Non-random mating in Adalia bipunctata (the two-spot ladybird). III. New evidence of genetic preference

Abstract

Isofemale lines of ladybirds produced from a selected stock varied widely in female preference for melanic males. An attempt to repeat these results failed. The ladybirds used in the repeat experiment were collected from a wild population in which melanic frequencies had dropped from 35 to 10 per cent in 3 years. In this repeat experiment, the overall mating rate was twice that of the original experiment. The failure of the repeat experiment can be attributed either to a loss of preference or to the preference not being expressed at high mating rates. New lines were set up from a sample collected in Glasgow where high levels of preferential mating occur in the wild population. Mating tests on these lines strongly corroborated the results of the original isofemale line experiment: some lines showed high preference, others intermediate or no preference. The overall mating rate was low -one-quarter of that in the unsuccessful repeat experiment. Samples collected from areas high in melanics showed high preference. Lower levels of preference were found where melanics are less common. Where no melanics occur, preference is absent. These results provide further evidence of genetic preference in ladybirds.

Nonrandom mating in the two-spot ladybird (Adalia bipunctata): The influence of weight on mating success

“…Kearns et al (1992) did not, however, confinn that female ladybirds could possess a simple mating preference for melanic males. O'Donald and Majerus (1992) subsequently presented further evidence that was consistent with a female preference for melanic males. This paper reports the results of further investigations into nonrandom mating in Adalia bipunctara.…”

“…Previous papers (Kearns et al, 1990(Kearns et al, , 1992O'Donald and Majerus, 1992) have analyzed the evidence for nonrandom mating in the two-spot ladybird, Adalia bipunctata, and presented new data on the same subject. Kearns et al (1990Kearns et al ( , 1992 concluded that there was evidence that the melanic morph gained a general mating advantage over the 1Department of Genetics, Downing Street, Cambridge CB2 3EH, U,K.…”

Effects of a larval antipredator response and larval diet on adult phenotype in an aposematic ladybird beetle

“…Several genetically distinct color morphs exist in native Asian populations but in Kentucky, H. axyridis populations consist entirely of the succinea color morph, which is homozygous recessive for predominantly red-orange, rather than black, elytral color (Komai 1956). Previous studies that examined`color' in ladybird beetles have typically focused on distribution of spot patterns (Komai 1956;Holloway et al 1995) or comparisons between discrete color morphs (e.g., melanic vs. nonmelanic elytra; Tan and Li 1934;Kearns et al 1990Kearns et al ,1992O'Donald and Majerus 1992;Osawa and Nishida 1992). Elytral color is highly and continuously variable within the succinea morph, ranging from a deep crimson to a pale yellow-orange.…”

The inheritance of female mating behaviour in the seaweed fly,Coelopa frigida

“…However, a second set of isofemale lines subsequently derived from the same (Keele) population, exhibited no female preference, and the original isofemale lines now appeared to mate at random (Kearns et al 1992). O'Donald & Majerus (1992) suggested that the different behaviour resulted from a reduction in the frequency of the preference gene in the Keele population. A drop in frequency of melanic males from 0-35 to 010 was observed in the three years between the two studies, and it is possible the female mating preference may also have declined in frequency.…”