42The enemy release hypothesis states that the absence of effective natural enemies can be a 43 fundamental aspect leading to the successful establishment of an invasive species. This study 44investigates the impact of the native braconid parasitoid Dinocampus coccinellae on European 45 populations of the invasive ladybird Harmonia axyridis. The parasitoid attacked adults and 46 fourth instars of the ladybird more frequently than pupae and third instars. When given a 47 choice, D. coccinellae attacked non-melanic adults and adults of a long term laboratory 48 population of H. axyridis more often than melanic adults and adults of a field population, 49respectively. However, in no choice tests the parasitoid attacked individuals of either morph 50 type and of the field and laboratory populations with the same frequency. Immature 51 development of D. coccinellae took longer at lower temperatures and when less advanced 52 developmental host stages (larvae and pupae) were successfully parasitized. The parasitoid 53 emergence rates ranged from 0 to 14.7% on field populations of H. axyridis depending on life 54 stage of the host attacked and up to 16.9% when adults of a long term laboratory population 55 were attacked. Successfully parasitized ladybirds showed reduced reproductive capacities (6-56 12% of unparasitized individuals) and aphid consumption rates (85% of unparasitized 57 individuals), but these effects together with the low emergence rates of the parasitoid suggest 58 that D. coccinellae may only have a marginal impact on the population growth of H. axyridis in 59Europe. 60 61

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The native coccinellid Adalia bipunctata (L.) (Coleoptera: Coccinellidae) may be an alternative to exotic species like Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) for the biological control of aphid pests in Europe. The availability of adequate factitious or artificial foods may help optimize its mass production. This study examines the nutritional value of Ephestia kuehniella Zeller (Lepidoptera: Phycitidae) eggs plus bee pollen, pea aphids Acyrthosiphum pisum (Harris) (Hemiptera: Aphididae) and mixtures of bee pollen and cysts of Artemia franciscana Kellogg (Branchiopoda: Artemiidae) and/or a lyophilized artificial diet based on bovine meat and liver. Reproducing adults of A. bipunctata were obtained on all diets tested, but immature survival, adult weights, development times and reproductive rates differed among diets. Over 84% of first instars fed on E. kuehniella eggs plus pollen or aphids survived to adulthood. Feeding predator larvae on pollen combined only with A. franciscana cysts or artificial diet yielded 40-55% immature survival, but survival increased to 74% when all of these components were mixed. Adult weights of A. bipunctata on the mixtures of pollen, A. franciscana cysts and/or artificial diet were 55-75% of those on aphids or on E. kuehniella eggs plus pollen. Lifetime fecundity was superior on E. kuehniella eggs plus pollen (1,864 eggs) to that on the other diets (264-889 eggs). The use of mixtures of plant and animal foods for A. bipunctata and other predators may contribute to increasing the cost-effectiveness of commercial mass production by reducing inputs of natural prey like aphids, or of nutritious but expensive factitious foods like lepidopteran eggs

The oleander aphid, Aphis nerii Boyer de Fonscolombe, is one of the common pests of ornamental plants in the families of Apocynaceae and Sclepiadaceae and distributed throughout the world, which has been responsible for the mortality of a large number of oleander (Nerium oleander L.) shrubs each year. In this research, the insecticidal activity of Ag nanoparticles against the A. nerii was investigated. Nanoparticles of Ag and Ag-Zn were synthesized through a solvothermal method, and using them, insecticidal solutions of different concentrations were prepared and tested on A. nerii. For comparison purposes, imidacloprid was also used as a conventional insecticide. In the experiments, the LC50 value for imidacloprid, Ag and Ag-Zn nanoparticles were calculated to be 0.13 µL mL -1 , 424.67 mg mL -1, and 539.46 mg mL -1, respectively. The result showed that Ag nanoparticles can be used as a valuable tool in pest management programs of A. nerii. Additionally, the study showed that imidacloprid at 1 µL mL -1 and nanoparticles at 700 mg mL -1 had the highest insect mortality effect.

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