Stink bugs – update

stinkbug2 An environmentally-friendly way of getting rid of stink bugs is to use a stick to knock them into a container with some methylated spirits in the bottom of it, so that you don’t have to come in direct contact with these smelly bugs that change colour from green to orange to brown-black as they grow.
However, a reader e-mailed me this week about his problem with lots of stink bugs on his orange tree that is too tall to use this method, and he wanted to know if he could spray the tree with metho, instead.

Spraying the bugs with methylated spirits would only further damage the tree. If you also have a tree affected by bronze orange bugs (stink bugs), these bugs are a sign that a tree is very under-nourished. It is probably extremely water-stressed, as plants can’t absorb nutrients from soil if it is not damp enough for the minerals to become water-soluble. Give the soil around the affected tree a thorough watering, then give it an application of complete organic fertiliser and then water in some organic seaweed tea. You haven’t said which climate area you live in. If you live in an area where water shortages are common, keep the tree pruned to a size where it can remain healthy on the amount of water that you and nature can provide.

Bronze orange bugs or stink bugs and harlequin bugs are sap sucking pests that can do a lot of damage to stressed citrus trees. Spined citrus bugs suck sap from fruit. Before dealing with these bugs, you need to don old clothes, sturdy shoes, gloves and goggles or sunglasses as bronze orange bugs eject a corrosive fluid with a vile smell when they are threatened.
Young bugs tend to cluster under the lower leaves of the trees and are easy to get at, but if trees are too large for knocking them into a tin, spread some large sheets of plastic under the tree, then use a broom stick or long pole to give the foliage a good shake and, when they drop to the ground, either squash them, or gather up the plastic and slide them into a large container with a suitable pest treatment in the bottom.
Organic-registered products such as Natrasoap (not ordinary soaps or detergents) or Eco-oil will kill these pests but they should not be used on heat-stressed or water stressed plants, or in high temperatures. However, either of these products can be used to spray stink bugs when they shelter around the base of the tree on hot days. Harlequin bugs like to shelter in weeds, and they can be sprayed where they are hiding. Get rid of weeds, particularly along fence lines to prevent re-infestation.
However, the best way to avoid these horrible pests is to take good care of your citrus trees.

Green vegetable bugs

Karen is new to organic gardening and is wants to know what to do about the green vegetable bugs that are attacking her tomatoes.

The green vegetable bug is a sap-sucking pest. They use weeds as hosts and attack vegetable plants that are stressed in some way. Of the chemical sprays required to kill these bugs, one will poison any birds that eat the bugs, and the other is deadly to bees and other beneficial insects. It can also metabolise in humans to a more toxic chemical, and is currently under review.
Chooks show no interest in eating these bugs. The best way to get rid of these organically is to put some methylated spirits into a soup tin or similar container. Put on gloves to protect your hands from any smelly juice they excrete and use a stick to knock them into the tin. Then get rid of weeds and plants that have finished bearing to prevent these pests continuing to breed.
To prevent further attacks (and this is the most important part of the treatment) have a look at why your tomato plants are stressed, and correct the problem. Some gardeners find it difficult to understand that pest and disease attack are only symptoms of unsuitable conditions for a particular species, but it is true. I noticed yesterday, that similar bugs are attacking some silver beet plants we have. We decided after picking the first of this silver beet that we did not like this variety as much as ‘Fordhook’ and decided to just feed the plants to the chooks, a plant or two at a time. Consequently, the silver beet did not receive the same attention as the other vegetables and, before long, these bugs moved in. The bugs are not attacking other vegetables that are receiving normal care.
When pests attack plants, the answer is always in the soil. It may be too dry or poorly drained. If water is in short supply in your area, hill up your tomatoes about 5 cm at a time. They will produce more roots along the stem and allow them to access water more efficiently. Tomato plants need a deep watering (under mulch) several times a week in dry weather, rather than a light daily watering.
Or, the plants may be short of the nutrients they require to produce pest-deterring pheromones. If you have skimped on fertiliser, after a thorough watering, give each plant a light feed of complete poultry-based fertiliser and a drink of seaweed extract tea.
Or, the soil may be too acid or alkaline for the plants and the nutrients they require can be locked out and unavailable to the plants. This can be difficult to determine without testing, except that, with tomatoes symptoms of phosphorus deficiency (purple colouring under leaves and slow growth) are a clue that soil is too acid or alkaline if you have applied adequate complete fertiliser. If soil is too alkaline, put some well-rotted horse or cow manure under the mulch around the plants. If soil is too acid, water in some dolomite or lime around the base of each plant. See Changing soil pH.