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Name This Pest! Worked out what this is from the last issue? Find out on the next page! t Stephen L. Doggett

Hint: after reading the Name This Pest in the last issue, you should be able to guess what this is, but do you know how to distinguish this from the tropical rat ? Bar = 1mm.

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Tropical Fowl Mite bacoti Text by Merilyn J. Geary

he Tropical Fowl mite, Ornithonyssus as this is a different insect pest altogether. In bacoti from the family , domestic dwellings or office buildings a newly Tis principally an ectoparasite of abandoned bird nest can be the source of a introduced, native and domesticated birds. It huge population of blood seeking . In is known to inflict bites to humans and a few most instances where treatment and control other mammalian hosts. However, it is one measures are required the mite infestation is of bird mite that is often mistakenly quickly eliminated. However there are many cited by the pest control industry and some householders where the perceived ongoing medical practitioners as the possible source bird mite infestation has not been controlled of unexplained skin irritation in the human effectively and the biting continues. Many population even in the absence of avian contact individuals are driven to using drastic measures and evidence to support past or present bird in unsuccessful attempts to eradicate the bird activity in a patient’s dwelling. mite problem from their property. The home owner’s claims can be further enhanced by The most common method O. bursa can make spurious web sites that provide inaccurate, contact with a human host is through nesting unsupported accounts and claims of bird mite birds in the roof cavity or eaves of domestic activity in relation to the human host. It is not dwellings and office buildings. Bites from these unusual for large quantities of pesticide to mites may also be inflicted whilst handling be applied by the home owner, household or working with infested birds, such as the contents, clothing, personal belongings poultry industry, wildlife encounters or simply destroyed and medical advice sort. Some collecting eggs from backyard chickens. individuals sell their cars and move to into alternative accommodation while they wait WHY ARE BIRD MITES A PROBLEM? for the multiple treatments by pest control companies to “fix” their mite problem. All too While there are other species of bird mite often the term “bird mites” is frequently used to ( & Dermanyssus describe the source of a home owner’s on going gallinae) that bite humans, in Australia O. skin irritation, crawling or biting sensations. The bursa appears to have the greatest health health problems associated with these “bird impact on some individuals. Occasionally these mite” infestations are complex, stressful and can infestations are incorrectly referred to “bird lice” be very expensive. which can be confusing to the home owner

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MEDICAL IMPORTANCE & CLINICAL been associated with the transmission of any PRESENTATION infectious disease, the mite does not burrow or live, lay eggs or complete its life cycle under has the capability of human skin. There is no specific treatment probing then piercing a human host’s skin with available for the irritation but a doctor or its mouthparts and injecting a minute amount pharmacist can recommend products to of saliva. The presence of this foreign substance alleviate itchiness or allergic reactions. stimulates the host’s immune response which can produce prolonged pruritic (itchy) lesions on any part of the human body causing ADULT & IMMATURE STAGE BODY considerable short term discomfort. Female STRUCTURE occupants of a household tend to be more The unfed O. bursa mite is a uniform pale sensitive to the bites of O. bursa. Multiple bites cream in colour and averages about 1mm in can lead to severe irritation and if the lesions length. The adult mite is unremarkable with are scratched secondary bacterial infections an oval unsegmented body shape that is may occur. The bites are difficult to discern from barely visible to the eye, although post blood other bites that is why it is essential feeding the mite is quiet obvious, when it can to correctly identify the presence of bird mites. appear bright red. Taxonomically the mite is In poultry production, mass feeding of this mite determined by the shape of the sclerotized has been known to result in exsanguination of dorsal and sternal plates, in addition to the newly hatched chickens and egg production length, number and arrangement of hairs or can be affected where control measures have setae located on these plates and the rest of not been implemented. This mite has not the body. Ornithonyssus bursa is similar to other

WWW.FAOPMA.COM || 99 P bird mites (Ornithonyssus sylvarium, Northern TREATMENT & CONTROL fowl mite) and especially the Tropical Rat mite E . This bird mite is more active throughout spring and early summer when nesting birds gain S access to domestic dwellings and commercial T DISTRIBUTION premises to raise their young. Although in poultry industries, backyard egg production Ornithonyssus bursa is widely distributed and and pet caged birds where the mite infestations reported throughout the warmer tropical remain uncontrolled it can be a constant year regions of the world. round problem.

BIOLOGY It is essential to undertake a thorough inspection of any building structure to locate This parasite of birds has 5 stages in its life cycle all areas where birds have gained access but it requires blood to complete this. After a to nest. The source of the biting complaint blood meal the adult female mite can deposit should be accurately identified and all traces of her eggs either throughout the nesting material nesting material and any dead birds removed. or directly on its bird host. Under relatively The residual nesting material, and in some even levels of humidity and the warmth from circumstances there is a significant quantity an occupied bird nest the mites thrive. The that has been accumulated in a roof space, mite’s eggs may hatch after just 1 day, although pose a potential fire hazard and could be delayed hatching will occur if the prevailing utilised by other pests such as rodents and conditions are not suitable or egg development stored product arthropods. The infested areas is incomplete. The newly hatched larval mite has must be thoroughly cleaned and treated with six legs, is largely colourless and does not blood an appropriately registered pesticide prior to feed at this stage. Within a day the larval mites repair or bird proofing measures utilised. Failure moult to an eight legged protonymph that to bird proof the area will see the same birds requires a blood meal to develop to the non- return to raise their young next breeding season feeding deutonymph stage. Moulting quickly and any remaining nesting material could be occurs with 24 hours to produce the blood utilised by other nesting birds. Roosting sites seeking adult, the life cycle can be completed on window ledges should cleared and rendered in 6-8 days under optimum conditions but can unsuitable for future use by resting birds. be extended if environmental parameters are unfavourable. In the absence of a bird host Domestic chickens, coops and roosts and caged these hardy little mites can survive in excess of a pet birds should be treated for parasites on a week or even longer but this will be dependent regular basis as part of the general maintenance on the prevailing temperature and humidity program. Any contact with wild birds should levels. be avoided as they are constant source of bird mites and other intestinal parasites. Any Without a bird host the mites will quickly new addition of chickens or birds should be disperse from the nest as they are extremely quarantined for a short period ensure they do mobile in seeking a suitable blood source. not carry any ectoparasites and are in good Mites can gain access to a human host via wall health.  cavities, windows and ventilation ducts, and occupants of rooms closest to the nest site Merilyn J. Geary runs the pathology service at the in the roof cavity may experience increased Department of Medical Entomology at Westmead bite rates. This mite is host specific and cannot Hospital, Sydney, Australia. complete its life cycle without a bird host.

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Name This Pest! Find out what this is in the next edition Stephen L. Doggett Stephen L. Doggett Hint: this often erroneously name insect is not a lice and often blamed for a variety of health related problems but is quite harmless.

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