II International Symposium on Guava and other Myrtaceae, 2010
The main problem in guava production is fruit fly damage; this insect feeds inside the fruit and ... more The main problem in guava production is fruit fly damage; this insect feeds inside the fruit and facilitates the entrance of pathogens and fruit drop. This study evaluated different materials used for making protective bags for guava fruits in order to reduce fruit fly damage and pathogen presence, as well as to extend their life expectancy in the field. The study took place during the dry and rainy seasons in Carrillos, Alajuela, Costa Rica. During the first phase, four different bagging materials were evaluated: waxed paper, nylon fabric, Taiwan bag and telephone book paper, the latter normally used by local farmers; for the second phase, only Taiwan and nylon bags were used. Highly significant differences (F = 66.75; p Taiwan > waxed paper > telephone guide paper. For the second period (F = 38.13; p < 0.0001) nylon bags protected more fruits than Taiwan bags. The longest duration of the bag in the field was obtained with nylon bags followed by telephone book paper, Taiwan and waxed paper bags. During the second phase Taiwan outlasted nylon bags. Telephone book paper and nylon yielded the highest amount of infected fruit during the first and second periods respectively. The highest number of fallen fruit was obtained in the control group during the first phase. During the dry season, the highest number of fruits affected by pathogens was found when the telephone book paper bags were used, while fruits bagged with nylon bags during the rainy season presented the highest number of fruits affected by pathogens. The results of this research show that the use of the nylon bag offered the highest protection against the fruit fly; however, it does not protect against pathogens which also affect guava production.
Hypsipyla grandella (Zeller) is the most important insect pest of the Meliaceae in the Neotropics... more Hypsipyla grandella (Zeller) is the most important insect pest of the Meliaceae in the Neotropics. This paper reviews the information on H. grandella parasitoids in Latin America and the Caribbean. Preliminary data on the parasitoid complex in Turrialba, Costa Rica, are presented, where apparent parasitisation of H. grandella during 1995–1996 reached 36%. The lowest level of parasitisation occurred during the dry season. The parasitoid Apanteles sp. (= Hypomicrogaster hypsipylae de Santis?) (Hymenoptera: Braconidae) was the most abundant larval parasitoid with a mean of 22 parasitoids per parasitised larva and a sex ratio of 3:1 females to males. Brachymeria conica Ashmead (Hymenoptera: Chalcididae) was found parasitising pupae, but at low frequency
Biological control in Latin America and the Caribbean: its rich history and bright future
The first biological control activities in Costa Rica date from around 1915, but it was only in t... more The first biological control activities in Costa Rica date from around 1915, but it was only in the 1950s that studies were conducted on the introduction, mass rearing and release of biocontrol agents in crops such as fruit trees, coffee, bananas, sugarcane, rice and pineapple. Subsequently, the use of entomopathogens became important in the 1990s as a strategy to be used in integrated pest management (IPM) programmes. From the 1990s, biocontrol laboratories were established and alliances were developed with national and international institutions and universities to strengthen biocontrol activities in the country. Currently, new areas of study have been incorporated in biocontrol research, such as molecular biology, host-plant resistance, identification of new biocontrol agents, the use of X-rays to sterilize hosts of natural enemies and the use of volatile compounds produced by the plant after pest attack to attract natural enemies. All these activities help to develop sustainable...
Vertical distribution of eggs of the macadamia nutborer Ecdytolopha torticornis Meyrick (Lepidopt... more Vertical distribution of eggs of the macadamia nutborer Ecdytolopha torticornis Meyrick (Lepidoptera: Tortricidae) and its preference of oviposition sites within and between macadamia cultivars were studied in Turrialba, Cartago, Costa Rica, in 1992 (N = 6,939). E. torticornis eggs were found throughout the foliar parts of the tree, but fewer eggs were laid in the crown top than in the mid or lower crown. Differences in the horizontal distribution of the eggs were not significant, albeit more eggs were found in the outer positions. The numbers of eggs found within the crowns of different clones were similar, implying that the nutborer has no preference for a particular cultivar.
Se estudió el efecto de 3 condiciones de luz (completa-548,63 W m-2, media luz-280,02 W m-2, somb... more Se estudió el efecto de 3 condiciones de luz (completa-548,63 W m-2, media luz-280,02 W m-2, sombra-76,38 W m-2), el uso de repelentes (ajo más chile, neem y pichichío) y el uso de bolsas de exclusión, en el daño de Cholus pilicauda a las flores de ginger rosado (Alpinia purpurata) en una plantación asociada con poró (Erythrina poeppigiana). El embolse de las flores redujo significativamente el número de flores dañadas, independientemente de la intensidad lumínica. No se encontró diferencias entre el número de flores dañadas con el uso de Azatina®<Harbri tt®<Pichichío, pero sí con el testigo (agua) que presentó el mayor número de flores dañadas. La sombra densa resultó en un mayor número de flores dañadas, seguida por luz completa y la media.
La broca del café Hypothenemus hampei (Ferrari) es considerada la plaga de mayor importancia en e... more La broca del café Hypothenemus hampei (Ferrari) es considerada la plaga de mayor importancia en el cultivo del café a nivel mundial. Al igual que muchos otros insectos, el comportamiento de la broca se ve modificado por distintas señales olfativas, lo cual ha impulsado la investigación en el campo de la olfatometría, por medio de una gran variedad de estrategias y alternativas. En este experimento se evaluaron 2 diseños innovadores de olfatómetros de flujo de aire de 4 vías para experimentación en H. hampei. Estos fueron fabricados totalmente en cristal y difieren entre ellos por la distribución angular de los brazos distribuidores de flujos de aire yla zona de ingreso y adaptación de los insectos al olfatómetro. Para evaluar la funcionalidad de estos diseños se utilizó, como atrayente de acción conocida, una mezcla de metanol-etanol 3:1 y se evaluó la cantidad de hembras adultas atraídas al tratamiento en cada olfatómetro. En el olfatómetro de 90° los insectos se vieron claramente ...
Los depredadores juegan un papel fundamental en los programas de manejo integrado de plagas; sin ... more Los depredadores juegan un papel fundamental en los programas de manejo integrado de plagas; sin embargo, por lo general, son poco utilizados debido a la falta de información sobre su efecto en las poblaciones plaga. En este estudio, se cuantificó la mortalidad de larvas y pupas de Ecdytolopha torticornis, causada por depredadores durante el período desde la caída de la nuez hasta la cosecha, en una plantación de macadamia en Costa Rica. Se encontró que los depredadores redujeron significativamente la abundancia de larvas del barrenador de la nuez, y que la hormiga de fuego, Solenopsis geminata F., fue el depredador más importante.
Biological control on crop infesting insects represent an useful method in modem agriculture. A s... more Biological control on crop infesting insects represent an useful method in modem agriculture. A search for parasitoids of the macadamia nutborer was carried out during a three year study, and their effect on the population fluctuation of the borer was determined. An egg parasitoid belonging to the family Trichogrammatidae and four larval parasitoids, Microgastrine I, Microgastrine II, Ascogaster sp. (Hymeoptera: Braconidae) and Pristomerus sp. (Hymeoptera: Ichneumonidae) were recovered. Parasitism percentage by Microgastrine I was 15% in 1991, 16% in 1992 and 4% in 1993; Microgastrine II was not collected in 1991, but accounted for a 4.3% of parasitism in 1992 and 3.7% in 1993; Ascogaster sp. was registered since 1992 with 3% parasitism (29% in 1993). We found an inverse relationship between total parasitism and the mean of damaged nuts. Parasitoids play an important role in the reduction of the G. aurantianum population.
The effect of parasitism on the population dynamics of the macadamia nutborer Gymnandrosoma auran... more The effect of parasitism on the population dynamics of the macadamia nutborer Gymnandrosoma aurantianum (Lepidoptera: Tortricidae)
RESUMEN Efecto de la calidad de la fuente de alimento sobre el daño a la nuez de macadamia por Gy... more RESUMEN Efecto de la calidad de la fuente de alimento sobre el daño a la nuez de macadamia por Gymnandrosoma aurantianum (Lepidoptera: Tortricidae). Se estudió el efecto del contenido de nitrógeno, de los compuestos secundarios (taninos y prohantocianidinas) y de la materia seca de 4 clones de macadamia y de los diferentes estados de desarrollo de la nuez, sobre la abundancia de Gymnandrosoma aurantianum. El contenido de nitrógeno varió entre clones y los estados de desarrollo de la nuez, siendo más alto en los clones más tolerantes 508>660>344>246. Los mayores contenidos de materia seca se encontraron en los clones tolerantes, 508 y 660, y en las capas externas de la nuez, que en los susceptibles 246 y 344 y en las capas internas (2 y 3). El contenido de proantocianidinas fue mayor en la segunda capa de los clones 508 y 660 que en la de los clones 246 y 344. Los resultados muestran cómo la calidad del alimento afecta el desempeño de las larvas del barrenador, donde éstas, ...
II International Symposium on Guava and other Myrtaceae, 2010
The main problem in guava production is fruit fly damage; this insect feeds inside the fruit and ... more The main problem in guava production is fruit fly damage; this insect feeds inside the fruit and facilitates the entrance of pathogens and fruit drop. This study evaluated different materials used for making protective bags for guava fruits in order to reduce fruit fly damage and pathogen presence, as well as to extend their life expectancy in the field. The study took place during the dry and rainy seasons in Carrillos, Alajuela, Costa Rica. During the first phase, four different bagging materials were evaluated: waxed paper, nylon fabric, Taiwan bag and telephone book paper, the latter normally used by local farmers; for the second phase, only Taiwan and nylon bags were used. Highly significant differences (F = 66.75; p Taiwan > waxed paper > telephone guide paper. For the second period (F = 38.13; p < 0.0001) nylon bags protected more fruits than Taiwan bags. The longest duration of the bag in the field was obtained with nylon bags followed by telephone book paper, Taiwan and waxed paper bags. During the second phase Taiwan outlasted nylon bags. Telephone book paper and nylon yielded the highest amount of infected fruit during the first and second periods respectively. The highest number of fallen fruit was obtained in the control group during the first phase. During the dry season, the highest number of fruits affected by pathogens was found when the telephone book paper bags were used, while fruits bagged with nylon bags during the rainy season presented the highest number of fruits affected by pathogens. The results of this research show that the use of the nylon bag offered the highest protection against the fruit fly; however, it does not protect against pathogens which also affect guava production.
Hypsipyla grandella (Zeller) is the most important insect pest of the Meliaceae in the Neotropics... more Hypsipyla grandella (Zeller) is the most important insect pest of the Meliaceae in the Neotropics. This paper reviews the information on H. grandella parasitoids in Latin America and the Caribbean. Preliminary data on the parasitoid complex in Turrialba, Costa Rica, are presented, where apparent parasitisation of H. grandella during 1995–1996 reached 36%. The lowest level of parasitisation occurred during the dry season. The parasitoid Apanteles sp. (= Hypomicrogaster hypsipylae de Santis?) (Hymenoptera: Braconidae) was the most abundant larval parasitoid with a mean of 22 parasitoids per parasitised larva and a sex ratio of 3:1 females to males. Brachymeria conica Ashmead (Hymenoptera: Chalcididae) was found parasitising pupae, but at low frequency
Biological control in Latin America and the Caribbean: its rich history and bright future
The first biological control activities in Costa Rica date from around 1915, but it was only in t... more The first biological control activities in Costa Rica date from around 1915, but it was only in the 1950s that studies were conducted on the introduction, mass rearing and release of biocontrol agents in crops such as fruit trees, coffee, bananas, sugarcane, rice and pineapple. Subsequently, the use of entomopathogens became important in the 1990s as a strategy to be used in integrated pest management (IPM) programmes. From the 1990s, biocontrol laboratories were established and alliances were developed with national and international institutions and universities to strengthen biocontrol activities in the country. Currently, new areas of study have been incorporated in biocontrol research, such as molecular biology, host-plant resistance, identification of new biocontrol agents, the use of X-rays to sterilize hosts of natural enemies and the use of volatile compounds produced by the plant after pest attack to attract natural enemies. All these activities help to develop sustainable...
Vertical distribution of eggs of the macadamia nutborer Ecdytolopha torticornis Meyrick (Lepidopt... more Vertical distribution of eggs of the macadamia nutborer Ecdytolopha torticornis Meyrick (Lepidoptera: Tortricidae) and its preference of oviposition sites within and between macadamia cultivars were studied in Turrialba, Cartago, Costa Rica, in 1992 (N = 6,939). E. torticornis eggs were found throughout the foliar parts of the tree, but fewer eggs were laid in the crown top than in the mid or lower crown. Differences in the horizontal distribution of the eggs were not significant, albeit more eggs were found in the outer positions. The numbers of eggs found within the crowns of different clones were similar, implying that the nutborer has no preference for a particular cultivar.
Se estudió el efecto de 3 condiciones de luz (completa-548,63 W m-2, media luz-280,02 W m-2, somb... more Se estudió el efecto de 3 condiciones de luz (completa-548,63 W m-2, media luz-280,02 W m-2, sombra-76,38 W m-2), el uso de repelentes (ajo más chile, neem y pichichío) y el uso de bolsas de exclusión, en el daño de Cholus pilicauda a las flores de ginger rosado (Alpinia purpurata) en una plantación asociada con poró (Erythrina poeppigiana). El embolse de las flores redujo significativamente el número de flores dañadas, independientemente de la intensidad lumínica. No se encontró diferencias entre el número de flores dañadas con el uso de Azatina®<Harbri tt®<Pichichío, pero sí con el testigo (agua) que presentó el mayor número de flores dañadas. La sombra densa resultó en un mayor número de flores dañadas, seguida por luz completa y la media.
La broca del café Hypothenemus hampei (Ferrari) es considerada la plaga de mayor importancia en e... more La broca del café Hypothenemus hampei (Ferrari) es considerada la plaga de mayor importancia en el cultivo del café a nivel mundial. Al igual que muchos otros insectos, el comportamiento de la broca se ve modificado por distintas señales olfativas, lo cual ha impulsado la investigación en el campo de la olfatometría, por medio de una gran variedad de estrategias y alternativas. En este experimento se evaluaron 2 diseños innovadores de olfatómetros de flujo de aire de 4 vías para experimentación en H. hampei. Estos fueron fabricados totalmente en cristal y difieren entre ellos por la distribución angular de los brazos distribuidores de flujos de aire yla zona de ingreso y adaptación de los insectos al olfatómetro. Para evaluar la funcionalidad de estos diseños se utilizó, como atrayente de acción conocida, una mezcla de metanol-etanol 3:1 y se evaluó la cantidad de hembras adultas atraídas al tratamiento en cada olfatómetro. En el olfatómetro de 90° los insectos se vieron claramente ...
Los depredadores juegan un papel fundamental en los programas de manejo integrado de plagas; sin ... more Los depredadores juegan un papel fundamental en los programas de manejo integrado de plagas; sin embargo, por lo general, son poco utilizados debido a la falta de información sobre su efecto en las poblaciones plaga. En este estudio, se cuantificó la mortalidad de larvas y pupas de Ecdytolopha torticornis, causada por depredadores durante el período desde la caída de la nuez hasta la cosecha, en una plantación de macadamia en Costa Rica. Se encontró que los depredadores redujeron significativamente la abundancia de larvas del barrenador de la nuez, y que la hormiga de fuego, Solenopsis geminata F., fue el depredador más importante.
Biological control on crop infesting insects represent an useful method in modem agriculture. A s... more Biological control on crop infesting insects represent an useful method in modem agriculture. A search for parasitoids of the macadamia nutborer was carried out during a three year study, and their effect on the population fluctuation of the borer was determined. An egg parasitoid belonging to the family Trichogrammatidae and four larval parasitoids, Microgastrine I, Microgastrine II, Ascogaster sp. (Hymeoptera: Braconidae) and Pristomerus sp. (Hymeoptera: Ichneumonidae) were recovered. Parasitism percentage by Microgastrine I was 15% in 1991, 16% in 1992 and 4% in 1993; Microgastrine II was not collected in 1991, but accounted for a 4.3% of parasitism in 1992 and 3.7% in 1993; Ascogaster sp. was registered since 1992 with 3% parasitism (29% in 1993). We found an inverse relationship between total parasitism and the mean of damaged nuts. Parasitoids play an important role in the reduction of the G. aurantianum population.
The effect of parasitism on the population dynamics of the macadamia nutborer Gymnandrosoma auran... more The effect of parasitism on the population dynamics of the macadamia nutborer Gymnandrosoma aurantianum (Lepidoptera: Tortricidae)
RESUMEN Efecto de la calidad de la fuente de alimento sobre el daño a la nuez de macadamia por Gy... more RESUMEN Efecto de la calidad de la fuente de alimento sobre el daño a la nuez de macadamia por Gymnandrosoma aurantianum (Lepidoptera: Tortricidae). Se estudió el efecto del contenido de nitrógeno, de los compuestos secundarios (taninos y prohantocianidinas) y de la materia seca de 4 clones de macadamia y de los diferentes estados de desarrollo de la nuez, sobre la abundancia de Gymnandrosoma aurantianum. El contenido de nitrógeno varió entre clones y los estados de desarrollo de la nuez, siendo más alto en los clones más tolerantes 508>660>344>246. Los mayores contenidos de materia seca se encontraron en los clones tolerantes, 508 y 660, y en las capas externas de la nuez, que en los susceptibles 246 y 344 y en las capas internas (2 y 3). El contenido de proantocianidinas fue mayor en la segunda capa de los clones 508 y 660 que en la de los clones 246 y 344. Los resultados muestran cómo la calidad del alimento afecta el desempeño de las larvas del barrenador, donde éstas, ...
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