- Author: Steven A. Tjosvold
Soon after LBAM was discovered in Alameda County in 2007, officials started recording the nursery and fruit crops it was detected on. A 2008 CDFA list included 152 species. Many of these were new hosts, not recognized or recorded earlier. Clearly, LBAM was taking advantage of the California flora and nursery crops smorgasbord.
In a scientific review article on the host range of Light Brown Apple Moth (LBAM) in 2011, the authors summarized that there are “At least 545 plant species in 363 genera from 121 families that have been reported as hosts.” Further they stated that “Light brown apple moth is one of the most polyphagous insects known.” (See Attached files at the bottom of page.)
Although we knew something about common hosts within nurseries, we did not know a lot about the hosts that often surrounded these nurseries. We surveyed the native hosts and weeds that surrounded these sites for more than 2 years, and found that there were many common native hosts and weeds that LBAM could colonize ( See figure above).
This has important implications since these closely associated hosts could be launching pads for the migration of moths into nursery or fruit crops. LBAM adults have been shown to migrate at least 100 meters from their original sources. (See figure above.)
It is important to scout and perhaps control weeds that are outside the nursery and crop perimeters to minimize impact on LBAM migration into production areas.
- Author: Steven A. Tjosvold
The Light Brown Apple Moth (LBAM) is an important invasive pest for California, and is established in much of California's coastal and some inland areas where nursery products are produced. It is a federally and state regulated pest in many ornamental and fruit crops.
Although the LBAM life cycle (egg to adult) progresses and develops through the entire year, our monitoring around the Monterey Bay Area production areas showed that there were peaks in LBAM flights consistently in the Fall (see red arrows).
These adults produce a focused generation of young larvae (see red circles), if detected early enough, could be targeted with a softer pesticide such at Bacillus thuringiensis (B.t., e.g. Dipel), which is active mainly on young larvae. B.t. is selective to moth larvae such as LBAM, therefore not interfering with parasitoids of LBAM, and it is relatively inexpensive.
A pesticide application, particularly with a short residual pesticide such as B.t., should be made when young larvae are detected through scouting. However, identifying larvae of LBAM has always been difficult. There are many look-alike leafrollers , especially when they are younger. We produced a LBAM identification guide and training video that helps identify adults, eggs, pupae, and most importantly, the targeted larvae.
LBAM ID Guide and Video at LBAM identification