BACKGROUND: The tribe Coccinellini is a group of relatively large ladybird beetles that exhibits remarkable morphological and biological diversity. Many species are aphidophagous, feeding as larvae and adults on aphids, but some species also feed on other hemipterous insects (i.e., heteropterans, psyllids, whiteflies), beetle and moth larvae, pollen, fungal spores, and even plant tissue. Several species are biological control agents or widespread invasive species (e.g., Harmonia axyridis (Pallas)). Despite the ecological importance of this tribe, relatively little is known about the phylogenetic relationships within it. The generic concepts within the tribe Coccinellini are unstable and do not reflect a natural classification, being largely based on regional revisions. This impedes the phylogenetic study of important traits of Coccinellidae at a global scale (e.g. the evolution of food preferences and biogeography). RESULTS: We present the most comprehensive phylogenetic analysis of Coccinellini to date, based on three nuclear and one mitochondrial gene sequences of 38 taxa, which represent all major Coccinellini lineages. The phylogenetic reconstruction supports the monophyly of Coccinellini and its sister group relationship to Chilocorini. Within Coccinellini, three major clades were recovered that do not correspond to any previously recognised divisions, questioning the traditional differentiation between Halyziini, Discotomini, Tytthaspidini, and Singhikaliini. Ancestral state reconstructions of food preferences and morphological characters support the idea of aphidophagy being the ancestral state in Coccinellini. This indicates a transition from putative obligate scale feeders, as seen in the closely related Chilocorini, to more agile general predators. CONCLUSIONS: Our results suggest that the classification of Coccinellini has been misled by convergence in morphological traits. The evolutionary history of Coccinellini has been very dynamic in respect to changes in host preferences, involving multiple independent host switches from different insect orders to fungal spores and plants tissues. General predation on ephemeral aphids might have created an opportunity to easily adapt to mixed or specialised diets (e.g. obligate mycophagy, herbivory, predation on various hemipteroids or larvae of leaf beetles (Chrysomelidae)). The generally long-lived adults of Coccinellini can consume pollen and floral nectars, thereby surviving periods of low prey frequency. This capacity might have played a central role in the diversification history of Coccinellini.

• MeSH
• biologická evoluce MeSH
• brouci klasifikace   genetika   růst a vývoj   fyziologie   MeSH
• fylogeneze MeSH
• larva fyziologie   MeSH
• molekulární evoluce MeSH
• predátorské chování MeSH
• preference v jídle MeSH
• zavlečené druhy MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

In insects, external chemical defences, such as reflex bleeding, have been proved to be an efficient strategy against various predators. At the same time, significant costs of reflex bleeding can be expected because bled haemolymph is lost and all valuable components included have to be renewed. Interestingly, this issue has rarely been investigated for adult insects. In this study, we examined the immune and fitness costs of repeated reflex bleeding in adults of the invasive ladybird Harmonia axyridis, investigating several haemolymph parameters. Reflex bleeding induced twice a week for three weeks resulted in a significant reduction in haemocyte concentration, total protein content, and antimicrobial activity against Micrococcus luteus, and a marginally non-significant decrease in antimicrobial activity against Escherichia coli. Repeated reflex bleeding did not result in significant body mass reduction. Interestingly, resource limitation in the form of complete food absence did not significantly interact with reflex bleeding, even though starvation itself had a strong negative effect on all haemolymph parameters investigated and individual body mass. Daily reflex bleeding did not result in decreased fecundity of young ladybirds during the first 30 days of their adult life, but the start of ladybird reproduction was delayed by about two days. Moreover, ladybirds bleeding larger amounts of haemolymph started their reproduction significantly later. Overall, our results indicate that repeated reflex bleeding weakens a ladybird's immune system and can increase their susceptibility to pathogens, but a ladybird's reproductive potential remains almost unaffected, even by very intensive reflex bleeding.

• MeSH
• brouci imunologie   fyziologie   MeSH
• Escherichia coli patogenita   MeSH
• hemolymfa MeSH
• imunitní systém * MeSH
• Micrococcus luteus patogenita   MeSH
• rozmnožování MeSH
• tělesná hmotnost MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

There is a controversy about whether the thermal constants, lower developmental threshold, rate of development and corresponding degree days required for development, change when a species is reared under different developmental conditions. We present a more precise way of measuring these constants using the linear relationship between the rate of development and temperature. First we use the equation proposed by Ikemoto and Takai (2000) to determine the linear phase of development and then a generalised linear model having a different variance at low and high temperatures, specific for each condition, to estimate the parameters of the linear relationship. Using this method, we show that providing the difference in food quality is sufficiently great, an aphidophagous ladybird develops significantly faster and starts developing at a significantly lower temperature on a good than on a poor quality diet. Adaptive significance of the thermal constants not remaining constant is discussed in terms of a trade-off between growth and rate of development, when temperature and food quality varies.

• MeSH
• brouci růst a vývoj   MeSH
• dieta MeSH
• Hemiptera růst a vývoj   MeSH
• vysoká teplota * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Because of their services to agriculture most ladybirds (Coleoptera: Coccinellidae) are intensively studied predators of mainly phytophagous pests. The study of the long-term variation in the composition of their communities was stimulated by recent dramatic changes in the abundance of some species. We review and evaluate possible effects of the main causes cited in the literature. Agricultural and habitat changes (particularly urbanization) affect coccinellid abundance, both negatively and positively. In the temperate zone dominant species occur most frequently associated with abundant prey populations on crops, weeds and planted stands of trees resulting from human activity. Invasive non-native species of coccinellids may endanger native species through intraguild predation or competition for resources, but their supposed serious negative effects on native species can differ considerably. Climatic change may influence coccinellid species in several ways, including indirect effects through lower trophic levels and desynchronisation of the phenologies of host plants, prey and coccinellid populations. In the near future we do not expect climate warming to have important effects on ladybird diversity globally, but local changes in the composition of coccinellid communities and abundance of particular species could occur.

• MeSH
• brouci * MeSH
• ekosystém * MeSH
• klimatické změny MeSH
• populační dynamika MeSH
• predátorské chování MeSH
• rostliny MeSH
• rozšíření zvířat MeSH
• zavlečené druhy MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

The ectoparasitic fungus Hesperomyces virescens was studied on its invasive host, the harlequin ladybird Harmonia axyridis, in the Czech Republic. A primary aim was to examine the relationship between fungal infection and elytral coloration of the ladybird. Furthermore, the role of host sex and mating status of females were analyzed. Beetles (n = 1,102) were sampled during autumn migration, and then sexed, weighed, and screened for infection. Females were dissected for detection of sperm in their spermathecae. Ladybirds were sorted according to color form and absorbance spectrophotometry was used to quantify carotenoid contents in their elytra. In individuals of the nonmelanic succinea form, the degree of melanization was measured using digital photographs and putative age groups were estimated based on background color of elytra. Sexual differences in infection patterns indicated transmission during copulation: males were infected mostly on elytra and venter, and females had infection almost exclusively on elytra. Mated females had higher infection rate than virgins. There was no influence of genetic color form on the fungal infection. Putative age groups (visual sorting to yellow, orange, and red) correlated with fungal infection. Infected individuals had elevated elytral carotenoid levels in comparison to uninfected individuals, which could be explained by host age. Infection-free succinea beetles were extensively melanized because they emerged later in the season at lower temperatures which induced melanization. Overall, we highlight that H. axyridis is a multivoltine species whose age, if not taken into account in ecophysiological studies, might present a considerable confounding factor.

• MeSH
• Ascomycota fyziologie   MeSH
• biologické modely MeSH
• brouci metabolismus   mikrobiologie   MeSH
• interakce hostitele a patogenu * MeSH
• karotenoidy metabolismus   MeSH
• melaniny metabolismus   MeSH
• pigmentace * MeSH
• sexuální chování zvířat * MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Novel members of the adipokinetic hormone family of peptides have been identified from the corpora cardiaca (CC) of two species of beetles representing two families, the Silphidae and the Coccinellidae. A crude CC extract (0.3 gland equivalents) of the burying beetle, Nicrophorus vespilloides, was active in mobilizing trehalose in a heterologous assay using the cockroach Periplaneta americana, whereas the CC extract (0.5 gland equivalents) of the ladybird beetle, Harmonia axyridis, exhibited no hypertrehalosemic activity. Primary sequences of one adipokinetic hormone from each species were elucidated by liquid chromatography coupled to electrospray mass spectrometry (LC-MS). The multiple MS(N) electrospray mass data revealed an octapeptide with an unusual tyrosine residue at position 4 for each species: pGlu-Leu-Thr-Tyr-Ser-Thr-Gly-Trp amide for N. vespilloides (code-named Nicve-AKH) and pGlu-Ile-Asn-Tyr-Ser-Thr-Gly-Trp amide for H. axyridis (code-named Harax-AKH). Assignment of the correct sequences was confirmed by synthesis of the peptides and co-elution in reversed-phase high-performance liquid chromatography with fluorescence detection or by LC-MS. Moreover, synthetic peptides were shown to be active in the heterologous cockroach assay system, but Harax-AKH only at a dose of 30 pmol, which explains the negative result with the crude CC extract. It appears that the tyrosine residue at position 4 can be used as a diagnostic feature for certain beetle adipokinetic peptides, because this feature has not been found in another order other than Coleoptera.

• MeSH
• adipokiny chemie   genetika   izolace a purifikace   MeSH
• brouci chemie   genetika   MeSH
• hmyzí hormony chemie   genetika   izolace a purifikace   MeSH
• hmyzí proteiny chemie   genetika   izolace a purifikace   MeSH
• molekulární sekvence - údaje MeSH
• peptidy chemie   genetika   izolace a purifikace   MeSH
• sekvence aminokyselin * MeSH
• tyrosin chemie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The harlequin ladybird, Harmonia axyridis, is one of the most successful invasive insect species worldwide. We investigated whether (i) chill coma recovery time (CCRt) changes during the ontogenetic development of this species, (ii) CCRt varies in response to repeated cold shocks, and (iii) CCRt could be a good predictor of winter survival ability in adults. CCRt decreased during larval development, the lowest CCRt values were observed in teneral adults (one and four days old), and significantly higher values were observed for older adults (16 and 32 days old). Repeated cold shocks (two hours at -3 °C), interrupted by short (30 min) warm periods (22 °C) resulted in decreased CCRt after the second cold shock, probably depicting an acclimation response, but then CCRt increased with additional cold shocks, likely revealing the accumulation of chill injuries. The CCRt of pre-overwintering individuals was not correlated with their winter survival. This indicates that CCRt is not a reliable measure of cold tolerance in H. axyridis. However, this result could be partially affected by the experimental setup - the use of laboratory-reared individuals who experienced standardized conditions and thus the variability in CCRt of tested animals could be much lower than the variability present in nature. The substantial variation observed over the ontogenetic development of H. axyridis poses important methodological implications for future studies, as animals of the same stage/age should be compared with each other. The observed U-shaped response to repeated cold shocks indicates that the expectation of linearity between cold exposure and insect response is an oversimplification of real situations.

• MeSH
• aklimatizace MeSH
• brouci růst a vývoj   MeSH
• larva růst a vývoj   MeSH
• nízká teplota MeSH
• reakce na chladový šok * MeSH
• roční období * MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Ongoing climate change results in increasing temperatures throughout the seasons. The effects of climate change on insect performance are less studied during the winter season than during the growing season. Here, we investigated the effects of various winter temperature regimes (warm, normal and cold) on the winter performance of the invasive ladybird Harmonia axyridis (Coleoptera: Coccinellidae). Winter survival, body mass loss and post-winter starvation resistance were measured for a laboratory-reared population as well as three populations collected from the field prior to overwintering. The warm winter regime increased the survival rate and body mass loss and reduced post-winter starvation resistance compared to those of the ladybirds in the cold winter regime. The effects of the temperature regime were qualitatively similar for the laboratory-reared and field-collected beetles; however, there were significant quantitative differences in all measured overwintering parameters between the laboratory-reared and field-collected populations. The winter survival of the laboratory-reared beetles was much lower than that of the field-collected beetles. The laboratory-reared beetles also lost a larger proportion of their body mass and had reduced post-winter starvation resistance. Winter survival was similar between the females and males, but compared to the males, the females lost a smaller proportion of their body mass and had better post-winter starvation resistance. The pre-overwintering body mass positively affected winter survival and post-winter starvation resistance in both the laboratory-reared and field-collected ladybirds. The significant differences between the laboratory-reared and field-collected individuals indicate that quantitative conclusions derived from studies investigating solely laboratory-reared individuals cannot be directly extrapolated to field situations.

• MeSH
• aklimatizace MeSH
• brouci růst a vývoj   MeSH
• hladovění * MeSH
• index tělesné hmotnosti * MeSH
• nízká teplota * MeSH
• populační dynamika * MeSH
• roční období * MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Our understanding of fungal diversity is far from complete. Species descriptions generally focus on morphological features, but this approach may underestimate true diversity. Using the morphological species concept, Hesperomyces virescens (Ascomycota, Laboulbeniales) is a single species with global distribution and wide host range. Since its description 120 years ago, this fungal parasite has been reported from 30 species of ladybird hosts on all continents except Antarctica. These host usage patterns suggest that H. virescens could be made up of many different species, each adapted to individual host species. Using sequence data from three gene regions, we found evidence for distinct clades within Hesperomyces virescens, each clade corresponding to isolates from a single host species. We propose that these lineages represent separate species, driven by adaptation to different ladybird hosts. Our combined morphometric, molecular phylogenetic and ecological data provide support for a unified species concept and an integrative taxonomy approach.

• MeSH
• analýza hlavních komponent MeSH
• Ascomycota klasifikace   genetika   izolace a purifikace   fyziologie   MeSH
• brouci parazitologie   MeSH
• DNA fungální chemie   genetika   metabolismus   MeSH
• fylogeneze MeSH
• mezerníky ribozomální DNA chemie   genetika   metabolismus   MeSH
• sekvenční analýza DNA MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The ambient temperature experienced during development is a crucial factor affecting survival and adult phenotype in ectotherms. Moreover, the exact response of individuals to different temperature regimes is frequently sex-specific. This sex-specific response can result in varying levels of sexual dimorphism according to the experienced conditions. The majority of studies have investigated the effects of temperature on individuals reared under a constant temperature regime throughout their whole preimaginal development, whereas information on stage-dependent variation in temperature effects is scarce. Here we investigate how the stage at which elevated temperature is experienced influences survival, adult body size and colouration in the harlequin ladybird Harmonia axyridis form succinea. The effects of timing of exposure to elevated temperature on the adult phenotype are assessed separately for males and females. Control individuals were reared at a constant temperature of 20 °C. Beetles in other treatments were additionally exposed to 33 °C for 48 hours during the following developmental stages: egg, 1(st) to 2(nd) larval instar, 3(rd) larval instar, 4(th) larval instar and pupa. Exposure to an elevated temperature during the early developmental stages resulted in lower survival, but the adult phenotype of survivors was almost unaffected. Exposure to an elevated temperature during the later developmental stages (4(th) larval instar or pupa) resulted in the decreased melanisation of elytra, decreased structural body size and increased dry mass. Furthermore, the timing of high temperature exposure affected the degree of sexual dimorphism in elytral melanisation and dry mass. We demonstrate that the effects of elevated temperature can vary according to the developmental stage at exposure. Detailed information on how ambient temperature affects the developmental biology of ectotherms is crucial for modeling population growth and predicting the spread of invasive species such as Harmonia axyridis.

• MeSH
• analýza přežití MeSH
• brouci anatomie a histologie   růst a vývoj   fyziologie   MeSH
• časové faktory MeSH
• fenotyp MeSH
• melaniny metabolismus   MeSH
• pigmentace fyziologie   MeSH
• pohlavní dimorfismus * MeSH
• teplota * MeSH
• velikost těla * MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH