera, Rhinotermitidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Phytophagous and fungivorous mites (Acari: Prostigmata, Astigmata) from Peru

This is an updated checklist of phytophagous and fungivorous mites from Peru (Prostigmata: Tetranychidae, Tarsonemidae, Tenuipalpidae, Tydeidae, Eriophyidae, Diptilomiopidae; Astigmata: Acaridae, Winterschmidtiidae). The data are mainly based on an extensive survey carried out in the Peruvian territory in 2006, as well as on the new records of mites from minor collections and previous records. In addition to the new data collection, the presence of predators associated with the phytophagous mites collected is noted.

Pathology of sarcoptic mange in red foxes (Vulpes vulpes): macroscopic and histologic characterization of three disease stages

Sarcoptic mange is a highly contagious skin disease that can have a devastating impact on affected wild mammal populations. There are notable variations in the clinical and pathologic picture of sarcoptic mange among species and among conspecifics. However, the origin of these variations is unclear. We propose a classification scheme for skin lesions associated with Sarcoptes scabiei infestation to provide a basis for a subsequent risk factor analysis. We conducted a case-control study focused on macroscopic and histologic examination of the skin, using 279 red foxes (Vulpes vulpes) found dead or shot in Switzerland between November 2004 and February 2006. All animals were submitted to gross necropsy following a detailed protocol. Selection criteria for cases (n=147) vs. controls (n=111) were the presence or absence of mange-like lesions, mite detection by isolation or histologic examination, and serologic testing for S. scabiei antibodies. Characteristic features of mange lesions were scored macroscopically in all foxes and histologically in 67 cases and 15 controls. We classified skin lesions and associated necropsy findings into three types of mange: A) early stage (n=45): focal-extensive skin lesions, thin crusts, mild to moderate alopecia, few mites, numerous eosinophils, and mild lymph node enlargement; B) hyperkeratotic, fatal form (n=86): generalized skin lesions, thick crusts with or without alopecia, foul odor, abundance of mites, numerous bacteria and yeasts, numerous lymphocytes and mast cells, severe lymph node enlargement, and emaciation; C) alopecic, healing form (n=16): focal lesions, no crusts, severe alopecia, hyperpigmentation and lichenification, absence of mites, mixed cell infiltration, and rare mild lymph node enlargement. We hypothesize that after stage A, the animal either enters stage B and dies, or stage C and survives, depending on largely unknown extrinsic or intrinsic factors affecting the host ability to control mite infestation.

Eight novel families of miniature inverted repeat transposable elements in the African malaria mosquito, Anopheles gambiae

Eight novel families of miniature inverted repeat transposable elements (MITEs) were discovered in the African malaria mosquito, Anopheles gambiae, by using new software designed to rapidly identify MITE-like sequences based on their structural characteristics. Divergent subfamilies have been found in two families. Past mobility was demonstrated by evidence of MITE insertions that resulted in the duplication of specific TA, TAA, or 8-bp targets. Some of these MITEs share the same target duplications and similar terminal sequences with MITEs and other DNA transposons in human and other organisms. MITEs in A. gambiae range from 40 to 1340 copies per genome, much less abundant than MITEs in the yellow fever mosquito, Aedes aegypti. Statistical analyses suggest that most A. gambiae MITEs are in highly AT-rich regions, many of which are closely associated with each other. The analyses of these novel MITEs underscored interesting questions regarding their diversity, origin, evolution, and relationships to the host genomes. The discovery of diverse families of MITEs in A. gambiae has important practical implications in light of current efforts to control malaria by replacing vector mosquitoes with genetically modified refractory mosquitoes. Finally, the systematic approach to rapidly identify novel MITEs should have broad applications for the analysis of the ever-growing sequence databases of a wide range of organisms.