Bug Whats Bugging Your Plants
Using chemical sprays in subduing pest insects is a great concern to both gardeners and consumers in common. There is a great environmental concern of possible health hazard to our children and gardeners in dispensing such chemicals.
It is quite unfortunate that chemicals being used for pest control are “non-selective” so target pest are not only killed but an entire range of insects, both good and bad insects fall victim.
Application of toxic chemicals to products that are meant for human consumption is one of the biggest problems in the modern era. The use of beneficial insects is being adopted by gardeners in many indoor gardens so that they can organically manage their pest troubles.
What do I mean by “beneficial” insects? These are insects that help the gardeners, by destroying pest insects and doing away with the need for using harmful and toxic chemicals. A System was developed by mother nature to regulate the level of pest infestations, by using the “good bugs” to control the “bad bugs”.
Good and favorable insects eradicate pest insects usually in one of two ways. They either parasitize them or they simply eat them.
1. Lady Bug
Perhaps among the most popular of beneficial garden insects to use is the Lady Bug, they are also known as the Asian Lady Beetle. Commonly used mainly for mite and aphid control by indoor gardeners.
The mature Lady Bug itself doesn’t eat very much, however it’s hungry larvae does. The Lady Bug will complete it’s life cycle in 4-6 weeks and in that time consume as many as 5000 aphids. If you’re not able to find them locally, they can be conveniently ordered online.
Parasitic insects depend on many of your common garden pests exclusively for food. Since they must lay their eggs either in or on them. Beneficial insects develop their undeveloped stages in or on the “host” pest insect, feeding on its body and inevitably killing the “host insect”.
The survival of the predator insects is completely dependent on eating garden pests. As a result, they essentially depend on pest insect for their continued existence.
2. Parasitic wasps
These are a group of some of the most effective beneficial insects. Wasps typically lay their eggs inside a pest, while the pest is still very young – in the egg, larval or pupa stage of their life. These wasps are extremely minute, commonly a fraction of the size of a common stinging wasp and are nearly impossible to see with the naked eye – even the largest of these wasps are usually no bigger than a 1/4 of an inch and the smallest being the size of a period you would find at the end of a sentence.
The “Host insects” aren’t very lucky, because the wasps’ larvae develops inside the pest, eventually killing them, then the wasp will emerge from it’s prey looking for a new host in which to lay their eggs and this cycle is continued.
One species of pest is most sought after by wasps. In the instance of Encarsia Formosa which looks for only whitefly eggs. Encarsia will lay their own eggs inside the whitefly eggs (this happens when the whitefly is at an immobile stage).
The larva then feeds on the whitefly embryo when the Encarsia eggs hatch, pupae then forms inside the whitefly egg, killing it if they hadn’t already. An exit open hole is chewed by the adult Encarsia wasp where it emerges from the whitefly egg casing and flies off in search of a new host to lay its eggs. Female Encarsia can lay about 50 to 100 eggs in its lifetime – which is pretty good knowing that their “lifetime” is only two to three weeks.
To keep these beneficial insects in your greenhouse, the essentials for life must be provided for; food and water. Normally most parasitic wasps like the sugary fluid secreted by flowers, known as nectar.
Once wasps have the prerequisites for their survival, living longer is usually not a problem and thus searching out for more host insects to lay their eggs, thereby eliminating more pest insects, as well creating consecutive generations of natural control.
Bear in mind that the smaller the wasp, the greater the requirement for plant life that has small flowers readily available, where the nectar is easier for the wasp to get at. A great plant to grow for wasps is Dill. The plant grows tall and, it has hundreds of tiny flowers gathered collectively which makes the nectar in these tiny flowers easy for tiny wasps to flock to.
Other good plants grow to help keep beneficial wasps around are fennel, caraway, parsley and coriander. I was taking a good look at my parsley plant some days back and found out the flowers were emerging on some of the stems, there were three ladybugs crawling and feeding on the nectar – other pests that had also took up residence did the same.
I also noticed three bumble bees visiting the parsley. Knowing that the parsley plant is an outdoor plant, I think I will be planting one in my newly constructed greenhouse!
Tiny flowers are being visited by Parasitic Wasps for its nectar, meanwhile the predator insects also come by to eat the pollen, particularly juvenile and adult ladybugs and lacewing.
Beneficial Nematodes, another powerful weapon against garden pests.
Nematodes detect either a minor rise in temperature or discharge of methane gas and this causes them to migrate through growing medium finding insect larvae. Nematode enters the host body through natural openings such as the mouth once they have found a “Host”. Immediately they gain access inside the host, symbiotic bacteria that paralyzes the host is then introduced and within 24 – 48 hours kills it.
Bacteria and decomposed host tissue are feed on by nematodes where they reproduce until their figures compel them out to find a fresh host. Larvae nematodes usually live on without a host for up to a year provided moisture levels and temperatures remains conducive for them to live.
Humid, dark environment is required for Nematodes to survive. Given that soil temperatures are kept consistent for indoor growing, hibernation of nematodes is not a problem. It is only when there is a drop in temperature during the winter that nematodes will burrow deeper in the soil and begin hibernation; when temperatures start rising in the spring they move closer to the soil surface.
Sadly, their return usually lags behind that of soil pests. beneficial nematodes are re-introduced for the most competent control early each spring or each time the growing medium is changed.
Nematodes that are beneficial prey on hundreds of different types pests such as the more common pesky ones such as fungus gnats, earwigs, pillbugs, weevils, grubs, wire worms and sow bugs. Regular application of beneficial nematodes during the spring/fall and after growing medium changes, will keep the majority of pests at bay.
Dealing With Mites
Another very prolific and problematic pest is the voracious Spider Mite. Indoor growers can struggle with them more since a controlled climate just happens to be perfect for Mite reproduction. During their brief 15 day life cycle, they can cause a massive amount of damage.
The mites suck the chlorophyll out of the plants leaves, slowly draining life out of the plant. When this pest starts to gain substantial numbers, the plant leaves will show the tell-tale sign of infestation with a yellow pin point speckling on the leaves where they are creating damage.
Spider Mites are usually found on the underside of the leaf. At a certain point in their life cycles they create what resembles spider webbing on the uppermost part of the plant, this indicates that they have reached a critical infestation. Mite damage cannot usually be ‘undone’ so prevention is key.
4. Persimilis-predator mite
Amazingly, there are even predatory mites for controlling spider mites. This mite is scientifically known as Phytoseiulus Persimilis. This long legged, red colored mite shouldn’t be confused with the destructive spider mite which which eventually develop an orange like color.
As an adult, the Persimilis will devour up to 20 mites per day that are either in the adult or still unhatched. A common feature of the mite family is that they reproduce exponentially as the temperatures rise.
The Persimilis mite is very beneficial in the fact that they reproduce more rapidly than the common Spider mite and will inevitably outpace them. However this predatory mite prefers high humidity, so dry climates will hinder their reproductive rates.
Persimilis are ravenous eaters and because of this it one of the best pest predators to use. Many large greenhouses and organic agricultural industry leaders rely on this mighty mite for pest control.
Being so efficient at pest control, in sufficient numbers they will often completely eradicate Spider Mites in due time. This is great news for gardeners that produce ornamentals or flowers where even the slightest amount of Spider Mite damage can ruin their crops.
However, this is a double edged sword and Persimilis will eventually run out of food and new predators will have to be reintroduced when pests re-emerge.
5. Predatory Midge
This predator preys on Spider Mites as well, Feltiella Acarisuga. Being a brownish-pink clor this midge is about 1/12 of an inch long. The Feltiella will lay eggs where ever there is a sufficient concentration of Spider Mites. When the young larvae eventually hatch they feed on the Mite eggs.
The young larvae eat primarily the eggs as the larvae matures it starts to feed on adult Spider Mites as well. They will eat up to 50 Spider Mites before pupating into a mature Midge. This whole process for this predator insect can last up to 15 days, with females laying up to 14 eggs at a time.
A great predator for controlling Aphids would be Lacewing larvae, being in a growth spurt stage as larvae they excel at devouring everything in their paths. Since they can’t fly yet and can only crawl, they tend to be very efficient at scouring a leaf surface. Thereby eradicating every last pest leaf by leaf.
Usually the best results for using predatory insects will involve the use of at least two types of pest predators. Once you commit to using natural pest control, you won’t be able to use any type of pesticides or your precious predators will fall victims to it as well.
Organic gardening requires more research and planning but the healthy rewards for you and Mother Nature are worth it!