The past few weeks have been “fun” with pest challenges in our garden and home. In the kitchen we battled ant infestations and pantry moths. In the yard the milkweed plants have been covered with oleander aphids, the California lilac (Ceanothus) was attacked by mealybugs accompanied by ants, and paper wasps (Polistes) have been trying to build a nest on the front porch.

How to tackle each of these issues? UC IPM (University of California Integrated Pest Management) Pest Notes and Quick Tips is my go-to for all these issues.

Inside the House:

Pantry Moths

The Indian meal moth (Pyralidae) is the most common moth found on food products in the home. When you see these small moths flying around your home, the larva is likely already in your food. We have had infestations in the past, but food they may get into is now in tightly sealed containers. We also keep pantry moth traps in several areas of the house as a preventative measure.  When we started seeing the moths flying around, we checked the traps and discovered 1-2 dozen moths in all of them. It is possible that we bought some food that had moths, though we could not find an infestation in any of our containers. To be safe, unopened boxes were put in the freezer for a couple of weeks. We also took everything out of the pantry, washed everything down and vacuumed around the kitchen (which also helps with ants). We replaced the moth traps and have not seen any since. https://ipm.ucanr.edu/QT/pantrypestscard.html

Ants 

Ants are beneficial insects who recycle nutrients and aerate the soil, but they are irritating to have in the house! They came in several times during a period of a couple weeks. We used soap and water to mop them up and to wash off their scent trail.  We tried to locate where they came from. In the kitchen they initially appeared along a counter. Later they seem to be coming in from the dishwasher area into the compost bucket under the sink. We pulled out the dishwasher to determine if they were coming from behind it and did not see an entry source. We also pulled everything out from under the sink and cleaned that area. We believe the compost pail was attracting the ants, so are now being vigilant in emptying it each day. We also vacuum and mop the floor daily. Ant baits have been set up in hidden spots (because we have a cat who thinks the baits are toys to play with). Baits are a longer-term strategy, so for now we continue to keep an eye out for scouts and wipe them up as we see them. Since we put the bait traps out, we have not seen any more, so fingers are crossed. https://ipm.ucanr.edu/QT/antscard.html 

Oleander aphids on milkweed plant, author photo.

In the garden:

Milkweed and oleander aphids (Aphis nerii)

I hoped I had escaped getting the detested orange oleander aphids this year, since in recent years they usually showed up earlier in the summer, but ultimately, they appeared. Most established plants can tolerate some aphids, but all aphids produce honeydew, which can attract ants and sooty mold. Since milkweed is the sole food source for the Monarch butterfly caterpillar, pesticides are not recommended. Thus, using strong sprays of water every couple of days helps manage them. Based on previous experience, I know they will reach the end of their life and ultimately disappear. https://ipm.ucanr.edu/QT/aphidscard.html

Mealybugs (Pseudococcidae)

While pruning my Ceanothus (California lilac) bush, I came across several branches covered with mealybugs and ants crawling all over them.   Mealybugs can affect the health of the plant by sucking the sap from the leaves and branches. They excrete honeydew, which is often accompanied by blackish sooty mold growth and ants. Ants protect the bugs and farm the honeydew as a food source. Natural enemies provide superb control of mealybugs, unless the infestation is heavy or disrupted by insecticides (which can kill the beneficial insects). I used the same management method here as I did with the oleander aphids – a strong stream of water to wash off the scale, honeydew, and ants, which I will repeat if needed. I also pruned the most heavily infested branches. https://ipm.ucanr.edu/QT/mealybugscard.html

Paper wasps (Polistes gallicus)

Unlike yellow jacket wasps (Genera Vespula) which are very aggressive, paper wasps rarely sting humans, unless they feel threatened. Paper wasps generally avoid areas of human activity, but exceptions are when their nests are located near doors, windows, or other high-traffic areas. We have had paper wasps previously build nests in out-of-the-way areas of our house and yard, where they have not been a problem. But this nest was under the eaves of our front porch near our front door. So, we knocked out the nest, hoping they would move to a different area of our house or yard. However, they returned 2-3 times – each time we knocked out the nest. They finally appear to have moved on. https://ipm.ucanr.edu/QT/yellowjacketscard.html 

 

Thanks to UC IPM, which provides information on garden issues and pests, along with giving scientifically researched options on how to deal with them, I have managed to either control or eliminate these pesky pests.

UC IPM Resources:

The above links are to Quick Tips, short, to-the-point cards on each topic. They are available for free at local UC Cooperative Extension offices. The references below are for Pest Notes, which may have multiple pages and offer more detailed information about each topic.

Ants: https://ipm.ucanr.edu/PMG/PESTNOTES/pn7411.html 

Pantry Pests: https://ipm.ucanr.edu/PMG/PESTNOTES/pn7452.html

Aphids: https://ipm.ucanr.edu/PMG/PESTNOTES/pn7404.html; https://ipm.ucanr.edu/PMG/PESTNOTES/pn7410.html

Mealybugs: https://ipm.ucanr.edu/PMG/PESTNOTES/pn74174.html

Wasps: https://ipm.ucanr.edu/PMG/PESTNOTES/pn7450.html 

 

Denise Godbout-Avant has been a UC Cooperative Extension Master Gardener with Stanislaus County since 2020.