Mate choice and polyandry benefit reproduction and progeny fitness in the ladybird Hippodamia variegata (Goeze)

Abstract

The effect of mate choice and polyandry on the reproductive performance and progeny fitness of a predaceous ladybird, Hippodamia variegata Goeze, was studied. The following mating combinations were used: (i) virgin female paired with the same and initially unmated male once per day (monogamy with limited mating), (ii.) virgin female paired once daily with an unmated male (polyandry with no mate choice) and (iii.) virgin female kept with five unmated males (polyandry with mate choice), with the food in each case an ad libitum supply of Aphis craccivora. Polyandrous females that had a free choice of mates were significantly more fecund (585.50± 13.80 eggs) and higher percentage of their eggs hatched (95.32± 1.99 %) than was the case for polyandrous females with no choice of mates (495.20± 14.25 eggs and 88.81± 3.29 %) followed by monogamous females (405.00± 16.20 eggs and 83.13± 2.07 %). Thus, mate choice and multiple mating by females is advantageous in terms of progeny production. The larvae that hatched from the eggs laid by these females were reared to maturity and their survival, duration of development and fitness determined. The fitness of offspring of polyandrous females (0.4787 ± 0.01) was better than that of polyandrous females that did not choose their mates (0.4418 ± 0.02) and monogamous (0.4057 ± 0.01) females. In addition, a greater percentage of the offspring of polyandrous females that chose their mates survived and developed faster than those of monogamous females with limited mating. These results reveal that polyandry with mate choice results in increased reproduction and better offspring quality. Hence, if one is interested increasing the production of H. variegata it is recommended that systems of production are developed that enable the females to be polyandrous and to select their mates.