Stink bugs and their near relatives, plant bugs, leaf footed bugs, and plant hoppers, can be some of the worse garden and home pests. The hard outer covering of the adult stink bugs can make them immune from many contact insecticides and the fact that they feed on internal plant juices means that poisons applied topically won't affect them. There are methods you can use to control and kill stink bugs so they won't ruin your tomatoes or use your house for a winter retreat.
Knowing about stink bug habits, preferences, and their lifecycle, can help when it comes to understanding how to combat these pests. Stink bug females lay clusters of small barrel shaped eggs on the leaves and stems of plants, usually lower down on plants. Eggs, numbering from 30 to 100, are laid in the early spring through midsummer by the adults that overwinter wherever they can find shelter from the cold. The young stink bugs have soft bodies, are wingless, and often stay together in groups until they start to mature. In warmer parts of the country, stink bugs can have up to 4 generations a year, leading to high populations of them by late summer. Adult stink bugs have a hard waxy covering, are strong fliers, possess powerful scent glands, and use their needle-like mouth parts to suck on plant juices. Adult stink bugs are attracted to the scents and colors of ripening fruits and certain flowers. With the coming of cooler weather they will search for places to overwinter such as under vegetation, under tree bark, under leaf litter, and in greenhouses, sheds, and inside houses.
The battle to prevent stink bugs starts in the fall. Clean up around the garden to do away with stink bug hiding places. Clean up all brush piles, dead vegetation, stacks of plant pots, and weedy fence rows. Check in sheds and greenhouses for overwintering bugs and fumigate to kill them or collect them using a vacuum cleaner. Starting in the early spring and continueing through the summer check for clusters of stink bug eggs on the lower parts of plants. Use a mirror on a stick to search under lower leaves and crush any eggs or groups of young stink bug nymphs that are found.
When row crops like peas and beans start to form small pods, use floating row covers to protect them from stink bug attacts. Knock any adult stink bugs you see into a coffee can with a small amount of mineral spirits, sealing the can with a lid each day so the solvent won't dry out. Don't crush the adult bugs because their strong odor can actually attract others of their kind. The colors red and yellow attract stink bugs so get or paint some tennis balls or strips of plastic (the size of a playing card) these colors and then cover them with Tangle trap, a sticky substance used for trapping insects. Hang these traps around the garden to catch the stink bugs before your crops start to ripen. There are also pheromone impregnated traps available for luring in stink bugs for the kill. You can also use trapping crops that stink bugs like such as sunflowers or zinnias. Plant these away from the garden to draw the stink bugs there where they can be killed or trapped.
There are some insecticides that can be used to kill stink bugs especially the young soft stink bug nymphs. Diatomaceous earth will kill stink bugs and the food grade DE is not toxic to people or pets. Contact insecticides including Carbaryl, Permethrins, and Sabadilla, are effective against the young nymphs. Malathion, Pyrethrin, and Endosulfan based pesticides have all been shown to kill stink bugs. Neem oil has been found to have little effect on stink bugs. Nicotine, which is a strong neurotoxin, will kill adult stink bugs if sprayed on them, but it is also toxic for mammals so you have to handle it carefully and wash all traces of it off the skin and any thing to be eaten. To make your own nicotine spray, crush some 10 cigarettes and put them in a half gallon of water to soak overnight. Strain the liquid in the morning and add 1/2 teaspoon of liquid soap to each half gallon. Spray on plants to kill all kinds of bugs including stink bugs but test it on tender plant first as some liquid soaps can burn plants. Castile or insecticide soaps are both safe to use on plants. Read and follow all directions and warnings given on any insecticides or products that you use.
To keep stink bugs out of the house over the winter, do a walk around each fall and seal up any cracks or openings that they may enter through. Check carefully around windows and doors. Soak any potted plants that are being brought in for the winter to chase any hiding bugs out of the soil layers. Fumigating attics or crawl spaces right after it turns cold will take care of any bugs trying to hide in these areas and be sure that any vents are covered with bug proof screening. Spraying the outside of the house with a pyrethrin based spray will help to repel stink bugs.