- 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.
- Author: Kathy Keatley Garvey
The elm leaf beetles and their larvae don't want to hold your hand--unless perhaps you're holding a elm leaf that they can eat.
A recent walk down the 200 block of Buck Avenue, Vacaville, California, revealed the damage this pest does. The stately canopied elms don't look so stately, what with the dry skeletonized leaves, the browning and the dieback.
And if you look closer, you'll see the leaves--the feeding site--dropping prematurely, and beetles and their larvae falling with them.
Infestations of these beetles can defoliate large elm trees, according to the UC Integrated Statewide Management Program's Pest Note on this pest, Xanthogaleruca (=Pyrrhalta) luteola.
Have you ever seen them? They're about 1/4 inch long, yellow to olive-green with a black stripe on each side and four black spots near the head. They are an invasive species from southern Europe, introduced here in the 1800s, and considered the most serious elm defoliator in the United States.
"Females lay yellowish eggs in double rows of about 5 to 25 on the underside of leaves," according to UC IPM. "Eggs become grayish before hatching. Larvae resemble caterpillars and are black when newly hatched and shortly after molting (shedding the old skin). After feeding, larvae become yellowish to green with rows of tiny dark tubercles (projections). Third-instar larvae grow up to 1/3 inch long and have dense rows of dark tubercles down their sides that resemble two black stripes. Pupae are orange to bright yellow."
We observed some natural enemies on site: lady beetles, aka ladybugs, and their larvae munching on the larvae of the elm leaf beetles. Yes, beetle larvae eating beetle larvae. Lady beetles and their larvae target soft-bodied insects, and not just aphids.
UC IPM says:
"The elm leaf beetle develops through four life stages: egg, larva, pupa, and adult. Adults commonly overwinter in bark crevices and woodpiles or in buildings. In spring they fly to elm foliage and chew leaves, and females lay eggs. Eggs hatch into larvae that develop through three instars (growth stages) over a period of several weeks while chewing on foliage and then crawl down the tree trunk. Mature larvae become curled and inactive (a stage referred to as prepupae), then pupate, sometimes in large numbers, around the tree base. After about 10 days as pupae, adults emerge and fly to the canopy to feed and, during spring and summer, lay eggs. The elm leaf beetle has at least one generation a year in northern California and two to three generations in central and southern California."
Elm trees with massive defoliation can weaken the tree and pave the way for diseases and damage from other pests.
If you have elm trees, especially European elm species, and you have these little buggers all over them, you might want to access the UC IPM Pest Notes to see how to manage them.
These beetles mean business.
/span>- Author: Kathy Keatley Garvey
It's a dog-eat-dog world out there.
It's also a 'cat-eat-'cat world, that is, when a caterpillar eats another caterpillar. Or in this case, when larva eats larva.
We recently spotted this lady beetle larva eating a syrphid fly larva on our yellow rose bush, "Sparkle and Shine." Both eat aphids, and that's exactly what they were doing until the lady beetle larva attacked--and began eating--the syrphid larva.
These insects are beneficial. The lady beetle, as an adult, continues to consume those pesky aphids. The syrphid fly adult, aka hover fly or flower fly, is a pollinator.
The hungry larva reminded us of Eric Carle's award-winning children's picture book, The Very Hungry Caterpillar, first published in 1969.
The synopsis (Wikipedia):
"One Sunday morning, a red-faced caterpillar hatches from an egg, and begins to look for some food. He eats through increasing quantities of fruit on the following five days, one apple on Monday, two pears on Tuesday, three plums on Wednesday, four strawberries on Thursday, and five oranges on Friday, and then, on Saturday, he has an enormous feast. By the end of Saturday, the inevitable happens and he is ill. After recovering from a stomach-ache, he returns to a more sensible diet by eating through a large green leaf before spinning a cocoon in which he remains for the following 2 weeks. Later, the 'big fat caterpillar' emerges as a beautiful butterfly with large, gorgeous, multi-coloured wings."
Well, in this case, the menu differed. Our lady beetle larva didn't eat an apple, pear, plum, strawberry or orange.
He/she ate its competitor.
If you have insects invading your kitchen or pantry, or if you've ever opened stored food products and discovered pests inside, you'll want to watch this new video from UC IPM. It describes several types of pantry pests, foods they are attracted to, and includes steps on how to prevent, manage and eliminate them from your home.
For more detailed information, read the Pantry Pests Pest Note. You can also read an article about pantry pests in the Retail and Garden Center IPM News at http://ipm.ucanr.edu/PDF/PUBS/retailipmnews.2015.july.pdf
Did you know that UC IPM has over 35 helpful home and garden videos? Visit http://ipm.ucanr.edu/IPMPROJECT/videolibrary-ur.html to watch more.
- Author: Kathy Keatley Garvey
Have you ever seen a monarch butterfly (Danaus plexippus) lay an egg on her host plant, the milkweed?
Have you ever seen a close-up of the egg? The larva or caterpillar? The chrysalis? The eclosure (when the adult emerges from the chrysalis)?
It's a fascinating sight.
Not all eggs will make it. Predators, such as lady beetles and their larvae, gobble up monarch eggs along with those tasty aphids. Birds, such as scrub jays, swoop down and make off with an occasional caterpillar. Then when the fifth instar finally starts to form a chrysalis, there's always the question of whether it will do so. Some are deformed and turn out to be half chrysalis and half caterpillar.
But once you've watched a complete metamorphosis, you'll never underappreciate monarchs again. In fact, you'll probably start rearing them every year. We just reared our first two this month.
It's easy to see why teachers and their students get so excited. We remember writing about Sal (Sally) Levinson's newly published book, Butterfly Papercrafts, which contains 21 indoor projects for outdoor learning. Levinson, who studied entomology at the graduate level at UC Riverside and UC Berkeley, wants to inspire youngsters to learn about our amazing world of butterflies through art and a little science.
It's intended for youngsters ages 5-12, but really, it's also a beginner's book for all ages and a teacher's treasure. And it's priced right--under $10 ($9.99). Readers can learn about the life cycle, from egg to caterpillar to chrysalis to adult; and craft a butterfly paper airplane, a caterpillar flip book, and a monarch finger puppet.
Meanwhile, North America's monarchs are heading for their overwintering sites in two main areas: the mountains of central Mexico, and choice spots along the California coast, including Pacific Grove and Santa Cruz.
"The annual migration of North America's monarch butterfly is a unique and amazing phenomenon," according to the U.S. Department of Agriculture's Forest Service website. "The monarch is the only butterfly known to make a two-way migration as birds do. Unlike other butterflies that can overwinter as larvae, pupae, or even as adults in some species, monarchs cannot survive the cold winters of northern climates. Using environmental cues, the monarchs know when it is time to travel south for the winter. Monarchs use a combination of air currents and thermals to travel long distances. Some fly as far as 3,000 miles to reach their winter home."
You'll see a migration map on the Forest Service website. You can check out the monarch sightings on this map and report the ones you see.
Go, monarchs!