Percorrer por autor "Mahzoum, Abdelkader"
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- A cochonilha negra, Saissetia oleae, como alimento para larvas e adultos de Chrysoperla carnea s.l.Publication . Villa, Maria; Mahzoum, Abdelkader; Benhadi-Marín, Jacinto; Pereira, J.A.As larvas de Chrysoperla carnea s.l. (Stephens) são amplamente utilizadas em programas de luta biológica devido à sua ação como predadores de insetos. Por sua vez, os adultos alimentam-se de meladas de hemípteros, pólen e néctar de flores. No olival são potenciais predadores de várias pragas. Assim, neste agroecosistema a existência de recursos alimentícios é essencial para manter as populações de C. carnea e melhorar a sua ação numa perspetiva de proteção biológica por conservação. A cochonilha negra, Saissetia oleae (Olivier), é uma praga secundaria da oliveira em grande parte da região mediterrânica. A existência desta praga pode proporcionar recursos alimentícios para as diferentes fases de desenvolvimento de C. carnea, nomeadamente, as ninfas como presas para alimentação das larvas do predador, e as meladas que o adulto excreta como fonte de energia para adultos. Assim, o objetivo deste trabalho foi avaliar o potencial de S. oleae como alimento para larvas e adultos de C. carnea. Para avaliar o efeito nas larvas, foram disponibilizadas diferentes densidades de ninfas de S. oleae a larvas de C. carnea, e avaliadas taxas de consumo; para os adultos, foram disponibilizadas meladas excretadas por S. oleae e avaliada a sobrevivência, em ambos os sexos, e fecundidade em fêmeas. Verificou-se que as larvas de C. carnea consomem eficientemente ninfas de S. oleae. Por sua vez nos adultos, o consumo de meladas melhora a sua sobrevivência em comparação ao controlo (água), mas não a reprodução, o que estará relacionado com a inexistência de proteína necessária para a formação de ovos. Assim, numa estratégia de proteção biológica por conservação, baixos níveis populacionais da praga podem contribuir para a manutenção e aumento de crisopídeos no olival
- Functional response of Chrysoperla carnea (Neuroptera: Chrysopidae) Larvae on Saissetia oleae (Olivier) (Hemiptera: Coccidae): implications for biological controlPublication . Mahzoum, Abdelkader; Villa, Maria; Benhadi-Marín, Jacinto; Pereira, J.A.Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) is a voracious predator of soft-bodied insects such as juveniles of scale insects and the black scale Saissetia oleae (Olivier) (Hemiptera: Coccidae) is an important pest of several crops, such as the olive tree. However, the predatory effciency of C. carnea on S. oleae has been unstudied yet. The present work aimed to study the functional response of larvae of C. carnea fed on S. oleae nymphs. In a controlled laboratory environment, increasing densities of S. oleae second and third nymph stages were offered to newly emerged specimens of the three larvae instars of C. carnea. After 24 h, the number of killed S. oleae was recorded and the functional response of C. carnea was assessed. The three larval stages of C. carnea displayed a type-II functional response, i.e., killed prey increased with higher S. oleae densities up to a maximum limited by the handling time. The attack rate did not significantly differ among the three instars while the maximum attack rate was significantly higher for the third instar. The handling time of the first larval instar of C. carnea was higher than that of the third instar. Our results demonstrated that S. oleae could act as a food resource for all larval stages of C. carnea. Furthermore, the third larval stage of the predator was the most effcient in reducing S. oleae densities. These results suggest that C. carnea larvae could contribute to S. oleae control in sustainable agriculture.
- Functional response of Chrysoperla carnea (Neuroptera: Chrysopidae) to Saissetia oleae (Olivier) (Hemiptera: Coccidae)Publication . Mahzoum, Abdelkader; Villa, Maria; Benhadi-Marín, Jacinto; Pereira, J.A.Lacewings are common biocontrol agents against a wide range of agricultural pests.These predators are highly voracious against soft-bodied preys such as juveniles of scale insects. In this context, the present work aims to study the use of Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) as biological control agent against Saissetia oleae (Olivier) (Hemiptera: Coccidae). For that, we studied the functional response of the larval instars of C. carnea to nymphs of S. oleae. Increasing densities (3, 5, 10, 15, 25 and 40) of S. oleae nymphs were offered to the three larval stages of C. carnea in a controlled laboratory environment. After 24 hours, the number of S. oleae consumed by C. carnea larva was recorded and the functional response calculated. The three larval stages of C. carnea displayed a type II functional response behavior. Prey consumption by C. carnea larvae increased with high S. oleae densities. Moreover, younger larvae showed a lower predation rate in comparison with the older ones. The search rate and handling time of the third instar larvae were lower than those of the younger larval instars, and the simulated max. attack rate of the third instar larvae was higher than those of the first and second instar larvae. Our results suggest that all larval stages of C. carnea could be important in S. oleae biological control in olive orchards, although the third larval stage of the predator was more efficient in reducing S. oleae densities than first and second C. carnea larval instars.
- Functional response of Chrysoperla carnea (Neuroptera: Chrysopidae) to Saissetia oleae (Olivier) (Hemiptera: Coccidae)Publication . Mahzoum, Abdelkader; Villa, Maria; Benhadi-Marín, Jacinto; Pereira, J.A.Lacewings are common biocontrol agents against a wide range of agricultural pests. These predators are highly voracious against soft-bodied preys such as juveniles of scale insects. In this context, the present work aims to study the use of Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) as biological control agent against Saissetia oleae (Olivier) (Hemiptera: Coccidae). For that, we studied the functional response of the larval instars of C. carnea to nymphs of S. oleae. Increasing densities (3, 5, 10, 15, 25 and 40) of S. oleae nymphs were offered to the three larval stages of C. carnea in a controlled laboratory environment. After 24 hours, the number of S. oleae consumed by C. carnea larva was recorded and the functional response calculated. The three larval stages of C. carnea displayed a type II functional response behavior. Prey consumption by C. carnea larvae increased with high S. oleae densities. Moreover, younger larvae showed a lower predation rate in comparison with the older ones. The search rate and handling time of the third instar larvae were lower than those of the younger larval instars, and the simulated max. attack rate of the third instar larvae was higher than those of the first and second instar larvae. Our results suggest that all larval stages of C. carnea could be important in S. oleae biological control in olive orchards, although the third larval stage of the predator was more efficient in reducing S. oleae densities than first and second C. carnea larval instars.