Root mealybugs
Pest insect
- No particular symptoms
- Slowed growth
- General weakening of the plant
- White substance inside the pot
- Leaf discoloration or dropping
| Difficulty High |
| Frquency Low |
| Reproductive rate Jusqu'à 100x |
| Lifecycle Jusqu'à 4 mois |
Root mealybugs, also known as ground mealybugs, are a group of insects that attack plants by piercing their roots to feed on their sap. They resemble miniature grains of rice in shape and color. Unlike other types of mealybugs, they establish themselves solely inside the soil, making them very discreet and difficult to notice.
Host plants
While root mealybugs can infest all types of plants, collections of succulents and hoyas are particularly at risk.
Screening
The presence of root mealybugs can be confirmed by the presence of their characteristic cottony substance. Upon repotting the plant, this white substance may be visible around the root ball or inside the pot. In advanced infestations, the insects may be seen on the soil surface near the plant's base. Root damage can cause misleading symptoms, similar to those of water deficiency or nutrient deficiencies.
Due to the discreet nature of this pest, infestations are often detected at an advanced stage, and their treatment can pose a considerable challenge. Infestation spreads through individuals entering the soil of neighboring plants via shared surfaces, contaminated water, and drainage holes.
Prevention
Root mealybugs are tropical insects not adapted to the continental climate and are exclusively present in indoor cultivation. Their spread is almost always associated with the introduction of infested plants or soil. It is advisable not to combine multiple plants in the same container. Stratiolaelaps scimitus is effective for preventing root mealybugs.
Treatment
Treating root mealybugs may involve completely replacing the soil, thorough root cleaning, introducing natural predators, and heat treatment, if the plant variety can withstand it. Repeated introductions of nematodes can be performed to treat a ground mealybug infestation.
Morphology
Nymphs measure barely 1.5 mm, while adults measure about 3 mm. They are white and covered with a waxy substance similar to that of standard mealybugs, although they lack the typical filaments of the latter. They are easily confused with small particles of perlite in the soil. Male individuals are winged, much smaller, and only live for a few hours, just enough for fertilization.
Behaviour
Adults are found near the roots from which they feed, while nymphs are located in crevices in the substrate or in chambers dug on the outer edge of the root ball.
Lifecycle
The life cycle of root mealybugs consists of three stages: egg, nymph, and adult. Females can live for several months depending on the species and environmental conditions. Males live for only a few days at most, just enough for fertilization. Under certain conditions, these insects can reproduce in the absence of males.