Aphytis melinus - Scale Control


The California red scale (Aonidiella auranti), a pest commonly found on citrus, roses, and ornamental plants. Another scale insect is the ivy or oleander scale (Aspidiotus nerii), which infests a variety of hosts such as cycads and palms. The San Jose scale (Quadraspidiotus perniciosus), walnut scale (Q. juglanregiae), and Dyctyospermum scale (Chrysomphalus dictyospermi) also affect a wide range of plants as their hosts.


Aphytis melinus is a small, light yellow parasitic wasp measuring around 1mm in size. This wasp targets various types of armored scale insects. It lays its eggs beneath the protective waxy coverings created by the scales. The larvae of the parasite develop under these scale coverings.

For effective control, female Aphytis melinus should be introduced during their second and third developmental stages, while they are still virgin females. On the other hand, male Aphytis melinus should be introduced during the second developmental stage and pre-pupae stage. These stages are crucial because the scales are not yet firmly attached to the host plant, allowing the parasites to access them.

In some cases, adult Aphytis melinus can also kill the scales by feeding on them. Once the scales are parasitized, they appear dried out and may exhibit dark spots when examined closely.


1-3 wasps per sq. ft., monthly as needed.

3-6 wasps per sq. ft., bi-weekly as needed.

Release wasps as soon as possible between plants in the morning or evening in mild/cool temperatures and low light levels.

It's important to note that these release rates serve as general guidelines and may vary based on the specific pest species, the crop or plant being treated, and level of infestation. Proper monitoring of the infestation and the subsequent effectiveness of the released beneficial insect population is crucial for determining the success of the biological control strategy.


At 80°F, Aphytis takes 13-18 days to develop from egg to adult. Adult lifespan is up to 25 days depending on environmental conditions and availability of resources. Females deposit 6-8 eggs per day.

It's important to note that these time-frames are approximate and can be influenced by factors such as temperature, humidity, and the availability of prey. Monitoring the development and activity of beneficial insect populations, along with environmental conditions, can help determine the progress and effectiveness of their role in pest control efforts.