Tag Archives: milkweed aphids

Trouble in Paradise

Aphids on butterfly weed.

Spring around here doesnít bring a late snow or severe tropical storm that can wreak havoc in a garden. Still we have our own problems that can dash the hopes of even the most optimistic gardener. Is your veggie garden getting attacked by every type of insect and fungal disease lately? Are your beautiful roses looking a bit bedraggle? If your piece of paradise is being devoured or disfigured by insect pests or fungal diseases hereís what can you do about it.

Insects are having a field day at this time of year, too. Put out wet rolled newspaper at night to collect earwigs in the morning. If you see notches on your rose leaves, it’s the work of leaf cutter bees. These guys are beneficial and will go away shortly.

If your rose leaves look like lace then you have the dreaded rose slug. I have a friend whose rose shrubs were really hit by these. It’s discouraging when you had visions of huge fragrant bouquets on every table. What to do?

Rose slugs can skeletonize your leaves in a short time. Treat right away so your roses will look like this.

The rose slug is actually the larvae of a wasp called a sawfly. Because they may have up to 6 generations per year they can do a lot of damage to your roses. Early detection is key. Start scouting for sawfly larvae in early May when they can be hand picked or washed from the leaves with a strong spray. If needed, spray the leaves with neem oil while the larvae are still small. Conventional insecticides are toxic to bees and kill the good bugs too. During the winter rose slugs pupate in the soil and removing a couple of inches will help with controlling their numbers. Even cultivating the soil any time will break up the cocoons.

Keep checking for aphids. They can suck the plant juices from tender new leaves in a short time. They are incredibly prolific. Female aphids can produce 50 to 100 offspring. A newly born aphid becomes a producing adult without about a week and then can produce up to 5 offspring per day for up to 30 days. Yikes, thatís a lot of aphids if you donít keep up with control. You may be able to dislodge them with a strong spray from the hose. If they persist, spray with organics like insecticidal soap, Neem or horticultural oil. As with all pesticide sprays, do this early in the morning or later then the plant is not in the sun. Be sure to test first to make sure the spray doesnít burn new growth.

Ants can also bring aphids up into trees and shrubs such as camellias, citrus and roses. The ants feed off the honeydew secreted by aphids, scale and other plant-juice sucking insects. Ants also protect these pests from natural predators. To keep them off, wrap trunks with a 1-2 inch wide strip of masking tape and coast with a sticky barrier like Tanglefoot. Keep the barriers free of dirt and replace when necessary.

A client of mine has a photinia hedge that is not doing well. At first I suspected fireblight as this species is prone to this infections but on closer inspection I found the problem to be leaf spot. The majority of leaf spots are caused by fungi but some are caused by bacteria. Either should be treated with an organic fungicide like Serenade which is non-toxic to bees and beneficial insects, Neem oil, copper or sulfur spray to prevent and control spreading. Affected leaves should be discarded. Many plants get various leaf spots and late spring showers are perfect for them to take hold.

There are so many things that can grow wrong in the vegetable garden, too. Between fungal and bacterial problems, insects, slugs, deer, birds, rodents, rabbits- the list is endless. Keep your eyes open and donít let a problem become a bigger one with time.

Troubles in the Garden

Milkweed aphids

Some of us enjoy sitting in our gardens, relaxing and watching birds and other wildlife. Others grow fruit and vegetables and know their way around the kitchen. Whatever you like to do sometimes pests get in the way.

In my own garden recently I discovered my butterflyweed covered with yellow milkweed aphids. Theyíre not interested in any other plants just this one. Oleanders get this same sucking pest also. Iíve washed them off twice with a strong spray of water but must have missed a few as they are back. Unfortunately, I havenít seen any monarch butterflies to help me with this problem. Iíd rather not even use an organic pesticide to control the outbreak. It would harm any monarch eggs that Iíve overlooked.

With pest control on my mind this week, I received an email from fellow Press Banner columnist, Dr. Terry Hollenbeck. ďI thought of you when I found an article in an old gardening magazineĒ, he wrote. ďItís ĎThe Home Gardenerí and was published in September, 1945

DDT ad_The-Home_Garden-Sept1945
DDT ad in ‘The Home Garden’ magazine published September 1945

Dr. Hollenbeck scanned the pages from his own magazine and sent them to me. Terry goes on to note that the editorial about the new wonder insecticide DDT warns readers in 1945 to proceed cautiously with it. Then later in the magazine on page 99 in a half page ad there appears an advertisement for DDT, the ďArmyís sensational insect killer that gardeners have been waiting forÖthat is absolutely safe to sprayĒ.

There has been a lot of research now on DDT and itís effects on our bodies and that of wildlife. I was surprised when I Googled DDT that itís still being used in the world and also found a published study debunking itís adverse effects on raptors. Guess one can find statistics to support any argument if you look hard enough.

Here is what I found out about current use of DDT that I found interesting.

Back in 1972 the EPA (Environmental Protection Agency) issued a cancellation order for DDT use in the United States based on research showing adverse environmental effects to wildlife and potential human health risks. Studies have continued to show a relationship between DDT exposure and reproductive effects in humans and as a result, today, DDT is classified as a probable human carcinogen by U.S. and International authorities.

India is the only country now producing DDT. China and North Korea having discontinued production in recent years. 12 countries still use DDT for vector control of mosquitos and protozoa – the parasitic diseases of malaria, dengue and black fever which kill more than 800,000 people each year.

Many organizations are now promoting an integrated approach to mosquito and protozoa carried diseases. Itís not a DDT or nothing solution. Some of these organisms are developing a resistance to DDT and other chemicals. Like in our own backyards, you have to look at the whole picture. Successful programs to educate communities about non-chemical methods of control mosquitos are underway in many countries such as Vietnam.

DDT is known to be very persistent in the environment. It accumulates in fatty tissues and can travel long distances in the upper atmosphere. Because of its persistence, there is still concern for residues in the U.S.
Today nearly 40 years after DDT was banned in the U.S. we continue to live with its long lasting effects. According to the organization Pesticide Action Network, USDA found DDT breakdown products in 60% of heavy cream samples, 42% of kale greens and 28% of carrots. These breakdown products of DDT were found in the blood of 99% of people tested by the CDC.

Something to think about when I see all those mustard yellow aphids on my asclepsias. Maybe Iíll get the hose out one more time or rub them off with a gloved hand.