As the weather warms up, we see more insect activity in gardens and landscapes, and you may also notice more activity of insect pests in your home. Common insect pests found indoors in springtime can include carpet beetles, fleas, fungus gnats, and boxelder bugs.

In our recent post on carpet beetles, we shared that the adults of these beetles prefer to be outdoors but the immature larvae can feed on fabric, carpet, or other natural materials in your home. See our Pest Notes: Carpet Beetles for more management information.

Cat fleas are the most common parasite on cats and dogs in California and you may find more fleas on your pets in spring and early summer. More than just a nuisance, fleas can transmit tapeworms or other diseases to pets or humans. Our Pest Notes: Fleas has more information on managing fleas.

If you have indoor plants, fungus gnats that infest soil and potting mix can be a nuisance. These small, delicate-looking flies are similar in appearance to mosquitoes but are smaller and do not bite. Instead, fungus gnats feed on fungi and organic material but can also chew roots of houseplants. You can find more information on these flies in Pest Notes: Fungus Gnats. You may also find our Pest Notes: Houseplant Problems helpful.

While boxelder bugs tend to group together outdoors, they occasionally come indoors and may be annoying. The adult females lay eggs in cracks and crevices of the box elder tree's bark in spring so you may be seeing more of these black and red bugs if you have host trees like box elder, maple, ash, apple, cherry, peach, pear, or plum. Learn more about these pests and their look-alikes in Pest Notes: Boxelder Bug.

Looking for more management information for springtime insect pests in the home? Join us for our upcoming webinar on Thursday, May 20 at 1:00pm with Dr. Andrew Sutherland, Area Urban IPM Advisor for the San Francisco Bay Area. Click here to register for our upcoming webinar and see the webinar website for more information about our webinar series.

 

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Western drywood termites (Incisitermes minor, Figure 1) are an important pest of structural wood in California, causing millions of dollars in damage annually. These termites are very cryptic, hidden in their galleries within wood members (pieces of wood), and only emerge during swarming. As a result, wood damage usually goes unnoticed for a long time.

Control options are generally categorized as either whole-structure treatment (heat treatment and fumigation) or local treatments (insecticide injection into the wood, high-power microwaves, electrocution, and other techniques).

Despite the high efficacy of fumigation, there has been increasing interest by property owners to use local treatments for eradicating drywood termites. This may be due to the high cost and inconvenience of fumigation. To learn more about decision-making associated with fumigation, visit this webpage. Local treatment of drywood termites can be ineffective because of the difficulty in locating active infestation sites within structures.

To address this issue, practitioners and researchers have considered different detection methods using traditional and modern technologies such as borescopes, moisture meters, and heat sensors as well as devices using X-rays, acoustic emission, and low-energy microwaves. Here we provide a review and some technical details on how to operate a specific device using microwave technology for detecting termite movement in structures.

Termatrac

Termatrac¹ is the brand name of a portable device that emits and receives low-energy microwaves to detect tiny movements in wood. This device is currently available as two models: Termatrac T3i All Sensor and Termatrac T3i Radar Only. Termatrac All Sensor includes a microwave emitter/sensor, a moisture meter, and a thermal sensor. The Radar- Only version, however, includes only the microwave technology (“radar”). Both devices generate a line graph output that represents termite movement within wood (Figure 2).

Although such output can be informative, interpreting the results might not always be easy and may also require considerable expertise. First, the output's line graph may represent detection of non-termite objects or the user themselves (body movement or hand shaking while holding the device). Second, the signal intensity varies depending on the depth of termite activity, so Gain settings may need to be adjusted for higher or lower sensitivity. Third, the relationship between termite density (number of termites per unit of area) and signal strength is not easily understood by users (Figure 3). Fourth, termites may not be present or active during inspection and this may lead to a false negative conclusion (concluding “no termites” when they are present) when inspecting an infestation. To address these issues, field and lab research experiments were conducted in California to evaluate the efficacy of the Termatrac device and to help termite inspectors accurately interpret the output signal.

 

 

Termatrac can be used in different positions (see Figure 4).

1. hand-held with radar surface flush against the inspection surface
2. mounted on a tripod with radar surface flush against the inspection surface
3. resting on a horizontal surface with radar surface flush against the inspection surface
4. with radar at 45° angle to the inspection surface using the back flap or a tripod

Field studies revealed that hand-held uses produce less accurate results than tripod/flap supported uses due to user hand shaking. Also, the device's output showed more noise (Noise is referred to a detected signal in the output that is not coming from drywood termites) from the user's body movement when used at 45° to the inspection surface as compared to flush against the inspection surface.

Recommendations

For optimal readings, Termatrac users should keep the following in mind. Users need to stand still when reading the output or the device will pick up their body movement and produce a false positive signal. This is especially true at high sensitivities.

Users also need to ensure that there are no moving objects (vehicles, plants swaying with the wind, airborne debris such as leaves and dusts, children, or animals (such as pets and birds) on the other side of the inspection surface (a wall for instance) which may create false positive signals. Also, water passing through pipes behind inspection surfaces may produce a strong signal. However, heavy machinery around the experiment sites did not produce any detectable noise despite being very loud.

The device should not be used to inspect unstable surfaces or non-fixed objects (e.g. yard fence) since these situations will increase the chance of false positive signals and inaccurate detection of termites.

To save time and increase accuracy when inspecting standard interior walls, users should first try to locate studs using a stud finder and then use Termatrac on those areas only. Users may also choose to focus on wooden window frames and windowsills since these have been observed to be one of the most commonly drywood termite detected spots in homes.

Findings

Lab studies showed that higher densities of termites may not necessarily produce stronger signal (Figure 3). At the highest sensitivity setting, Termatrac T3i was able to detect a single drywood termite behind 5 cm (2 inch) of wood and 1.3 cm (0.5 inch) of drywall (total thickness of test “wall”: 6.3 cm / 2.5 inch).

Drywood termites move within their galleries continually and therefore may not be present in all gallery regions at all times. Furthermore, termite activity may change throughout the day depending on temperature and other factors (Figure 5). As a result, if you suspect an active infestation in a wall but are not getting a detectable Termatrac signal, it is worth moving on to other areas and then returning in a few minutes to re-inspect the suspect location.

To conclude, Termatrac can be very useful in some termite detection. Like other termite detection devices, Termatrac has limitations and requires training and experience before a user can efficiently and accurately detect termites. With this said, an experienced Termatrac user can obtain valuable information about termite presence and activity when the infested wood members are in accessible locations.

¹Mention of a product does not constitute an endorsement.

 [Originally published in the Winter 2020 issue of the Green Bulletin.]

 

 

It's often easier to prevent pests before they become a problem than to try and get rid of them once they infest a home. While some pests can be active year-round, cooler temperatures trigger some pests to find shelter indoors.

Creatures such as rats or insects are typically looking for food, water, and shelter. Eliminate or reduce access to these resources to deter pests. There are a variety of tools that are readily available which can help block or limit a pest's entrance into the home. Here are a few suggestions to prevent creatures from stirring in your home this season.

Rats, Mice, and Tree Squirrels

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  House mice prefer grains but will consume many different foods. (Credit: R Marsh)
  Keep tight fitting lids on garbage cans and compost containers to prevent these rodents from finding a food source near your home and eventually coming indoors.
• Examine the exterior of your home for signs of rat or mice droppings or other evidence, then seal any cracks or gaps larger than 1/4 inch.
• Thin vegetation between shrubs and buildings using pruning shears or trimmers and trim back overhanging trees.
• Place traps outside your home to catch rodents before they enter. See our previous post on snap traps for more information.
• Screen or block potential entrances under eaves or overlapping roof sections to exclude rodents. Sheet metal or 1/8-inch wire hardware cloth are suitable materials that can keep out rats, mice, and tree squirrels.

Termites

Several types of termites exist in California, including subterranean, drywood, and dampwood species. It is important for you to identify what type of termite you have before managing. Reduce your risk of termite infestation by doing the following:

• Remove wood piles or scrap wood near structures.
• Repair any foundation cracks, plumbing leaks, or exterior defects in structural wood.
• Finish exterior wood using sealants or paints.

Cockroaches

• Monitor for cockroaches using sticky cockroach traps. Commercially available open-ended traps are a good option.
• Remove potential food sources by cleaning up any spilled food or dirty dishes.
• Store food in tightly sealed containers.
• Vacuum cracks and crevices regularly to remove food and debris.
• Decrease clutter, especially in kitchens and bathrooms, to reduce hiding places for cockroaches.

Pantry Pests

Stored-product pests, also called pantry pests, are typically brought into the home from infested packages. The most common pantry pests are moths and beetles.

• Use pheromone traps monitor and detect pests. These are typically available in stores for moths or beetles, and some traps attract several pest species.
• Store food such as flours, grains, and cereals in containers with tight fitting lids and keep them dry to prevent pantry pests.
• Clean shelves, bins, and food storage areas regularly.

Several other creatures can also be considered pests during winter months. Spiders (which are also beneficial), fleas, and bed bugs can live comfortably in temperature-controlled indoor environments. Visit our website for more information about these and other pests.

 

 

 

 

 

 

[Article originally published as "Not a Creature Was Stirring" in the Winter 2019 issue of the Retail Nursery and Garden Center IPM Newsletter.] 

 

 

Integrated Pest Management Workshop for Retail Nurseries and Garden Centers

Register now for this hands-on, train-the-trainer workshop designed especially for retail nursery and garden center employees, managers, owners, and affiliates. The workshop, offered by the University of California Statewide IPM Program and UC Cooperative Extension, will help you and your employees gain new skills to better serve customers and keep them coming back!

When:   Monday, November 4, 2019
Where:  Scottish Rite Masonic Center, Sacramento, CA
Time:    8:30 AM to 3:15 PM
Cost:     $40 per person

Topics will include:

-Insects, diseases, and vertebrate pests of vegetable gardens
-IPM tools and resources for the public
-Less toxic pesticides for vegetable pests

Your $40 registration fee includes a copy of the Vegetable Pest Identification card set, light breakfast, lunch, and training materials.

Don't miss this opportunity! Register online and see the full agenda at https://ucanr.edu/sites/RetailTrainingSac2019/

Registration is open exclusively for retail affiliates until Friday, October 18th at 5:00 PM. After this deadline, we will open registration to the general public.

If you are not affiliated with the retail nursery industry but want to attend, add your name to the training waitlist.

Please help us spread the word by sharing this message with your employees, owners, managers, and colleagues! Or, if you don't work at a nursery, please share with your local nursery or garden center.

We hope to see you there!

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Additional trainings will be held in Oakland in January 2020 and in San Diego in February 2020. Stay tuned for details and registration!