- Author: Amy Murillo
- Posted by: Elaine Lander
Backyard chickens are increasingly being raised as pets, for egg production, and for youth development and science projects. While raising chickens can be an interesting and economically beneficial activity, chickens and other fowl may also have pest problems. Chickens are natural hosts to a variety of arthropod pests (called ectoparasites), including mites, lice, and fleas which feed on chickens and use chicken coops as habitats. These pests may cause discomfort to birds and decrease their egg production. This article aims to help people who keep chickens understand and learn treatment options for the common ectoparasites that can affect their animals.
There are two main species of mite found in backyard chicken flocks: the northern fowl mite (NFM; Ornithonyssus sylviarum) and poultry red mite (PRM; Dermanyssus gallinae). Both mite species feed on blood. NFM live on chickens in the fluffy feathers of the vent region (Figure 2a). PRM live off the animal in cracks and crevices near the birds, such as on perches (Figure 2b), in nestboxes, or in coops. Mites can bite people but cannot survive or reproduce on human blood and will not infest human bodies. Learn more about biting mites in homes and other structures here.
Scaly leg mites (Knemidocoptes mutans) may also affect chickens. These mites are microscopic and identification must be confirmed by an expert. However, the signs of a scaly leg mite infestation are obvious and include scabby or crusty legs or feet (Figure 3). Scaly leg mites spread by direct contact between animals, so quarantining infested birds can limit infestations within a flock.
Lice, mites, and fleas also parasitize wild birds and rodents and could be introduced to flocks by wild animals or even by contaminated equipment or people. To reduce pests in backyard flocks, focus on good biosecurity, which includes all practices that help to prevent or reduce disease in your flock. New chickens should be quarantined for at least two weeks to avoid introducing parasites (or other diseases) to the flock, washing hands and boots should occur before visiting the flock, and chickens should be separated from other animals. Birds should also be examined for signs of pests regularly to catch infestations early, which are easier to deal with than a large outbreak.
Insects and mites are very susceptible to water loss, so using natural materials that cause desiccation can be highly effective for general control. One such compound is diatomaceous earth (DE). Food-grade DE can be mixed with clean play sand in containers to create dustbathing areas for birds. Dustbathing is a natural behavior chickens perform to keep their feathers clean. The addition of DE helps to suppress pest populations.
Insecticides can be an effective tool for pest control. Farm stores often sell sprays or dusts that can be applied directly to birds or to coops for insect control. It is important to always read and follow the label instructions to avoid poisoning birds, people, or other animals. Pests that live in the environment, such as poultry red mites and sticktight fleas, are trickier to control since they may not be visible on chickens.
Murillo AC, Mullens BA. 2016. Diversity and prevalence of ectoparasites on backyard chicken flocks in California. Journal of Medical Entomology. 53: 707-711. https://www.researchgate.net/publication/290211878_Diversity_and_Prevalence_of_Ectoparasites_on_Backyard_Chicken_Flocks_in_California
Veterinary Entomology website with pest resources for professionals and the public: https://www.veterinaryentomology.org/poultry
For more backyard poultry resources, check out: https://ucanr.edu/sites/poultry/Resources_335/Production/type/backyard/
- Author: Andrew Mason Sutherland
- Posted by: Elaine Lander
Most pest management professionals have served clients who swore they were being bitten by unseen pests. Perhaps the usual suspects (bed bugs, fleas, and mosquitoes) were ruled out by thorough inspection and monitoring devices. But what about mites? There are several species of mites known to bite humans within homes and other structures, many times causing significant physical symptoms and psychological distress. Clients can easily fall prey to misinformation online when learning about these tiny pests, however, so be prepared to educate them and help them solve their problem.
In all cases, biting mites found indoors are blood-sucking nest parasites of other animals living nearby, especially rodents or birds. The most common species in California, the tropical rat mite (Ornithonyssus bacoti) (Figure 1), is often associated with the nests and runways of roof rats and other commensal rodents. Also common are northern fowl mites (Ornithonyssus sylviarum), known to inhabit nests of commensal birds, such as pigeons, starlings, sparrows, and swallows. Less common but perhaps increasing in prevalence is the chicken mite or red mite (Dermanyssus gallinae).
All three of these common species will take blood meals from humans, especially if their primary hosts have been controlled, removed, or have migrated away. For instance, successful rat control programs (Figure 2) may result in hundreds of starving rat mites wandering nearby areas in search of blood. If rats were nesting in wall voids, attics, subareas, or living spaces, then there is a good chance the resident rat mites will be attracted to the humans in the structure when the rats are no longer around.
A similar phenomenon occurs when migratory birds leave nests in autumn if nests are situated in window alcoves, eaves, or other areas abutting a living space. With the rise in popularity of backyard chickens (Figure 3), primary hosts for both northern fowl mites and chicken mites, problems can occur when coops are adjacent to walls of the home or near windows or exterior doors. Mite populations associated with chickens reportedly peak and are most likely to affect humans in spring and summer, while rat mite issues tend to be most common in late summer and autumn. Problems can occur any time of year, of course, when the primary host has been removed.
Such monitoring tools can also give clues as to where the nest of the primary host is or was. In multi-unit housing situations, the source of these wandering mites may be in adjacent units, the hallway, stairwells, or utility areas. In single-family homes, the source may even be outside, such as a bird or rat nest in the landscape. Tropical rat mites are known to travel along pipes, utility wires, tree branches, fencing, and exteriors of structures to find new hosts.
The best way to confirm a biting mite issue is to capture a specimen. Though very small (about 1/16 inch (1.5 mm) or less in diameter), all three common species can be observed without magnification. Mites may be yellowish or whitish before feeding but will be dark red when engorged with blood. Ask the client about areas of the home where bites are most common. When active, mites may be seen crawling on walls, floors, or furniture. For positive identification, mites should be captured alive and preserved in rubbing (isopropyl) alcohol or ethanol (at least 70%). This can be accomplished with the help of a fine wet paintbrush and a ready vial of alcohol.
Identification to species requires clearing and slide mounting of the specimen and close examination by an acarologist (mite specialist). Some county vector control programs can identify mite specimens and some entomologists can prepare and photograph specimens, but there are few acarologists in California who may be able to provide identification services. Be prepared for such positive identification to take a week or longer.
Once mites have been confirmed, management should focus on removal of the primary hosts and their nests. Humans are incidental hosts and are not known to support reproducing populations of Ornithonyssus and Dermanyssus. That means that, in theory, once the rat or bird hosts have been eliminated from the structure, the mites will slowly die. Depending on temperature, season, and mite life stage, however, this could take weeks. Some experts report that tropical rat mites can survive without primary hosts for six weeks or longer, feeding incidentally on humans and their pets that entire time, often causing red itchy welts.
Biting mites may be more common than we realize, escaping detection due to their small size and their cryptic habits. Much research still needs to be done to better understand the biology and ecology of these pests as well as to develop effective monitoring and management tools. Sometimes, mites cannot be detected, and rodents and birds are seemingly not present, but your client's dermal symptoms (“bites”) persist. In such cases, it may be prudent to consider other causes of dermatitis, such as environmental irritants, reactions to medications or drugs, stress, some medical conditions, or even delusional infestation (aka delusory parasitosis), a psychiatric condition. A newly revised UC IPM publication, Pest Notes: Itching & Infestation: What's Attacking Me?, may help identify the problem. To learn more about management of commensal rodents and birds, review these UC IPM titles: Rats, House Mouse, and Cliff Swallows.
Like outdoor plants, houseplants can also experience pest problems. Did you know that too much or too little watering is the most common way that houseplants die? They can also suffer from too much or too little light, incorrect fertilization, and a variety of pests and diseases. Knowing the proper growing conditions for your houseplant and checking regularly for signs of pests or disease are the best ways to keep your houseplants healthy.
If your houseplant is looking unhealthy, our newest publication Pest Notes: Houseplant Problems can help you find out what may be wrong. Authored by UCCE Environmental Horticulturalists Dennis Pittenger and Donald Hodel, this new resource can help you narrow down the cause of a plant problem and decide what actions to take. If you find . You'll find sections on many common pests like aphids, mites, and mealybugs as well as leaf spots, wilting, or other disease symptoms. Once you've figured out the problem, you will also be able to find out how to manage to manage it use less toxic methods.
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Roses can grow well with little to no pesticide use and numerous natural enemies, or “good bugs” exist to help hunt or parasitize common rose insect pests.
Find solutions for common invertebrate pests on roses in UC IPM's recently updated Pest Notes: Roses: Insects and Mites. This revised publication by rose experts Mary Louise Flint, Extension Entomologist Emerita, and John Karlik, UC Cooperative Extension Advisor, Kern County will help you identify insect pests, select rose varieties, and consider management options. The Pest Notes has been expanded to include color photographs as well as updates on the rose midge and other new pests.
- Author: Ben Faber
The weather continues to offer new opportunities. Recently there have been reports of Avocado Brown Mite infesting trees. This is a pest (Oligonychus punicae) of dust and disturbance. Normally found along picking roads and up against areas that are dusty. Not a problem. But growers in San Diego and Ventura have both commented on their unusual presents and some cause for concern. It's early appearance in the season when the spider mite destroyer hasn't yet built its population is the most likely reason. But……………
Avocado brown mite is a sporadic pest, mostly in coastal growing areas. Bronzing of leaves, mite cast skins, and partial defoliation of some trees by avocado brown mite is most noticeable from about July to September. Severe infestations tend to occur in border row trees along dirt roads, where road dust is detrimental to mite predators. Ash deposited on leaves from wildfires reportedly also causes brown mite outbreaks.
Avocado brown mite feeds almost entirely on upper leaf surfaces. Bronzing damage is not severe when mite numbers are low to moderate (about 10 to 20 adult females per leaf). If the spider mite destroyer lady beetle (Stethorus picipes) is present and reproducing well at this time, brown mite does not normally become a problem. Damage occurs if avocado brown mite averages about 80 to 100 adult females per leaf (about 200-300 motile stages, adults and nymphs combined). At these higher densities mites also colonize the lower leaf surface and sometimes fruit, and partial defoliation can occur. These higher numbers cause leaf bronzing along the midrib, then along smaller veins, and finally the entire leaf turns brown.
Brown mite is related to Persea Mite (http://ipm.ucanr.edu/PMG/r8400211.html) but rarely causes the damage that its relative can cause. The Persea Mite feeds mainly on the bottom of the leaf and forms web-covered colonies which help to distinguish it from O. punicae (first described in Carthage?).
At this stage, unless there is severe defoliation, it might be best to leave it alone until biocontrol kicks in or we get a hot spell to burn it out. Keep the trees adequately watered and flushing new leaves to outgrow it. Call a PCA if you are worried.
More about the weather:
And whatever happened to the Bagrada Bug?
Photo: Brown mite feeding on top of leaf surface