- Author: Dong-Hwan Choe
- Author: Kathleen Campbell
- Author: Michael K Rust
- Posted by: Elaine Lander
Many parks, recreational areas, and outdoor venues in California are home to yellowjacket wasps (Vespula spp.). Yellowjackets are commonly attracted to human food items, creating a serious nuisance and a potential stinging threat. If found, nests (usually underground) can be effectively treated with targeted insecticide applications (e.g., dusts containing pyrethroids). However, baiting could be a feasible alternative method to suppress yellowjackets over a wide area, especially if nests cannot be located. Currently, only one active ingredient (esfenvalerate) is registered for use within bait in California to control yellowjackets,...
- Author: Siavash Taravati
- Posted by: Elaine Lander
Western drywood termites (Incisitermes minor, Figure 1) are an important pest of structural wood in California, causing millions of dollars in damage annually. These termites are very cryptic, hidden in their galleries within wood members (pieces of wood), and only emerge during swarming. As a result, wood damage usually goes unnoticed for a long time.
Control options are generally categorized as either whole-structure treatment (heat treatment and fumigation) or local treatments (insecticide injection into the wood, high-power microwaves, electrocution, and other techniques).
Despite...
Roses in the garden can be infected with a variety of bacteria, fungi, and viruses, leading to diseases like powdery mildew and rust. Roses may also be damaged by nutrient deficiencies and other environmental problems.
Our Pest Notes: Roses: Diseases and Disorders was recently updated by University of California experts John Karlik, Deborah Golino, and Maher Al Rwahnih. This free publication provides an integrated approach to managing rose problems that includes careful variety choice, proper irrigation, correct pruning, and sanitation. Although some rose enthusiasts might consider regular application of fungicides a necessary...
Plantains are common weeds in lawns, athletic fields, ornamental plantings, roadsides, and pastures. Two species, broadleaf and buckhorn plantains (Plantago major and P. lanceolate) are commonly found throughout California year-round.
Plantains grow well in irrigated turf and lawns that are frequently mowed since they grow low to the ground. They can be a major pest for turfgrass managers since they grow in dense clumps, creating both an aesthetic and tripping hazard in turf. When plantains infest ornamental plantings, they can crowd out desired plants.
These weeds are difficult to control because they can resprout from the crown, even after it's cut off. Early removal of seedlings before they...
What is Armillaria Root Rot?
Armillaria root rot is a severe fungal disease that affects trees, woody plants, and some herbaceous plants including palms and succulents.
Also known as oak root fungus, Armillaria root rot can rapidly kill trees and presents a challenge to management since infected woody roots can persist for years underground. No plants are completely immune to Armillaria root rot, so prevention is key. Deeply planted trees are often more susceptible to this disease.
The distinctive “honey mushrooms” growing from the base of a tree signals an infection, but they may not always be present. Other visible symptoms include flat cankers on the trunk, wilting, and canopy...
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