INFLUENCE OF TEMPERATURE AND HUMIDITY ON MORTALITY AND RATE OF DEVELOPMENT OF IMMATURE STAGES OF THE MITE TYROPHAGUS PUTRESCENTIAE (SCHRANK) (ACARINA: ACARIDAE) REARED ON MOLD CULTURES

Tyrophagus putrescentiae (Schrank), a mite that infests stored food products, was reared individually on mold cultures at all combinations of five temperatures and four humidities. Mortality during immature stages was lowest at 72.5° F and 80% to 90% R.H. Development was usually accelerated by an increase in either of these two factors. Temperature and humidity had a direct influence on mortality and rate of development, but humidity also had an indirect effect by affecting the mold on which the mite feeds. Adults obtained at 70% R.H. were usually relatively small in size. Sex ratio of the adults was approximately one to one; the males developed faster than the females.

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INFLUENCE OF TEMPERATURE AND HUMIDITY ON LONGEVITY, FECUNDITY, AND RATE OF INCREASE OF THE MITE TYROPHAGUS PUTRESCENTIAE (SCHRANK) (ACARINA: ACARIDAE) REARED ON MOLD CULTURES

Canadian Journal of Zoology ◽

10.1139/z61-081 ◽

1961 ◽

Vol 39 (6) ◽

pp. 869-876 ◽

Cited By ~ 19

Author(s):

I. Rivard

Keyword(s):

Egg Production ◽

Food Products ◽

Egg Laying ◽

Oviposition Period ◽

Tyrophagus Putrescentiae ◽

Influence Of Temperature ◽

Adult Females ◽

Rate Of Increase ◽

Temperature And Humidity

Adult females of Tyrophagus putrescentiae (Schrank), a mite that infests stored food products, were reared individually on mold cultures at all combinations of five temperatures and four humidities. A definite diminution in life usually occurred with increase in either temperature or humidity, and the oviposition period was the most affected. Total egg-production and rate of laying were highest at 72.5° F and 90% R.H., and both generally decreased with an increase in temperature or decrease in humidity from these values. Peak of egg-laying, however, was reached sooner at higher temperatures but egg-production was maintained at relatively high levels for shorter periods. Rate of increase was greatest and approximately the same at 90% R.H. within the range 72.5° to 81.5° F.

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Influence of Humidity on Mortality and Rate of Development of Immature Stages of the Grain-Infesting Mite Tyrophagus castellanii (Hirst) (Acarina: Acaridae) Reared on Mould Cultures

The Canadian Entomologist ◽

10.4039/ent90721-12 ◽

1958 ◽

Vol 90 (12) ◽

pp. 721-724 ◽

Cited By ~ 5

Author(s):

I. Rivard

Keyword(s):

Direct Effect ◽

Constant Temperature ◽

Immature Stages ◽

Food Material ◽

Predator Prey ◽

Rate Of Development ◽

Fresh Food ◽

Temperature And Humidity

It was observed that populations of Tyrophagus castellanii (Hirst) reared on cereal flakes and yeast for studies of predator-prey interactions were feeding on moulds rather than on the food material, and that an increase in humidity increased their rates of development. To discover whether this was caused by the direct effect of humidity on the mites or by a greater supply of fresh food brought about by an increase in humidity, rearings were made with a technique developed by Rivard (1958). The mites were reared exclusively on mould cultures under controlled temperature and humidity conditions. It was also possible with this technique to regdate modd growth to some extent, so that a supply of fresh food was always available to the mites. This is a report on the influence of various humidities on mortality and rate of development of the immature stages of T. castellanii at a constant temperature.

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