Phytoparasitica (2001) 29, 68-69

I. Glazer, L. Salame, S. Goldenberg and D. Blumberg (2001)
Susceptibility of sap beetles (Coleoptera: Nitidulidae) to entomopathogenic nematodes
Phytoparasitica 29 (1), 68-69
18th Conference of the Entomological Society of Israel, May 18, 2000, Bet Dagan, Israel, lecture
Abstract: Nitidulid beetles (Coleoptera) are considered serious pests of date palms throughout the world. They attack ripe fruit, causing it to rot, and damage is reflected both in reduced yield and fruit quality. The present study was an evaluation of the susceptibility of different sap beetles to entomopathogenic nematodes. We further tested nematode efficacy in pots filled with soil infested by third-instar larvae of the two beetle species. In a petri dish assay, mortality levels of Carpophilus humeralis and C. hemipterus exposed to Heterorhabditis sp. IS-5 strain indicated that the latter species is less susceptible than the former to nematode infection. Exposure of both sap beetle species to different nematode strains gave moderate levels of mortality (35-65%) with the heterorhabditid strains HP88, IS-5 and IS-25. The IS-12 strain of Heterorhabditis sp. showed poor virulence (<35% mortality) against larvae of C. humeralis as well as larvae and pupae of C. hemipterus. The nematode species Steinernema riobrave showed moderate virulence (35-65% mortality) to larvae and pupae of C. humeralis as well as to larvae of C. hemipterus. Exposure of C. humeralis to different concentrations of Heterorhabditis sp. strain IS-5 in pots containing sand resulted in high mortality (>65%). In contrast, the lower concentrations (500 and 1000 nematodes/pot) caused low mortality (<35%) of C. hemipterus. Other heterorhabditid strains caused 95-100% mortality of C. humeralis in the pot assay. The HP88 strain of Heterorhabditis bacteriophora and the Tx strain of S. riobrave showed poor effectiveness. Incubation of different nematode strains with the C. humeralis larvae at high temperature (32°C) resulted in an increase in insect mortality with the IS-12 and IS-21 strains, whereas reduced mortality was recorded with the HP88 strain treatment at the higher temperature. The IS-5 and IS-12 strains were equally effective in all three soil types tested, whereas the IS-19 strain was more effective in the Almog type soil than in the others.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Daniel Blumberg

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
evaluation - screening - selection

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Urophorus humeralis	Date palm (Phoenix dactylifera)	Israel
	Carpophilus hemipterus	Date palm (Phoenix dactylifera)	Israel
Steinernema riobrave/Xenorhabdus cabanillasii (entomopathogen)	Urophorus humeralis	Date palm (Phoenix dactylifera)	Israel