Virulence Of Egyptian Steinernematid Nematodes Used Against The Red Palm Weevil, Rhynchophorous Ferrugineus (Oliv.)

• M. M. Shamseldean and A. A. Atwa
• Applied Center for Entomonematodes, Faculty of Agriculture, Cairo University, Giza, Egypt.

Abstract

Three Egyptian isolates of entomopathogenic nematodes (EPN) belong to the genus Steinernema were tested both in the laboratory and the field against the red palm weevil, Rhynchophorus ferrugineus (Oliv.). These isolates were collected from 3 different governorates, EGG4 (from Giza), EBNE (from Behera), and EIKF (from Ismailia). A relatively high mortality rates of 100% were recorded in the laboratory when 2nd instar larvae and adults of the red palm weevil were exposed to these 3 local isolates of Steinernema spp. Mortality percentages in the 6th instar larvae were 100, 92, and 95% for EGG4, EBNE and EIKF respectively. In contrast, mortality rates in last instar larvae were 90, 78, and 85% when EGG4, EBNE and EIKF were used respectively. Field application of these three Egyptian isolates was conducted against the red palm weevil. Nematode suspension were injected through 4 perforated PVC tubes inserted into artificial tunnels. These tunnels were made by a hammer drill at 45o angle into the core of the date palm tree 20 cm above the location or level of insect infestation. The field applications were achieved by the injection of 120 ml of nematode suspension into each artificial tunnel with a rate of 3000 IJs/ml of suspension, which is equal to 1,440,000 IJs/palm tree in each treatment. The field results indicated that, using the EPNs did a significant recovery rate in the treated trees in comparison with the control. Rates of recovered trees was 88.9 and 91.9% when EGG4 was used, meanwhile, EBNE gave 77.8 and 77.1% of recovered trees throughout the years 2001 and 2002 respectively. In contrast, 83.3 and 72.2% of the trees were recovered when EGG4 and EIKF isolates were injected respectively during the year 2003.