| Abstract |
Amidst rising concerns over rampant synthetic chemical applications and their deleterious effects, the
identification of alternative biopesticides has become paramount. Entomopathogenic and entomophilic
nematodes (EPNs) of the families Steinernematidae, Heterorhabditidae and Rhabditidae are used as biocontrol
agents (BCAs) against several insect pests. In this study, local nematodes as BCAs were explored in different
agricultural areas of Talakag, Bukidnon and Claveria, Misamis Oriental. Insect-baiting using the larvae of the
superworm, Zophobas morio and greater wax moth, Galleria mellonella was carried out. Out of 70 soil samples
collected, only 10 samples harbored nematodes from the different sampling areas in Talakag (carrot, cabbage,
broccoli, bell pepper, maize, mungbean and potato) and in Claveria (cabbage, eggplant, chayote, cassava, dragon
fruit, maize and pineapple). Through morphology and analyses of ITS and SSU rDNA regions, we identified and
confirmed nematode isolates belonging to family Rhabditidae: Oscheius and Metarhabditis spp. from Talakag
and Claveria. Unexpectedly, the widely recognized EPNs Heterorhabditis and Steinernema were not recovered
in this study. Furthermore, the efficacy of the local nematode isolates from Talakag was assessed against the
last instar larvae of pineapple white grub, Anomala orientalis under laboratory conditions. At 48 hours post
inoculation, the mean mortality induced by O. carolinensis, O. colombiana and M. amsactae were 100%, 100%
and 55.6%, respectively. For nematode isolates from Claveria, Oscheius sp. and Metarhabditis sp., the efficacy
will be tested against the cotton cutworm, Spodoptera litura and then compared with the commercially available
Steinernema siamkayai. Our findings highlight the potential of locally-occurring nematodes to be utilized as BCAs
of agricultural target pests after further comprehensive trials. |
Mindanao State
University - Iligan Institute of Technology