Story last updated at 4/17/2013 - 2:14 pm
Do aphids make you crazy? Does the very thought of them in your garden fill you with trepidation? You're not alone. My neighborhood survey results indicate pest frustration levels in the following order: aphids, slugs, spider mites, and deer. Thank goodness the deer don't reproduce like the aphids!
This year I'm hoping to stay ahead of massive population explosions by trying to think like an aphid. One way to help the cause is to remove all plant material in gardening areas where overwintering eggs may be lurking. Aphids can be tricky and tend to lay eggs on trees or other perennials rather than the plants you may have seen them on. Since they may fly off to mate and lay eggs in fall, it seems nearly impossible to control the egg population.
One might as well expect an invasion sooner or later, so early detection is the next best plan. It pays to monitor plants frequently before all heck breaks loose. The species that show up in my gardening areas are light green in color so, although they are large enough to see, they blend in well on plants. These soft-bodied insects with long legs and antennae use their long, slender mouthparts to pierce stems and leaves; boldly sucking out plant fluids from our precious cucumbers right under our noses. Aphids may also transmit viruses from plant to plant, targeting a wide variety of plants such as squash, bean, potato, cucumber, lettuce, pepper, dahlia, zinnia and many more.
The good news is that locating them is made easier because there are usually a lot of them. The bad news is that there are a lot of them. Look for them on new growth like buds and flowers and the underside of leaves and watch out for their tricks. Aphids will sometimes slip around to the back side of a stem or run and hide under a leaf, practically admitting guilt, when approached.
Curling, yellowing or distorted leaves and stunted shoots might indicate a large infestation in the works. If any of those problems occur, double check under leaves because aphids are pretty sneaky.
They're out to get us! The more I research aphids, the more I can't believe the way they roll. Aphids get their spring agenda in gear when overwintering eggs hatch out all female aphids that are already pregnant with the next generation. Reproducing through parthenogenesis, a form of female cloning, aphids are frighteningly prolific.
If all goes well in their world, the aphids that hatch from the eggs will each give live birth to 50-100 females in seven to 10 days. Then each of those aphids might bear another 50-100 aphids in seven to 10 days. Just imagine - if 100 eggs hatch and each of those aphids produce 100 more aphids, you already have 10,000 aphids just a couple weeks after the spring hatching. Aphids will continue to reproduce in this manner throughout the summer. Obviously the population can quickly become overwhelming.
It gets better. Researchers have found that aphids respond to seasonal and environmental changes in amazing ways. If the population becomes too large for available plant food, some aphids are able to grow wings to seek greener pastures. In fall, the increase in night length triggers a change so that male and sexually reproductive females are produced instead of all asexual females. These aphids, usually having wings, are able to find each other, mate and lay eggs on plants anywhere to secure the next generations through the cold months of winter.
When under attack, I first try to wash aphids off with a strong spray of water or, if necessary, to spray with insecticidal soap, which has to actually make contact with the aphid to work so it's important to spray the undersides of leaves as well as the tops, but try not to overdo it.
The University of Alaska Fairbanks, Cooperative Extension Service's Integrated Pest Management Program (IPM of Alaska) has documented pesticide resistant aphids throughout the greenhouse industry in Alaska. Aphids can develop resistance easily and since they give birth to genetically identical females and survive on a wide range of hosts, they have efficient mechanisms to develop insecticide resistance.
IPM researchers have observed that pest resistant strains are created through the use and over-reliance of insecticides and suggest one should never increase dosages. By killing off susceptible aphids, the remaining resistant ones become the larger segment of the population. Formerly effective insecticides may no longer be effective against the remaining population or most of their descendants.
Aphids can be a challenge, there's no doubt, so remember to get out there and begin the detective work early on before the little suckers can try any funny stuff.
Carla Petersen writes from Thorne Bay. She is a freelance writer and artist. View her work at whalepassoriginals.com. She can be reached at firstname.lastname@example.org.