Ocorrência do ácaro-do-enrolamento-do-trigo Aceria tosichella Keifer (Prostigmata: Eriophyidae) no Rio Grande do Sul.

2009

Zmienność genetyczna, specyficzność żywicielska i zdolność do przenoszenia wirusa mozaiki smugowatej pszenicy (WSMV) w obrębie kompleksu gatunków Aceria tosichella

Wydział Biologii: Instytut Biologii Środowiska

Potential new sources of wheat curl mite resistance in wheat to prevent the spread of yield-reducing pathogens

The wheat curl mite (WCM), Aceria tosichella Keifer (Trombidiformes: Eriophyidae), is a major pest in cropping regions of the world and is recognised as the primary vector of several yield-reducing pathogens, primarily affecting wheat. Management of WCM is complicated due to several aspects of the mite's biology and ecology; however, commercially viable mite resistant wheat varieties may offer practical long-term management options. Unfortunately, mite populations have adapted to previously identified sources of resistance, highlighting the need for further sources of resistance and the value of stacking different resistances to give greater degrees and longevity of control. In this study we assessed the susceptibility of 42 wheat-derived genotypes to mite population growth using a new experimental method that overcomes methodological limitations of previous studies. Experimental wheat lines included a variety of wheat genotypes, related Triticeae species, wheat-alien chromosome amphiploids, and chromosome addition or substitution lines. From these we identify new promising sources of WCM resistance associated with Thinopyrum intermedium, Th. ponticum and Hordeum marinum chromosomes. More specifically we identify group 1J and 5J chromosomes of the L3 and L5 wheat-Th. intermedium addition lines as new sources of resistance that could be exploited to transfer resistance onto homoeologous wheat chromosomes. This study offers new methods for reliable in situ estimations of mite abundance on cereal plants, and new sources of WCM resistance that may assist management of WCM and associated viruses in wheat.

Danos causados pelo acaro aceria guerreronis a diferentes genótipos de coqueiro.

1998

Flutuação populacional do ácaro da necrose do coqueiro (Aceria guerreronis) em coqueiro no estado de Sergipe.

O objetivo do trabalho é estudar a flutuação da população do ácaro da necrose do coqueiro A. guerreronis, utilizando um método indireto de contagem da população em meio líquido.

Additional morphological characters and a new host for Aceria gymnoscuta Navia & Flechtmann (Acari, Eriophyidae)

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

Primeiro relato de atividade patogênica de Hirsutella thompsonii (Fischer) sobre o ácaro-da-erinose-da-lichia Aceria litchii (Keifer)

The litchi erineum mite, Aceria litchii (Keifer) is found in all producing regions attacking leaves and flowers of litchi plants. The mite attack young leaves and causes the erinea on leaf surface, which later become brown galls with velvety appearance. Severe attacks can cause leaf drop and destruction of branches end directly production affecting. In 2009 year it was registered a heavy infestation of the pest on litchi plants (Litchi chinensis Sonn.) in the municipality of Casa Branca, São Paulo, Brazil (2127'O; 4702'S; 679 m altitude). In June, many galls caused by mite infestation showed a mycelium of white coloration and many eriophyid dead. The fungus was identified as Hirsutella thompsonii (Fischer). The results suggest that galls may facilitate the fungus development and its permanence on the plants. Thus, the possibility of mite biological control with H. thompsonii should be investigated.

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

Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV

Aceria litchii (Keifer) em lichia: ocorrência sazonal, danos provocados e identificação de possíveis agentes de controle biológico

Pós-graduação em Agronomia - FEIS

A Method to Estimate the Population Level of Aceria litchii (Prostigmata: Eriophyidae) and a Study of the Population Dynamics of This Species and Its Predators on Litchi Trees in Southern Brazil

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

Development of a Methodology and Evaluation of Pesticides Against Aceria litchii and Its Predator Phytoseius intermedius (Acari: Eriophyidae, Phytoseiidae)

The litchi erineum mite, Aceria litchii (Keifer), is the major pest of litchi, Litchi chinensis Sonnerat (Sapindaceae). This study evaluated the effect of 11 pesticides on the survival of A. litchii as well as on the survival and reproduction of Phytoseius intermedius Evans& McFarlane, the predator most found in association with it in Brazil. The containment of A. litchii in small petri dishes whose bottoms were covered with a solidified paste made of a mixture of gypsum and activated charcoal (9: 1 in volume), kept humid, was shown to be adequate for this type of study. For the evaluation of the effect of pesticides on A. litchii, mites leaving the erinia from the pieces of litchi leaves (removed from the plants approximate to 24 h earlier) were sprayed under a Potter tower and immediately transferred to the 2.5-cm-diameter petri dishes. After 2, 12, 24, and 48 h of the application, the dishes were examined to evaluate the mite survival. The four pesticides causing the highest levels A. litchii mortality, as well as azadirachtin, were tested for the effect on P. intermedius. For this test, experimental units consisted of discs of uninfested litchi leaves also sprayed under a Potter tower before introducing the predators. Survival and oviposition of the predator were evaluated every 24 h for 5 consecutive days; viability of the eggs laid was also evaluated. Highest mortality of A. litchii occurred with the application of fenpyroximate, sulfur, abamectin, and hexythiazox. Azadirachtin was considered moderately harmful to the predator P. intermedius, whereas other pesticides were classified as harmful. Despite the low efficiency of azadirachtin in the control of the pest, its relative selectivity to P. intermedius would encourage the evaluation on field condition, especially for use in organic production systems.

Status of Aceria guerreronis Keifer (Acari: Eriophyidae) as a Pest of Coconut in the State of Sao Paulo, Southeastern Brazil

The coconut mite, Aceria guerreronis Keifer, is one of the main pests of coconut palms (Cocos nucifera) in northeastern Brazil. The objective of this study was to evaluate the levels of the coconut mite and other mites on coconut palms in the state of So Paulo and to estimate the possible role of predatory mites in the control of this pest. The effect of cultivated genotypes and sampling dates on the mite populations was also estimated. We sampled attached fruits, leaflets, inflorescences, and fallen fruits. The coconut mite was the main phytophagous mite found on attached and fallen fruits, with average densities of 110.0 and 20.5 mites per fruit, respectively. The prevalent predatory mites on attached and fallen fruits were Proctolaelaps bulbosus Moraes, Reis & Gondim Jr. and Proctolaelaps bickleyi (Bram), both Melicharidae. On leaflets, the tenuipalpids Brevipalpus phoenicis (Geijsks) and Tenuipalpus coyacus De Leon and the tetranychid Oligonychus modestus (Banks) were the predominant phytophagous mites. On both leaflets and inflorescences, the predominant predatory mites belonged to the Phytoseiidae. Neoseiulus baraki (Athias-Henriot) and Neoseiulus paspalivorus (De Leon), predators widely associated with the coconut mite in northeastern Brazil and several other countries, were not found. The low densities of the coconut mite in So Paulo could be related to prevailing climatic conditions, scarcity of coconut plantations (hampering the dispersion of the coconut mite between fields), and to the fact that some of the genotypes cultivated in the region are unfavorable for its development.