ABSTRACT
Abstract The soybean (Glycine max (L.): Fabaceae) is considered the most important agricultural crop in Brazil. Phytophagous tetranychid mites as Mononychellus planki McGregor, Tetranychus ludeni Zacher and T. urticae Koch have been considered pest in soybean crops. Neoseiulus idaeus Denmark & Muma (Phytoseiidae) is a predatory mite of T. ludeni and T. urticae. The aim of the present study was to evaluate the biological performance of N. idaeus when fed on T. urticae, T. ludeni and M. planki, coming from the Northwest region of Rio Grande do Sul state, Brazil. The study was conducted in the laboratory with individual predators supplied with different preys. The mean duration (days) of N. idaeus egg-adult development was similar independently of supplied prey (T. ludeni - 5.29±0.03; M. planki - 5.34±0.05 and T. urticae - 5.23±0.03 days). Female viability was 90% when fed on M. planki and 100% when fed on T. ludeni and T. urticae. Mean fecundity of N. idaeus was lower when fed on M. planki (4.6±1.58 eggs/female) and higher when fed on T. ludeni (21.8±3.22) and T. urticae (26.2±2.41). The mean generation time (T) was lower when N. idaeus fed on M. planki than when fed on T. ludeni and T. urticae. The net reproductive rate (Ro) was 4.42±0.49 on M. planki, 17.77±0.55 on T. ludeni and 20.59±0.48 on T. urticae. The innate capacity for increase (rm) was lower when N. idaeus was fed on M. planki (0.09) and higher when such predator was fed on T. ludeni (0.20) and T. urticae (0.22 females/females/day). These results demonstrated that N. idaeus is able to reach the complete development feeding on all the three tetranychid species. Mononychellus planki demonstrated to provide a sub-optimal diet if compared to T. ludeni and T. urticae.
Resumo Soja (Glycine max (L.): Fabaceae) é a mais importante cultura agrícola brasileira. Tetraniquídeos fitófagos são pragas na cultura, Mononychellus planki McGregor, Tetranychus ludeni Zacher e T. urticae Koch. Neoseiulus idaeus Denmark & Muma (Phytoseiidae) é o ácaro predador de T. ludeni e T. urticae. Este estudo teve como objetivo avaliar o desempenho biológico de N. idaeus quando alimentado com T. urticae, T. ludeni e M. planki da região noroeste do Rio Grande do Sul, Brasil. O estudo foi realizado em laboratório com predadores individualizados com diferentes presas. A duração média (dias) de N. idaeus desenvolvimento ovo-adulto foi semelhante independentemente da presa fornecida (T. ludeni - 5.29 ± 0.03; M. planki - 5.34 ± 0.05 e T. urticae - 5.23 ± 0.03 dias). Viabilidade feminina foi de 90% quando alimentados com M. planki e 100% em T. ludeni e T. urticae. Fecundidade de N. idaeus foi menor com M. planki (4.6 ± 1.58 ovos / fêmea) e maior com T. ludeni e T. urticae, 21.8 ± 3.22 e 26.2 ± 2.41, respectivamente. O tempo médio de uma geração (T) foi menor quando N. idaeus alimentados com M. planki do que quando em T. ludeni e T. urticae. A taxa líquida de reprodução (Ro) foi de 4.42 ± 0.49 em M. planki, 17.77 ± 0.55 em T. ludeni e 20.59 ± 0.48 no T. urticae. A capacidade inata de aumento (rm) foi menor em M. planki (0.09) e maior quando alimentados com T. ludeni (0.20) e T. urticae (0.22 fêmeas / fêmea / dia). Estes resultados demonstraram que N. idaeus é capaz de utilizar e desenvolver em todas as três espécies de tetraniquídeos. Mononychellus planki demonstrou ser a presa menos adequada para este predador do que T. urticae e T. ludeni.
Subject(s)
Animals , Male , Female , Soybeans , Pest Control, Biological , Mites/physiology , Reproduction , Brazil , Crops, Agricultural , Tetranychidae/growth & development , Tetranychidae/physiology , Fertility , Mites/growth & developmentABSTRACT
Abstract Pachira aquatica Aubl. is commonly used as an ornamental plant in urban areas of Brazil. The objective of the study was to investigate the occurrence of mites on P. aquatica, with emphasis on Brachytydeus formosa (Cooreman), and to describe aspects the external features of its mouthpart. The study was conducted in 2012 in Jaboticabal, State of São Paulo, Brazil. Ten trees of P. aquatica were selected for the experiment. Approximately 130 leaflets were collected from each tree, which were located in different quadrants (north, south, east, and west) and strata (upper, middle, and lower). The leaflets were placed in paper bags and transported to the laboratory. The mites were prepared on optical microscope slides. A total of eleven species of mites were found, belonging to eight different families. The species and genera of the organisms included B. formosa, Eutetranychus banksi (McGregor), Agistemus sp., Tyrophagus putrescentiae (Schrank, 1781), Brevipalpus phoenicis (Geijskes), Brevipalpus sp., Cheletogenes sp., Iphiseiodes zuluagai Denmark & Muma, Euseius sp., Neoseiulus sp., and only one specimen from the Bdellidae family. The predominant species was B. formosa, with 8,142 mites equally distributed among the four quadrants and mostly in the middle and upper strata of the plant. B. formosa mites from leaflets of P. aquatica were separated for the study of the external mouthpart morphology by scanning electron microscopy (SEM).
Resumo Pachira aquatica Aubl. é frequentemente utilizada como planta ornamental em áreas urbanas no Brasil. O objetivo do trabalho foi conhecer os ácaros associados a P. aquatica com ênfase em Brachytydeus formosa (Cooreman), bem como descrever alguns aspectos morfológicos do seu aparato bucal. O estudo foi realizado em 2012, em Jaboticabal, estado de São Paulo, Brasil. Foram selecionadas dez árvores de P. aquatica para realização do experimento. Cerca de 130 folíolos foram coletados de cada árvore localizados em diferentes quadrantes (norte, sul, leste e oeste) e estratos (superior, médio e inferior). Os folíolos foram colocados em sacos de papel e transportados para o laboratório. Os ácaros foram preparados em lâminas de microscopia óptica. No total foram encontradas onze espécies de ácaros, pertencentes a oito famílias. As espécies encontradas foram B. formosa, Eutetranychus banksi (McGregor), Agistemus sp., Tyrophagus putrescentiae (Schrank, 1781), Brevipalpus phoenicis (Geijskes), Brevipalpus sp., Cheletogenes sp., Iphiseiodes zuluagai Denmark & Muma, Euseius sp., Neoseiulus sp., e apenas um exemplar da família Bdellidae. A espécie predominante foi B. formosa, com 8.142 ácaros igualmente distribuídos nos quatro quadrantes e principalmente nos estratos médio e superior da planta. Ácaros de B. formosa dos folíolos de P. aquatica foram separados para o estudo da morfologia externa do aparato bucal utilizando-se microscopia eletrônica de varredura (SEM).
Subject(s)
Animals , Biodiversity , Food Chain , Malvaceae , Mites/physiology , Bombacaceae/growth & development , Microscopy, Electron, Scanning , Malvaceae/growth & development , Mites/ultrastructure , Mouth/ultrastructure , Tetranychidae/physiology , Tetranychidae/ultrastructureABSTRACT
Background Strawberry is a pseudofruit mainly cultivated in temperate climate regions. Considering its high levels of ascorbic acid and phenolic compounds, the consumption of strawberry fruit can be beneficial to health. The Brazilian strawberry production revolves around 3000 tons per year, significantly influencing the food market and generating income to farmers. However, this production can be partially impaired by two-spotted spider mite (TSSM) Tetranychus urticae Koch infestations, due to decreases in the quality and quantity of fruit. Since there are no data in the literature about alterations caused by TSSM infestation in strawberry plants, our work aimed towards evaluating nutritional and physicochemical parameters of TSSM-infested strawberry plants, along with the related chemical treatment (CT) (acaricide) or biological treatment (predatory mite Phytoseiulus macropilis Banks). Results Strawberry fruit from TSSM-infested plants present the highest levels of acidity and exhibit low levels of anthocyanin and phenolic compounds, while fruit from TSSM-infested plants + biological control using predatory mite shows high levels of soluble solids, phenolic compounds and ascorbic acid, along with a high soluble solid content/titratable (SSC/TA) acidity ratio, which indicates high quality fruit. Conclusions Our results suggest that TSSM infestation decreases fruit quality and that the biological control of TSSM using a predatory mite is a suitable alternative to organic production, since the presence of predatory mite does not affect fruit quality and development.
Subject(s)
Animals , Pest Control, Biological , Tetranychidae/physiology , Fragaria/parasitology , Fragaria/chemistry , Mites/physiology , Predatory Behavior , Tick Control , Phenolic Compounds/analysisABSTRACT
The mite Tetranychus mexicanus (McGregor) is considered a pest of a variety of plant species in the Americas. Although this mite apparently causes economic damage to Annonaceae, little is known about its biology. Here we studied the biology of T. mexicanus on soursop (Annona muricata), sweetsop (Annona squamosa) and araticum (Annona coriaceae). The first two species are the most important economical Annonaceae species in northeast Brazil; araticum is commonly found in the region, but not commercially explored. The mites were collected in the field from leaves of A. muricata and maintained in the laboratory for six months on detached leaves of A. muricata, A. squamosa and A. coriaceae, respectively, before observations started. Tetranychus mexicanus developed more slowly on A. squamosa than on the two other hosts, but oviposition was considerably lower on A. coriaceae. As indicated by the calculated life table parameters, biotic potential was higher on A. muricata than on the other hosts. Despite the observed differences in the T. mexicanus biology on the different evaluated hosts, development and reproduction were satisfactory in all of the hosts used.
Subject(s)
Animals , Annonaceae/parasitology , Tetranychidae/physiologyABSTRACT
The two spotted spider mite, Tetranychus urticae Koch, is a nontarget herbivore of Bt-cotton, but acquires and accumulates higher levels of Cry toxin than that expressed by transgenic plants. This work investigated the development and reproduction of T. urticae and of the predator Phytoseiulus macropilis Banks, during three successive generations looking for potential nontarget effect. In addition, behavioral studies on feeding preference, oviposition, and predation were carried out on Bt and non-Bt cottons. The development and reproduction of T. urticae and P. macropilis was conducted using leaf discs of Bt and non-Bt cottons. Arena containing leaf discs from both cotton types connected by a slide coverslip were also used in the behavioral studies. Averages of the three generations showed that the Bt-cotton does not affect the development, survival of immature stages, and reproductive output of T. urticae and of the predator P. macropilis. Furthermore, the preference for feeding and oviposition of T. urticae and P. macropilis were similar on both cotton types. In addition, P. macropilis exhibited similar predatory behavior on T. urticae fed on both cotton types. Levels of Cry1Ac toxin in T. urticae was 3.97 times greater than that found in the Bt-cotton plants as determined using a ELISA test. Despite of the amount of toxin acquired by the prey (T. urticae), no detectable levels of Cry1Ac were found in the predatory mite P. macropilis.
Subject(s)
Animals , Acari/physiology , Gossypium/parasitology , Plants, Genetically Modified/parasitology , Tetranychidae/physiology , Behavior, Animal , Gossypium/geneticsABSTRACT
Gerbera (Gerbera jamesonii Bolus and Hook,) is an ornamental Asteraceae of great commercial value, and pests can affect adversely its cultivation. More than 20 species of arthropods cause economic damage on gerbera, among them the two spotted mite, Tetranychus urticae Koch, 1836 (Acari: Tetranychidae), considered a key pest for this and other ornamental plants. In this work, some life-cycle aspects of T. urticae on gerbera, considered important for the knowledge of its population dynamics and for pest management programs, were studied. Mites were reared on 3-cm diameter arenas of gerbera leaf discs maintained on distilled water in Petri dishes, under laboratory conditions of 25 ºC, 70 ± 10 percent RU and 14-hour photophase, with only one egg left per arena, in a total of 262 arenas. Egg viability was 96.5 percent and 97.1 percent for unmated and mated females, respectively. Unmated females originated larvae which lived for 3.2 days and the stages of protonymph and deutonymph, 1.9 and 1.6 days, respectively; those from mated females lived 3.5 days and for protonymphs and deutonymphs, 2.0 and 1.6 days, respectively. Except for the duration of one generation (T), with similar values, 18.6 and 19.7 days, respectively for unmated and mated females, the net reproductive rate of increase (Rº), the innate capacity to increase in number (r m) and the finite rate of growth (λ) were different for mated and unmated females, respectively 11.5 and 24.6 for R0; 0.12 and 0.17 for r m and 1.13 and 1.19 for λ.
A gérbera, Gerbera jamesonii Bolus and Hook, é uma planta ornamental pertencente à família Asteraceae de grande valor comercial. Dentre os vários fatores que podem afetar adversamente o seu cultivo se encontram as pragas. Mais de 20 espécies de artrópodes causam danos econômicos em gérbera, entre elas encontra-se o ácaro-rajado, Tetranychus urticae Koch, 1836 (Acari: Tetranychidae), considerado praga-chave dessa e de outras plantas ornamentais. O presente trabalho teve por objetivo estudar alguns aspectos do ciclo biológico de T. urticae em gérbera considerados importantes para o conhecimento da dinâmica populacional da espécie e para os programas de manejo de pragas. Os ácaros foram criados em arenas constituídas de discos de folhas de gérbera de 3 cm de diâmetro, sobre água destilada, colocados em placas de Petri, em condições de laboratório, a 25 ºC, 70 ± 10 por cento de U.R. e 14 horas de fotofase, deixando-se um ovo por arena, perfazendo um total de 262 arenas. A viabilidade dos ovos foi de 96,5 e 97,1 por cento para fêmeas não acasaladas e acasaladas, respectivamente. As larvas provenientes de fêmeas não acasaladas tiveram duração de 3,2 dias e os estágios de protoninfa e deutoninfa foram de 1,9 e 1,6 dias, respectivamente. Já para fêmeas acasaladas a fase de larva teve uma duração de 3,5 dias, a de protoninfa e deutoninfa 2,0 e 1,6 dias, respectivamente. À exceção da duração de uma geração (T) que tiveram valores próximos, 18,6 e 19,7, respectivamente para fêmeas não acasaladas e acasaladas, a taxa líquida de reprodução (Rº), capacidade inata de aumentar em número (r m) e razão finita de crescimento (λ) foram diferentes para fêmeas acasaladas e não, sendo respectivamente 11,5 e 24,6 para R0; 0,12 e 0,17 para r m e 1,13 e 1,19 para λ.
Subject(s)
Animals , Female , Male , Asteraceae/parasitology , Host-Parasite Interactions/physiology , Tetranychidae/physiology , Asteraceae/classification , Asteraceae/physiology , Fertility , Population Dynamics , Tetranychidae/classificationABSTRACT
The functional response of the phytoseiid predator Chileseius camposi González y Schuster, 1962 (Acarina:Phytoseiidae) on densities of its prey Panonychus ulmi (Koch, 1836) was evaluated under controlled temperature (20 ± 2 ºC),, relative humidity (75 ± 15%) and photoperiod (16:8h L:D). A functional type II response was displayed (Hollings disk). Holling, Wolf transformation and Rogers models gave similar values for estimating parameters of the Hollings disk equation; however, estimates produced by the Livdahl and Stiven model were higher. Values of attack rate and handling time can be considered within the normal range for phytoseiid generalists. Rev. Biol. Trop. 56 (3): 1255-1260. Epub 2008 September 30.
La respuesta funcional del ácaro fitoseido nativo Chileseius camposi González y Schuster, 1962, sobre el ácaro fitófago introducido Panonychus ulmi (Koch, 1836) (Acarina:Tetranychidae) fue evaluada en condiciones controladas de temperatura (20 ± 2 ºC), humedad relativa (75 ± 15%) y fotoperíodo (16:8 h L:O). Una respuesta funcional de tipo II, fue determinada (disco de Holling). Los modelos de Holling, Wolf y Rogers dieron valores similares para la estimación de los parámetros de la ecuación del disco de Holling, la estimación de estos parámetros por el modelo de Livdahl y Stiven fueron mayores. Los valores encontrados para la razón de ataque y el tiempo de manipulación pueden ser considerados dentro del ámbito normal para fitoseidos generalistas.