Tip Top Bio-Control Technical Bulletin

Phytoseiulus macropilis
Predatory mite

Host Pest:
Spider mites.

Life stages:
Egg, Larvae, Protonymph, Deutonymph and Adult.

Sex Ratio:
Females predominant 4:1

Development:
The female lays an average of 2.4 eggs per day for about 30 days. Depending on temperature, macropilis can complete egg to larvae in as little as 5 days. This predator can consume 7 adult spider mites or 20 immatures or 25 eggs per day. It is capable of multiplying its numbers 44 times in 17 days. This high rate of reproduction enables it to overcome its slower reproducing host in a relatively short time.

Uses:
P. macropilis readily feeds on the Two spotted mite and other members of the Family Tetranychidac. It does not reproduce on pollen, insects or plants.

Biology:
P. macropilis is about 0.5 mm in length, reddish orange in color and has a pear shaped body. It is very similar to P. persimilis.

Environment:
This predator is well adapted to mild temperatures and high humidity (60-80% relative humidity at 70° F.). Does not do well in hot greenhouses or dry interior areas.

Pesticides:
Susceptible to pesticides. Field tolerance will vary with spray timing, application methods, weather and crop. Avoid spraying crop one week before or after releasing predators. Pyrethroides and organophosphates are highly toxic to most predators. Some materials may be toxic to predators for up to four weeks.

Storage:
Highly perishable, the predators should be used immediately upon delivery.

Augmentation:
Introduce macropilis at first sign of spider mite activity. Apply macropilis when spider mites infest less than 10% of the leaves. If the spider mites average more than one/leaf, treat with a miticide before using macropilis. Apply macropilis at the rate of 2 per sq. meter of planted area or 2 per damaged leaf or 2 per plant, if plants are small.

Monitoring:
Spider mite and predator populations should be checked at least once a week. Reintroduce macropilis at regular intervals in interior plantscapes and greenhouses.