Las larvas de sírfidos afidófagos (Diptera: Syrphidae: Syrphinae) tienen estructuras bucales fuertemente esclerotizadas que les permiten capturar y alimentarse de sus presas. Para considerar las larvas del sírfido Pseudodoros clavatus como depredadores eficientes, se analizó inicialmente la morfología de las partes bucales y, en segundo lugar, se evaluó el potencial como controlador biológico de Aphis craccivora. Se encontró que las partes bucales se componen de dos grupos de escleritos dentales, y además posee dos elementos exteriores o escleritos triangulares los cuales están ausentes en el primer estadio, aparecen en el segundo y permanencen en el tercero. Esta estructura probablemente sirve para anclar la parte anterior del depredador dentro de la presa lo que impide su escape. La succión se caracterizó por un movimiento activo del esqueleto cefalofaríngeo y un movimiento peristáltico del abdomen. Para evaluar la respuesta funcional de la especie, se estableció la cría de este depredador a partir de las larvas y adultos obtenidos en campo y se realizaron pruebas con diversas densidades de la presa (10, 20, 30 áfidos) y el depredador (1, 2, 3 larvas de tercer estadio). Los Resultados sobre depredación se observaron a las 24 horas y revelaron que a mayor presencia de áfidos más consumo por parte de las larvas. Se observó aproximadamente un 100% de depredación cuando se utilizan dos o más individuos.

The larvae of aphidophagous hoverflies (Diptera: Syrphidae: Syrphinae) have bly sclerotized mouthparts that allow them to capture and eat their prey. To consider the larvae of the syrphid Pseudodoros clavatus as efficient predators, the morphology of larval mouthparts was analyzed and larvae were evaluated as potential biological control of Aphis craccivora. As a result, mouthparts are composed by two groups of dental sclerites, corresponding to the tento pharyngeal and hypopharyngeal sclerite. Mouthparts have two outer elements or triangular sclerites which are absent in the first instar, appear in the second and remains in the third instar. This structure probably works to anchor the front part of the predator in the dam that prevents its scape. Suction is characterized by an active movement of the cephalopharyngeal skeleton and a peristaltic movement of the abdomen. In assessing the functional response of the species, the breeding of this predator was established departing from the larvae and adults obtained in the field, test were done with different prey density (10, 20, 30 aphids) and different predator densities (1, 2, 3 third-instar larvae). The results of predation assays were observed on 24 hours showing that a bigger the presence of aphids, bigger the consumption of the larvae. A 100% of predation was observed when two or more individuals were used.

Este estudo descreve a fauna de insetos predadores, parasitóides e formigas associada a pulgões em couve (Brassica oleracea L. var. acephala D.C.), cultivada em sistema orgânico. O pulgão foi identificado como Lipaphis pseudobrassicae Davis, sendo este o primeiro registro da espécie atacando couve no Brasil. Parasitismo primário por Diaeretiella sp. e Aphidius sp. e hiperparasitismo por Aphydencyrtus sp., Alloxysta sp., Pachyneuron sp. e Syrphophagus sp. foram observados. Vinte espécies de Coccinellidae foram coletadas, sendo que oito delas foram observadas, tanto na fase adulta como larval, atacando o pulgão: Hyperaspis (Hyperaspis) festiva Mulsant, que foi a mais abundante (72,5% do total de insetos predadores obtidos), Cycloneda sanguinea (L.), Eriopis connexa Germar, Coleomegilla maculata DeGeer, Hippodamia convergens Guérin, Heterodiomus sp., Scymnus (Pullus) sp.1 e Scymnus (Pullus) sp.2. Larvas de Syrphidae afidófagas coletadas nas folhas de couve infestadas por L. pseudobrassicae pertencem às espécies Allograpta exotica (Wiedemann) e Ocyptamus gastrostactus (Wiedemann). Larvas e pupas de Syrphidae foram parasitadas por Pachyneuron sp., Syrphophagus sp. e Diplazon laetatorius Fabricius. Larvas de Chrysopodes sp. foram observadas alimentando-se de L. pseudobrassicae. Espécies de formigas associadas às colônias desse pulgão foram Ectatomma quadridens Fabricius e Pheidole sp.

This study describes the fauna of predator insects, parasitoids and ants associated with aphids on kale (Brassica oleracea L. var. acephala D.C.) in organic system. The aphid was identified as Lipaphis pseudobrassicae Davis, and this is the first record of the species attacking kale in Brazil. Primary parasitism by Diaeretiella sp. and Aphidius sp. and hyperparasitism by Aphydencyrtus sp., Alloxysta sp., Pachyneuron sp. and Syrphophagus sp. were observed. Twenty species of Coccinellidae were collected, and eight of them were observed in adult and larval stages attacking the aphid: Hyperaspis (Hyperaspis) festiva Mulsant, which was the most abundant (72.5% of all predator insects obtained), Cycloneda sanguinea (L.), Eriopis connexa Germar, Coleomegilla maculata DeGeer, Hippodamia convergens Guérin, Heterodiomus sp., Scymnus (Pullus) sp.1 and Scymnus (Pullus) sp.2. Aphidophagous Syrphidae larvae collected on leaves of kale infested by L. pseudobrassicae belong to the species Allograpta exotica (Wiedemann) and Ocyptamus gastrostactus (Wiedemann). Larvae and pupae of Syrphidae were parasitized by Pachyneuron sp., Syrphophagus sp. and Diplazon laetatorius Fabricius. Larvae of Chrysopodes sp. were observed feeding on L. pseudobrassicae. Species of ants associated with the colony of this aphid were Ectatomma quadridens Fabricius and Pheidole sp.