- Author: Kathy Keatley Garvey
The katydid nymph did.
It did appear in May.
The UC Statewide Integrated Pest Management Program (UC IPM) tells us that katydid nymphs appear in our gardens in April or May.
This little nymph was right on time, barely, as it surfaced in our Vacaville garden on May 28.
The nymph, a leafeater, is usually so camouflaged in the vegetation that we don't see it--unless it's hanging out on a California golden poppy blossom or a neon pink rock purslane. The adult katydid can be an economic pest when it feeds on such crops as mandarins.
Frankly, it can look quite comical as it "walks the walk," its long threadlike antennae probing the way as it descends a stem in the early evening.
- Author: Lauren Fordyce
There are many types of “good bugs” commonly found in the garden or landscape. In integrated pest management (IPM) we refer to “good bugs” as “natural enemies” or “beneficial organisms”. Natural enemies can include insects, but also mites, pathogens, and vertebrates like birds and lizards. They can kill or reduce pest populations by feeding directly on the pest, parasitizing the pest, or infecting the pest with a pathogen, reducing the need for pesticides.
Keep an eye out for the common natural enemies listed below and learn to recognize their egg and immature stages too!
- Lady beetles (ladybugs). There are about 200 different species of lady beetles in California. Many species feed on soft-bodied pest insects like aphids, soft scales, mealybugs, whiteflies, mites, and psyllids. They will also eat pest insect eggs and larvae.
- Soldier beetles (leatherwings) adults feed on aphids and other soft-bodied insects. Their larvae live in the ground and feed on pest eggs, larvae, and pupae in the soil.
- Lacewings feed on mites, aphids, caterpillars, leafhoppers, mealybugs, psyllids, scales, and thrips! While some adult lacewings can be predacious, their larvae are most useful in pest control.
- Syrphid flies, also called hover flies or flower flies, resemble bees and are pollinators. Their larvae feed on aphids, mealybugs, and other soft-bodied insects.
- Assassin bugs can feed on caterpillars and other larvae, as well as adults and nymphs of beetles. They are known to attack just about any insect, but can bite people if provoked.
- Spiders. While many people fear spiders, they can actually help control many pests in and around the home and garden. Flower spiders, jumping spiders, and wolf spiders are examples of common beneficial garden spiders.
To learn more about natural enemies, see these resources:
- Pest Notes: Biological Control and Natural Enemies of Invertebrates (fact sheet)
- Natural Enemies Gallery
- Natural Enemies and Beneficial Insects: What Are They? (webinar)
- Author: Lauren Fordyce
While preparing your garden for planting this spring, you may have found white grubs in the soil. Discovering these fairly large, white grubs can be alarming, but they usually won't cause significant plant damage.
Grubs are the soil-dwelling larvae of beetles in the Scarabaeidae family, also simply called scarabs. They are generally curled in a C-shape with whitish bodies and 6 legs. Grubs of some species may be less than 0.5 inch long, while other species may be up to 2 inches. Some grubs feed on living plant material while others do not.
Masked chafer beetle grubs are often what people find in garden beds in California. If you find large grubs in compost, those are likely the larvae of the green fruit beetle (also commonly called figeater beetle and green fig beetle). Japanese beetles are not usually present in California, but there are a few small hot spots under eradication efforts by the California Department of Food and Agriculture.
In most cases, the presence of grubs does not require pesticide treatment and populations of 6 or less per square foot won't cause significant damage. If you notice them in your garden beds, they can be hand-picked and killed. Some may choose to feed them to their backyard chickens or leave them out for wild birds. Beneficial nematodes can be applied to control grub infestations.
To learn more about common white grubs, visit https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=56797
- Author: Kathy Keatley Garvey
Remember when San Francisco 49'ers wide receiver Brandon Aiyuk credited his spectacular 51-yard catch in the 2024 NFC championship game with the Detroit Lions to a ladybug (note that entomologists correctly call it a "lady beetle") landing on his shoe before the game?
Well, those attending the 110th annual UC Davis Picnic Day activities on Saturday, April 20 at Briggs Hall--home of the UC Davis Department of Entomology and Nematology--can also net some luck.
Children are encouraged to take home a couple of the beetles at the UC Statewide Integrated Pest Management Program (UC IPM) booth in the courtyard of Briggs. (Adults can do so, too. Maybe they'll name their beetles "Brandon" and "Aiyuk.")
The ladybug is actually a beetle (Coleoptera), not a bug (Hemiptera). It's associated with good luck because it eats the aphids that try to destroy our crops. It can eat as many as 5000 aphids in its lifetime, scientists estimate.
"These beetles have become a cultural icon of sorts because of their appearance and their beneficial habits," writes UC Davis distinguished professor Lynn Kimsey, former director of the Bohart Museum of Entomology, in her insect fact sheet on lady beetles. "Both adults and larvae feed on aphids and other small, soft-bodied insects...They are ferocious predators on small insects." (See what the UC Statewide Integrated Pest Management Program says about lady beetles.)
Ever seen a close-up shot of a lady beetle eating an aphid? The predator and the prey...
Ever seen a cellar spider snaring and eating a lady beetle? The predator and the predator...one becomes prey.
Ordinarily, the lady beetle's bright red coloration serves as a "warning" to predators. Plus, lady beetles are known to ooze a foul-tasting chemical that tastes so bad that predators leave them alone. This lady beetle engaged in "reflex bleeding," exuding an alkaloid toxin (which did not deter the predator).
Lady beetles will be just a few of the bugs at Briggs Hall during UC Davis Picnic Day. You'll also see cockroach races, maggot art, and displays featuring ants, bees, walking sticks, mosquitoes, nematodes, butterflies, spiders, whip scorpions, and more. Check out "bug" activities at Briggs Hall here. UC Davis Picnic Day is free and family friendly.
Spring is here and if you are like us, you can't wait to get outside and see how your plants and garden are doing! As usual, UC IPM has useful tips for the month of April to prevent pests in the garden and landscape. To see more tips specific to your region, visit the Seasonal Landscape IPM Checklist on the UC IPM website. Here are some general tips to get you started:
- Cover fruit trees with netting to exclude birds and other vertebrate pests.
- Aphids are out already so look for them and their natural enemies such as predaceous bugs like lacewings, lady beetles, and syrphid flies. On sturdy plants, spray aphids off with a strong stream of water or apply insecticidal oils or insecticidal soaps to kill them.
- Manage ants. Plants infested with honeydew producing insects like aphids, whiteflies, and mealybugs may attract ants who take that honeydew back to the nest to feed the colony. Manage ants around landscape and building foundations using insecticide baits and trunk barriers.
- Whitewash tree trunks to deter borers and prevent sunburn. Apply to young trees or older bark on susceptible trees newly exposed to sunlight.
- Look for signs of clearwing moths boring in ash, birch, pine, poplar, and willow.
- Check for signs of powdery mildew on apple, crape myrtle, grape, rose, and stone fruits. Take preventative measures, like pruning, to provide better air circulation between plants.
- Watch for yellowjackets and other wasps building nests in undesirable locations. Knock down newly started nests and use lure or water traps to control populations.
- Prevent mosquitoes by eliminating standing water in gutters, drain pipes, flowerpots, etc. Place Bt “dunks” (Bacillus thuringiensis subspecies israelensis) in birdbaths and ponds to selectively kill mosquito larvae.
- Adjust watering practices as rainfall decreases. Check irrigation systems for leaks and broken emitters and perform maintenance as needed. Consider upgrading the irrigation system to improve its water efficiency.
- Monitor stone fruit trees for pests such as aphids, borers, brown rot, caterpillars, powdery mildew, and scale insects.
Don't see your county on the checklist or want to provide feedback? Let us know!