Pest		Threshold	Reference
	barley thrips	3 1/2 or more adults per plant before heading	UI Bulletin 742 (1993)
	cereal leaf beetle	3 larvae, 3 eggs (or both) per plant	UI CIS 994 (1993)
	English grain aphid flowering water stage milky ripe	2-4 per head or tiller 8 per head or tiller 10-20 per head or tiller	UI Bulletin 697 (1991)
	greenbug	25 per head or tiller before soft dough	UI CIS 817 (1992)
	Russian wheat aphid fall spring	seedling (1 tiller) 10% infested plants; larger plants, treat if plants are stressed winter grain (until 1st node), 5% plants infested; spring grain (until heading), 10% tillers infested; heading through soft dough, 20 aphids per plant on 10-20% flag leaves or stems OR more than 3 aphids per head at flowering, more than 8 per head at water stage, more than 15 per head at milky ripe	UI CIS 817 (1992)

Thresholds are not available for these pests: brown wheat mite; cutworms/armyworms, -army cutworm, -bertha cutworm, -black cutworm, -spotted cutworm, -variegated cutworm, -western yellowstriped armyworm; garden symphylan; grasshoppers/crickets; Hessian fly; leafhopper; oat bird-cherry aphid; rose grass aphid; slugs; stinkbugs; two-spotted spider mite; wheat curl mite; wheat sawfly; wheat stem maggot; wireworm/false wireworm.

References: UI Bulletin 697 Irrigated spring wheat production guide for southern Idaho, UI Bulletin 742 Idaho spring barley production guide, US CIS 543 Some common aphids infesting Idaho crops, UI CIS 778 The English grain aphid, UI CIS 817 Russian wheat aphid, UI CIS 994 Cereal leaf beetle - a new pest in Idaho.

Revised: August 12, 2008

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