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.

Incidence of tarsonemid mites on Cocos nucifera L. (Arecaceae) from Oman with description of a new species of Nasutitarsonemus Beer and Nucifora (Acari: Tarsonemidae)

Coconut is an important crop grown in the coastal plain of the Dhofar region, south-eastern Oman, on the edge of the Arabian Peninsula desert. It holds a particular place in the landscaping of the region and is also of great interest for the production of coconut drinking water. One of the main pests of coconut in this region is the coconut mite (Aceria guerreronis Keifer). In surveys conducted to understand the dynamics of that mite and its association with other arthropods, the incidence of tarsonemid mites was determined. Steneotarsonemus furcatus de Leon was the most commonly found tarsonemid on fruits as well as on growing tips of coconut seedlings, always at low levels. A few representatives of an undescribed tarsonemid species were also found. That new species is here described as Nasutitarsonemus omani Lofego and Moraes, sp. nov. A key to the species of this little-known genus is provided.

Ocorrência e diversidade de ácaros (Acari, Arachnida) associados a Tabebuia roseo-alba (Ridl.) Sand (Bignoniaceae), no município de São José do Rio Preto, São Paulo, Brasil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ácaros predadores associados ao ácaro-da-erinose da lichia

O objetivo deste trabalho foi identificar ácaros predadores em plantas de lichia e correlacionar o desenvolvimento populacional dessas espécies com o do ácaro-da-erinose da lichia, Aceria litchii. A pesquisa foi desenvolvida no Município de Casa Branca, SP, com árvores adultas, de 12 anos de idade, da variedade Bengal. Mensalmente, de agosto de 2008 a setembro de 2009, foram coletadas folhas para avaliação dos níveis populacionais de A. litchii e de ácaros predadores. Foram registrados 6.557 indivíduos da família Phytoseiidae. A espécie mais abundante foi Amblyseius compositus (42,6%), seguida por Phytoseius intermedius (31,2%), Euseius concordis (14,1%), Amblyseius herbicolus (8,8%) e Iphiseiodes zuluagai (3,3%). O desenvolvimento populacional de A. compositus, E. concordis e I. zuluagai correlacionou-se positivamente com o de Aceria litchii, o que indica relação de predação.

Análise da presença de vírus em alho semente da segunda e quarta gerações, produzidos por termoterapia e cultura de tecido

The garlic (Allium sativum L.) can be naturally infected by a complex of filamentous viruses belonging to the genera Potyvirus, Carlavirus and Allexivirus. Accumulation of these viruses occurs especially by vegetative propagation through cloves. As the cultivated garlic plant does not produce true seed worldwide, virus-free plants can only be obtained by tissue culture of stem apices and thermotherapy. Using these techniques, garlic seeds were produced at the School of Agricultural Sciences - UNESP, Botucatu, and evaluated by RT-PCR for the presence of potyvirus, carlavirus and allexivirus. In the second generation of microcloves propagated in a greenhouse, 6.6% infection was detected, only by allexivirus. In the fourth generation, however, there was 60% incidence by allexivirus, 35% by potyvirus and all negative by carlavirus. The high rate of infection by allexivirus may be related to the greater difficulty of removing the species of viruses belonging to this genus, as observed by other authors, and also based on the infection and transmission of the virus by the mite, Aceria tulipae, during the storage of bulbs from one year to the other. The garlic at the fourth generation corresponds to cloves weighed less than 1 gram and not selected for commercial multiplication. Selection for the size of cloves has a positive effect on the choice of cloves with lower rates of viral infection, as the technique of thermotherapy and tissue culture do not eliminate the virus completely. Results also emphasize the need of fumigation for the garlic seed stored from one year to the other in order to prevent the transmission of allexivirus during storage.