V.T. Gkounti, D. Markoyiannaki and D.Ch. Kontodimas
The pathogenicity of indigenous isolates of Beauveria bassiana, Metarhizium anisopliae and Isaria fumosorosea was evaluated in the laboratory against larvae and adults of the sisal weevil, Scyphophorus acupunctatus. Inoculation was achieved via immersion of individuals into conidia suspensions of different concentrations. All three fungal species proved high pathogenicity against larvae of the weevil, causing 100% mortality in most of the treatments. Beauveria bassiana caused the highest mortality of the adults (86.67±12%), followed by M. anisopliae (46.67±17.8%) and I. fumosorosea (40±17.5%). Mean survival time also differed significantly among treatments and life stages of the weevil. In total, larvae survived significantly fewer days than adults post infection. Results of the present study indicate the potential of indigenous strains of entomopathogenic fungi as biological control agents against the invasive weevil.
O. Melita, V. Gkounti, D. Kontodimas, D. Papachristos and F. Karamaouna
The Cretan date palm, Phoenix theophrasti, is a less susceptible and suitable host for the red palm weevil compared to the Canary palm, P. canariensis, even at high pest pressure. Nevertheless, P. theophrasti is not invulnerable to the red palm weevil, hence under continuous and high pest pressure young offshoots/palms can be deadly infested. The slow development of the insect in the Cretan date palm should probably allow a larger ‘window of time’ for an effective plant protection management against the pest.
A. Michaelakis, E. Anastasaki, P.G. Milonas, D.P. Papachristos, D. Kontodimas, C.M. Pontikakos, D.G. Raptopoulos, N.A. Babilis and M.A. Konstantopoulou
Mating disruption (MD) has been a successful approach for pest control of several lepidoptera. Field trials to evaluate the efficacy of communication disruption of low pheromone load formulation on Thaumetopoea pityocampa were carried out in 2010 and 2011 in an urban park. The efficacy of MD was assessed by comparing male T. pityocampa catches in pheromone traps, between MD and Control areas. In the 1st year of the application the percentage of male inhibition ranged from 85 to 100% during the 1st month of the flight period and 95-100% during the whole flight period in the 2nd year. The pheromone remained in the polymeric matrix was almost 30% after 7 weeks under laboratory aging conditions. Combining the pheromone release results with the male disorientation results we can assume that after 7 weeks the remaining pheromone concentration was still sufficient to achieve MD. This study indicates that air permeation with the major sex pheromone component (Z)-13-hexadecen-11-ynyl acetate, at a rate of 20 g/ha for one application per season, can affect the orientation of T. pityocampa males. Since mating disruption is an environmentally safe method for pest control, it could be a valuable tool to control T. pityocampa in urban areas and parks.