Agriculture: Lettuce Pest Management Guidelines


  • Protaphorura fimata
  • Description of the Pest

    Springtails are minute, primitive insect-like organisms. Their bodies are less than 0.1 inch (2.5 mm) long, wingless, and with a forked appendage (furcula) at the tip of the abdomen used for springing into the air. Unlike other springtails, Protaphorura fimata lacks a furcula, and, when disturbed, does not jump but instead curls up. It also lacks pigmentation and eyes.

    Springtails lay their round eggs in small groups in moist soil, especially where organic matter is abundant. The immature stage is usually whitish, and adults tend to be whitish, bluish, or lack the pigmentation. The immature stage differs from the adult stage only in size and color.


    Most springtails are harmless scavengers and are considered as beneficial organisms because they aid in the decomposition of decaying plant material. However, some species may cause stunted seedling growth by damaging germinating seeds, roots and leaves of seedlings when present in large numbers. The seedlings may appear wilted and may die if damaged when young. Damage occurs as minute, rounded pits on young leaves or roots, or as irregular holes in thin leaves. Mature plants are typically not significantly injured.


    Recent additions of organic matter (e.g., adding compost or incorporating a cover crop as green manure) as well as intensive irrigation (high soil moisture level for seed germination) can temporarily increase springtail numbers dramatically. P. fimata can be suppressed to a large extent with early applications of synthetic insecticides directed to the seed line. Pyrethroid and neonicotinoid insecticides or seeds coated with insecticide (e.g., clothianidin) typically targeted to manage other soilborne arthropods also reduce springtails.

    Monitoring and Treatment Decisions

    Monitoring is the key to determine the presence and population size of springtails. Threshold for treatment has not been established, but potato or beet slices can be used to monitor P. fimata presence or absence in the field, which will aid in reducing unnecessary insecticide applications.

    • Cut thin slices [0.2 inch (5 mm)] of beet root or potato (preferably of darker color), place them in the subsurface of the soil about 2 inches deep, and cover with a plastic cover - e.g., white plastic bowls, 3.5 inches in diameter and 1.5 inch deep.
    • Assess the slices about 24 hours after deployment. Slices tend to desiccate when left in the field for longer periods of time, and thus become less attractive to P. fimata.
    Common name Amount per acre** REI‡ PHI‡
    (Example trade name) (hours) (days)
    Not all registered pesticides are listed. The following are ranked with the pesticides having the greatest IPM value listed first—the most effective and least harmful to natural enemies, honey bees, and the environment are at the top of the table. When choosing a pesticide, consider information relating to air and water quality, resistance management, and the pesticide's properties and application timing. Always read the label of the product being used.
    (NipsIt INSIDE) Seed coating 12
    Restricted entry interval (REI) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (PHI) 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.
    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).
    Text Updated: 04/17
    Treatment Table Updated: 04/17