Studies on Biology of Ascid mite, Blattisocius keegani (Acari: Gamasida: Ascidae) When Fed on Two Astigmatid Mites at Different Laboratory Conditions

Document Type : Original Article

Authors

Plant Protection Research Institute, A.R.C. Dokki, Giza, Egypt

Abstract

Blattisocius keegani (Mesostigmata: Ascidae) is a predatory mite that has
traditionally been studied as a biological control agent in stored products.
The developmental time (incubation period, life cycle and longevity), fecundity
and food consumption of the predatory mite B. keegani (Fox) (Ascidae)
were investigated at 25 and 35°C and 75% R.H when fed on the two astigmatid
mites, Rhizoglyphus echinopus and Lepidoglyphus destructor.The
incubation period of B. keegani was not affected when fed on the preys
at tested temperature. The duration of life cycle for both sexes of B.
keegani
was obviously affected by the type of food employed at different
temperature. The longest period lasted 12.6 days when predatory females fed on R.
echinopus
larvae
at 25ºC, but the shortest period recorded on L. destructor larvae at
35ºC for predator males was 10.22 days.The female longevity of  B. keegani was also affected
when the predator fed on the two tested preys at two temperature,  as the maximum longevity was 26.7 days for female at 25ºC on R. echinopus
larvae, and the minimum corresponding period was 16.54 days for male on L. destructor at 25ºC. The
adult female of B. keegani laid the highest number of eggs (41.6)
when fed on R. echinopus at 35ºC, while the lowest number of eggs was observed
when fed on L. destructor larvae (35.4 eggs) at 25ºC. The food consumption of the different predator stages
increased with its growth. The larval stage of both female and male had the
least prey consumption than the other stages (protonymph and deutonymph) and
the predator male individuals consumed lower number of introduced prey than the
female individuals. The total amount of consumed prey individuals during
the whole life span was 88.9 larvae of R. echinopus at 25ºC, changed to
record 98.0 preys at 35ºC, while, the number of devoured L. destructor
was 81.6 and 87.2 prey at 25 and 35ºC, respectively. The B. keegani
male devoured 80.0 & 85.0 larvae of R. echinopus and 74.8 & 80.7
larvae of L. destructor at 25 and 35ºC., respectively.

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