From UC IPM Pests in the Urban Landscape blog.
According to Gary Goodman, District Manager of Sacramento Yolo Mosquito and Vector control, many residents are anxious and excited to get outside and enjoy the warm weather so it's important to protect yourself from mosquito bites by wearing a good mosquito repellent.
The Centers for Disease Control and Prevention (CDC) recommend using an insect repellent that contains the active ingredients DEET, Picaridin, IR3535 or the plant-based oil of lemon eucalyptus.
Aside from personal protection against mosquito bites, it's important to ensure mosquitoes are not breeding at home. Drain stagnant water from sprinklers, irrigation, and rainstorms. Be sure to check your backyard and dump any water in flower pots, kiddie pools, tires, pet dishes, bird baths and other common household containers that can hold water.
Another ongoing concern is the invasive mosquito Aedes aegypti which has been detected in several counties throughout Southern California and the Central Valley. For county level information, see this map. Invasive mosquitoes pose a significant health threat because they can transmit dangerous viruses including Zika, dengue fever and chikungunya. Surveillance efforts have continued since the initial detection last August. To date, no cases of Zika virus have been reported in California.
For more information on mosquito identification and management, see our recently revised Pest Notes: Mosquitoes. Additional information on vector-borne diseases is available on the California Department of Public Health website.
- Author: Anne E Schellman
Pomegranate trees are often used in gardens and landscapes in Stanislaus County. They make a great tree and usually have relatively few problems. Recently, someone contacted the Master Gardener help line to describe some odd-looking insects she found on her tree, so we asked her to send a few photos. 
The insects are called leaffooted plant bugs. They use piercing-sucking mouthparts to feed on fruits, nuts, and ornamental plants. When they attack pomegranates, their feeding may cause the seeds inside to darken and wither. Large groupings of the bugs can leave behind an unattractive excrement on the fruit, although it is still safe to eat.
Adults overwinter in large groups this time of year, so we advised our caller to take a bucket of soapy water out to her tree and to brush the leaffooted bugs into it. This would help decrease the population before the adults could lay more eggs in spring. (up to 200!) We were impressed the caller was able to find the eggs and capture this image. Can you find them on this pomegranate twig below?
For more life cycle and management information, read the UC IPM Pest Notes: Leaffooted Bug. And remember, if you have a gardening or pest management question, you can call our help line at (209) 525-6802 or send us an email at ucmgstanislaus@ucanr.edu
- Author: Anne E Schellman
Last week, someone called our helpline about a strange phenomenon happening on her backyard plants. She described the symptoms as “big, white, masses of fluffy cotton.” I asked her to email some photos our helpline address (ucmgstanislaus@ucanr.edu).
When I opened her email, I was surprised to see images of what appeared to be giant whiteflies. This pest invaded California in the early 1990's and was until recently only found in Southern California and along the coast. The Stanislaus County Agricultural Commissioner's Office confirmed that giant whiteflies are present in our County.
If you've heard of whiteflies or dealt with them in your landscape, you may wonder how giant whiteflies are different, aside from being larger. Both pests suck plant juices and weaken plants. The main difference is that giant whiteflies tend to feed together in large groups. This large population creates waxy looking deposits that create a “bearded appearance” or what the caller described as “fluffy cotton” on plants. If you look closely at the infestation, you may see the pests living on the undersides of the leaves.
If you find giant whiteflies in your landscape, there are a few things you can do. For small infestations, pull off affected leaves, place them in a sealed bag, and discard them. For larger ones, direct a strong stream of water at the undersides of the leaves to knock giant whiteflies off and kill them.
Visit the UC IPM publication Pest Notes: Giant Whitefly for more information about this pest, or call our helpline at (209) 525-6802 to speak with a UCCE Master Gardener.
