Effect of temperature on the life cycle and predatory capacity of ladybird beetle Micraspis discolor Fabricius (Coleoptera: Coccinellidae)

Abstract

ABSTRACT:The effects of temperature on the development and the predatory capacity of Micraspis discolor larvae were studied in laboratory. Two temperature levels 23.50°C and 30.71 o C on average, were used to assess the life cycle and developmental stages of the ladybird beetle M. discolor. The life cycle of M. discolor was 27.38 days at 23.50°C and reduced to 19.77 days at 30.71°C, the total larval period was 13.42 and 9.9 days, respectively. The pre-oviposition period of the ladybird beetle M. discolor was 4.95 days at 23.50°C and 5.23 days at 30.71°C. The female beetles laid 282 eggs and the hatching percentage of egg was 81.03 at 30.71°C and 179 eggs and the hatching percentage of egg was 88.73 at 23.50°C. At temperature 30.71°C and 23.50°C, the pupal periods were 4.91 and 2.92 days, respectively. The longevity of adult ladybird beetles was slightly prolonged when they were reared at 30.71°C compared with that when they were reared at 23.50°C. Feeding on the second insturs of B. brassicae the predatory capacity of M. discolor larvae consumed an average 206.28 prey per day at 30.71°C and 161.84 prey per day at 23.50°C.

Effect of temperature on predation by Harmonia axyridis (Pall.) (Coleoptera: Coccinellidae) on the walnut aphids Chromaphis juglandicola Kalt. and Panaphis juglandis (Goeze)

“…This agrees with the finding of Schwarz and Frank (2019) that H. axyridis, as well as three other lady beetle species, consumed more aphid biomass under increasing temperatures. Hong et al (2013) also found that the predation capacity of Micraspis discolor Fabricius (Coleoptera: Coccinellidae) feeding on Brevicoryne brassicae L. (Hemiptera: Aphididae) was higher at 30.7°C than at 23.5°C. The handling time by H. axyridis of walnut aphids was shortened as the temperature increased, which is in accordance with the finding of Jalali et al (2010) who reported that the handling time of Adalia bipunctata L. (Coleoptera: Coccinellidae) to Myzus persicae Sulzer (Hemiptera: Aphididae) significantly decreased as the temperature increased from 19 to 27°C.…”

Impact of Heat Stress on the Predatory Ladybugs Hippodamia variegata and Propylaea quatuordecimpunctata

“…Another key (temperature-dependent) variable is ladybugs’ contribution to biological control [ 14 ]. Laboratory assays have demonstrated how temperature modulates predation rates of various ladybug species and development stages as well as targets prey items, e.g., Exochomus nigripennis (Erichson) larvae on Gossyparia spuria (Modeer) [ 11 ], Cheilomenes sexmaculata (Fabricius) larvae and adults on Megoura japonica (Matsumura) [ 15 ], or Micraspis discolor (Fabricius) larvae on Brevicoryne brassicae (L.) [ 16 ]. Hence, to sustain or promote ladybug-mediated biological control in (temporally) hot production settings or under climate change scenarios, it is essential to gain a better understanding of these temperature-related impacts [ 17 , 18 ].…”