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The effect of host plant and isolation on the genetic structure of phytophagous insects: A preliminary study on a bruchid beetleGwendal RESTOUX, Martine HOSSAERT-MCKEY, Betty BENREY, Nadir ALVAREZEur. J. Entomol. 107 (3): 299-304, 2010 | DOI: 10.14411/eje.2010.038 Genetic differentiation is a consequence of the combination of drift and restriction in gene flow between populations due to barriers to dispersal, or selection against individuals resulting from inter-population matings. In phytophagous insects, local adaptation to different kinds of host plants can sometimes lead to reproductive isolation and thus to genetic structuring, or even to speciation. Acanthoscelides obtectus Say is a bean bruchid specialized on beans of the Phaseolus vulgaris group, attacking both wild and domesticated forms of P. vulgaris and P. coccineus. This study reveals that the genetic structure of populations of this bruchid is explained mainly by their geographical location and is not related to a particular kind (wild or domesticated) of bean. In contrast, the species of bean might have led, to some extent, to genetic structuring in these bruchids, although our sampling is too limited to address such process unambiguously. If confirmed, it would corroborate preliminary results found for the parasitoid species that attack Acanthoscelides species, which might show a genetic structure depending on the species of host plant. |
Prey abundance and intraguild predation between Adalia bipunctata (Coleoptera: Coccinellidae) and Macrolophus pygmaeus (Hemiptera: Miridae)Vincenzo TROTTA, Juliana DURÁN PRIETO, Paolo FANTI, Donatella BATTAGLIAEur. J. Entomol. 112 (4): 862-865, 2015 | DOI: 10.14411/eje.2015.080 Macrolophus pygmaeus Rambur (Hemiptera: Miridae) and Adalia bipunctata (L.) (Coleoptera: Coccinellidae) are two predatory insects commonly used as biological control agents. In order to determine the incidence with which both species attack and eat each other [Intraguild predation (IGP)], the direction and symmetry of the interaction between A. bipunctata and M. pygmaeus were characterized. In addition, whether the intensity of IGP between these two predators increased when the number of extraguild prey Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae) decreased, was also determined. Unidirectional sensu stricto IGP between A. bipunctata and M. pygmaeus was recorded: when IGP occurred, A. bipunctata was always the IG predator that killed and ate M. pygmaeus, the IG prey. However, the intensity of IGP was a function of the abundance of the extraguild prey, A. pisum, since IGP increased when the number of extraguild prey decreased. These results are discussed in terms of theoretical models that predict stability and the outcome of using natural enemies to control pests. |
Rarity of blister beetles (Coleoptera: Meloidae) in Southern Africa correlates with their phylogeny and trophic habits, but not body sizeMonica PITZALIS, Valentina AMORE, Francesca MONTALTO, Luca LUISELLI, Marco A. BOLOGNAEur. J. Entomol. 111 (4): 529-535, 2014 | DOI: 10.14411/eje.2014.058 Ecologists have identified several correlates of biological rarity in animals. Among the various correlates identified so far, three are explored in this paper: (a) abundance is correlated with absolute body size in animals; (b) phylogenetically primitive taxa are overrepresented in samples of rare species; (c) more specialized species are rarer than less specialized species. Here we use Namibian blister beetles (Coleoptera: Meloidae) as a model system for exploring these issues. We used data from five field expeditions, which resulted in the identification of 891 beetles belonging to 76 species collected from 191 sites. 13% of the species accounted for over 50% of the individuals; 22% of all species were represented by singletons. Abundance patterns differed significantly among the different trophic categories, with non-pollinophagous (non-specialized) species being more abundant than weed-eaters and pollinophagous (specialized) species. Species of phylogenetically basal tribes were less abundant than those of more derived groups. Trophic category and phylogenesis did not have a synergic effect in determining the relative abundance of the species, and body size had no influence on their abundance. |
Effects of cold acclimation, cooling rate and heat stress on cold tolerance of the potato tuber moth Phthorimaea operculella (Lepidoptera: Gelechiidae)Chamran HEMMATI, Saeid MOHARRAMIPOUR*, Ali ASGHAR TALEBIEur. J. Entomol. 111 (4): 487-494, 2014 | DOI: 10.14411/eje.2014.063 This study was carried out to investigate the effects of cold acclimation, cooling rate and heat stress on supercooling capacity and cold hardiness of the potato tuber moth (PTM), Phthorimaea operculella Zeller (Lepidoptera: Gelechiidae). Supercooling points (SCP) of first and last instar larvae, prepupae and pupae were -21.8, -16.9, -18.9 and -18.0°C, respectively. Cold acclimation (1-week at 0 and 5°C) did not affect SCPs of acclimated last instar larvae, prepupae and pupae. LT50s (lower lethal temperature for 50% mortality) for first and last instar larvae, prepupae and pupae were -15.5, -12.4, -17.9 and -16.0°C, respectively. Cold acclimation resulted in a significant decrease in mortality of all developmental stages. In addition, the mortality rates of the different developmental stages decreased with decrease in cooling rate. In addition, heat hardening (kept at 40°C for 2 h) significantly reduced mortality of all developmental stages exposed to LT50 conditions, suggesting that heat hardening also affects cold tolerance. Results indicate that none of the stages could tolerate subzero temperatures below their SCPs, indicating that this species might be a chill tolerant insect. These adaptive responses may allow PTM to enhance its cold tolerance and colonize cold regions. |
Characterisation of sixteen additional polymorphic microsatellite loci for the spreading but locally rare European butterfly, Brenthis ino (Lepidoptera: Nymphalidae)Christophe LEBIGRE, Camille TURLURE, Nicolas SCHTICKZELLEEur. J. Entomol. 112 (2): 389-392, 2015 | DOI: 10.14411/eje.2015.047 Whilst the overall geographic range of the lesser marbled fritillary, Brenthis ino (Rottemburg, 1775), is currently expanding, this species is patchily distributed at a local spatial scale due to its use of flower rich semi-natural meadows and the aggregated distribution of its host plant. Therefore, understanding the dispersal patterns of this butterfly and the effect of increasing fragmentation of the landscapes in central and Western Europe on its population dynamics is key to determining whether this patchy distribution can lead to metapopulation structuring and dynamics. One way to determine the degree to which local populations are isolated from one another is to use high resolution molecular genetic markers and thence quantify gene flow and genetic drift. Eleven microsatellite loci have previously been developed for this species, but six showed evidence of null alleles, effectively violating key assumptions of the models used to infer gene flow. We therefore developed a set of new primer pairs to amplify a suite of 16 highly polymorphic microsatellite loci (number of alleles ranged from 2-30) of which nine were found to conform to the Hardy-Weinberg's expectations, whilst at the same time not showing any clear signature for the presence of null alleles. We further describe how these primers were optimized for landscape and metapopulation genetics studies in Belgian Ardenne. |
The importance of termites (Isoptera) for the recycling of herbivore dung in tropical ecosystems: a reviewBernd P. FREYMANN, Robert BUITENWERF, Og DESOUZA, Han OLFFEur. J. Entomol. 105 (2): 165-173, 2008 | DOI: 10.14411/eje.2008.025 While the key role of termites in the decomposition of litter in the tropics has been acknowledged for a long time, much less information exists on their importance in the recycling of dung of primary consumers, especially herbivores. A review of published studies shows that a diverse group of termites (at least 126 species) has been reported to feed on a wide range of mammalian dung (18 species). Predominantly, wood-feeding and polyphagous wood-litter feeding species were found to feed also frequently on dung. Moreover, we found that termites can quickly remove large amounts of mammalian dung, especially in the dry season, when on average about 1/3 of the dung deposited in a given habitat is removed by termites within one month (with the highest rates observed in savannas). No distinctive preference for mammalian dung over other organic food sources was observed for fungus-growing termites (Macrotermitinae), whereas the majority of the non-fungus growing taxa studied prefer dung over other food. As termites bring large quantities of dung below the soil surface, disturb and enrich soils with nutrients, dung feeding by termites appears to be a previously underestimated process important in the functioning of tropical ecosystems. |
Rearing of Microplitis mediator (Hymenoptera: Braconidae) and its host Mamestra brassicae (Lepidoptera: Noctuidae)Elodie BELZ, Céline E. GÉNEAU, Moritz FÜRST, Oliver BALMER, Pius ANDERMATT, Lukas PFIFFNER, Léon WESTERD, Henryk LUKAEur. J. Entomol. 111 (3): 443-447, 2014 | DOI: 10.14411/eje.2014.043 Establishing continuous and reliable colonies of pest-parasitoid systems in the laboratory is an essential requirement for carrying out manipulative experiments on biological control. Here we describe in detail the rearing protocols that we optimized for the efficient rearing of the cabbage moth Mamestra brassicae and its key parasitoid Microplitis mediator. |
BOOK REVIEW: Neild A.F.E.: The Butterflies of Venezuela, Part 2: Nymphalidae II (Acraeinae, Libytheinae, Nymphalinae, Ithomiinae, Morphinae).Z. FRICEur. J. Entomol. 107 (4): 686, 2010 | DOI: 10.14411/eje.2010.077 Meridian Publications, London, 2008, 275 pp., ISBN 978-0-9527657-1-4. |
Thermal constants of egg development in carabid beetles - variation resulting from using different estimation methods and among geographically distant European populationsPavel SASKA, Miroslav VLACH, Jana SCHMIDTOVÁ, Andrey V. MATALINEur. J. Entomol. 111 (5): 621-630, 2014 | DOI: 10.14411/eje.2014.077 Using equations based on the law of total effective temperatures, we estimated the thermal constants (LDT, the lower development threshold, and SET, the sum of effective temperatures) of egg development for 14 populations of 13 species of carabid beetles (eight belonging to the tribe Zabrini, one to Platynini and four to Pterostichini). We compared the estimates of the thermal constants obtained using three commonly used equations (D = SET / (T - LDT); 1 / D = a + b . T, where LDT = -a / b, and SET = 1 / b; and D . T = SET + D . LDT) and two data formats: data points for all the individuals and means for each temperature. We found that, for most species, estimates of both LDT and SET of egg development obtained using the three models were similar and that using means resulted in larger standard errors (SE) than using all data points. We provide evidence for inter-correlation among the thermal constants, showing that a decrease in the estimate of one constant is accompanied by an increase in the estimate of the other constant. For seven species for which sufficient data were available we investigated the geographical variation in their thermal constants. We found significant variation in both constants for three species, in only one in one species and in three species there was no significant variation among geographically distant populations at p < 0.05. For eight out of the nine autumn-breeding species studied, egg mortality significantly increased at high temperatures. For future studies, we recommend the use of the third method (D . T = SET + D . LDT) for estimating thermal constants for several reasons: (i) it is linear (i.e., simple to compute); (ii) the thermal constants are parameters of the equation, and therefore, their SEs are directly estimated; (iii) it allows the use of all data points (i.e., reduces the SE of the estimates of thermal constants); and (iv) the thermal requirements of different species or populations can be directly compared using ANCOVA. |
Book review: Sonenshine D.E. & Roe R.M. 2013: Biology of Ticks. 2nd ed.D. SOJKAEur. J. Entomol. 112 (3): 564, 2015 | DOI: 10.14411/eje.2015.069 Sonenshine D.E. & Roe R.M. 2013: BIOLOGY OF TICKS. 2nd ed. Oxford University Press, New York. Vol. 1: ISBN 978-0-19-974405-3 (hard cover), 560 pp., price USD 133.00, GBP 97.00; Vol. 2: ISBN 978-0-19-974406-0 (hard cover), 496 pp., price USD 133.00, GBP 97.00. |
Comparison of the exotic and native ant communities (Hymenoptera: Formicidae) in urban green areas at inland, coastal and insular sites in SpainJoaquín REYES-LÓPEZ, Soledad CARPINTEROEur. J. Entomol. 111 (3): 421-428, 2014 | DOI: 10.14411/eje.2014.044 Currently the introduction and spread of invasive species is an issue of great concern. To effectively manage this problem it is essential to know what constitute invasion hotspots. In this respect, the role of urban green areas in the conservation of biodiversity is a controversial matter. These areas may either favour colonization by alien species or shelter species of high conservation value. We evaluated the influence of location (island, coastal or inland) on the exotic and native ant fauna recorded in 27 urban green areas in Spain. A forward-stepwise discriminant analysis revealed differences between these locations in terms of the composition of the fauna, with exotic species identified as being the most important discriminating variable. There is a gradient: inland-coastal-island, along which there is significant increase in importance in terms of species richness and abundance of particular exotic species and decrease in the dominance of both common and rare native species. Areas located on the Island were more susceptible to invasion by alien ants. Coastal areas were also more susceptible to invasion than inland areas. These results possibly reflect the greater probability of an invasive species reaching these locations and the milder weather conditions at these sites, which would favour their establishment. |
BOOK REVIEW: Waldbauer G.: A WALK AROUND THE POND: INSECTS OVER AND IN THE WATER.T. SOLDÁNEur. J. Entomol. 107 (2): 246, 2010 | DOI: 10.14411/eje.2010.032 Harvard University Press, Cambridge, Massachusetts, London, England, 2006, vi + 286 pp. ISBN 0-674-02211-4. Price USD 22.95. |
Quantitative evidence for spatial variation in the biennial life cycle of the mountain butterfly Erebia euryale (Lepidoptera: Nymphalidae) in the Czech RepublicIrena KLECKOVA, Pavel VRBA, Martin KONVICKAEur. J. Entomol. 112 (1): 114-119, 2015 | DOI: 10.14411/eje.2015.003 Erebia euryale (Esper, 1805) is a montane-zone representative of a Holarctic butterfly genus the species of which occur mainly in alpine areas. As in many mountain insects, E. euryale frequently undergoes a prolonged biennial larval development, which can be synchronised across mountains, resulting in prominent biennial peaks in adult emergence. However, the extant reports are often contradictory, suggesting that populations are not synchronized. We present the first quantitative assessment of the situation in the Czech Republic, based on five years of monitoring adults along transects in three major mountain systems in this country. We detected a two order magnitude difference in biennial fluctuations in adult abundance, with peaks in even years (i.e. 2010, 2012) in the Šumava Mts (southwest Czech Republic). There were less distinct odd year (i.e. 2009, 2011, 2013) peaks in the Hrubý Jeseník Mts (northeast) and no fluctuations from year to year in the number of adults recorded in the Krkonoše Mts (north). Although the mechanisms behind these patterns remain unknown, we hypothesize that rugged terrain desynchronises and flat terrain synchronises the length of development of E. euryale. Finally, the different periodicity in the fluctuations in individual mountain ranges is hypothesized to be affected by interactions with larval parasitoids or reflect the different postglacial histories of respective populations. |
Book review: Thorp J.H. & Rogers D.C. (eds) 2015: Ecology and General Biology. Thorp and Covich's Freshwater Invertebrates.M. PAPÁÈEKEur. J. Entomol. 112 (3): 565-566, 2015 | DOI: 10.14411/eje.2015.070 Thorp J.H. & Rogers D.C. (eds) 2015: Ecology and General Biology. Thorp and Covich's Freshwater Invertebrates. Vol. 1. 4th ed. Academic Press, Elsevier, Amsterdam, Boston, Heidelberg, London, New York, Oxford, Paris, San Diego, San Francisco, Singapore, Sydney, Tokyo, 1118 pp. ISBN 9780123850263 (Print Book), 9780123850270 (eBook). Prices: Print Book + eBook: EUR 210.95 (currently reduced to EUR 126.57); Hardcover EUR 118.00; eBook EUR 92.95. |
New fossil Procercopidae (Hemiptera: Cicadomorpha) from the Middle Jurassic of Daohugou, Inner Mongolia, ChinaJun CHEN, Bo WANG, Haichun ZHANG, Xiaoli WANG, Xiaoting ZHENGEur. J. Entomol. 112 (2): 373-380, 2015 | DOI: 10.14411/eje.2015.044 Anthoscytina Hong, 1983 is the largest genus within the Mesozoic Procercopidae, the stem group of the superfamily Cercopoidea. Herein, we describe two new species from the Middle Jurassic of Daohugou, northeast China. Anthoscytina brevineura Chen, Wang & Zhang, sp. n. and Anthoscytina elegans Chen, Wang & Zhang, sp. n. are established on the basis of new well-preserved fossils. Although these two new species are very similar, some stable differences in tegminal venation and colour patterns confirm their species status. Sinotettegarcta longa Hong, 1986 is transferred to Anthoscytina, and to avoid secondary homonymy, a new name Anthoscytina hongi Chen, Wang & Zhang, nom. n. is proposed for that species. In addition, Anthoscytina aphthosa Ren, Yin & Dou, 1998 and Anthoscytina macula Hu, Yao & Ren, 2014 are transferred from Anthoscytina to Stellularis Chen, Yao & Ren, 2015. |
Modification of the rotating model method for studying the sexual discriminative abilities of butterflies (Lepidoptera)Tsuyoshi TAKEUCHIEur. J. Entomol. 112 (4): 860-861, 2015 | DOI: 10.14411/eje.2015.078 Recently, Imafuku & Kitamura (Eur. J. Entomol. 112, 2015: 328-333) succeeded in inducing males of two territorial butterflies, Chrysozephyrus smaragdinus and Neozephyrus japonicus, to respond to wing models by rotating the models. Based on the results of two-choice tests in which males stayed longer within 50 mm of the female model than the male model the authors claim that males of both of these butterflies identify females using the patterns on the wings. I think this study provides a new method for studying the discriminative abilities of butterflies. In contrast to static models, however, butterflies attracted to rotating models do not land on the models but remain at some distance from the moving models. A close approach to a model, therefore, does not always reflect the animal's preference. I suggest a better way of using this method for testing the discriminative ability of butterflies. |
Does the prediction of the time of egg hatch of Thaumetopoea processionea (Lepidoptera: Notodontidae) using a frost day/temperature sum model provide evidence of an increasing temporal mismatch between the time of egg hatch and that of budburst of Quercus robur due to recent global warming?Eiko WAGENHOFF, Annika WAGENHOFF, Rainer BLUM, Holger VEIT, Daniel ZAPF, Horst DELBEur. J. Entomol. 111 (2): 207-215, 2014 | DOI: 10.14411/eje.2014.030 Thaumetopoea processionea is a serious defoliator of oak and of medical concern whose abundance has consistently increased throughout Europe during the past two decades. This study validates a previously published frost day/temperature sum model for predicting time of egg hatch of this species using five years of recent field data from South-West Germany. This model proved satisfactory for predicting the time of egg hatch of T. processionea. Hence, the model was used to retrospectively predict the time of egg hatch of T. processionea in the Karlsruhe area, which indicates that the time of egg hatch has fluctuated over the past 130 years. In the last two decades, however, predicted time of egg hatch is much earlier than the long-term average due to the increase in winter and early spring temperatures. Comparison of predicted time of egg hatch of T. processionea and long-term records of the time of foliation of its common host Quercus robur revealed that in the study area the temporal advance in the timing of both events was similar. This is not in accordance with recently published research on spring-feeding folivores, which report a diverging trend in the timing of egg hatch and budburst of their host plants as a consequence of human-induced climate change. |
Morphometry and number of spermatozoa in drone honeybees (Hymenoptera: Apidae) reared under different conditionsAdel M. MAZEEDEur. J. Entomol. 108 (4): 673-676, 2011 | DOI: 10.14411/eje.2011.085 The effects of three factors operating during pre-emergence development period on some characteristics of drones were studied. Weight of newly emerged drones, length of forewing, length of tibia, length of femur, length and width of basitarsus and number of spermatozoa in drones from colonies in which the workers had access to drone brood (A), the size of brood cells differed (B) or the colony had a queen or was queenless (C), were determined. For this purpose, 9 colonies were chosen at random from the test apiary and prepared so that each contained one empty Langstroth frame with six small sub-frames containing drone combs, three of which were used to test the effect of one level and the other three the other level of each factor. The results showed that, colony status had a greater effect on the parameters measured than either the size of the brood cells or whether the workers had access to sealed brood cells. Most of the parameters were significantly different in C, whereas only a few in B and non in A were significantly different. The distance between discriminant scores in each experiment enhanced the previous results, as it was highest in C, followed by B and then A. Optimal drone characteristics may be recorded for colonies in which the queens were induced to lay unfertilized eggs in newly built drone combs, and then removed and the drone brood reared in a queen less colony. |
Relationship between the development of Simulium maculatum (Diptera: Simuliidae) and the thermal regimeRasa BERNOTIENĖ, Galina BARTKEVIÈIENĖEur. J. Entomol. 108 (3): 397-402, 2011 Warmer temperatures in the past 30 years have significantly influenced the seasonal development of insects throughout Europe. As a result of the outbreaks of black flies that have occurred in southeastern Lithuania since the 1970s it is hypothesized that this increase in black fly activity is due to the change in climate. To test this hypothesis the development of Simulium maculatum Meigen under different conditions was determined. This revealed that the time of hatching of S. maculatum eggs in Lithuania was influenced by winter air temperatures, especially those in March. Pupation in S. maculatum is associated with the increase in air and water temperatures that occur at the end of April and in May. The emergence of S. maculatum black flies occurs most often in May. At a water temperature of 13.2°C (1999), S. maculatum took 42 days to develop and half this time (21 days) when the water temperature was 18.8°C (2005). The number of black flies that emerged each year was determined by air temperature but unaffected by rainfall in June (either per month or per ten-day period). |
Carabid beetle assemblages associated with urban golf courses in the greater Helsinki areaJarmo SAARIKIVI, Laura IDSTRÖM, Stephen VENN, Jari NIEMELÄ, D. Johan KOTZEEur. J. Entomol. 107 (4): 553-561, 2010 | DOI: 10.14411/eje.2010.064 Golf is a popular sport, with increasingly large areas of urban and peri-urban land being designated for golf course development. Yet, more than half of the land area of a typical golf course is considered rough and out-of-play areas that can, if managed appropriately, provide habitats for wildlife. Using pitfall traps, 6944 carabid beetles belonging to 72 species were collected from five urban golf courses and three areas designated for golf course development around the city of Helsinki, Finland in 2007. The courses were rich in carabid species and distinct in their species assemblages. Golf courses were dominated by habitat generalists, species capable of flight and medium to large-sized species. The three courses with areas designated for further golf course development showed that the assemblages of beetles associated with these golf courses have retained many elements from the pre-existing habitats. The oldest golf course is characterised by a more evenly distributed and diverse carabid beetle assemblage, probably due to its higher habitat heterogeneity and longer successional development. However, even this golf course is dominated by generalist species, implying that golf courses may not provide suitable habitats for specialists. It is assumed that the high species richness of golf courses is attributed to the high habitat diversity of these environments, ranging from the strongly human-modified to more natural patches, which provide habitats for many generalist and open-habitat species. Golf courses may, however, with the appropriate management of out-of-play areas provide an opportunity for conserving biodiversity. |
Genetic and morphological differentiation between isolated Polish populations of "glacial relict", an endangered butterfly, Oeneis jutta (Lepidoptera: Nymphalidae)Lech KRZYSZTOFIAK, Anna KRZYSZTOFIAK, Krzysztof FR¡CKIEL, Anna BIA£A, Adrianna KILIKOWSKA, Jerzy SELLEur. J. Entomol. 107 (1): 115-120, 2010 | DOI: 10.14411/eje.2010.014 This is the first study of the morphological and molecular variation in two peripheral populations of the butterfly Jutta Arctic, Oeneis jutta, a glacial relict species endangered by the fragmentation of its habitat in Poland. An analysis of the morphological characteristics indicates that both Polish populations are similar but differ significantly in some characteristics. Levels of genetic variation were assessed using mitochondrial cytochrome oxidase subunit I (COI) and NADH dehydrogenase subunit 5 (ND5) gene fragments together with a segment of the mtDNA control region (CR) and a nuclear elongation factor-1a (EF-1a) gene sequence. In addition, the pattern of molecular variation in specimens from eastern and northern Europe was examined. Interestingly, the analysis of variation in a 932-bp sequence of the nuclear EF-1a gene in representatives of the populations studied revealed a relatively higher level of diversity than that of mitochondrial genes. There was evidence of divergence between the peripheral populations and lack of gene flow between them. The two closely situated populations had a high FST value (0.69), which clearly indicates their isolation. These populations appear to be demographically independent breeding units, with distinctive allele frequencies and consequently should be recognized as separate units for management and conservation. The preliminary results are in accord with an a priori subdivision based on collection areas and suggest that habitat fragmentation has affected the genetic diversity and structure of these populations. |
The link between food and reproduction in aphidophagous predators: a case study with Harmonia axyridis (Coleoptera: Coccinellidae)Edward W. EVANS, Derrick I. GUNTHEREur. J. Entomol. 102 (3): 423-430, 2005 | DOI: 10.14411/eje.2005.060 For polyphagous predators, the link between food consumption and reproduction is not always straightforward, and instead may reflect that even predators with very broad diets may have reproductive tactics that are tied to consumption of a restricted range of prey. We studied the consumption and use of two prey species for reproduction by the ladybird, Harmonia axyridis Pallas. This polyphagous predator feeds on both pea aphids [Acyrthosiphon pisum (Harris)] and larvae of the alfalfa weevil [Hypera postica (Gyllenhal)] that it encounters when foraging in alfalfa fields. When provided a diet of pea aphids or of alfalfa weevils and/or sugar water, females of H. axyridis laid eggs in large numbers only on the diet of aphids. Females laid no eggs on diets of weevils or sugar alone, and laid only small numbers of eggs when the two foods were provided together. When placed on a diet of aphids, females began laying eggs earlier, and laid more eggs altogether, when they had previously fed on weevils versus sugar water. The predators' consumption rates of aphids were greater than their consumption rates of weevils, and they produced less frass per mg of prey consumed on an aphid versus weevil diet. The predators searched more actively when maintained on a weevil versus aphid diet. Hence, lower rates of food intake and assimilation, and greater allocation of nutrients and energy to searching, appear to contribute to the reduced egg production of H. axyridis females that feed on weevils versus aphids. Alfalfa weevils are also less suitable prey than pea aphids for larval survival and development of H. axyridis. Thus, the differing responses of H. axyridis adults to these two prey types may reflect that these predators are well adapted in the linking of their feeding and reproductive behavior. |
Abundance and species richness of overwintering ground beetles (Coleoptera: Carabidae) are higher in the edge than in the centre of a woodlotAnthony ROUME, Annie OUIN, Laurent RAISON, Marc DECONCHATEur. J. Entomol. 108 (4): 615-622, 2011 | DOI: 10.14411/eje.2011.080 Semi-natural habitats are key components of rural landscapes because they shelter a significant number of overwintering arthropods that are beneficial to agriculture. However, woodlots are semi-natural habitats with high patch-level heterogeneity and this aspect has been poorly studied. The purpose of this study was to determine the influence of woodlot heterogeneity on overwintering ground beetles. Woodlot heterogeneity was characterized in terms of distance from the woodlot boundary and date of the most recent logging operation. We used emergence traps to quantify the population density of ground beetles that overwintered in the different parts of the woodlot. In woodlot edges the densities and species richness of ground beetles were significantly higher than in the rest of the woodlot. Ground beetles that are active in crop fields overwintered in the edges but not in the inner zone of the woodlot. Species assemblages of ground beetles overwintering in the edges were highly diverse. The date of the most recent logging operation did not explain the distribution of ground beetles that overwintered in the woodlot. Our results show that woodlots, and in particular their edges, are used as a winter shelter by ground beetles that spend part of their life in crops, which potentially favours biological control in adjacent crop fields. |
Fluorimetric determination of hydrogen peroxide production by the haemocytes of the wax moth Galleria mellonella (Lepidoptera: Pyralidae)Ondøej VA©ÍÈEK, Ivana PAPE®ÍKOVÁ, Pavel HYR©LEur. J. Entomol. 108 (3): 481-485, 2011 The aim of this study was to investigate whether haemocytes of Galleria mellonella (Lepidoptera: Pyralidae) larvae produce reactive oxygen species (ROS) like human blood phagocytes. The production of ROS was measured first using luminol-enhanced chemiluminescence of un-stimulated and stimulated (four activators with different modes of action) haemolymph or isolated haemocytes. However, spontaneous and activated production of ROS remained at the background level. In subsequent experiments an ultrasensitive fluorescence method using Amplex Red reagent to detect hydrogen peroxide (H2O2) was used. After optimization, Amplex Red was successfully used for determining H2O2 production by both un-stimulated and stimulated haemocytes. To determine the affect of pH and ions on the measurement, several diluent solutions were tested. This revealed that Ca2+ and Mg2+ ions are less important for the reaction in insect than mammalian cells. Among the activators tested, phorbol myristate acetate (PMA) and calcium ionophore (Ca-I) had the best stimulatory effect on insect samples, while opsonised zymosan particles (OZP) was the best activator for human phagocytes. In conclusion, the haemocytes of G. mellonella produce H2O2 as an important innate immunity factor, but under different conditions and in different amounts, which probably results in them being less effective in killing microbes than human phagocytes. |
Ground-dwelling arthropod communities present in three types of Cantabrian (NW Spain) heathland grazed by sheep or goatsRocío ROSA GARCÍA, Francisco J. OCHARAN, Berta M. JÁUREGUI, Urcesino GARCÍA, Koldo OSORO, Rafael CELAYAEur. J. Entomol. 107 (2): 219-227, 2010 | DOI: 10.14411/eje.2010.029 The abundance, diversity and community composition of ground-dwelling arthropods present in three different types of Cantabrian heathland grazed by small ruminants were studied. A factorial design of three vegetation types (heather-, gorse- or grass-dominated) and two grazer species (sheep or goats) with two replicates was established in twelve 0.6 ha paddocks. Ground-dwelling arthropods (Araneae, Opiliones, Isopoda, Julida, Microcoryphia, Hemiptera, Coleoptera and Hymenoptera) were recorded using pitfall traps and plant cover and canopy height assessed in each paddock in 2005, 2006 and 2007. Higher abundances and more families of ground dwelling arthropods were recorded in areas dominated by heather, although certain species were more numerous in areas dominated by grass. The direct effects of the grazer species on arthropods were subtle compared to their great effect on the vegetation. Significant interactions between grazer species and vegetation were observed for some taxa and the overall arthropod community composition. Gradient analyses indicate that arthropod assemblages that include Lycosidae, Opiliones and Carabidae differed between vegetation types and years, but are not affected by the grazer species. Our study shows that areas dominated by shrubby and diverse heather had the highest diversity and abundance of arthropods. Species composition varied along a gradient in the structure of the vegetation, which in turn was modified by the grazer species. |
Seed preferences of Pyrrhocoris apterus (Heteroptera: Pyrrhocoridae): Are there specialized trophic populations?Marta KRISTENOVÁ, Alice EXNEROVÁ, Pavel ©TYSEur. J. Entomol. 108 (4): 581-586, 2011 | DOI: 10.14411/eje.2011.075 The populations of the firebug Pyrrhocoris apterus (Heteroptera: Pyrrhocoridae) in Europe exhibit three kinds of host plant associations: feeding on seeds of (1) Tilia spp. (Tiliaceae), (2) Malvaceae (s. str.), and (3) Robinia pseudacacia (Fabaceae). The three host plant taxa often grow in different habitats and localities. We have tested the hypothesis that P. apterus forms on different host plants specialised "trophic populations" which also influence its food preference. We have collected P. apterus from localities with Tilia platyphyllos, Malva neglecta or Robinia pseudacacia as host plants and tested their preferences in a multiple choice test involving seeds of Tilia cordata, T. platyphyllos, Althaea officinalis, Alcea rosea and Robinia pseudacacia. The original host plant of P. apterus population had no influence on food preferences. However, the preferences differed between adults and the third instar larvae. The adults preferred seeds of Robinia pseudacacia followed by Althaea officinalis, while the preferences of larvae were less pronounced and ranked in order Althaea officinalis, Robinia pseudacacia, and Tilia platyphyllos. Existence of trophic populations of P. apterus was not confirmed by our experiment. Durations of feeding were longer on preferred species of seeds in both adults and larvae. |
Contribution to the biochemical characterization of the silk and structure characterization of the cocoons of the horse chestnut leaf miner Cameraria ohridella (Lepidoptera: Gracillariidae)Veronika HNÌVSOVÁ, Dalibor KODRÍK, Franti¹ek WEYDAEur. J. Entomol. 108 (4): 711-715, 2011 | DOI: 10.14411/eje.2011.091 This study of the proteins in the silk of the summer and winter cocoons of the horse chestnut leaf miner Cameraria ohridella revealed they can inhibit protease activity. The inhibitory activity of the summer silk was higher against both the fungal proteinase K and bacterial subtilisin than that of the winter silk. Also, the winter silk was more effective in inhibiting proteinase K than subtilisin. Further, it was demonstrated that some of the silk proteins are glycosylated probably by mannose carbohydrates. An electron microscopy study of the cocoons revealed the presence of silk fibres with different diameters in some pupal chambers. |
Some ethological aspects of the trophobiotic interrelations between ants (Hymenoptera: Formicidae) and larvae of the sawfly Blasticotoma filiceti (Hymenoptera: Blasticotomidae)Tatiana A. NOVGORODOVA, Olga B. BIRYUKOVAEur. J. Entomol. 108 (1): 47-52, 2011 | DOI: 10.14411/eje.2011.006 Some ethological aspects of the interrelations between ants and the larvae of Blasticotoma filiceti Klug, 1834 were investigated in the Altai Republic and Novosibirsk Region in 2006-2008. The interactions of ants with the larvae of this sawfly are determined by the concealed way of life style of B. filiceti. The majority of the ant-sawfly encounters occurred near holes in fern fronds at the moment when larvae excreted liquid or left their tunnels before descending to the soil prior to overwintering. Sawfly larvae visited by more aggressive ants, such as Formica s. str., leave the fern fronds slowly, which enables them to avoid inciting attacks by ants. The behaviour of the ants while collecting the larval excretion is similar to their behaviour at sugar troughs. The organisation of the collecting larval excreta by ants was investigated in detail in the cases of Formica polyctena Förster, 1850 and Myrmica rubra Linnaeus, 1758. The individual fern plants with sawfly larvae are attended by relatively constant groups of foragers in both cases. However, the highly social red wood ants interact with sawfly larvae in a more complex way. While the working groups of M. rubra tending sawfly larvae consist only of non-aggressive "unspecialized" foragers, those of F. polyctena include also a few "on duty" ants that protect the trophobionts, at least from the other ants. |
Comparative study of larval head structures of Megaloptera (Hexapoda)Rolf G. BEUTEL, Frank FRIEDRICHEur. J. Entomol. 105 (5): 917-938, 2008 | DOI: 10.14411/eje.2008.119 External and internal head structures of the larva of Neohermes are described in detail. The results are compared to conditions found in other representatives of Corydalidae, in Sialidae, and in Raphidioptera and Neuroptera. Corydalidae and Sialidae are mainly characterised by plesiomorphic features such as distinct frontal and coronal sutures, six stemmata, a movable labrum with a full set of muscles, a thin tentoriomandibular muscle, a distinct maxillary groove, 4-segmented maxillary palps, an oblique arrangement of the extrinsic maxillary muscles, a labium with all components except for the glossae and paraglossae, 3-segmented labial palps, and a largely complete muscle system. The partly reduced maxillary groove, the strongly elongated stipes, the apical membranous stipital collar, the close connection of the palp and galea, the subdivision of the galea, the strongly shortened palp, the bipartite tentoriocardinal and tentoriostipital muscles, the anterolateral submental notch, the lateral tentoriopharyngeal muscle, and the postgular plate are autapomorphies of Corydalidae. An additional antennomere is present in large corydalid species. The monophyly of the subfamilies Corydalinae and Chauliodinae is not supported by features of the larval head. The reduced condition of the anterior and dorsal tentorial arms and the antennal muscles, the transverse labial muscle, the loss of muscles of the salivary duct, and possibly the lateral origin of M. frontopharyngalis posterior are autapomorphies of Sialidae. The monophyly of Megaloptera is suggested by the insertion of a peg-like or spine-shaped sensillum on the antepenultimate antennomere, the vestigial salivary duct, and a verticopharyngeal muscle composed of several bundles. The distinct neck region, the parietal ridge, and the anterior position of the posterior tentorial grooves are features shared by Corydalidae and Raphidioptera. Arguments in favour of a clade comprising Megaloptera and Raphidioptera are the presence of a circular ridge anterad of the neck region, an increased number of Semper cells and retinula cells in the stemmata, the presence of a gula in adults, a similar cleaning behaviour, and molecular data. Potential autapomorphies of Neuropterida are the prognathism of the larvae and the absence of a mandibular mola. However, the polarity of these characters is unclear. A derived condition found in most groups of Endopterygota, but not in Hymenoptera, is the presence of one or two sensorial appendages on one of the intermediate antennomeres, usually the penultimate. Larval autapomorphies of Endopterygota suggested in earlier studies are confirmed for Corydalidae. |
Effect of insect-resistant transgenic maize on growth and development, utilization of nutrients and in vivo activity of the detoxification enzymes of the Asian corn borer, Ostrinia furnacalis (Lepidoptera: Pyralidae)Min Juan SHI, Pei LING LU, Xiao Li SHI, Yi Zhong YANGEur. J. Entomol. 108 (4): 547-552, 2011 | DOI: 10.14411/eje.2011.070 There is little systematic research on the effect of transgenic maize expressing Bacillus thuringiensis (Bt) toxins on insect survival and the response in vivo of their detoxification enzymes. Results of laboratory bioassays indicate that the whorl leaves of transgenic maize lines G03-2396 and G03-2739 significantly affected the survival of neonate and third instar larvae of the Asian corn borer, Ostrinia furnacalis (Güenée). Neonate mortality two days after being fed on G03-2739 was 72.5% and exceeded 92.5% four days later. The percentage mortality of third instar larvae six days after being fed whorl leaves from G03-2396 exceeded 65%. The resistance of whorl leaves to insect attack was greater than that of maize-ears, but less effective against attacks by third instar larvae. Neonate development was more prolonged when they were fed on whorl leaves of both the transgenic maize lines. In contrast, low pupation (<80% of that recorded in the controls), ecolosion and fecundity were recorded following ingestion of maize-ears, with pupal weights 10-14 mg lower than that of controls. The growth rates of third instar larvae recorded three and six days after feeding on whorl leaves were lower, but food utilization, conversion and relative metabolism were not significantly affected. Relative food ingestion, relative growth rate and other nutritional indicators of third instar larvae were significantly lower six days after the ingestion of ears and that of fifth instar larvae after three days. In vivo activity of carboxylesterase was decreased to a greater degree after three days when the larvae were fed on whorl leaves than ears, with no significant effect on fifth instar larvae. Furthermore, in vivo activity of glutathione S-transferase (GST) of third instar larvae was significantly affected following the ingestion of whorl leaves. These results are discussed in the context of the literature on the resistance of transgenic plants and of improving the resistance of plants to attack by the different larval stages of insects. |