- Author: Ben Faber
A new pest for avocado? Old pest? How much damage will it do? Don't know yet.
Tracy Ellis, the San Diego County Ag Commissioner Entomologist has partially identified what appeared to be two pest and a parasitoid, as only one pest and a beneficial that is doing it's duty going after the pest.
The insect determination has come back for both larvae (one a leaf miner and one a leaf roller) as the same insect! It has been determined to be C-rated gracillariid miner Caloptilia sp. (Lepidoptera: Gracillariidae) at this time. An image of the adult moth is not yet available.
Apparently, the larval stage transitions from a miner to a roller, in what's called hyper-metamorphosis. Starting as a miner and abandoning the mine to roll the leaf. CDFA scientist Marc Epstein is taking a closer look at this insect . Marc does not know if it is a local insect that adapted to avocados or is an import, as many in this family have not been studied or sequenced.
The leaf roller/folder has appeared down in San Diego and Santa Barbara. It's not clear whether it will be a pest of the fruit at this time.
The results for the parasite came back as Hymenoptera. That too needs greater study.
Above is a photo of both insect stages. They can be found together in the same habitat.
The damage from the leaf miner generally looks like this
And miner looks like this
The damage from the leafroller looks like this:
Larval leafroller with the parasite on it.
And the parasite , once it grows up from being a maggot, looks like this
It's still not clear what damage this might do. Maybe nothing significant. Maybe this is an aberration only for this year. Stay tuned.
- Author: Elaine Lander
- Author: Karey Windbiel-Rojas
Below are a few such pests that you might be encountering now in your gardens and landscapes.
Masked Pests
Masked chafers are golden brown beetles with dark heads that give them their name. The adults are not typically considered pests although they do show up on window screens, in pools, or wander into the home. The immatures, white C-shaped grubs, are considers pests because they feed on the roots of grasses and possibly other plants. Learn more about this masked pest here.
Pests with Covers
Leafrollers are a group of moths that feed and pupate within rolled-up leaves. The immature caterpillars roll or web together the leaf to use as protective cover. Several species of leafrollers can be found in California. The fruittree leafroller is the most common and can be found on many ornamental trees and fruit and nut trees including ash, birch, maple, poplar, almond, apple, apricot, citrus, pear, and walnut.
Visit the UC IPM website to find out more about pests and personal protective equipment needed when applying pesticides. Stay safe this summer!
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- Author: Ria DeBiase
Light brown apple moth is currently under a California Department of Food and Agriculture quarantine that regulates the interstate shipment of plants to keep the moth from spreading to new areas. It has been quarantined in various counties throughout coastal California ranging from Mendocino to San Diego.
An exotic and invasive pest from Australia, light brown apple moth has a host range of more than 2,000 plants. It is a pest to a wide range of ornamental and agricultural crops, including caneberries, strawberries, citrus, stone fruit, apples, and grapes. The caterpillars eat leaves and buds, leading to weak or disfigured plants. They also can feed directly on fruit, causing the fruit to be unmarketable.
Correct field identification of the light brown apple moth is the first step in containing the spread of this moth. Unfortunately several other leafroller caterpillars, including the orange tortrix, omnivorous leafroller, avocado leafroller, and apple pandemic moth, look similar to light brown apple moth caterpillars. This makes photo identification tools that can go into the field with workers, like the Field Identification Guide for Light Brown Apple Moth in California Nurseries, a useful resource for nursery workers.
The field guide was created by Steven Tjosvold, Neal Murray, University of California Cooperative Extension; Marc Epstein, Obediah Sage, California Department of Food and Agriculture; and Todd Gilligan, Colorado State University with the UC Statewide Integrated Pest Management Program (UC IPM).
For more information on light brown apple moth and other leafrollers found in nurseries, see the UC Pest Management Guidelines for Floriculture and Nurseries.
- Author: Larry J Bettiga
European grapevine moth (EGVM), Lobesia botrana, was detected in several Napa County vineyards in the fall of 2009. Native to Mediterranean Europe this invasive insect’s preferred host is grape. Although it is related to other tortricid moths found in vineyards (orange tortrix and omnivorous leafroller) it does not tie leaves together or feed on leaf tissue. EGVM larvae feed on grape flower parts and berries. Late season feeding on berries results in increased incidence of bunch rots.
The adult moth is approximately ¼ inch long with the first pair of wings having a mosaic-pattern (fig.1). Eggs are laid singly which is different than the overlapping egg masses of other vineyard tortricid moths. There are five larval instars. The fully-grown fifth instar is approximately ½ inch (fig. 2). Mature larvae spin a cocoon in which they pupate.
In response to the Napa County finds a statewide trapping program was started in March 2010 to determine if EGVM exists in other grape growing areas of California. The program is a coordinated effort between the county agricultural commissioners, CDFA and USDA. Specific pheromone lures in red “Delta” sticky traps are being used. Early results from the 2010 trapping program has expanded the quarantine area in Napa County and moths have been caught in traps in Sonoma, Solano, Mendocino and Fresno Counties.
Growers wanting to conduct their own trapping programs can purchase the traps and the EGVM specific pheromone lure from commercial vendors.
Additional Information:
UC website: http://www.ipm.ucdavis.edu/EXOTIC/eurograpevinemoth.html
CDFA website:
http://www.cdfa.ca.gov/PHPPS/egvm/index.html
Figure 1. Adult female EGVM |
Figure 2. Earlier stages of EGVM larvae are tan to yellow-brown, while latter stages become dark colored. |