As most gardeners already know, each type of garden plant is affected by specific and/or common insect pests. In the case of eggplant, this veggie is extremely susceptible to foliar damage by the red spider mite (RSM). If left untreated, this pest can devastate the plant’s entire leaf canopy. However, if damage is light, this plant seems to tolerate RSM damage as the plant matures.
Here in Central Missouri, where I’ve been gardening for some 23 years, I unfortunately have not witnessed a ‘light’ RSM infestation in this crop. Hence, to successfully grow a crop of eggplant, it is necessary to purchase seedlings that are free of mite damage or grow your own nursey stock. Once the weather conditions are favorable, we transplant eggplant seedlings into the garden and immediately cover the crop with a permeable white cloche. The cloche allows entry of water, sunlight and air but excludes most insects. Once the plants begin producing fruit, we remove the cloche since the plants are then beginning to reach the top of the cloche. By that time, eggplant seems to either develop a greater tolerance to, or avoidance of, this particular pest.
Eggplant under cloche
Of course, we don’t assume that the battle is over, so we continue to monitor all plants for presence pf RSM. Even during the time spent under the protection of the cloche, we will monitor all plants. If a breech was to occur in the cloche, for whatever reason, this will certainly provide entry of RSM.
In the case of eggplant, I recommend an insecticidal soap (foliar spray) to keep populations of RSM at bay. I’ve employed neem oil in the past however it doesn’t seem to be as effective in controlling RSM as does an insecticidal soap. Because eggplant also can suffer from flea beetle and whitefly insect pressure, it may be useful to tank mix these two insecticides, or perhaps use singly in alternate spray applications.
Also, keep in mind that the eggplant leaves are heavily pubescent thus providing a great place for all aforementioned insects to reside. Unfortunately, these pests seem to enjoy hanging out on the underneath side of the leaf. So, be sure to apply insecticide to both sides of each leaf for greater control.