- Author: Denise Godbout-Avant
Fascinating Bat Bits
Bats are the only true flying mammal, making up a quarter of the world's mammals. There are 1,100 species of bats, with forty species in the USA. California has twenty-five species, most of which are insectivores.
Bats are one of only three mammals that generally sleep upside down, with sloths and manatees being the other two.
According to the U.S. Forest Service, fruit-eating bats are responsible for dispersing seeds that grow into bananas, avocados and 300 other plant species around the world. Agave plants (which are the source of tequila and mezcal) evolved to supply most of their nectar after dark to attract the nocturnal bats to cross-pollinate their flowers.
Insect eating bats often consume their own weight in insects each night, eating up to a thousand mosquito-size insects in an hour! It is estimated that bats' value to agriculture could exceed $23 million per year.
Bats are excellent fliers with some species flying up to 60-100 mph. They can locate and catch insects in midflight in total darkness, using echolocation, which is the ability to locate objects by reflected sound waves.
Where Do Bats Live?
Usually, males and females with young will roost separately, but in late summer or early autumn, males may join the colony. In the winter when insects become scarce, some bats hibernate, while others may migrate to warmer areas, returning in the spring months.
Bat Myths and Facts
Because of their nocturnal habits, bats are rarely seen, so seem mysterious and are often misunderstood.
Myth - Bats suck people's blood.
Myth - Bats are blind.
Fact - Bats do have small eyes, but they are functional. Megabats, which are larger bats such as fruit bats (found in forests of Africa, Asia, Australia, and Europe), search for their food using both sight and smell.
Myth - Bats fly towards and get tangled in people's hair.
Fact - Bats hang upside down from their roosts and tend to drop down and flap their wings before they start to lift off in flight. So, though it may appear the animals are swooping down on you and want to nest in your hair, they're not. In fact, bats don't make nests.
Bats as Pests
Like many mammals, bats can contract rabies. It is rare for a rabid bat to bite a human. According to the World Health Organization, an estimated 59,000 humans die from rabies each year, with 99% of these deaths being due to contact with rabid, unvaccinated dogs.
Most bat parasites such as fleas and mites are host specific and cannot survive on other animals. No evidence exists of disease transmission to humans or domestic pets from bat parasites.
Bat droppings, known as guano, can harbor a widespread fungus found in soil, Histoplasma capsulatum, which causes Histoplasmosis in humans. However, most human infections come from birds.
If You Find a Bat. . .
If you find a bat laying on the ground, please leave it alone, especially in the spring or fall, when they may be migrating and are just resting during their long journey. If after an hour or two, the bat has not moved, it is likely sick and should be avoided. If it is in an area where children or pets can access it, you may want to trap it. While wearing leather gloves, carefully put a box over it and slide a piece of cardboard underneath it to trap it. Then contact your local wildlife rescue organization (in Stanislaus County that is the Stanislaus Wildlife Care Center at 1220 Geer Rd., Hughson, 209-883-9414).
Bats in Trouble
One of their most dire threats comes from white-nose syndrome (WNS), a disease that has decimated bats in the USA and Canada. Bats that hibernate during the winter do so to ration their energy and survive during a time of year when insects are scarce. The WNS fungus grows on bats' skin which disturbs their hibernation, thus increasing the amount of energy they are using, resulting in dehydration, starvation and often, death. However, a 2015 breakthrough appears promising. A team of researchers treated infected bats infected with a common bacterium on bananas which seems to stop the growth of the fungus. The treated bats were successfully released back to the wild.
How Can You Help Bats
- Learn more about bats, educating friends and family.
- With an iNaturalist app on your smartphone, you can take part in citizen science by observing bats in a park or your own backyard.
- Build a bat house. Bats need places to roost, rest, raise young. UC IPM gives information how to build a backyard bat house: http://ipm.ucanr.edu/PMG/PESTNOTES/pn74150.html. Other bat house links are provided in Resources. Choose a pesticide-free open location with five to seven hours of sunlight. Bats prefer interior temperatures of 80-100ºF during the summer.
- Stay out of caves when directed. Bats need to be undisturbed in caves, particularly in the winter months. If you do visit caves where bats live, clean your shoes before and after to avoid tracking white nose syndrome to another cave.
Where to Go See Bats

- Yolo Bypass Wildlife Area: Not far from Sacramento, this colony resides under the Yolo Causeways, a 3-mile-viaduct on Interstate 80. These are Mexican Free-tailed bats (Tadarida brasiliensis) who take up residence in the crevices in the concrete bridge. The colony numbers up to a quarter-million bats in size. If you want to see the bats yourself, you can find a place with a good view, but you can also book tours that are specifically designed to get you close enough to see the colony. https://www.yolobasin.org/bats2022/
- Consumnes River Preserve: Near Lodi, several species of bats are found in both the riparian forest and in a bat-friendly bridge built over the Cosumnes River. https://www.nature.org/en-us/get-involved/how-to-help/places-we-protect/cosumnes-river/
All About Bats Webinar
Webinar: “All About Bats”
Where: On Zoom
When: Wednesday, October 12, 2022, from 1:00-2:30 p.m
Instructor: Rachael Long, UC ANR Integrated Pest Management for Yolo, Solano and Sacramento Counties
Cost: Free
Register: https://ucanr.edu/all/about/bats
Resources
What Insects Do Bats Eat? https://ucanr.edu/blogs/bugsquad/index.cfm?tagname=bats
Bats, Allies to Farmers: https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=23708&postnum=23708
Bats in the Belfry: https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=17395
Fear of Bats and Its Consequences by Merlin Tuttle: https://secemu.org/wp-content/uploads/2018/05/Tuttle_et_al_2017.pdf
Bat Myths: https://kids.nationalgeographic.com/nature/article/bat-myths-busted
Myth Busters: https://www.nps.gov/subjects/bats/myth-busters.htm
Nature Conservancy – Bats: https://www.nature.org/en-us/get-involved/how-to-help/animals-we-protect/bats/
Bat Conservation and Management – Bats in Buildings:https://batmanagement.com/blogs/bat-exclusion-control/bats-in-buildings
White nose syndrome: https://blog.nature.org/science/2015/05/27/bananas-to-bats-the-science-behind-the-first-bats-successfully-treated-for-white-nose-syndrome/
All About Bat Houses: https://batmanagement.com/pages/lc-bh-overview
Selecting a Quality Bat House: https://www.merlintuttle.org/selecting-a-quality-bat-house/
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Help the Monarch Butterfly
Thanks to the Great Valley Seed Company, we are giving away free seed packets of narrowleaf milkweed (Asclepias fasciculata) while supplies last. Plant the seeds in full sun this fall to create a milkweed patch. The monarch butterfly population has declined by 90% since the 1980's. Their caterpillars only eat milkweed, so the more patches we can establish in Stanislaus County, the better! An item of note is we are asking people not to plant tropical milkweed (Asclepias curassivica), which harbors a disease that is killing the butterfly.
Water Wise Plants
Our table will showcase a colorful poster about water wise plants, along with a helpful handout listing attractive plant choices. Be sure not to miss one of our Water Wise Landscaping classes at a local library by reading this post. At the booth, pick up a copy of our upcoming classes so you never miss an event!
Have a Pest Problem?
Stop by our table and pick up our Quick Tips cards in English or Spanish on topics like ants, powdery mildew, gophers, cockroaches, and more! Ask a Master Gardener a question about your vegetable garden or pest problem.
For more information about the fair, visit the Stanislaus County Fair Website. https://stancofair.com/
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- Author: Ed Perry
If you decide to fight them, now is a good time to plan your strategy since the most critical time to protect your fruit from the pest is spring. Warm spring weather causes most of the first generation moths to emerge within a few weeks. The moths may take 6 weeks or more to emerge during a cool spring. Once they have emerged, the codling moths are still affected by temperature. They do not lay eggs or mate when it's below 62°F at sunset or fly when it's 55°F.
The moths emerge from pupae in early spring about the time when fruit trees are in full bloom. Each moth lays 50 to 75 eggs on fruit, twigs, or leaves. Eggs hatch into larvae which tunnel into the young fruit. Inside the fruit, the larvae feed for several weeks, then tunnel to the fruit's surface and search for protected sites such as under tree bark, in branch wounds, weeds, grass or other litter. The larvae changes first to a pupa, then to an adult and repeats the cycle.
You can also trap many larvae under bands. Take a 6-inch wide strip or burlap or corrugated cardboard, wrap it around the trunk several times, then fasten it in place with a loop of wire or twine. If you use corrugated cardboard, the exposed flutes (ridges) must be at least 3/16 of an inch wide and face toward the tree; otherwise, the larvae won't form cocoons in them. Place a band on each tree no later than mind-May. During warm weather remove the band once a week, and during cool weather once every two weeks. Destroy all the larvae and pupae under the band, and then put the band back on the tree. Keep doing this until you've harvested all the fruit.
Insecticidal sprays are usually the most effective means of controlling codling moths. Sprays give best control when you apply them just after a large number of larvae hatch, but before they burrow into the fruit. These times are several days after a period of peak moth flight and vary according to the year and location.
When using any chemical, carefully follow dilution rates and other directions given on the container label. Do not spray within the number of days before harvest indicated on the label. You can read more details about the life cycle of this pest and management, including chemical controls in the UC IPM Pest Notes: Codling Moth.
Ed Perry is the emeritus Environmental Horticultural Advisor for University of California Cooperative Extension (UCCE) in Stanislaus County where he worked for over 30 years.
[From the UC IPM blog Pests in the Urban Landscape]
1. Aphids
These insects may be small, but they can quickly build up large populations. With many different species in California that feed on vegetables, flowers, fruit trees, and woody ornamentals, aphids are a common sight in landscapes and gardens. Year after year, aphids continue to hold the top spot. Learn more about aphids and their management in Pest Notes: Aphids.
2. Fungus Gnats
3. Thrips
Another tiny insect sometimes found on houseplants, thrips are slender insects about the size and shape of a dash printed in a newspaper. They suck out the cell contents, leaving a discolored speckling on leaves or stunting plant growth. For more about thrips monitoring and management, visit our Pest Notes: Thrips.
4. Mealybugs
If you've found soft, oval insects that are white in color with wax filaments on your indoor or outdoor plants, it is likely you have mealybugs. These wingless insects are often found in clustered colonies. In yards and gardens, handpicking, pruning, or high-pressure water sprays can reduce populations. For small infestations indoors, spot treatments may help reduce populations. For houseplants with severe infestations, consider disposing of the plant. Find additional information in Pest Notes: Mealybugs.
5. Carpet Beetles
6. Peach Leaf Curl
Peach leaf curl can affect the blossoms, fruit, leaves, and shoots of peach and nectarine trees. The symptoms of the disease first appear in spring, when distorted red foliage emerges. However, focus management for nonresistant varieties in the late fall and early winter, after leaves drop. Read more about this disease in our Pest Notes: Peach Leaf Curl.
7. Clothes Moths
New to the top ten list this year were clothes moths. These pests tend to hide when disturbed, so you may not realize you have an infestation until after the moths have already damaged fabric, fur, or feathered items. Some clothes moths make webs while others are casemaking moths. Regularly monitoring and cleaning clothing and storage areas can help prevent or reduce infestations. Find more identification and management information from Pest Notes: Clothes Moths.
8. Springtails
9. Whiteflies
Whiteflies are not actual flies but are tiny insects that are often found on the underside of leaves, feeding on the phloem of many different plants. Certain species can cause significant loss in vegetable gardens; other species found in fruit trees are less damaging. Both adult and immature whiteflies also attack houseplants. Management information can be found in Pest Notes: Whiteflies.
10. Scales
Scales are small, legless insects that look like tiny scabs on the stems, leaves, or fruit of plants. While some scale species can weaken a plant when abundant, other species do not appear to damage plants at all. Think you have a problem with these insects? Visit our Pest Notes: Scales for identification and management options.
/h3>/h3>/h3>/h3>/h3>/h3>/h3>/h3>/h3>/h3>To confirm your plant has hoplia beetles, inspect a flower and you may also spot this culprit (or three) hiding inside. The beetles are small, brown, and their undersides look like they've been dusted in gold. If you hold one in your hand, they will “play dead” and not move so you can examine them.
The best way to manage hoplia beetles is regularly handpicking or shaking them off the flowers into a bucket of soapy water and then disposing of it. This can help reduce beetle populations in the future. You can also fill white, 5-gallon buckets with water and a few drops of detergent. The white color may attract the beetles which will fall into the bucket and drown. Luckily, their populations begin to dwindle by June. You can read more details about these methods in the UC IPM Pest Note: Hoplia Beetles.