The Centers for Disease Control and Prevention issued a Health Advisory recently in response to increased reports of illness associated with products containing the pesticide ivermectin. Ivermectin is an active ingredient that is typically used to treat internal animal parasites such as roundworms, threadworms, and other parasites, and external parasites such as head lice. It is an anti-parasitic pesticide not an anti-viral. The FDA has not approved ivermectin for use in treating or preventing COVID-19.

The CDC health advisory states “Veterinary formulations intended for use in large animals such as horses, sheep, and cattle (e.g., “sheep drench,” injection formulations, and “pour-on” products for cattle) can be highly concentrated and result in overdoses when used by humans. Animal products may also contain inactive ingredients that have not been evaluated for use in humans. People who take inappropriately high doses of ivermectin above FDA-recommended dosing may experience toxic effects.”

Incorrect use of any pesticide can lead to injury, negative health impacts, or severe illness. Be sure to always read and understand the label when using pesticides and only use them where specified on the label. As a reminder, disinfectants are pesticides too, and should be used properly to minimize health risks.

Part of the University of California Integrated Pest Management Program's mission is to provide pesticide information to residents of California to protect human health and the environment. We address public health issues as they relate to pests of homes, people, pets, structures, and plants. Part of our educational efforts in this area is on pesticide use and safety. We do not and cannot comment on medically advised prescriptions or treatment for human diseases and ailments such as influenza, measles, asthma, COVID-19, or any other contagious diseases. However, it is within our charge to share information about registered pesticides, their safe use, and consequences to human health.

Visit our website for more information on pesticides in homes and landscapes. If you suspect that you or someone you know is experiencing serious illness due to pesticide exposure, contact the Poison Control hotline at 800-222-1222.

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.

Lice

The most common pests found on backyard chickens include several species of lice (singularly called a louse), including the chicken body louse and fluff louse. Lice live full-time on chickens and feed primarily on feather material. Lice are generally chicken specific but may infest related poultry species (such as turkeys or pheasants). Adult and immature lice are pale yellow in color, and eggs are found in white clusters, usually at the base of feathers. Lice may be found on any or all parts of the chicken, depending on the louse species (Figure 1). Lice can irritate birds, causing increased preening and decreased egg production.

Mites

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.

Fleas

The sticktight flea (Echidnophaga gallinacea) can also be found on backyard chickens. This flea is not bird specific and is often introduced to flocks by rodents, cats, or other mammals. Adult fleas embed themselves in the skin of chickens while they feed on their blood (Figure 4). Females drop eggs without detaching, and immature fleas develop in the environment, feeding on detritus and adult fleafeces. It can take a month or longer for fleas to complete development to the adult stage, resulting in newly emerging adults even after treatment of birds.

Management

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.

References:
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/

[Original article published in the Spring 2021 issue of the Retail Newsletter.]

 

Human lice (singular “louse”) are parasitic insects found on people. Adult lice are small (about 1/8 inch (3 mm) long or less) wingless insects that move by crawling. There are three species of lice that exclusively feed on humans: the head louse, the body louse, and the crab or pubic louse.

The head louse (Pediculus humanus capitis) and the body louse (Pediculus humanus humanus) are members of the same species, but the crab (pubic) louse (Pthirus pubis) is from a different insect family. All are pests of public health importance. Treatment is usually prescribed by medical professionals and should be focused on the infested person and their belongings. Use the following descriptions to identify these pests and help your clients seek out proper care from medical professionals.

Crab louse

These lice have a short, round body (not elongated), with hairy tubercles (small, knobby projections of the body wall) on the abdomen. The front legs are shorter and slimmer than the middle and hind legs (Figure 1). Adults and eggs are usually found on pubic hairs but may sometimes be found on other areas of the body such as beards, mustaches, eyelashes, and underneath the arms.

Head louse vs. body louse

Unlike the crab louse, these lice have elongated bodies (Figure 1) and lack tubercles on their abdomen. Head and body lice look almost identical since they are members of the same species. Positive identification requires consideration of specific morphological and behavioral differences (see Table 1). Body lice are known to transmit serious human diseases such as epidemic typhus, trench fever, and louse-borne relapsing fever. Head lice are not known to be an effective vector of diseases even when a pathogen is found in the louse's body.

Human lice elimination involves removal of lice from human body as well as from clothing and living environments. A head lice infestation on a person should be managed by the client. Head lice can be removed with a lice comb or treated with special lice shampoo or lotions containing one or more active ingredients. Human lice have developed resistance to many over-the-counter products containing permethrin or other pyrethroids. Therefore, it is believed that the most effective head lice treatment products are the ones containing ivermectin or spinosad. Body lice can be killed by dry cleaning clothing and bed sheets. Also, vacuuming and treating carpets may improve body lice management especially when the infestation is heavy. Body lice infestations can also be managed by reducing crowding and improving body and clothing hygiene. Head lice infestations, however, are not associated with poor hygiene, at least in developed countries.

For more details about the head louse, including thorough management options and guidance, see the recently revised Pest Notes: Head Lice.

[Article originally published in the Fall 2020 issue of the Green Bulletin.]

 

Bright metallic colors, flitting from flower to flower. Wasps.  And they are going after other wasp species and bees.  It's hard being a bee.

These wasps are parasites, and like their namesake cuckoo birds, they lay their eggs in the nests of other species (wasps or bees in this case). Since the cuckoo wasps depend on trickery and camouflage to fool their hosts, you might expect them to be drab. Scientists have not figured out whether the bright colors serve any function, and it wasn't known until 2009 that the color is actually produced by light refracting through open spaces between six layers of cuticle in the wasps' exoskeletons.

Cuckoo wasps favor warm Mediterranean climates, and California is a center of cuckoo wasp biodiversity in North America – 166 species in CA and 230 in the US. Maybe because there are so many native bee species in California is the reason there are so many cuckoo wasp species. They are most active in dry, open areas between May and August, with adults foraging on flower nectar as they follow favored routes multiple times a day searching for solitary wasps and bees to parasitize.

Cuckoo wasps are classified in the family Chrysididae, in the order Hymenoptera, and they are sometimes called Gold Wasps, Emerald Wasps or Jewel Wasps. The family name comes from the Greek, chryso, meaning gold. Besides green, they come in red, blue and purple and the thick cuticle of their exoskeleton (they are described as “heavily armored”) is often “pitted.” The common name refers to their habit of depositing their eggs in other insects' nests; a strategy practiced by birds like the Old World Cuckoos and the New World Cowbirds. Some sweat bees look similar, but cuckoo wasps tend to be “chunkier.”

Cuckoo wasps, like the majority of bees and wasps, are solitary. In highly social species like honeybees and paper wasps, there is a caste system. Since the queen is the only female that lays eggs, she is the only one outfitted with an ovipositor. And, since part of their job is defense, the workers' vestigial ovipositors have been modified into stingers. Solitary wasps need ovipositors, and many (but not all) sources say that cuckoo wasps have lost the ability to sting.

Read and see more about cuckoo wasps: The Cuckoo Wasp: A gorgeous parasite by David Lukas

And Lynn Kimsey's blog: https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=26461