Development ofDermatophagoides pteronyssinus(Acari: Pyroglyphidae) at Constant and Simultaneously Fluctuating Temperature and Humidity Conditions

Abstract

House dust mites are found in almost all dwellings in New Zealand and are a major risk factor in the development of asthma and perennial allergic rhinitis. We studied the longevity, life stage length, and fecundity of a New Zealand strain of European house dust mite, Dermatophagoides pteronyssinus (Trouessart), at constant (23 degrees C, 75% RH) and the fluctuating conditions typically found in dry (18-25 degrees C, 60-38% RH) and damp (18-23 degrees C, 70-55% RH) New Zealand dust mite microhabitats in carpets. All the adult mites placed in the "dry" conditions died within 18 d. Mites in the "da conditions had developmental times, oviposition, and death rates that were not significantly different from constant conditions. These mites are tolerant of fluctuating temperatures, but they are more susceptible to environments that strongly fluctuate in humidity.

Effects of high and low temperatures on development time and mortality of house dust mite eggs

“…If RH is kept at 75%, at 16°C ambient temperature life cycle duration increases to about 122 days, whereas at 35°C, life cycle decreases to ca.15 days (Arlian et al 1990). When Dp mites were reared under constant temperatures between 18 and 25°C but at fluctuating RH between 38 and 60% (dry conditions), between 55 and 70% (damp conditions) or at 75% (optimal conditions), every mite in the dry conditions died within 18 days whereas survival and development of the 'damp' mites were not significantly different from those reared under optimal conditions (Pike et al 2005). Thus, the ability to adapt to changes in RH is an indication of the mite's phenotypic plasticity.…”

Activated Charcoal Suppresses Breeding of the House Dust Mite, Dermatophagoides Pteronyssinus, in Culture

“…Firstly, activated charcoal is able to absorb large quantities of moisture and thus could reduce relative humidity constantly to below 50%. Arlian estimated that 10 days at 28℃ and 50% relative humidity is lethal for D. pteronyssinus (14), although a recent study suggested that in other countries, such as New Zealand, house dust mites tended to live twice as long under these conditions (15). However, in our study this mechanism is unlikely as the cultures were kept at a constant relative humidity of 75% during the culture period of four weeks.…”

Extrato enriquecido em der f 1 derivado de Dermatophagoides farinae aumenta a reatividade para anticorpos IgG4 específicos

“…Eles apresentam entre 0,1 e 0,6 mm de comprimento, ciclo de vida com metamorfose completa (holometábolo) passando pelos estágios de ovo, larva, protoninfa, tritoninfa e adulto. O período de desenvolvimento pode sofrer variações de acordo com a espécie e também devido às condições abióticas, como temperatura e umidade (ARLIAN; RAPP; AHMED, 1990;DE BOER, 1998;PIKE;CUNNINGHAM;LESTER, 2005). Trata-se de um grupo bastante diverso, distribuindo-se diferentemente em cada região do mundo.…”