Poultry Lice

Poultry lice are tiny, wingless, 6-legged, flat-bodied, insects with

Figure 1. Lice eggs at the base of the feather shaft

broad, round heads. They lay their eggs on the host bird’s feathers, especially near the base of the feather shaft (Figure 1). A female louse will lay 50 to 300 eggs at a time, which she cements to the feather shaft. There are several species of lice that affect poultry, and multiple species can affect a bird at any given time. Some species can be localized on specific locations like the quill lice; or others can be found over most of the body surface like the chicken body lice. The lice found on poultry do not suck blood as the lice found in other species of animals; rather they feed on dry skin scales, feathers, and scabs. However, they will ingest blood extruding from irritated skin. The entire life cycle of the lice occurs on the host bird, primarily in the feathers. Poultry lice are host specific and cannot be transferred to humans.

Fall and winter are the most common times to observe lice infestations. Inspect the ventral region of the bird for live lice crawling on the bird and for nits (lice eggs) as most infestations start in this area of the bird’s body. Eggs are white and commonly appear in bunches on the lower feather shaft. Feathers of infested birds may have a moth-eaten appearance. Due to the feather damage, the bird may have a dull or roughened appearance.

Poultry Mites

All classes of poultry are susceptible to mites, some of which are blood-suckers, while others burrow into the skin or live on or in the feathers. Others occur in the air passages and in the lungs, liver and other internal organs. Poultry mites cause retarded growth, reduced egg production, lowered vitality, damaged plumage and even death. Much of the injury, consisting of constant irritation and loss of blood, is not apparent without careful examination.

Of primary concern to the poultry man is the Northern Fowl Mite (Ornithonyssus sylviarum) which is a frequent and serious pest of chickens. Heavy infestations result in low condition of the birds and lower egg production, as well as a scabby skin condition. The mite remains on the bird and does more damage than any other species of mite. The mite does not leave the host bird, as do may species of mites, and can be observed on birds in large numbers during daylight hours. It prefers the feathers below the vent and around the tail, but can be found on all parts of the body. The mite is extremely small and a microscope or magnifying glass may be needed to see it.

The female northern fowl mite lays eggs on feathers where the young mites complete their development without leaving the host. Since they remain on the fowl most of the time, treatment of the birds is necessary to destroy the mites.

The Common Chicken Mite (Dermanyssus gallinae) is the most common mite found on all types of poultry. It is a blood-sucker, and when present in large numbers, loss of blood and irritation may be sufficient to cause anemia. Egg production is seriously reduced.

This mite feeds at night, and usually remains hidden in cracks and crevices during the day. It attacks birds at night while they are on the roost. In heavy infestations, some mites may remain on the birds during the day. About a day after feeding, the female lays eggs in cracks and crevices of the house. The eggs hatch and the mites develop into adults within about a week. During cold weather, the cycle is slower. A poultry house remains infested four to five months after birds are removed.

Since the mite feeds on wild birds, these birds may be responsible for spreading infestations. However, it is more likely that spread of the mite is promoted by using contaminated coops. Human carriers are also important. Since these mites do not stay on the birds during the day, apply treatments to houses and equipment as well as the birds.

The Scaly-Leg Mite (Knemidocoptes mutans) lives under the scales on feet and legs of poultry. It also may attach to the comb and wattles. It causes a thickening of scales on the feet and legs that gives the impression that the scales are protruding directly outward, rather that laying flat on the limb. It spends its entire life cycle on the birds and spreads mainly by direct contact.

The Depluming Mite (Knemidocoptes laevis, variety gallinae) causes severe irritation by burrowing into the skin near the bases of feathers and frequently causes feathers to be pulled out or broken. The mite is barely visible to the naked eye and can be found in follicles at the base of the feathers. The mites crawl around the birds at times, spreading from bird to bird.

Lesser Mealworm

Darkling Beetle Adult	Darkling Beetle Larva

The adult darkling beetle has become one of the most widespread, consistent insect pest problems, next to the house fly, in caged chicken layer and broiler facilities. Beetle populations in infested poultry houses can reach enormous populations as high as 1,000 beetles per square meter. When this infested manure or litter is removed from houses and spread on fields, beetles quickly disperse and sometimes become a nuisance by migrating into neighboring fields and residences. Beetles either fly or crawl at night toward lights. This behavior often results in poor community relations and legal actions.

In addition, in poultry operations, this insect feeds on poultry feed, damages insulation, harbors and vectors several disease organisms, and annoys poultry workers.

Identification

The lesser mealworm adult beetle is about 1/4-inch long, reddish-brown to black colored, with distinct longitudinal grooves on the wing covers, body oval shaped and slightly flattened.

Eggs are about 1/16-inch long and creamy white to tan colored. They are slender with slightly rounded ends.

Larvae are about 1/3-inch long, tan to light brown colored with slender, segmented bodies and three pairs of legs (resemble small wireworms).

Pupae are about 1/4-inch long, creamy white to tan colored with legs tucked alongside to the body (segmented appearance).

Life Cycle and Habits

The entire life cycle requires about 40 to 80 days at 70^oF to 95^oF, usually occurring in the poultry house manure or litter.

Temperature is more important than moisture in rates of development and survival. Moisture levels of about 12 percent are optimum.

After mating, within six to ten days, a female beetle has the potential to lay over 2,000 eggs in the manure and litter, especially under feed and water lines. Adults can live over three to twelve months, continuing to produce eggs most of their life at one to five day intervals. Eggs are laid individually or in small clusters. Eggs hatch in four to seven days. There is little egg hatching below 60^oF or above 100^oF. The larval stage takes 35 to 65 days or longer, with six to eleven molts occurring. Larva sometimes migrate out of the breeding material into floors, insulation and the perimeter of the house to pupate. The pupa stage usually lasts four to fourteen days.

Both adults and larva are very active and quickly burrow into the litter when disturbed. They clump (aggregate) in groups throughout the house, feed on most anything (decaying litter, poultry feed, bird carcass and even each other - cannibalistic).

Economic Importance

Direct effects of darkling beetle activity are almost solely the result of these insects feeding on either poultry feed or building insulation and structures. Larvae bore and tunnel into insulation (polystyrene, polyurethane, fiberglass, etc.) to pupate, resulting in heat loss during cold weather and additional electricity is needed for fans in hot weather.

Indirect effects regard health concerns. Beetles harbor disease organisms such as fowl pox, E.coli, Salmonella spp., Newcastle disease and avian leukosis in addition as the intermediate host of poultry tapeworms and cecal worms. Although the role of darkling beetles in actual transmission has not yet been definitely established, it is suspected that this pest harbors and vectors a number of pathogens that affect bird health and performance.

Beetle larvae consumed by floor birds (turkey, poults, etc.) display growth depression and increased mortality. There is reinfection of the flock when chickens eat the beetles or when beetles defecate near chicken feed.

Lesser Mealworm Facts

• Originated in eastern Africa where associated with the nests and guano of various bird and bat species.
• Occurs in accumulations of immense, protected, moist amounts of manure and litter from broilers, breeders, pullets, and caged layer chickens, turkeys, and other avian commercial operations such as quail and Cornish hens.
• Highly active both through running and, at night, through flight. (Prefer a dark daytime hiding place).
• Congregate in areas where there are warm, moist conditions.
• Sensitive to freezing and high temperatures with dehydration occurring in environments not containing enough moisture.
• Tend to avoid excessively wet areas, especially where anaerobic microbial activity is high (fermentation of wet feed or soupy manure).
• All life stages tend to clump together in close contact in areas where food, water, and environmental conditions are best for survival.
• In native Africa, beetles were nest scavengers, consuming bits of feed, nest litter, portions of manure, dead plant and animal material.
• In USA, poultry operations, beetles eat feed, litter, manure solids, and even portions of dead and dying birds.
• Will move out of the chicken area of these buildings and into insulation.
• Have no natural enemies and carry a large variety of avian viruses, bacteria, fungi, and parasites without observable negative effects on the beetles. They are exceptionally sturdy and durable.
• Cannibalistic at all stages, and can actually lower their own populations through predation when conditions are too dry or food is in short supply.
• Conditions favoring beetle cannibalism often stimulates their migration, resulting in them becoming pests in insulation or in other buildings near poultry operations.
• They cannot survive freezing or temperatures above 90^oF for any length of time unless they have access to much free moisture.
• They can consume large quantities of feed in a short period of time.
• Through their active consumption of edible organic matter and their burrowing, these beetles do help recycle poultry wastes and remove material that otherwise would be excellent for fly development.
• Low to moderate beetle populations can have a very positive effect on controlling fly populations in large, caged-layer houses where manure and litter are allowed to build-up.
• Both adults and larvae are nocturnal and remain active 24 hours a day, favoring dark interiors of buildings during the day.
• Beetles are actively attracted to artificial light sources at night. Security lights around poultry facilities may help control nocturnal migration to a slight extent by keeping them in an area and preventing them from detecting distant light sources.

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