The two-spot ladybird, Adalia bipunctata, is a species of small, flying beetle that is found in northern Europe and other parts of the world. The wings of these beetles are covered by two tough structures known as elytra, as shown in Fig. 2.1. Fig. 2.1 A. bipunctata is an important predator of insect pests such as aphids. These insect pests feed on plants, including many crop species. Population numbers of $$\(A\)$$. bipunctata fluctuate in response to changes in the population numbers of their prey. The elytra of A. bipunctata show phenotypic variation. The three most common morphs (forms) found in northern Europe are known as typica (T), quadrimaculata (Q) and sexpustulata (S). - The typica morph, shown in Fig. 2.1, is mostly red with two black spots and is described as non-melanic. - The other two morphs are described as melanic as they are mainly black with some red. - The distribution of the colours in these three morphs is shown in Fig. 2.2. Fig. 2.2 In northern Europe, the populations of $$\(A\)$$. bipunctata hibernate (are inactive) during the winter. As the temperature increases in early spring, the populations become active. The populations remain active and produce three generations before the next winter begins. It was observed that in some areas in populations of A. bipunctata, the proportion of non-melanic to melanic phenotypes in the early spring was different to the proportion later in the year in the autumn. Researchers carried out a study in one area of Germany to compare the proportion of non-melanic to melanic phenotypes in early spring with the proportion in autumn after three generations had been produced. The data were collected over a period of 12 years. The results are shown in Fig. 2.3. Fig. 2.3 (i) Outline a method that could be followed to collect the data shown in Fig. 2.3. ....................................................................................................................................... . ....................................................................................................................................... . ....................................................................................................................................... . ....................................................................................................................................... . ....................................................................................................................................... . ....................................................................................................................................... . ....................................................................................................................................... . ................................................................................................................................. (ii) The researchers concluded that there was a change in the proportion of the two phenotypes between spring and autumn, with the non-melanic phenotypes always showing a higher percentage frequency in the spring. Suggest two pieces of extra information about the investigation that researchers should provide to improve confidence in their conclusion. ....................................................................................................................................... . ....................................................................................................................................... . ....................................................................................................................................... . ....................................................................................................................................... . ....................................................................................................................................... . .................................................................................................................................

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