Control biológico de Trioza Alacris Flor (Hemíptera, Triozidae) y Cacoecimorpha pronubana (Hübner) (Lepidóptero, Tortricidae) en un vivero de laurel

Abstract

[EN] The infestation level of the laurel psylla, Trioza alacris Flor (Hemiptera, Triozidae) was studied in a nursery dedicated to laurel production, located in Aldaia, province of Valencia, during the months of July to August 2023 and April to May 2024. During this period, phytophagous monitoring was carried out using six yellow sticky traps in the shade and the collection of 20 shoots of about 10 centimetres to observe nymphs, eggs and adults. In addition, biological control consisted of four releases of Anthocoris nemoralis Fabricius (Hemiptera, Anthocoridae), a psyllid predatory bug, carried out on 19 July and 9 August 2023, 15 April and 6 May 2024. After each release, two evaluations were carried out every seven days to check the effectiveness and establishment of the predator. For this purpose, the shaded area was divided into two zones by a black cloth, thus differentiating the treated zone from the control zone. The assessment was carried out by sampling 20 shoots in each zone, counting psylla nymphs and adults and observing the presence of the predator. In the treated area, 200 anthocorids were released per shoot, at a rate of two anthocorids per plant. On the other hand, the occupancy level of the carnation caterpillar, Cacoecimorpha pronubana Hübner (Lepidoptera, Tortricidae), was studied during the months of October to December 2023. The monitoring was carried out using four DELTA traps with the sex pheromone of the species and collecting 10 shoots to observe caterpillars, eggs and pupae. Biological control of the pest was carried out with Bacillus thuringiensis, separating the treated area from the control area. Two treatments were carried out on 2 and 23 November 2023. After the treatments, two weekly evaluations were carried out. To check effectiveness, 10 outbreaks were sampled in each zone, noting caterpillars, eggs and pupae. A higher level of psylla infestation was recorded in the control area compared to the biological control area in both 2023 (2,11 ± 0,16 vs. 0,85 ± 0,08) and 2024 (1,96 ± 0,12 vs. 0,85 ± 0,08). There was a significant decrease in pest level after the release of anthocorids mainly from the second week after the first release (F = 27,62; l.g. = 1; p = 0,0000) in 2023. Whereas in 2024 it had an effect from the first week after the second release (F = 8,36; l.g. = 1; p = 0,0043). Therefore, we conclude that biological control based on A. nemoralis is a good tool for control of laurel psylla in shade culture. In the case of carnation caterpillar, neither of the two Bacillus thuringiensis treatments had a significant effect on the pest level (F = 3,40; l.g. = 1; p = 0,0732) (F = 1,56; l.g. = 1; p = 0,2198). Further studies on the biology of the pest and the effect of B. thuringiensis on pest control are needed.

[ES] La psila del laurel, Trioza alacris Flor (Hemíptera, Triozidae) es una plaga grave en el cultivo del laurel. La psila se localiza en las hojas tiernas de la planta y su alimentación causa enrollamiento de las hojas, quedando amarillas y finalmente acaban necrosándose los tejidos, lo que provoca una importante pérdida de calidad en la planta. Por otra parte, en este vivero, se encontró otra plaga que supone un descenso adicional de la calidad, la oruga del clavel, Cacoecimorpha pronubana (Hübner) (Lepidóptera, Tortricidae). Este lepidóptero provoca desecación de la hoja.

Para su control se ha seguido la evolución poblacional de ambas plagas durante los meses de julio de 2023 hasta junio de 2024. Para ello se realizó el monitoreo de la psila del laurel utilizando seis trampas amarillas pegajosas y la recogida de 20 brotes de unos 10 centímetros para observar tanto ninfas, huevos y adultos. El monitoreo de la oruga del clavel se llevó a cabo mediante la recogida de 10 brotes de unos 10 centímetros donde se observaban las orugas, huevos y crisálidas.

El control biológico consistió en dos sueltas de Anthocoris nemoralis, una chinche depredadora de psílidos, realizadas el 19 de julio de 2023 y el nueve de agosto de 2023. Posteriormente a cada suelta se realizaron dos evaluaciones cada siete días para comprobar la efectividad e implantación del depredador. Para ello se dividió el sombraje en dos zonas mediante una tela negra, diferenciando así zona tratada y zona testigo. La evaluación se realizó muestreando 20 brotes en cada zona, contando las ninfas y adultos de psila y, observando la presencia del depredador. En la zona tratada se soltaron 200 antocóridos/suelta, a razón de dos antocóridos por planta. La oruga del clavel se trató con Bacillus thuringiensis, separando zona tratada de zona control. Se realizaron dos tratamientos el dos y el 23 de noviembre de 2023. Posteriormente a los tratamientos se realizaron dos evaluaciones cada siete días. Para comprobar la efectividad se muestrearon 10 brotes en cada zona, anotando las orugas, huevos y crisálidas. En este TFM se muestran los resultados del control biológico en ambas plagas, y si el control biológico puede ser la estrategia principal de control, dando un valor añadido a las plantas producidas en este vivero.