Nematology (2022) 24, 559-570

Puping Ta-oun, Ralf-Udo Ehlers and Prakaijan Nimkingrat (2022)
Effects of soil texture and moisture on the host searching abilities of Steinernema siamkayai against Bactrocera latifrons
Nematology 24 (5), 559-570
Abstract: Soil texture and moisture have significant effects on the infectivity and persistence of entomopathogenic nematodes (EPN). Both EPN and chili fruit flies (Bactrocera latifrons) spend most of their lifetime in soil, therefore making it possible to consider the successful use of EPN against chili fruit flies. This study aimed to investigate the effects of soil texture and moisture contents on chili fruit fly pupation and adult emergence, and on the infectivity of the EPN, Steinernema siamkayai, against this pest. The results revealed that the highest percentage of pupation occurred at a depth of 2 cm in all soil types. At a depth of 5 cm in the sandy clay loam only, no pupation of B. latifrons was observed. The adult emergence ranged from 51.9 to 82.5%, with significant differences between soil types. The horizontal movement of S. siamkayai showed that the concentration of EPN at a rate of 20 000 dauer juveniles pupa^-1 yielded maximum pupae mortality (77.5-91.3%) in all soil types containing 15% moisture. In the vertical displacement test, S. siamkayai was capable of killing pupae up to a distance of 15 cm in all soil types. These results confirmed the potential of S. siamkayai to be used within pest control programmes of various soil textures, as long as the soil moisture contents allow its dispersal and host infection.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Ralf-Udo Ehlers

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution
environment/habitat manipulation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Bactrocera latifrons		Thailand
Steinernema siamkayai/Xenorhabdus stockiae (entomopathogen)	Bactrocera latifrons		Thailand