Fitness evaluation of Oenopia conglobata contaminata (Menetries) (Col.: Coccinellidae) fed on different diets

Abstract

Due to the importance of coccinellid predators as biological control agents of insect pests, the effects of different factitious and artificial diets on reproductive parameters of Oenopia conglobata contaminata (Menetries) were studied under laboratory conditions (26±1ºC, 60±5% relative air humidity and a photoperiod of 16h light : 8 h dark). In this study, various combinations of Ephestia kuehniella (Zeller) eggs, bee pollen, cysts of Artemia urmiana Günther and lyophilized artificial diet were used. All diets affected fitness parameters of the ladybeetle. The adult weight (12.00±1.30 mg), fecundity (725±29.31 eggs), oviposition rate (15.72±0.85 eggs), fertility (4.86±0.34 larvae) and number of egg clusters (66.16±2.87) were higher on unlimited E. kuehniella eggs plus pollen (UEkP) than those on the other diets. The adults lived longer when fed on EkPLd (the E. kuehniella eggs plus pollen and a mixture of lyophilized diet) and UEkP diets (58.57±2.38 and 62.77±3.64 days, respectively) than when fed on the other offered diets. More eggs were hatched when adults reared on EkPLd and EkLd (the E. kuehniella eggs plus a mixture of lyophilized diet) diets(36.44±1.93 and 40.01±2.58 %, respectively). The parameter values were increased when the E. kuehniella eggs were used in a mix with bee pollen and artificial lyophilized diet and resulted in producing the heavier adults with longer longevity and more fertile eggs. Certainly, the diet will be more cost-effective than natural prey for mass production of the predatory coccinellid, O. conglobata contaminata.