The above four "culprits" are the main insects that one has to deal with when taking care of Tulasi devi. One or two of any of these insects would not do much damage to Tulasi devi (of course we don't want any damage done to Tulasi devi). However, these insects reproduce at a very fast rate and can wreak havoc, killing her in a period of a month or two. And, the more there are, the more difficult it becomes to check them. So, with that in mind, it is important that one vigilantly attacks them from the first time any are spotted along with having deterrents in place to prevent them from coming, and in this way Tulasi devi can stay pest-free and grow strong and healthy.
This is the insect that I have the most personal experience with, and they can be a real hassle to get rid of. Mealy bugs are small white or grey oval-shaped insects. They are generally pretty immobile, with a waxy layer covering them, and like to hide in any cracks they can find on Tulasi devi or under leafs. Their mission in life is to suck life juice out of whatever plants they are on, and reproduce. They use their mouth to put a hole into the stem of Tulasi devi, and suck up whatever nutrients they can get out. When mealy bugs reproduce they lay eggs within their waxy covering which are fertilized by male mealy bugs which are incredibly small and fly (mealy bugs are one of the most sexually dimorphic animals).
Unfortunately, mealy bugs are hard to get rid of once they develop a presence on Tulasi devi. The eggs are very very small and baby mealy bugs are also very small. They will hide in any cracks, especially on manjaris, and they reproduce fairly quickly, especially in warm weather during the summer. They can be individually picked off of Tulasi devi with tweezers. However, this takes quite a lot of time and is not the most effective. The most effective option is through natural sprays which will be discussed more in depth further down...
The magenta on the manjari is the mealybug, of course they are actually white but this way you can see better to judge their size and shape.
Spider mites are a quite damaging insect and can be difficult to detect. Why are they difficult to detect? They are no larger than the size of this period. They are red to dark red, and live on Tulasi leaves. They seem to prefer the underside of leaves, but will also live on the top of them. Their defining characteristic, though, is their webs. They will form colonies with webs coving the leaves they live on. They use these webs to move from leaf to leaf and also seem to lay eggs on the webs (as well as on the underside of leaves near the "veins") Spider mites also get nutrients by sucking the life juice out of Tulasi devi, and if left unchecked will quickly kill her.
Fortunately, spider mites can be gotten rid of with sprays like mealy bugs.
Scale insects are similar to mealy bugs and feed in the same way. The difference is that while mealy bugs have soft bodies and are mobile (though don't usually move very much), scale insects are completely immobile. They find a spot on the bark to live, and simply stay there and feed. Because they are the same color as the bark, they can be difficult to find, but if one is found then it is definitely a good idea to look for more. I have very little experience with these, but from the experience that I do have, the best way to get rid of them is by hand. Just take a flat-head screwdriver or some similar tool and push the scale insect off. They stick onto Tulasi devi pretty tight so some force is needed, but be careful to not hurt Tulasi devi as much as possible.
White flys are very tiny insects that look like small white gnats. They feed on the underside of Tulasi devi's leaves and just like the above insects suck out her life juice. These reproduce quickly and must be taken care of immediately. Not only will their feeding cause damage, but also their saliva is toxic and they leave behind what is known as "honeydew", which encourages mold to grow. The good news is that the same treatment for spider mites and mealy bugs works for white flies.
Some other less common insects to watch out for include aphids and fungal gnats. Aphids are known all over the world for the damage they do to plants, but they don't seem so attracted to Tulasi devi in my experience. Fungal gnats, however, are attracted to Tulasi devi, and live in the soil where they eat the roots. If you see gnats in the soil, most likely they are fungal gnats. Be sure to address them with the solutions below quickly, as they have the potential to cause some damage to Tulasi devi.
While ants do not do damage to Tulasi devi directly, they do help other insects damage Tulasi devi and protect them against beneficial insects. Ants "farm" insects in order to collect honeydew, which is a sweet liquid that sap-sucking insects will give off when "tickled" by ants. Ants farm mealy bugs and aphids mainly, which consists of moving them from plant to plant, protecting them from predators, and collecting their honeydew. So, if you see ants on Tulasi devi, you can be sure of what they are up to. The best way to get rid of them is with diatomaceous earth, as described below.
Solutions to the Insect Problems
The cure for pest insects that I have the most experience with and have had a good amount of success with is with using natural sprays. Prabhupada made it very clear that we are not to use chemical sprays. So, if we look towards nature we can find a few good options for taking care of the insects. The first and probably most well known option is neem oil. Neem oil is not harmful to any mammals, birds, earthworms, or beneficial insects such as ladybugs. It is, however, harmful to white flies, mites, aphids, mealy bugs, and fungal gnats, to name a few. It works by "imitating" an important hormone in the bodies of the insects, thus resulting in the insects forgetting to eat, sleep, mate, and defend (in other words they become yogis :)). In my experience it has been moderately effective in treating all of the above insects except for mealy bugs. Mealy bugs I have found to require additional treatment. The second option I know of is orange oil. Orange oil works by stripping the waxy coating from inside of the insects lungs, thus resulting in suffocation. Orange oil is completely safe for humans, and smells very nice (unlike neem oil). I have used it in combination with neem oil and had wonderful results. I combine 1 tbsp of neem oil insecticidal soap concentrate (will be linked to later in the page) and 1 tbsp of orange oil in 32oz of water, put that in a spray bottle, and thoroughly spray all over Tulasi devi- on the top and bottom of leaves, on manjaris, on the soil, around the pot, and on all of the branches and stems once a week. This is can be very time consuming, but is well worth the effort. Orange oil and neem oil together have been a cure-all for me, and even deter ants.
So, with the above recipe given... is there any need for any other suggestions?
You can also make a diluted solution of mint Dr. Bronner's Castile Soap and water and put it on each individual leaf for spider mites, but this takes a very long time and can hurt Tulasi devi if not done properly. Another approach is beneficial insects, such as lady bugs, mealybug destroyers, lacewings, etc, but these insects are typically specific to certain pests, not to mention expensive. And on top of that, if they are kept in the kind of conditions that Tulasi devi thrives in (very hot and humid), the insects may die. I have personally experienced this problem with ladybugs. Of course these insects may come to help Tulasi devi on their own, in which case they should be encouraged in their service!
This big guy is a mealybug destroyer, the best friend of anyone who takes care of Tulasi devi. As the name suggests, he eats the notoriously hard to get rid of mealy bugs. They are very expensive to buy in my experience, but if you life in California and keep Tulasi devi outside, then a few of these are likely to show up!
Diatomaceous earth is very good for preventing insects from coming to Tulasi devi. It is a white powder, made of pulverized sea fossils. To a human being, it is completely harmless. However, on the microscopic level it is extremely sharp, like razor blades. When it comes in contact with the outside of an insect, and what to speak of the inside, it wreaks havik. Any and every insect that touches diatomaceous earth will die, from ants, to fungal gnats, to mealybugs, even cockroaches. The disadvantage of diatomaceous earth is that it must be dry to be effective. Therefore, if put on top of the soil, every time Tulasi devi is watered, it would have to be reapplied (after the top of the soil dries of course). The way I have used it is as a defense against ants. I take a little bit of the powder in my fingers and rub it all around Tulasi devi's stem. As long as it is there, the ants will not cross it for anything.
I bought the quart and it has lasted a very long time. 1 quart is 64 tbsp, which means 64 spray bottles full of solution. For the 16 Tulasi plants we have in San Diego, 1.5-2 spray bottles are enough for one application.