How to Manage Pests

UC Pest Management Guidelines

Asparagus beetle larvae are dark green-gray grubs about 1/3 inch (9 mm) long when fully grown. Adults are blue-black beetles with a red prothorax. Their elytra (wing covers) have yellow spots and red borders.

Spotted asparagus beetle larvae are orange colored and adults are reddish orange with six prominent black spots on each wing cover.

Asparagus beetles injure the plant by feeding on the tips of tender young shoots. After leaves come out, asparagus beetles and their larvae gnaw on the surface of the stems and devour the leaves. If injury to the fern is severe, the crown is weakened, particularly if the asparagus stand is young.

Although they are found wherever asparagus is grown, asparagus beetles are not normally serious pests in California. Some local infestations do occur, however, and control measures may be necessary to prevent serious injury to the asparagus stand, particularly when the stands are young. If beetles are feeding on spears early in the season, let some plants near the edge of the field produce fern growth to attract the beetles away from the spears. If necessary, treat these areas.

Common name		Amount/Acre**	P.H.I.+
(trade name)			(days)
When choosing a pesticide, consider information relating to water quality and impact on natural enemies and honey bees.
A.	CHLORPYRIFOS*
	(Lorsban) 4E	1 qt	1
	MODE OF ACTION: An organophosphate (Group 1B)1 insecticide.
	COMMENTS: Limited to 3 applications/year; apply only to the fern stage. Avoid drift and tailwater runoff into surface waters.
B.	METHOMYL*
	(Lannate) LV	1.5–3 pt	1
	SP	0.5–1 lb	1
	MODE OF ACTION: A carbamate (Group 1A)1 insecticide.
	COMMENTS: Reentry interval for both materials is 2 days. Apply at 5–7 day intervals as needed. Do not apply more than 4.5 lb a.i./acre/crop.
C.	CARBARYL*
	(Sevin XLR Plus)	2–4 qt	1
	MODE OF ACTION: A carbamate (Group 1A)1 insecticide.
	COMMENTS: Apply to ferns or brush growth. Repeat applications as necessary but not closer than 7 days and not more than 5 applications/year.
D.	PERMETHRIN*
	(Ambush, Pounce) 25WP	3.2–6.4 oz	1
	MODE OF ACTION: A pyrethroid (Group 3)1 insecticide.
	COMMENTS: Apply by ground equipment only. Do not apply more than 0.4 lb a.i./acre/season.
E.	PYRETHRIN/ROTENONE
	(Pyrellin E.C.)	1–2 pt	0
	MODE OF ACTION: A botanical (Group 3)1 and a synergist (Group 21) insecticide.
	COMMENTS: Apply at intervals of 7 days or less and repeat as necessary. Less effective than other materials.
** See label for dilution rates. + Preharvest interval. Do not apply within this many days of harvest. * Permit required from county agricultural commissioner for purchase or use. 1 Modes of action are important in preventing the development of resistance to pesticides. Rotate chemicals with a different mode-of-action group number, and do not use products with the same mode-of-action group number more than twice per season. For example, the organophosphates have a group number of 1B; chemicals with a 1B group number should be alternated with chemicals that have a group number other than 1B. Mode of action is assigned by IRAC (Insecticide Resistance Action Committee). For additional information, see their Web site at http://www.irac-online.org/.

PUBLICATION

UC IPM Pest Management Guidelines: Asparagus
UC ANR Publication 3435
Insects
W. E. Chaney, UC Cooperative Extension, Monterey Co.
E. T. Natwick, UC Cooperative Extension, Imperial Co.
C. B. Fouche, UC Cooperative Extension, San Joaquin Co.
Acknowledgment for contributions to the insects section:
R. J. Mullen, UC Cooperative Extension, San Joaquin Co.

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