Phytoparasitica (1996) 24, 85-86

Phyllis G. Weintraub and A.R. Horowitz (1996)
Phenology and monitoring of Liriomyza huidobrensis in potatoes in Israel
Phytoparasitica 24 (1), 85-86
Shoshana Yathom Memorial Meeting, December 28, 1995, Bet Dagan, Israel
Abstract: The pea leafminer, Liriomyza huidobrensis (Blanchard), was monitored, using yellow sticky traps, at four locations in southern Israel in the spring of 1995. The initial populations were low until the second week of April, when there was a sudden population increase at all localities. This population peak was independent of potato age and appeared not to be related to the average daily temperature or hours of daylight. Sampling techniques for adult leafminers were compared using yellow sticky traps and hand vacuuming. With respect to yellow sticky traps, comparisons were made between traps placed horizontally and perpendicularly to the ground at various heights above the ground in 50-cm high potato plants. Traps placed at plant height caught the most flies with both orientations. A higher percentage of females was caught nearer to the ground, presumably because there were new ovipositional sites on secondary and tertiary branches close to the ground. Eggs and larval tunnels were counted on whole potato plants (11 leaves). Eggs were laid on all leaves, but the largest number was found on the second to fifth distal leaf. The number of tunnels increased with leaf age. Monitoring larvae in potato plants is difficult because of the thickness of the leaf and requires evaluation under a microscope with substage lighting. Diel activity was monitored at two locations from 0500 to 1900 hours, using yellow sticky traps and hand vacuum sampling in May and June. Activity patterns were identical at the two sites. Immediately after sunrise (0545) there was a burst of activity that declined rapidly through the morning hours as the temperature increased (to 27.5°C), and activity did not increase at the end of the day as temperatures declined. Sampling activity with a hand vacuum confirmed these results under low adult populations but not under high, and indicated that parasitoid activity (primarily Diglyphus isaea) is not correlated with leafminer activity. In fields that were not treated with insecticides, seasonal parasitoid-to-leafminer ratios were approximately 2:1. In fields treated with abamectin, ratios were approximately 1.6:1 and in fields treated with methamidophos, ratios at the end of the season were 2:100.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Phyllis G. Weintraub, Abraham Rami Horowitz

Research topic(s) for pests/diseases/weeds:
pheromones/attractants/traps
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Liriomyza huidobrensis	Potato (Solanum tuberosum)	Israel