Abstract
Lady beetles (Coleoptera: Coccinellidae) are a classical group for studying the mechanisms that determine local and temporal trends in colour polymorphism. Here we report long term trends in variation in the percentage of different morphs in a population of Hippodamia variegata (Goeze) at Štúrovo, Slovakia (47°48´N, 18°43´E). The morphs differ in the number and location of the spots on their elytra. Beetles were sampled from stands of herbaceous plants using a standard method each year in August over a period of 74 years from 1937 to 2011. Twenty two morphs (out of 74 possible) were recorded in a total sample of 6,984 individuals. Four dominant morphs made up 90% of the total sample and varied in their annual frequency independently of one another. Frequency of "pale" morphs (0-3 spots per elytra), supposedly favoured by a warm climate, increased from 1981 to 2000s' during a period of climate warming, but only after a decrease that took place between 1937 and 1981, which did not parallel a change in climate. Moreover, the differences in the extent of the melanization of the elytral surface are too small to significantly affect thermoregulation in the different morphs. Therefore, the results presented do not provide unequivocal support for climate change determining the long term trends in the variation in the proportions of the different morphs.
Highlights
Morphological polymorphisms are well studied and provide evidence of natural variation and microevolutionary processes occurring in nature (Ford, 1964)
We should address a problem associated with this type of study, which is the absence of a genetic analysis of spot pattern polymorphism in H. variegata (Majerus, 1994)
In coccinellids where the morphs differ fundamentally in pattern and base coloration of the elytra, the inheritance the pattern is via multiple alleles of a major gene
Summary
Morphological polymorphisms are well studied and provide evidence of natural variation and microevolutionary processes occurring in nature (Ford, 1964). These studies seems “marginal” compared to the flood of information from molecular studies (Lowe et al, 2004) they are important because they provide direct evidence of interaction between environmental factors and animal characteristics at the organismic level. The pattern on the elytra varies in terms of the base colour and number, size and shape of spots. The few species that are the classical subjects of these studies have a small number of morphs in which the base colour of the elytra differs and is determined by major genes. Mechanisms balancing the ratio of particular morphs in populations are still open to dispute and worthy of further study (Majerus, 1994)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
