Attractiveness and effects of insectary plant flowers on certain aphidophagous insects as bio-agents

The relative attractiveness of flowering plants to some aphidophagous species; predators (Syrphus corollae Fabricius, Chrysoperla camea Steph., Coccinella undecimpunctata L and Paederus alferii Koch,and the parasitic wasp Aphidius sp. Flowers included: coriander (Coriandrum sativum L) chamomile, (Matricaria chamomilla, ) geranium (Pelargonium graveolens Ait) and Fennel ( Foeniculum vulgare .Miller) sweet basil ( Ocimum basillicum, L, ). The obtained results revealed that the tested natural enemies exhibited different degrees of selectivity in response to olfactory stimulant produced by the flowers. Chamomile flowers exhibited higher attractiveness to the hoverflies (S. corollae) than to the other tested predators Chry camea exposed to different flowers oduor showed the highest attractiveness to fennel followed by coriander with no significant differences. Coriander, chamomile and fennel flowers attracted the highest percentage of C. undecimpunctata adults with no significant differences. P alferii recorded the highest percentage of attractiveness towards sweet basil ( Ocimum basillicum, L, ) flowers Choice tests illustrated that Chry. carena, S. corollae and C. undecimpunctata exhibited the lowest preferabilty to geranium and sweet basil. On the contrary. P, alferii ., showed the highest preferabilty to sweet basil flower. Flower color may influences choice. Yellow and white flowers were particularly attractive Chamomile, fennel, and sweet basil flower colors were prefte:d by all tested natural enemies. Choice and no choice tests recorded that the aphelinid parasitoid Aphidius sp, exhibited the highest percentage of attractiveness and preferability to flower color of chamomile and coriander . coriander and chamomile flowers increased longevity in C. undecimpunctata. Mean longevity was 45.0 ± 8.9 days with only water, 51.0 ± 3.0 days with chamomile flowers and 58.7 ± 6.5 days when given access to coriander flowers. Parasitism percentage by the aphelinid parasitoid, Aphidius sp adult significantly increased when fed on coriander or chamomile in comparison with control. So, Coriander and Chamomile could be a potential insectary plants for enhancing parasitoid fitness and efficacy.