Dicyphus hesperus (MiriLiv) is a highly adaptable predatory mirid bug that has become an important tool in greenhouse IPM programs. While it is best known for its effectiveness against whiteflies, it is a generalist and can also help against aphids, thrips, psyllids, mealybugs, spider mites, and moth eggs.
As a generalist predator, MiriLiv not only feeds on multiple pest species but can also survive on pollen when prey is scarce, ensuring it remains active in the crop throughout the season. Its ability to move easily across plants like tomatoes with high trichome density make it especially valuable in vegetable and ornamental production.
Life Cycle:
-
Egg stage: Females insert their eggs into leaf veins and stems, where they remain protected until hatching. Under optimal conditions, eggs hatch in about nine days.
-
Nymphal stage: The insect passes through four nymphal stages over the next 17–18 days. During this time, the nymphs are highly active and feed aggressively on juvenile stages of aphids and other soft-bodied pests.
-
Adult stage: Within four days of emerging, adults begin reproducing. Females typically lay one to three eggs per day and can live for four to five weeks, maintaining steady pressure on pest populations.
-
Development time: The complete cycle from egg to adult takes around 34 days, allowing populations to establish and sustain themselves when introduced early in the season.
Key Benefits of MiriLiv:
|
Benefit |
Explanation |
|
Generalist predator |
Persists in the greenhouse by feeding on both pests and pollen, ensuring survival even when prey numbers are low. |
|
Direct aphid suppression |
Both nymphs and adults actively feed on aphids, keeping populations under control. |
|
Adapted to hairy crops |
Long legs allow easy movement across crops like tomatoes, where other predators struggle. |
|
Strong mobility |
Capable of flying efficiently to locate and suppress pest hotspots throughout the crop. |
Application Guide:
MiriLiv should be released preventatively to establish a stable population before pest outbreaks occur. For best results, sprinkle directly onto plants where pollen and prey are present, as this helps the predators establish quickly. Early-season introductions, supported with supplemental food such as BugFeed and banker plants like mullein, ensure multiple generations develop and persist in the crop. Once established, MiriLiv provides continuous suppression of aphids, whiteflies, and other pests.
Storage and Handling:
Use MiriLiv immediately upon arrival whenever possible. If short-term storage is unavoidable, keep at 15°C with 60% relative humidity in a dark location for no longer than one day. Avoid refrigeration or freezing, as these conditions reduce survival and effectiveness. Optimal establishment occurs at 24–27°C with humidity above 60%. Providing at least 12 hours of light per day further supports predator activity and reproduction.
Release Strategies for Growers:
Releases should focus on building predator populations before pest levels increase. Preventative use is the most cost-effective strategy, as curative releases often require higher numbers and are less efficient.
|
Strategy |
Release Rate |
Repeat Every |
|
Preventative |
0.5/m² |
7–14 days |
|
Curative |
2–5/m² |
7 days |
For tomato crops, a banker system with mullein plants can greatly improve establishment and persistence. We recommend 50 mullein plants per acre in conventional tomato production and introducing 20 Dicyphus per mullein plant over 5–6 weeks. To sustain populations, apply BugFeed to mullein once per week. In conjunction with this banker system, releases should also be made directly onto the tomato crop. A general guideline is 750 Dicyphus per acre at 12 weeks crop age, followed by a repeat application 4 weeks later.
These guidelines are a starting point and may vary by crop type, growing media, and pest pressure. Regular scouting and adjustments are essential to maintain an optimal predator-to-prey ratio.