RESUMEN
In recent years, the control of pear psyllid in northern Italy has not been particularly problematic, due to the presence of two insecticides (abamectin and spirotetramat) specifically for this pest, and due to the adoption of integrated pest management. However, the withdrawal of these two specific insecticides is imminent and, therefore, it has become necessary to find alternative control tools. More recently, potassium bicarbonate, known for its fungistatic activity against many phytopathogenic fungi, has also shown some activity against some insect pests. In the present study, the efficacy and possible phytotoxicity of potassium bicarbonate were tested in two field trials on second generation Cacopsylla pyri by spraying two different salt concentrations (5 and 7 kg ha-1), with or without polyethylene glycol as an adjuvant. Spirotetramat was used as a commercial reference. The results showed that potassium bicarbonate could positively control the number of juvenile forms (with a mortality percentage of up to 89% at the infestation peak), even though spirotetramat was still more effective. Therefore, potassium bicarbonate appears to be a sustainable integrated tool for psyllid control, especially in the wake of the imminent withdrawal of spirotetramat and other insecticides currently used on this pest.
RESUMEN
The Asiatic Kuwana pine mealybug, Crisicoccus pini (Kuwana, 1902) (Hemiptera, Pseudococcidae), is reported in Italy for the first time. It was detected in September 2015 on maritime pine, Pinus pinaster, and stone pine, Pinus pinea, trees growing in the town of Cervia (Ravenna Province), Northern Italy. The mealybug has caused yellowing and decline of the pine trees. Pinus pinea is recorded here as a new host for C. pini.
Asunto(s)
Hemípteros/clasificación , Pinus/parasitología , Enfermedades de las Plantas/parasitología , Distribución Animal , Estructuras Animales/anatomía & histología , Estructuras Animales/crecimiento & desarrollo , Animales , Tamaño Corporal , Femenino , Bosques , Hemípteros/anatomía & histología , Hemípteros/crecimiento & desarrollo , Italia , Tamaño de los ÓrganosRESUMEN
Aim of the study was to investigate the performance of the new insecticide "spirotetramat" as an alternative solution of "abamectin" for the control of Cacopsylla pyri L. (Hemiptera: Psyllidae) in the context of an IPM program in European pear, Pyrus communis L.. Laboratory bioassays for the estimation of LC50 and LC90 of both insecticides were performed using four populations collected in Emilia-Romagna (Italy) orchards where different pest management strategies were used (organic, integrated, and conventional). The same populations were also analyzed for the main insecticide detoxifying activities in nymphs by spectrofluorimetric in vitro assays. The performance of the two insecticides was also tested on field on one population under integrated pest management conditions. The laboratory experiments showed that the LC90 of spirotetramat were lower than the highest field concentration allowed in Europe (172.80 mg AI liter(-1)) giving reassurance about the efficacy of the product. Concerning the abamectin, the laboratory bioassays did not show strong indications of resistance development of C. pyri populations of Emilia-Romagna. A similarity in enzyme detoxifying activity was observed in both insecticides indicating a general absence of a significant insecticide resistance. The field trial showed a high efficacy (>90 %) of spirotetramat on C. pyri already after 15 d from application, and it was significantly higher from abamectin. Overall, spirotetramat is one more choice for C. pyri control, as well as abamectin in order to minimize the risks of occurrence of insecticide resistance.
Asunto(s)
Compuestos Aza , Hemípteros , Insecticidas , Compuestos de Espiro , Animales , Control de Insectos , Ivermectina/análogos & derivados , Dosificación Letal MedianaRESUMEN
The European grapevine moth, Lobesia botrana (Denis & Schiffermüller) (Lepidoptera: Tortricidae), is the key pest of vineyard, Vitis vinifera L. In Italy, failures in field chemical pest control have been recently reported. The susceptibility to insecticides indoxacarb, methoxyfenozide, and emamectin benzoate was then evaluated in a L. botrana population collected from a vineyard in Emilia-Romagna (northeastern Italy) where pest management programs achieved unsatisfactory results. The field trial showed that the indoxacarb efficacy toward L. botrana was very low in the two timings of application (7.9 and -1.5%) in comparison with untreated control, while the efficacy of methoxyfenozide (76.1%) and emamectin benzoate (88.8%) was high. The decreased efficacy of indoxacarb was also supported by the results of the laboratory bioassay on neonate L. botrana larvae, in which the resistance ratio was 72-fold in comparison with that of the susceptible strain.