Pesticides on new garden plants; a disaster for insects

Elephant hawk moth

One of the problems I had to deal with lately, is finding the right food plants for certain animals, especially insects species. Some plants I have in my garden, but when the animals require a specific plant, that is not really common, the only option is to buy one at for example a garden center. Unfortunately, that isn’t always a solution, as I experienced this the last week.

Dying nymphs

With a lot of plants you buy in your local garden center, the issue is that they are treated with pesticides. The first time I had to deal with this was approx. 1,5 years ago. I bought some eggs of stick insect Calvisia marmorata on Marktplaats, the Dutch EBay. They feed on Cherry laurel. I didn’t have this plant in my garden, but they can be found in most garden centers, so I bought one at a local store. The eggs hatched and the nymphs were doing fine at first. Until they suddenly started to die and in the end none of them survived. The only possible cause of death I could think of was the laurel, that had to be treated with pesticides somehow and thoroughly washing the leaves down before feeding them apparently wasn’t enough to get rid of the poison.

Elephant hawk moth

From that moment on, I´m really careful with newly purchased plants. This week my worries became even stronger. Last summer, I received a phone call that someone had found some unusual caterpillars while they were mowing weeds. They thought I could maybe use them for my photography project. I’ve picked them up and put them in a large fauna box together with some food plants their saviors gave me. With the help of the Vlinderstichting, the Dutch Butterfly association, I discovered that they were Elephant hawk moth caterpillars; this is a moth in the family Sphingidae, who hibernates as pupae and will not emerge as a butterfly until the next year. So, I’ve put the pupae in a cool and safe spot over winter and this week, the first butterflies have emerged.

No food plants

My plan was to keep a number of butterflies together is a special butterfly enclosure, hoping they would reproduce so I could document the growth and development of the caterpillars from the day that they were born. But I needed the right plants to feed the caterpillars. I contacted some local plant-breeders, but soon realized that I was asking awkward questions, because they didn’t seem to want to answer my when I asked where I could find some pesticide free plants. Through a website for bio plant-breeders I found a breeder in Boskoop, who works without pesticides. Just to make sure I had safe plants and they were in stock, I sent them an e-mail to ask if the plants I was looking for were pesticide free and available. Unfortunately, they couldn’t help me either. They work without chemicals, but also buy plants from other breeders and they just couldn’t guarantee that all plants were completely safe. Eventually, I came to the conclusion that I couldn’t document the development of this beautiful moth, because I simply couldn’t find the right plants to feed them.

Garden plants as a death trap

It was quite shocking to realize how bad the situation with the pesticides is and that it’s no wonder that insect numbers are declining so rapidly. It’s not just the agriculture and food production that’s the cause of this problem, but also plants in our own garden. What’s even worse, is that, as a consumer, there is little you can do. The industry is not transparent on what chemicals they use and pesticide free plants are very hard to find. The only option you have is to modify your choice of plants to the product range of pesticide free plant-breeders or to cultivate your own plants by using organic seeds. I hope that someday pesticide free plants are as common as for example organic vegetables, but I’m afraid that won’t be happening in the near future.