Development of Glyptotendipes tokunagai (Diptera: Chironomidae) Under Different Temperature Conditions

Abstract

The nonbiting midge, Glyptotendipes tokunagai Sasa (Diptera: Chironomidae), is an organism that can be used as a water quality indicator. Development of this insect under different temperatures was evaluated. The highest egg hatching rate was 99.12 +/- 1.47% at 30 degrees C, and the lowest was 84.50 +/- 11.09% at 10 degrees C. No eggs hatched at temperatures of 8 and 42 degrees C. Developmental rate (1/h) increased gradually as temperature increased from 10 to 35 degrees C with a peak rate (0.045 +/- 0.0079) at 35 degrees C. The estimated lower thermal threshold for egg hatching was 9.3 degrees C. Adult emergence rate was highest (80.6%) at 30 degrees C and lowest (22.2%) at 15 degrees C. The developmental times (egg to adult) for both males and females decreased from 2,102.6 to 457.2 h and from 2,337.1 to 619.8 h as temperatures increased from 10 to 30 degrees C. The estimated lower thermal thresholds for males and females were 11.4 and 10.4 degrees C, respectively. The body sizes of all G. tokunagai decreased as temperature increased from 15 to 35 degrees C. From the results of this study, the approximate rearing temperature for G. tokunagai is suggested to be 25-30 degrees C for egg hatching, larval development, and emergence. Our results demonstrate that G. tokunagai is a potential test insect species that can be reared in the laboratory by providing optimal temperature conditions.