September 2010. A mite infestation in a newly constructed house at Davuilevu, Fiji. The initial infestation started in the kitchen from one of the drawers which was pine outside and ply on the inside. The mites have now spread over the house, and can be seen as white 0.2 mm specks. On closer inspection, the legs and mouthparts are pink.
They are found crawling on the inside concrete walls, on and inside the refrigerator, surface of varnished cabinets, drawers, chairs and even in the remote control of the TV. The occupants have vacated the house and are seeking a method to eradicate the mites. The house has been sprayed twice by a pest control company, but this has not solved the problem.
The mite was thought to be an adult female belong to the Acaridae, or a family close to it. There are many possible species that can only be identified with slide-mounted specimens, but they are best known as pests of stored products. Each species has food preferences (e.g., grains, cheese, bulbs, dried meats).
The source of the infestation could be internal or external to the dwelling: consider any foodstuffs brought into the home, or the type of mulch used around the house. Whatever has happened, these mites have a reached a huge population on food source, which has now likely been depleted, and they are roaming to find other sources. Since the dwelling is new, it is likely an external source – such as garden mulch that has dried out.
There’s not much to do, but wait. Keep the home well ventilated, if possible, as most species do poorly in very dry conditions. Look for the source and try to remove or modify it.
There was also a suggestion that they had come from mynah birds, and, in fact, there are some in the vicinity of the house. The roof cavity should be inspected, and any nests removed and, perhaps, sprayed with malathion or kerosene.
By coincidence, an entomological technician with DEEDI, Cairns, Australia, reported a similar infestation, in a house on the Atherton Tablelands, north Queensland. Mites appeared to have been breeding in an open container in which there was a culture of mealworms (Tenebrio molitor) and about two cups of rolled oats and breakfast muesli. The bottom 4 cm of the container held a mass of pinkish mites of various stages. The mites were exiting the container and climbing over the furniture, walls and floors.
Methylated spirits (approx. 75% strength) was sprayed on the mites, but without effect. The floors and windowsills were vacuumed, and naphthalene flakes sprinkled in the corners, crevices and inside cupboards. Afterwards, the house was fumigated with Mortein.