Investigation of feeding rate of the ladybird, Chilocorus bipustulatus (L.) on the kiwi white scale, Pseudaulacaspis pentagona and citrus brown scale, Chrysomphalus dictyospermi

Amir Hossein Toorani | Habib Abbasipour | Anis Aboutalebian | Behnam Amiri

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URL :   http://research.shahed.ac.ir/WSR/WebPages/Report/PaperView.aspx?PaperID=116745
Date :  2019/08/06
Publish in :    نهمين همايش کنترل بيولوژيک کشاورزي و منابع طبيعي


Keywords :Armored scale insects, Citrus, Kiwi, ladybird, predator, temperature

Abstract :

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The ladybird, Chilocorus bipustulatus L. (Col.: Coccinellidae) is one of the most important predators of armored scale insects (Diaspididae) that feed on different ages of larvae and adult insect of kiwi white scale, Pseudaulacaspis pentagona (Targioni-Tozzetti) and citrus brown scale, Chrysomphalus dictyospermi (Morgan) in kiwi and citrus orchards in northern Iran. In this research, the feeding rate of different stages of ladybird (1st instar, 2nd instar, 3rd instar, 4th instar and adults (males and females) ) of listed pests were evaluated in 10 replications at 20, 25, 30 and 35°C, 80 ± 5 RH and photoperiod of 16:8 (L:D). Two hundred eggs were placed for the 1st and 2nd instar and one thousand eggs for the 3rd and 4th instar and male and female insects. Statistical analysis was performed using a factorial experiment (age and temperature) based on the completely randomized design with SPSS version 22 software. Mean comparison was performed by Tukeys multiple comparison test. The analysis of variance results showed that there is a significant difference in feeding rate between different stages and also between different temperatures (age stage: P. pentagona (F=269.58, df=5, P0.005), C. dictyospermi (F=77.95, Df=5, P0.005), temperature: P. pentagona (F=127.3, df=3, P0.005), C. dictyospermi (F=66.71, df=3, P0.005). Mean comparison results showed that the highest amount of feeding on eggs of kiwi white scale and citrus brown scale was belonged to adult female (2371.7±383.19) and (2690.61±193.03), respectively which had a significant difference with other temperatures. Between temperatures, the highest feeding rate on the kiwi white scale and citrus brown scale was observed at 25°C (1875.88±137.74) and (2056.28±150.39), respectively. Low levels of feeding rate of both hosts at different stages were seen at 1st instar larvae and also between different temperatures were seen at 35°C. Therefore, adult female insects had a high nutritional potential at 25°C and therefore, it was possible to use these findings in mass production and predator release programs.