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ABSTRACT Larvae of Hydrotaea species are facultative predators of larvae of other fly species on poultry farms, chicken feces, pig, and decaying carcasses. The Neotropical species H. albuquerquei occurs together with M. domestica in these environments and might be useful in the biological control of the latter. To verify the predatory capacity of H. albuquerquei larvae on the larvae of M. domestica, we varied the size of the larvae and the densities of the predators and prey under controlled laboratory conditions. Adults were collected from a poultry farm for the experiment, and the larvae they produced were reared in the laboratory. The second and third instar larvae of H. albuquerquei, when at higher densities, suppressed populations of house fly larvae when the latter were smaller than the former. This means that the functional response increases gradually with an increase in prey population density and predator size. In these conditions, one H. albuquerquei larva consumes up to 29 M. domestica larvae at high prey densities and could reduce 100% of the house fly population under a 50% prey density. This study confirmed a pattern previously observed in other predatory larvae and our results have implications for the biological control and integrated pest management programs of M. domestica in poultry and swine farms.
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Abstract The biological control used for the control of Tetranychus urticae (Koch) is the predator mite Phytoseiulus persimilis (Athias-Henriot). It is important to the know the effects of acaricides on the biological behavior the Abamectin on the functional response of P. persimilis. The functional response of the predator was of type II exposed to concentration of Abamectin, the functional response parameters: successful attack rate (a'), handling time (Th), search efficiency and the maximum predation theory (T/Th) were affected by the acaricide. The predator spends more time in persecute, dominate, consume and prepair it self to the next searching comparing with the proof subject an the predation ability was affected.
Resumo O controle biológico utilizado para o controle de Tetranychus urticae (Koch) é o acaro predador Phytoseiulus persimilis (Athias-Henriot). É importante conhecer os efeitos dos acaricidas sobre o comportamento biológico do predador. Foi avaliado o efeito tóxico de a Abamectina na resposta funcional de P. persimilis. A resposta funcional do predador foi tipo II exposta a concentrações subletais de Abacmetina, os parâmetros da resposta funcional: taxa de ataque (a'), tempo de manipulação (Th), a eficiência na procura e predação teórica máxima (T/Th) foram afetados pelo acaricida. O predador passa mais tempo na procura, dominar, consumir e se preparar para a próxima procura em comparação com a testemunha e sua capacidade de predação foi afetada.
Asunto(s)
Animales , Ivermectina/análogos & derivados , Acaricidas/farmacología , Ácaros/efectos de los fármacos , Ácaros/fisiología , Ácaros/parasitología , Ácaros/patogenicidad , Ivermectina/farmacología , Control Biológico de Vectores/métodos , Tetranychidae/efectos de los fármacos , Tetranychidae/parasitologíaRESUMEN
Abstract Larval feeding studies of both ornamental and consumable fish species are important for formulating successful management, and culture strategies for conservation purposes. In the present study, we evaluated prey selectivity for the tropical gar Atractosteus tropicus in the larval stage (first 8 weeks) using the zooplankton Artemia fransiscana, Daphnia pulex and Moina macrocopa as prey following the hypothesis that prey selection of the fish species is related not only to prey species preferences but to the difference in prey densities present in the environment. Functional responses were tested at prey densities of 0.2, 0.5, 1.0, 2.0, 4.0 and 8.0 ind. mL-1 and analyzed using Manly's α. For prey selectivity, we used the three zooplankton species at three different densities. In these two experiments the fish larvae were allowed to feed for 45 min. To quantify feeding behavior (encounters, attacks, captures, ingestions, rejections) we used a density of 1 ind. mL-1 using each prey species based on 10 minutes of direct observation. Our results showed a functional response Type II for A. tropicus preying mostly on A. franciscana and M. macrocopa. The Manly's α index showed that M. macrocopa and A. franciscana are the most preys selected. The values for encounters for the three prey species were relatively constant during the eight weeks. Encounter values for the cladocerans were low in comparison to A. franciscana; however, high success in capture and ingestion was observed for all prey species used. Our results from the functional response experiments supports the hypothesis that A. tropicus is an active predator presenting a functional response of a carnivorous fish and the shift in prey selection suggests that even at low prey availability, A. tropicus is able to manipulate and feed on zooplankton of wide range in size. Also, according to our results, we suggest the use of a mix of A. franciscana and M. macrocopa to feed A. tropicus in culture systems in concentrations ≈ 2 ind. mL-1 during the first 3 weeks of age and then shift to M. macrocopa from the 4 week. Our results, in conjunction with studies on the survivorship of the juveniles would aid in conservation efforts and improve the production of gars in aquaculture. Rev. Biol. Trop. 66(3): 1018-1033. Epub 2018 September 01.
Resumen Estudios sobre alimentación en etapa larvaria en peces ornamentales como de consumo son importantes para formular estrategias exitosas de manejo y cultivo con fines de conservación. En el presente estudio evaluamos la selectividad de presa del pejelagarto Atractosteus tropicus en etapas larvarias (primeras 8 semanas) utilizando el zooplancton Artemia fransiscana, Daphnia pulex y Moina macrocopa como presas, probando la hipótesis de que la selección de presas en peces está relacionada no solamente a la preferencia por la especie de presa sino también a la diferencia en la densidad de presas en el ambiente. También se probó la respuesta funcional con densidades de presa de 0.2, 0.5, 1.0, 2.0, 4.0 y 8.0 ind. mL-1. Para la selección de presa, utilizamos las tres especies de zooplancton en tres densidades diferentes. En ambos experimentos, las larvas de los peces se alimentaron por 45 min. Para cuantificar el comportamiento alimenticio (encuentros, ataques, capturas, ingestiones y rechazos), se usó una densidad de 1 ind. mL-1utilizando cada especie de presa mediante observación directa por 10 minutos. Nuestros resultados muestran que A. tropicus presenta una respuesta funcional Tipo II, depredando principalmente A. franciscana y M. macrocopa. El índice α de Manly mostró que las especies M. macrocopa and A. franciscana fueron las mayormente seleccionadas. Los valores de encuentros para las tres especies de presa fueron relativamente constantes a lo largo de las ocho semanas. Los valores de ataque, captura e ingestión para los cladóceros fueron bajos; sin embargo, se observó gran éxito en la captura e ingestión para todas las especias de presa utilizadas. Nuestros resultados sobre los experimentos de respuesta funcional soportan la hipótesis de que A. tropicus es un depredador activo y presenta una respuesta funcional relacionada con especies de peces carnívoras y que el cambio en la selección de presas sugiere que aún a bajas densidades y disponibilidad de presas, A. tropicus es capaz de manipular y alimentarse de presas de diferentes tamaños. También, sugerimos el uso de una mezcla de A. franciscana y M. macrocopa para alimentar a A. tropicus en sistemas de cultivo en concentraciones ≈ 2 ind. mL-1 durante las primeras tres semanas de edad y después cambiar a M. macrocopa a partir de la cuarta semana. Nuestros resultados, junto con estudios de sobrevivencia de los juveniles pueden ayudar a generar esfuerzos de conservación y mejorar la producción de pejelagarto en acuicultura.
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Zooplancton , Batrachoidiformes , Alimentación Animal , Peces , MéxicoRESUMEN
Abstract The biological control used for the control of Tetranychus urticae (Koch) is the predator mite Phytoseiulus persimilis (Athias-Henriot). It is important to the know the effects of acaricides on the biological behavior the Abamectin on the functional response of P. persimilis. The functional response of the predator was of type II exposed to concentration of Abamectin, the functional response parameters: successful attack rate (a), handling time (Th), search efficiency and the maximum predation theory (T/Th) were affected by the acaricide. The predator spends more time in persecute, dominate, consume and prepair it self to the next searching comparing with the proof subject an the predation ability was affected.
Resumo O controle biológico utilizado para o controle de Tetranychus urticae (Koch) é o acaro predador Phytoseiulus persimilis (Athias-Henriot). É importante conhecer os efeitos dos acaricidas sobre o comportamento biológico do predador. Foi avaliado o efeito tóxico de a Abamectina na resposta funcional de P. persimilis. A resposta funcional do predador foi tipo II exposta a concentrações subletais de Abacmetina, os parâmetros da resposta funcional: taxa de ataque (a'), tempo de manipulação (Th), a eficiência na procura e predação teórica máxima (T/Th) foram afetados pelo acaricida. O predador passa mais tempo na procura, dominar, consumir e se preparar para a próxima procura em comparação com a testemunha e sua capacidade de predação foi afetada.
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Background & objectives: Culex quinquefasciatus is the principal vector of lymphatic filariasis (LF). Application of alternative vector control methodologies are aimed at reduction of mosquito breeding sites and biting activity through the use of biological control methods. In the present study, functional response of aquatic Hemipteran backswimmer, Anisops sardea was assessed against Cx. quinquefasciatus larvae in laboratory bioassay. Methods: The functional respons of A. sardea was assessed against IIIrd instar larvae of Cx. quinquefasciatus. Respective handling times and coefficient of attack rates were determined by a non linear polynomeal regression equation. Results: The results of rates of predation in variable prey densities exhibited a ‘linear rise to plateau curve’, associated with ‘Type -II’ functional response. The logistic regression estimated a significant negative linear parameter (P1<0) which also supported the same observation. Associated ‘attack rates’ and ‘handling times’ were also calculated using the Holling Disc Equation. Interpretation & conclusions: The results of present experiments indicate that A. sardea can be used as a biocontrol agent against the larval forms of Cx. quinquefasciatus in temporarily available breeding places of mosquito with relatively clear water. However, a detailed field study has to be done to confirm these findings.
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In this work, the stage preference and functional response of the indigenous reduviid bug Rhynocoris longifrons feeding on five different densities of the cotton aphid Aphis gossypii, Phenacoccus solenopsis, and Dysdercus cingulatus was examined in Petri dish arenas containing cotton leaves under laboratory conditions. The reduviid predator exhibited a Type II functional response at all hemipteran pests evaluated when data were fit to Holling's disc equation. Predatory rate gradually increased while the predator grew older and adults consumed maximum number of D. cingulatus and P. solenopsis. An opposite trend was observed, while the reduviid was provided with Aphis gossypii. The rate of attack on P. solenopsis was quite low but fairly consistent, with the different life stages of the predator generally more effective. Further investigation of the biological control potential of R. longifrons against cotton pests under pot and controlled filed should be done due to the predator's ability to kill adult stages of all prey species evaluated. These results indicated that R. longifrons could eat more aphids at high prey densities; however, predators also considerably reduced other cotton pests too so it could be considered a prospective candidate for use as a commercial biological control agent for cotton hemipteran pests in India.
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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.
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Animales , Femenino , Masculino , Ácaros/fisiología , Conducta Predatoria/fisiología , Modelos Biológicos , Densidad de Población , Tetranychidae/fisiologíaRESUMEN
The effect of the defense of the prey Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) on predation rates of Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) females was studied. P. nigrispinus preyed 1.0, 1.4, 1.2, 3.8 and 3.0 and 0.4, 0.8, 1.6, 2.8 and 3.2 third instars of S. frugiperda larvae with and without defense, respectively, with the densities of one, two, four, six and eight larvae. The attack rate and the manipulation time were, respectively, 0.67 ± 0.39-h and 6.72 ± 2.88 h for P. nigrispinus females fed with larvae with defense and 2.51 ± 0.16-h and 0.51 ± 0.77 h for those without defense. The functional response of the predator P. nigrispinus varies with the defense and the density of the prey S. frugiperda, with larger consumption of prey without defense at higher densities.
Objetivou-se determinar o efeito da defesa da presa Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) na taxa de predação por fêmeas de Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae). Podisus nigrispinus, predou 1,0; 1,4; 1,2; 3,8; 3,0 lagartas de terceiro estádio de S. frugiperda com defesa, respectivamente, nas densidades de uma, duas, quatro, seis e oito lagartas, enquanto esses valores foram de 0,4; 0,8; 1,6; 2,8; 3,2 lagartas sem defesa, respectivamente, nessas densidades. A taxa de ataque (a) e o tempo de manipulação (Th) foram, respectivamente, de 0,67 ± 0,39-h e 6,72 ± 2,88 horas para fêmeas de P. nigrispinus alimentadas com lagartas com defesa e de 2,51 ± 0,16-h e 0,51 ± 0,77 horas para aquelas sem defesa. A resposta funcional do predador P. nigrispinus varia com a defesa e a densidade da presa S. frugiperda, com maior consumo de presas sem defesa em altas densidades.
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O presente trabalho objetivou estudar a biologia de Agistemus brasiliensis Matioli, Ueckermann & Oliveira nas temperaturas de 15; 20; 25; 30 e 35°C, alimentada com Brevipalpus phoenicis (Geijskes) e pólen de Thypha sp. em condições de laboratório. Tabelas de vida de fertilidade foram calculadas para determinar os parâmetros biológicos. A temperatura ideal para o desenvolvimento de A. brasiliensis foi 29°C. Os valores de T (ciclo de vida - dias), R0 e r m, na temperatura de 30°C, foram de 13,95; 16,25 e 0,20, respectivamente. A potencialidade de predação de A. brasiliensis foi estudada para as densidades populacionais de 5; 10; 20; 40 e 60 adultos de B. phoenicis a 29°C, em arenas de 3 cm de diâmetro, sobre frutos de laranja-pêra. A densidade de 20 ácaros foi suficiente para que o predador consumisse seu número máximo de presas (7,6 ácaros por dia). Densidades acima de 40 ácaros da leprose proporcionaram 4,7 ovos por dia, em comparação aos 2,5 ovos por dia obtidos na densidade de 20 ácaros da leprose.
The present work aimed to study the biology of Agistemus brasiliensis Matioli, Ueckermann & Oliveira at the following temperatures, namely 15, 20, 25, 30 and 35°C, fed with Brevipalpus phoenicis (Geijskes) and Typha pollen, in laboratory conditions. Life tables were calculated to evaluate the biological parameters. The optimal development of A. brasiliensis took place at 29°C. The values of T (time of generation - days), R0 and r m at 30°C were, 13.95, 16.25 and 0.20, respectively. The prey consumption of A. brasiliensis was studied at the densities of 5, 10, 20, 40 and 60 leprosis mite females per cage (3 cm in diameter) on citrus fruits at 29°C. The maximum prey, namely 7.6 B. phoenicis females per day, were consumed at a density of 20 leprosis mites. At densities of above 40 leprosis mites per cage, A. brasiliensis oviposits 4.7 eggs per day, in comparison to 2.5 eggs per day at 20 mites per cage.
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Ácaros y Garrapatas/parasitología , Ácaros y Garrapatas/patogenicidadRESUMEN
The predation rate of unmated and mated females of Podisus nigrispinus (Dallas) was evaluated on different densities of Alabama argillacea (Huebner) caterpillars (50 ± 10 mg), in laboratory and field conditions. In the laboratory, the predator females were maintained in 500 ml plastic jars with five different densities of prey (one, two, four, eight, and 16). In the field, caterpillars at the same densities were caged on flowering cotton plants. Under both conditions, females gained weight and increased the predation rate when the availability of prey increased, although higher values were obtained for females kept in the laboratory. Weight gain and predation rate did not differ between unmated and mated females under both conditions. In the field, P. nigrispinus searched 94.7 percent of the available foliar area under low prey density, and 21.2 percent under high prey density. The estimated handling time and attack rate were, respectively, 3.37 ± 0,82h and 0.076 ± 0.013h-1 in the laboratory, and 3.33 ± 0.93h and 0.017 ± 0.003h-1 in the field. The functional response corresponded to a type II for both conditions. The number of killed caterpillars observed and estimated by the model were highly correlated for both laboratory (r = 0.78) and field (r = 0.70) conditions.
Avaliou-se a taxa de predação de fêmeas virgens ou acasaladas de Podisus nigrispinus (Dallas) em diferentes densidades de lagartas de Alabama argillacea (Huebner) em condições de laboratório e de campo. Em laboratório, empregaram-se potes plásticos de 500 ml contendo fêmeas do predador, uma folha de algodão e lagartas de A. argillacea (50 ± 10 mg) nas densidades de uma, duas, quatro, oito e 16 lagartas. No campo, algodoeiros na fase de florescimento foram engaiolados, sendo empregadas as mesmas densidades de lagartas que no laboratório. Em ambas as condições, as fêmeas de P. nigrispinus apresentaram ganho de peso e aumento de sua taxa de predação com o aumento da densidade de lagartas de A. argillacea, mas com valores maiores para fêmeas em laboratório. Nas duas condições, o ganho de peso e a taxa de predação foram semelhantes para fêmeas virgens ou acasaladas. No campo, P. nigrispinus explorou 94,7 por cento e 21,2 por cento da área foliar disponível na menor e maior densidade de presas, respectivamente. O tempo de manipulação e a taxa de ataque estimadas foram de 3,37 ± 0,82h e de 0,076 ± 0,013h-1 em laboratório, e de 3,33 ± 0,93h e de 0,017 ± 0,003h-1 em campo. A resposta funcional em laboratório e no campo foi caracterizada como do Tipo II. Os números observados e estimados de lagartas predadas pelo modelo foram significativamente correlacionados com as condições de laboratório (r = 0,78) e de campo (r = 0,70).
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Este trabalho teve como objetivo determinar a resposta funcional do parasitóide Aphidius colemani Viereck, através da determinação do número de múmias de Myzus persicae (Sulzer) formadas e da sua razão sexual, nas densidades de 20, 40, 60 e 80 ninfas sobre folhas de pimentão, à temperatura de 21±1ºC. Também foi avaliada sua resposta funcional através do número de ataques do parasitóide sobre os hospedeiros e pelo seu comportamento de busca, à temperatura de 23±1ºC, nas densidades de zero, quatro, oito, 16 e 32 M. persicae sobre discos foliares de pimentão (43mm) em placas de Petri (50 mm). A resposta funcional de A. colemani foi do tipo II, tanto para o número de múmias formadas (12,4; 22,7; 33,0 e 31,6), quanto para o número de ataques do parasitóide (0; 4,1; 6,8; 13,2 e 19,2), obtendo-se aumento gradativo do número de hospedeiros aceitos com o aumento da densidade do hospedeiro, até estabilizar-se. A razão sexual foi 0,57 em média, não sofrendo influência significativa da densidade do hospedeiro (P<0,05). O número de toques com a antena do parasitóide nos hospedeiros (encontros) aumentou gradativamente com o aumento da densidade do hospedeiro, sofrendo um aumento brusco na densidade mais alta (32 hospedeiros), indicando um aumento no comportamento de busca do parasitóide. O tempo da primeira visita de A. colemani não variou com a densidade. Quando os hospedeiros estavam presentes, foi de 1526,9 a 1638,0 segundos, porém, na ausência de hospedeiros, o parasitóide permaneceu no disco foliar por tempo menor (340,1 segundos).
This research aimed to determine the functional response of parasitoid Aphidius colemani Viereck, by determining the number of mummies of Myzus persicae (Sulzer) formed and its sexual ratio at densities of 20, 40, 60 and 80 2nd - and 3rd - instar nymphs on sweet-pepper leaves, at temperature of 21±1ºC. The functional response was also evaluated by calculating the number of attacks of the parasitoid on the host and its search behaviour on leaf discs of sweet-pepper leaves (43mm) in a Petri dish (50mm). The temperature of 23±1ºC and the densities of zero, four, eight, 16 and 32 nymphs of M. persicae were used. A. colemani's functional response was of type II, not only for number of mummies formed (12.4; 22.7; 33.0 and 31.6) but also for number of attacks (0; 4.1; 6.8; 13.2; and 19.2), with a gradual increase in the number of host density and reaching a plateau. The average sexual ratio was 0.57 and showed no significant influence in host density (P<0.05). The number of contacts made by parasitoid's antennae onto their hosts (encounters) increased gradually with higher host densities, with an abrupt increase in the highest density (32 hosts), indicating an increase in searching behaviour of the parasitoid. The time of the first visit of A. colemani has not varied with the host density. In the presence of hosts it lasted from 1526.9 to 1638.0 seconds; in the absence of host, the parasitoid stayed on the leaf disc for a short time (340.1 seconds).