As we notice a decline in butterflies, we should consider which pesticides we use and how often we use them. Nature itself is responsible for natural rise and fall and rise again of butterfly populations. Man also can have a hand in population numbers.
Most humans like pesticides. They keep bugs out of our food, ticks and fleas off our pets, and termites from eating our houses. The problem is that pesticides are often used when they are not necessary, when less pesticide would have been a better choice, when a less damaging pesticide would be a better choice, or simply without thought.
The USDA conducted studies in south Florida for years, seeking the best pesticide to kill mosquitoes that would cause the least damage to butterflies. Caterpillars and butterflies (farm raised, not from the wild) were placed in contained areas and after the area was sprayed by the state, they were collected and the amount of pesticide on them was measured. No-spray zones were checked to be sure that pilots were calculating the spray area correctly and winds wouldn’t cause the spray to touch no-spray zones. This study was done multiple times each year for many years. We applaud this type of study. Losing a loved one to a mosquito borne disease is terrible. When we can protect humans and butterflies (as much as possible) at the same time, we’re ahead of the game.
Many nurseries aren’t aware that they are killing butterflies. A gentle education can help change the manner in which nurseries handle plant pests.
There are times pesticides are necessary. For example: Our three-story house had termites in two places in the walls. Yes, we had the house treated. We continue to have it treated. The choice we made was to have it treated in the winter, when insects aren’t active. By the time butterflies, caterpillars, bees, and other insects that could be affected are out and about, the pesticide has left the soil and plants are safe for caterpillars again.
When a wasp nest is near our door entrance, we spray a wasp spray. One grandchild was prescribed an epi-pen due to his reaction to a wasp sting. We cannot take a chance of him being stung.
When aphids are too numerous for us to handle without treating them, we use soapy water to kill them. Yes, soapy water is a pesticide.
When caterpillars begin to kill my summer squash vines (they get in the main stem) or my cabbage/broccoli is eaten with cabbage worms (we don’t have Cabbage White butterflies here), I will use Bt, an organic soil-dwelling bacteria that kills caterpillars. It disappears within a week. My vegetables are safe from these pests. (I pick off tobacco hormworms off my tomatoes by hand.)
When fire ants build beds next to the grandchildren’s swimming pool or are so numerous that they are killing caterpillars in our garden, we use Amdro bait around the pool or near their beds, avoiding areas where host plants are growing.
Each of us must make decisions based on our specific needs but these decisions should be made after consideration. Will it cause damage beyond my target? Is a less damaging pesticide available? Will the pesticide affect my neighbor’s property?
As we make these choices, it may be a good time to consider the fact that sometimes an organic pesticide may cause more damage than a non-organic pesticide. Bt, an organic pesticide, can live in the soil if the actual bacteria (instead of a crystal from the bacteria) is used in the pesticide.
Organic pyrethrin (pyrethrum) is made from a chrysanthemum species, related to the flowers we buy. It is a widely used organic pesticide. It is well known for how deadly it is to bees and aquatic animals. It has been known to kill mammals and although the chance of death in humans is low, infants are particularly susceptible to pyrethrum. It is a common belief that organic pesticides are safe for people and the environment. One should just as carefully consider which organic pesticide to use as one would an inorganic pesticide. Organic does not mean less toxicity or safer. It means it is of organic nature.
The next time any of us reach for a container of pesticide or recommend a type of pesticide to a friend, we should stop and think. Is this the right pesticide for the job? Is there a pesticide that causes less harm that will do the job as effectively OR effectively enough? Can I control this pest without pesticides?