Tip Top Bio-Control Technical Bulletin

Neoseiulus fallacis
Spider Mite Predator

Target Pests:
Neoseiulus fallacis are known to control the European Red Mite (Panonychus ulmi) below economic thresholds in fruit orchards. Also targets Two-Spotted Spider Mite (Tetranychus urticae), Spruce Spider Mite (Oligonychus ununguis) and Southern Red Mite (Oligonychus ilicis).

Description:
Neoseiulus fallacis is a native predatory mite that feeds on spider mites, rust mites and small insects. It is one of the most important biological control agents in North American berry and orchard crops. Adults have pear-shaped bodies, 0.l5mm long; they are tan to light orange in color, shiny, with long legs. Immature predators are cream colored and semi-transparent. Their eggs are oval and 0.3mm long.

Product information:
Fallacis is available in a granular carrier (usually vermiculite or corn grits). This formulation should be applied as soon as possible. Fallacis packages can be held at 10-15°C (50-60°F), out of direct sunlight, for 1-2 days--but quality and egg laying will be lower.

Lay the container on its side at room temperature, out of direct sunlight, for 1/2 hour.
Check the product by sprinkling some of the vermiculite onto a sheet of white paper and using a 10-15X hand lens or magnifier. Active mites should be visible. Gently rotate the bottle to mix the mites with the carrier and distribute the contents over the invested plants.

Release Rates:
Apply Fallacis at the first sign of a mite infestation for optimum effectiveness. Fallacis will usually become established in the crop after one introduction, where they remain if mites or pollen are available for food. When prey becomes scarce, Fallacis moves to the top of the plant and usually disperses throughout the crop on the wind.

When predators are found on each infested leaf it usually means that the biological control program will be successful. It may take another 2-6 weeks for new plant growth to show improvement, depending on growth rates.

General Introduction Rates
1-5 Fallacis/m sq. (10 ft sq.)

For greenhouse crops, apply predators to all infested plants. Use the lower rate for preventative introductions onto mite susceptible plants; use the higher rates if there are established mite populations.

Lifespan of N. Fallacis:
Development from egg to adult takes from 7-9 days at 21°C (70°F) to 3 days at 32°C (85°F). At 26°C (78°F) a fourfold increase in numbers can occur within 4 days. In the field, under optimum conditions, populations can increase from 10 predators/100 leaves to 200-500 predators/100 leaves, in just 2 weeks.

- Adult females lay 1-5 eggs per day, for a total of 26-60 eggs over their 14-62 day lifetime. The eggs hatch in 2-3 days. Eggs are oval and twice the size of two-spotted mite eggs.
- Newly hatched predators do not eat, but later stages and adults feed on all stages of prey. Female Fallacis eat 2-16 spider mites per day.
- Adult females enter diapause in response to the short days in the fall (14 hours or less). They stop reproducing and move into sheltered areas, such as under bark or ground cover.

Strategic Considerations:
To reduce mortality of predatory mites from pesticides, release predators 10 days after spraying.

The pesticide fenbutatin oxide (Vendex®) can be used with Fallacis for additional control of spider mites if "hot-spots" develop. It does not harm Fallacis, but avoid over spraying, which reduces the predator's food supply and their ability to reproduce.

Spreader-stickers, supreme oils and soaps are harmful to predators contacted by the spray, but have little residual activity.