Improving the artificial diet for adult of seven spotted ladybird beetleCoccinella septempunctataL. (Coleoptera: Coccinellidae) with orthogonal design

Abstract

AbstractIn this study, an orthogonal array design with 16 factors at two levels (216) was performed to develop an artificial diet rearing the adults of seven spotted ladybird beetleCoccinella septempunctata. The parameters of weight gain and survival rate of adults, preoviposition period, fecundity and hatching rate of diet-fed adults were monitored. The 16 factors were included: pork liver, infant formula, sucrose, olive oil, yolk, corn oil, yeast powder, cholesterol, casein, casein hydrolysate, vitamin powder, 65% juvenile hormone III, protein powder, vitamin E, honey and pumpkin. Results indicated that pork liver, sucrose, yolk, yeast powder, juvenile hormone, pumpkin and honey were the main ingredients of the artificial diet contributing to weight gain and survival rate of adults, preoviposition period, fecundity and hatching rate. A follow-up fed with a selection of improved formulas confirmed the validity of the optimization as predicted by the orthogonal array analysis, indicating the usefulness of this method for selecting artificial diets forC. septempunctata. The weight gain and fecundity of adults reared on the improved artificial diet were 87.46 and 62.70% of those reared onAphis craccivora; the survival rate and hatch rate were similar between the diet-fed and aphid-fed, while the preoviposition period was significantly shorter forC. septempunctatafed on the diet than onA. craccivora. The latter formula was superior to any formerly developed formulas and may thus have potential for the improved artificial diet mass rearing ofC. septempunctata.