How to Manage Pests

UC Pest Management Guidelines


Seedcorn Maggot

Scientific name: Delia platura

(Reviewed 11/05, updated 1/10)

In this Guideline:


Larvae of the seedcorn maggot are small, pale or dirty-colored, yellowish white, legless maggots with tough skin. Adults are grayish brown flies and about 0.20 inch long.


Seedcorn maggots feed on the seed and may destroy it. Injury is most severe during wet, cold periods.


In California, seedcorn maggots are only occasional pests. They are usually associated with high levels of organic matter in fields that have recently had a cover crop disked in.

Common name Amount/Acre R.E.I.+ P.H.I.+
(trade name)   (hours) (days)

Calculate impact of pesticide on air quality
Bee precaution pesticide ratings
The following materials are listed in the order of usefulness in an IPM program, taking into account efficacy and impact on natural enemies and honey bees as well as the environmental impact. Not all registered pesticides are listed. Always read the label of the product being used.
  (Thimet) 20G 4.5 oz/1000 row ft 72 30
  COMMENTS: Apply at planting; do not place granules in direct contact with seed. Do not feed tops to livestock.
  (Lorsban) 15G 8 oz/1000 row ft 24 30
  COMMENTS: In-furrow at planting time. T-band or band at planting or postemergence.
+ Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (P.H.I.) is the number of days from treatment to harvest. In some cases the REI exceeds the PHI. The longer of two intervals is the minimum time that must elapse before harvest.
* Permit required from county agricultural commissioner for purchase or use.
1 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 to help prevent the development of resistance. 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 Group numbers are assigned by IRAC (Insecticide Resistance Action Committee). For more information, see



[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Sugarbeet
UC ANR Publication 3469

Insects and Mites

E.T. Natwick, UC Cooperative Extension Imperial County
Acknowledgement for contributions to Insects and Mites:
C. G. Summers, Entomology, Kearney Agricultural Center, Parlier
D. R. Haviland, UC IPM Program, Kern County
L. D. Godfrey, Entomology, UC Davis

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