Environmental Entomology (1992) 21, 1258-1266

Margaret Skinner and Bruce L. Parker (1992)
Vertical distribution of pear thrips (Thysanoptera: Thripidae) in forest soils
Environmental Entomology 21 (6), 1258-1266
Abstract: Between July and December, pits (30 cm deep) were excavated in sugar maple forests to determine the vertical distribution of pear thrips, Taeniothrips inconsequens (Uzel). In well-drained, fine sandy loam, 67.3% of the larvae occurred in the upper 10 cm and <10% were below 18 cm. The highest percentages of thrips were found at 4-6 and 6-8 cm. In the litter, 0.01% of the thrips were found. Pear thrips distribution in clay and gravelly, sandy, and shallow, poorly, and well-drained fine sandy loam soils differed significantly (P = 0.0001). However, the percentage of thrips to 10 cm was not significantly different among soil types. The hand-held bulb planter (barrel 10 cm long) was suitable for large-scale sampling, giving a volume of soil that could be processed quickly to extract thrips. About 67% of the pear thrips soil population was captured using this tool during the inactive phase of the thrips: Vertical distribution of thrips changed during periods of adult emergence from and reentry into the soil. In May during emergence, >40% of the thrips were located in the upper 4 cm, whereas during dormancy, only 21% of the thrips were found that deep. In early June, when larvae reenter the soil, thrips were commonly found in the litter, but by mid-June, vertical distribution had stabilized, suggesting that downward movement of thrips into the soil had ceased.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Bruce L. Parker, Margaret Skinner

Research topic(s) for pests/diseases/weeds:
surveys/sampling/distribution
environment - cropping system/rotation

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Taeniothrips inconsequens	Maple (Acer)	U.S.A. (NE)