Mammillaria geminispina · Succulent
Mealybugs: Isolate the plant and dab infested areas with a cotton bud dipped in methylated spirits.
Root mealybugs: Repot into fresh sterile compost and treat the root ball with a systemic insecticide drench.
Root rot: Ensure well-draining cactus compost and allow soil to dry completely between waterings.
Vine weevil: Use nematode treatments in spring and autumn or apply a systemic insecticide to the compost.
Scale insects: Scrape off visible scales and spray with horticultural oil or insecticidal soap.