Phytoparasitica (2001) 29, 84-85

O. Bar-Shalom and Z. Mendel (2001)
Seasonal changes in the seed bank in date palm (Phoenix dactylipera) orchards and the involvement of the date-stone beetle (Coccotrypes dactyliperda)
Phytoparasitica 29 (1), 84-85
18th Conference of the Entomological Society of Israel, May 18, 2000, Bet Dagan, Israel, lecture
Abstract: Factors affecting the seasonal changes in the volume of the date palm seed bank on the orchard floor were studied in plantations located near Lake Kinneret. The spatial occurrence of the seeds on the orchard floor displayed a significant aggregated distribution, as 80% of the seeds were found at a distance of 1.5 m from the base of the trunk. The seed bank renewal started with dropping on the ground of immature fruits in July and August, due mainly to the feeding injury of adults of the date-stone beetle, Coccotrypes dactyliperda, which consists of ~20% of the annual seed bank. Further increase of the seed bank is due to the accumulation of mature dates between August and October, during fruit picking. The date-stone beetle breeds solely on the seeds, whereas other date seed consumers, insects or mammals, are opportunistic. The date-stone beetle is the major causal factor of reduction of the seed bank. In October, the beetles colonized ~10% of the seeds; however, seed colonization increased to 95% in March. The level of infestation was reduced to 70% in July with the beginning of green-fruit drop. The other main groups of seed consumers are microorganisms, moths and sap beetles utilizing up to 7%, 30% and 7% of the seeds, respectively. On specific sites, rodents or wild hogs have been consuming much of the seed bank in certain years. The beetle is absent in the southern Jordan Valley and the Arava, most probably due to low humidity. High beetle populations occur in the area surrounding Lake Kinneret, the Bet She'an Valley and the Gaza Strip. The beetle population buildup is very rapid, establishing six - eight generations annually. The attack on the green fruits is probably a maturation-feeding behavior, displayed at the time when suitable seeds for breeding are scarce.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Zvi Mendel

Research topic(s) for pests/diseases/weeds:
damage/losses/economics
population dynamics/ epidemiology

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Coccotrypes dactyliperda	Date palm (Phoenix dactylifera)	Israel