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Molecular evidence resolving the confusion of two species of Spilopteron (Hymenoptera: Ichneumonidae) caused by marked geographical colour variationMasato ITO, Kyohei WATANABE, Kaoru MAETOEur. J. Entomol. 112 (3): 543-556, 2015 | DOI: 10.14411/eje.2015.068 The delimitation of two ichneumonid species, Spilopteron apicale (Matsumura) and S. tosaense (Uchida), was investigated using DNA sequences of the mitochondrial COI and nuclear 28S rRNA genes, as well as adult morphology. The two species have long been confused and were until recently speculated to be the same species with continuous colour variation. Our molecular and morphological studies reveal that there are two distinct species: a dark species confined to northern or high latitude localities (S. apicale) and a widely distributed species with a marked geographical gradient in body colour (S. tosaense) across the Japanese Archipelago. In the latter species, female body colour became significantly darker with latitude and altitude. A lectotype of Chorischizus apicalis Matsumura, 1912 is designated. |
Bacillus in the guts of honey bees (Apis mellifera; Hymenoptera: Apidae) mediate changes in amylase valuesMiao WANG, Wen-Zheng ZHAO, Hong XU, Zheng-Wei WANG, Shao-Yu HEEur. J. Entomol. 112 (4): 619-624, 2015 | DOI: 10.14411/eje.2015.095 Amylase is one of three main enzymes involved in the breakdown and utilization of macromolecules. In honey bees (Apis mellifera), amylase was traditionally believed to originate only as secretion of the bee. However, other sources of amylase production, such as microbes in the guts of bees remained to be studied. In our research, we compared the differences in the amylase values in rape flower nectar and honey in the stomachs of bees. Then, culture-dependent and culture-independent (16sDNA) methods were used to isolate and identify bacteria in rape flower nectar and bee stomach honey. The dominant bacteria were added to nectar, and the amylase values of nectar with added gut microbes and nectar without added microbes were compared. Our findings indicate that the amylase value was significantly increased, which correlates with the increase in number of bacteria that occurred from nectar to honey in the stomachs of bees. The dominant bacteria in honey bee stomachs were mainly Bacillus during the flowering season of rape. Experiments confirmed that the amylase levels in nectar increased significantly when bacteria were added. These results indicate that bacteria in the foregut of bees help in the processing floral nectar into honey. |
Inhibitory effects of plant latex on trehalase activity and trehalase gene expression in the red flour beetle, Tribolium castaneum (Coleoptera: Tenebrionidae)Nujira TATUN, Boonguea VAJARASATHIRA, Jatuporn TUNGJITWITAYAKUL, Sho SAKURAIEur. J. Entomol. 111 (1): 11-18, 2014 | DOI: 10.14411/eje.2014.002 Plant latex contains proteins and other components that defend plants against herbivorous insects. We determined the inhibitory activity of methanolic extracts of latex obtained from three species of plant: mulberry, Morus alba; jackfruit, Artocarpus heterophyllus; and weeping fig, Ficus benjamina, against trehalase in the red flour beetle, Tribolium castaneum. We also determined the changes that occurred throughout the life of the insect in the enzymatic activities of soluble and membrane-bound trehalase and the expression profiles of the genes encoding the two types of trehalase. Soluble trehalase activity was higher than membrane-bound trehalase activity in larvae and adults, whereas there was little difference in eggs, prepupae and pupae. The expression of the trehalases, TcTre-1 and TcTre-2, changed during insect development but did not coincide closely with changes in enzymatic activity, indicating that these changes did not necessarily depend on gene expression. All of three plant latices tested inhibited the activities of both the soluble and membrane-bound trehalase. At the gene expression level, these latices reduced the expression of TcTre-1 but not TcTre-2, indicating that the latices contain component(s) that selectively inhibit gene expression or at least differentially inhibit these two trehalase genes. The inhibition of trehalase activity resulted in a 140% increase in the concentration of trehalose in the beetle and a decrease in glucose concentration to 72% of the control. These findings show that the latices tested contain components that inhibit trehalase activity and TcTre-1 expression and thus, may contribute to the plants' defense against herbivorous insects. |
Functional response and predatory interactions in conspecific and heterospecific combinations of two congeneric species (Coleoptera: Coccinellidae)Bhupendra KUMAR, Geetanjali MISHRA, OMKAR*Eur. J. Entomol. 111 (2): 257-265, 2014 | DOI: 10.14411/eje.2014.025 In the present study, the predatory interactions between two locally abundant large lady beetles, Coccinella septempunctata L. (C7) and Coccinella transversalis F. (Ct) provided with either an extremely scarce, scarce, sub-optimal, optimal or abundant supply of the pea aphid, Acyrthosiphon pisum (Harris) were investigated. For this, three 2-predator combinations (conspecific C7 + C7 and Ct + Ct, and heterospecific C7 + Ct) of 10-day-old unmated adult females were used. The relationships between the proportion of prey consumed by the predators in the conspecific and heterospecific combinations when provided with five different abundances of prey were similar in consisting of a decelerating (type II) functional response when provided with an extremely scarce to optimal supply of prey, followed by an accelerating (type III) functional response when provided with an optimal to abundant supply of prey. It is likely that the modified type II functional response recorded in the present study was a consequence of using a small experimental arena (Petri dish). The multiplicative risk model analysis revealed that the predators interacted antagonistically except in the C7 + C7 combination provided with an extremely scarce supply of prey where the predators had an additive effect. The predators in the heterospecific C7 + Ct combination consumed fewer aphids when provided with an extremely scarce, scarce, sub-optimal or optimal supply of prey prey than the predators in conspecific C7 + C7 combination but a similarly high number when provided with an abundant supply of prey. In addition, the efficiency of converting prey biomass into their own biomass was higher in the heterospecific C7 + Ct than in the conspecific C7 + C7 or Ct + Ct combinations at all prey densities. Although the conversion efficiency of the predators in the conspecific and heterospecific combinations provided with an extremely scarce supply of prey was the highest recorded, their growth rate was the lowest. In contrast, both the conversion efficiency and growth rate of the predators in the three combinations were highest when provided with an abundant supply of prey. It may, therefore, be concluded that when the predators in the combinations occupy similar ecological niches, they will probably consume less prey than they require when prey is both scarce and abundant because the predators interact antagonistically. |
Recorded and potential distributions on the iberian peninsula of speciesof Lepidoptera listed in the Habitats DirectiveHelena ROMO, Edgar CAMERO-R., Enrique GARCÍA-BARROS, Miguel L. MUNGUIRA, José MARTÍN CANOEur. J. Entomol. 111 (3): 407-415, 2014 | DOI: 10.14411/eje.2014.042 Abstract. Using data on the known Iberian distributions of 10 species of Lepidoptera listed in the Habitats Directive referenced to the 10 × 10 km UTM grid, we determined their potential distributions and their relationships with selected bioclimatic factors associated with mean temperature and precipitation using Ecological Niche Factor Analysis (ENFA). Scores for Specialization and Marginality were determined in order to evaluate the relationships between the predictions of the model and climatic factors. The number of squares on the Iberian Peninsula in which the species are recorded and those squares predicted to be favourable for these species were determined if they matched the network of Protected Natural Areas. This suggested that a further eight 10 × 10 km squares should be included in Protected Natural Areas. The results also indicate that climate determines the distributions of most of the species. Although overall there is a close association between the observed and predicted distributions, the less thoroughly documented geographic ranges (i.e. those of the moth species) depart from this pattern. |
Cryptic diversity and signs of mitochondrial introgression in the Agrilus viridis species complex (Coleoptera: Buprestidae)Mikko PENTINSAARI, Marko MUTANEN, Lauri KAILAEur. J. Entomol. 111 (4): 475-486, 2014 | DOI: 10.14411/eje.2014.072 The jewel beetle genus Agrilus (Buprestidae), with approximately 2880 recognized species, is taxonomically challenging due to the great similarity of species. An example of taxonomic ambiguity is the Agrilus viridis species group, particularly the viridis complex that comprises many varieties differing both ecologically and morphologically. The status of these varieties has remained largely unresolved and no consensus exists on their status. We used geometric morphometrics in combination with the DNA barcode marker sequence in order to evaluate the possible distinction among populations of A. viridis feeding on Alnus, Betula and a variety of Salix species in Finland. We found that morphology supports the existence of two species, one feeding on Betula and Alnus, the other feeding on Salix. The findings based on DNA barcodes are more complex, suggesting possible introgression events in the species' history. Our results suggest that the Betula/Alnus and Salix feeding forms of A. viridis represent distinct species that have, while maintaining their morphological integrity, probably experienced repeated hybridization events in the past. DNA barcoding provides valuable additional information for taxonomic studies based on careful morphological study and information on their ecology, but drawing taxonomic conclusions from barcode data alone can lead to considerable confusion. |
New fossil taxa of Monophlebidae (Sternorrhyncha: Coccoidea) from Baltic amberEwa SIMON, Dagmara ŻYŁAEur. J. Entomol. 112 (2): 381-388, 2015 | DOI: 10.14411/eje.2015.038 The family Monophlebidae is distributed worldwide and is classified as one of the "archaeococcoid" families. After almost 160 years since Germar & Berendt (1856) described the first and so far only fossil monophlebid species, Monophlebus irregularis, two new fossil species of a new and undoubtedly monophlebid genus Palaeophlebus gen. n. are described from Baltic amber. Morphological features of the new genus and its two species, P. hoffeinorum sp. n. and P. kotejai sp. n., are discussed. |
Reproductive performance of Propylea japonica (Coleoptera: Coccinellidae) under various light intensities, wavelengths and photoperiodsSu WANG, Kun WANG, J.P. MICHAUD, Fan ZHANG, Xiao-Ling TANEur. J. Entomol. 111 (3): 341-347, 2014 | DOI: 10.14411/eje.2014.053 Cocccinellid beetles are largely diurnal species that are known to utilize visual cues in foraging and reproduction and to respond in specific ways to various light conditions. The present study evaluated the mating behavior and reproductive performance of Propylea japonica (Thunberg), a species indigenous to Asia, under various conditions of light intensity, photoperiod, and wavelength. Video-recording was used to continuously observe mating pairs for 24 h and a night vision system was employed to record nocturnal activity. Subsequently, males were removed and eggs were collected from females for 10 days and held under the same photic conditions to determine their fertility. The frequency and duration of copula varied among photic regimes in all experiments and tended to be negatively correlated, but more copulations occurred in photophase than in scotophase. White light at 1500 lux yielded higher egg production when compared to other light intensities, but egg fertility was higher at lower light intensities and highest in complete darkness, a result inferred to reflect egg sensitivity to light. Both fecundity and fertility were greater when 1500 lux white light was provided in a 16L : 8D photoperiod compared to shorter days. Green light yielded the highest net fertility compared to other wavelengths. A scheme is proposed to optimize photic conditions for reproductive adults of P. japonica and their eggs in colonies mass-reared for biological control applications. |
Bactrocera oleae (Diptera: Tephritidae) organophosphate resistance alleles in Iberia: Recent expansion and variable frequenciesIsabel PEREIRA-CASTRO, Barbara VAN ASCH, Fernando TRINDADE REI, Luís TEIXEIRA DA COSTAEur. J. Entomol. 112 (1): 20-26, 2015 | DOI: 10.14411/eje.2015.019 The olive fly, Bactrocera oleae (Rossi, 1790) (Diptera: Tephritidae), is the most important pest of olive trees globally, causing losses that, in the absence of control measures, can exceed 90% of the crop. In the Mediterranean basin, where the overwhelming majority of production is concentrated (~ 98%), organophosphate insecticides (OPs) have been the main tool for B. oleae control for the last four decades, leading to the development of resistance to these compounds. Mutations of the Ace gene, which codes for acetylcholinesterase, the target enzyme of OPs and other insecticides, have been identified as the underlying cause, with studies reporting mid to very high frequencies of resistance alleles in several countries. Interestingly, no resistance alleles were detected in Portugal, at the Western end of the Mediterranean basin. As the original study was done almost a decade ago and did not include many samples, we decided to re-evaluate the situation, by analysing a larger number of individuals from multiple locations in Western and Southern Iberia (Portugal and Spain). In our present study, resistance-associated Ace alleles were found to have become widespread in both regions, but with highly varying frequencies. Together with the observed haplotype distributions, this finding is consistent with previous suggestions of a recent, selection-driven spread and has implications for the importance of Ace mutations in organophosphate resistance in the field as well as the importance of gene flow between Mediterranean populations of B. oleae. |
Ability of males of two theclini species (Lepidoptera: Lycaenidae) to discriminate between sexes and different types of females based on the colour of their wingsMichio IMAFUKU, Tasuku KITAMURAEur. J. Entomol. 112 (2): 328-333, 2015 | DOI: 10.14411/eje.2015.034 Many territorial species of butterfly are sexually dimorphic in their wing colours, and males of such species frequently fight each other, probably attracted by the rival's wing colour. On the other hand, male behaviour should be directed to acquiring mates to increase their fitness, and thus should be sensitive to (usually cryptic) female wing colour. The present experiments aimed to determine whether the conspicuous male colour or cryptic female colour is more attractive to the territorial males of two lycaenid species, Chrysozephyrus smaragdinus and Neozephyrus japonicus. A pair of female and male wing models was presented simultaneously in the field to a male. The results indicate that the males of both species were preferentially attracted by the female wing model. In N. japonicus, in which the wing colour of females is polymorphic, males preferred particular types of female wings, in that they were more strongly attracted to the type-B model with a blue patch on the forewing than the type-O model, which lacked a blue patch. |
Demographic parameters of Diuraphis noxia (Hemiptera: Aphididae) and Hippodamia variegata (Coleoptera: Coccinellidae) recorded in the context of D. noxia infesting resistant and susceptible cultivars of wheatLeila ZANGANEH, Hossein MADADI, Hossein ALLAHYARIEur. J. Entomol. 112 (3): 453-459, 2015 | DOI: 10.14411/eje.2015.053 The Russian wheat aphid (RWA), Diuraphis noxia (Kurdjumov), is a serious pest of small grains and can cause losses of about 80% in wheat yields. Chemical control is ineffective against this pest so the combined use of host plant resistance and biological control is seen as a possible better means of controlling this pest. In this study, the potential effect of Omid (resistant) and Sardari (susceptible) cultivars of wheat on life table parameters and daily fecundity of RWA and its predator, Hippodamia variegata (Goeze), were determined using the age-stage two-sex life table theory. The results indicate that the rm, R0, λ, T and GRR of RWA were -0.005 ± 0.01 day-1, 0.9 ± 0.24 offspring per individual, 0.99 ± 0.01 day-1, 21.16 ± 1.79 days and 13.34 ± 2.91 offspring on Omid and 0.159 ± 0.01 day-1, 6.9 ± 0.54 offspring per individual, 1.17 ± 0.01 day-1, 12.14 ± 0.26 days and 12.73 ± 1.22 offspring on Sardari. The corresponding values for H. variegata fed on RWA reared on Omid were 0.24 ± 0.01 day-1, 399.35 ± 53.01 eggs, 1.27 ± 0.01 day-1, 24.67 ± 0.28 days and 544.23 ± 75.86 eggs and on Sardari 0.20 ± 0.006 day-1, 221.56 ± 34.68 eggs, 1.23 ± 0.01 day-1, 26.50 ± 0.41 days and 402.72 ± 67.55, respectively. The resistance of wheat cultivars significantly affected life table parameters and mean fecundity of RWA and H. variegata. Our results indicate that combining both host plant resistance and predators in the integrated pest management of RWA could result in a synergistic effect. |
Epitrix papa sp. n. (Coleoptera: Chrysomelidae: Galerucinae: Alticini), previously misidentified as Epitrix similaris, is a threat to potato production in EuropeMarina J. ORLOVA-BIENKOWSKAJAEur. J. Entomol. 112 (4): 824-830, 2015 | DOI: 10.14411/eje.2015.096 A nonnative pest of potato recently established and causing significant economic damage in Portugal and Spain was initially identified as Epitrix similaris Gentner and included on lists of quarantine pests. The identity of this pest was doubted by some experts, since E. similaris is a rare species previously recorded only from California and does not damage potato in its native range. Our comparison of 20 specimens of this pest from Portugal with paratypes of E. similaris has revealed that it is not E. similaris. The name "Epitrix similaris" should be removed from lists of quarantine pests. The damage to potato tubers caused by the larvae of this pest is similar to that of E. tuberis Gentner, but examination of paratypes of E. tuberis has revealed that the pest is not E. tuberis. This pest differs from all species of Epitrix recorded in the Holarctic and from all known Epitrix pests of potato in the world. Herewith it is described as a new species Epitrix papa sp. n., whose native range is unknown. |
Form, function and evolutionary significance of stridulatory organs in ant nest beetles (Coleoptera: Carabidae: Paussini)Andrea DI GIULIO, Simone FATTORINI, Wendy MOORE, James ROBERTSON, Emanuela MAURIZIEur. J. Entomol. 111 (5): 692-702, 2014 | DOI: 10.14411/eje.2014.083 Stridulatory organs in the myrmecophilous carabid beetle tribe Paussini have long been recognized and used as a defining character of some genera and higher level taxa, however their morphology has only roughly been described. Here, we describe the fine morphology of Paussini stridulatory organs using scanning electron (SEM) and focused ion beam (FIB) microscopy. Within this tribe, there are three types of stridulatory organs, each with different positions of the scraper (plectrum) and file (pars stridens). Type I (abdomen-femur type) is located on the abdomen (scraper) and metafemur (file) in the subtribe Paussina (sensu Geiselhardt et al., 2007, Naturwissenschaften 94: 871-894). Type II (thorax-femur type) and Type III (femur-thorax type) are located on the mesothorax and mesofemur in two different genera of the subtribe Platyrhopalina, however in Euplatyrhopalus the scraper is located on the mesothorax and the file is located on the mesofemur (Type II), whereas in the genus Platyrhopalopsis the structures are reversed in that the file is located on the mesothorax and the scaper is located on the mesofemur (Type III). The independent evolution of three types of stridulatory organs in three lineages of Paussini suggests that acoustical communication has played an important role in the evolution of ant nest beetles. While the roles of stridulation in this group remain speculative, we verified that all three types of stridulatory organs are present in both sexes and are similar to stridulatory organs known in their host ants which also use stridulation as a method of communication. We discuss the possibility that the beetles stridulation could (1) facilitate their exploitation of ant colonies, and (2) be involved in mate recognition and courtship. |
Morphometrics, life history and population biology of the Ponto-Caucasian slave-making ant Myrmoxenus tamarae (Hymenoptera: Formicidae)Nana GRATIASHVILI, Masaki SUEFUJI, Shalva BARJADZE, Jürgen HEINZEEur. J. Entomol. 112 (1): 175-179, 2015 | DOI: 10.14411/eje.2015.025 Abstract. The ant genus Myrmoxenus consists of about ten socially parasitic species including active slave-makers and workerless "degenerate slave-makers". Myrmoxenus tamarae was previously known only from type material, two workers collected at Daba, Georgia and nothing was known about its life history, colony structure or the morphology of its sexuals. An inspection of colonies of M. tamarae near the type locality in 2010 indicates that young queens of M. tamarae invade Temnothorax nests and kill the host queen by throttling. The simultaneous presence of two slave species in a single colony (an undescribed species related to T. nylanderi and a species morphologically resembling T. unifasciatus) indicates that M. tamarae is an active slave-maker. The genetic structure of the colonies matches that expected for a monogynous and monandrous ant, but three of eight colonies inspected appeared to contain workers belonging to an additional genetic lineage. |
Effects of host size and laboratory rearing on offspring development and sex ratio in the solitary parasitoid Agrothereutes lanceolatus (Hymenoptera: Ichneumonidae)Takatoshi UENOEur. J. Entomol. 112 (2): 281-287, 2015 | DOI: 10.14411/eje.2015.048 Agrothereutes lanceolatus is a solitary ectoparasitoid attacking mature larvae, prepupae and pupae of tortricid and pyralid moths, including Homona magnanima, which is an important pest of tea. Adult A. lanceolatus are sexually dimorphic and vary considerably in size in the wild, suggesting they parasitize a variety of hosts of different sizes. Here, the effects of host size on offspring survival, size and sex ratio in A. lanceolatus were investigated. Wild-caught and laboratory-reared parasitoids were used to identify the effects of laboratory rearing on the above three biological parameters. The percentage of hosts producing parasitoid offspring was not dependent on host size regardless of parasitoid generation. Offspring survival was lower in laboratory-reared generations than the F1 generation. Large parasitoids emerged from large hosts. The offspring sex ratio (proportion of females emerging) was positively correlated with host size. The sex ratio at the egg stage (= primary sex ratio) inferred from maternal fertilization act also changed in response to host size, although there was imperfect control of female egg deposition. Thus, the observed sex-ratio resulted from maternal control of offspring sex ratio. A striking difference was detected in the offspring sex ratio in the different generations. Offspring sex ratio was more male-biased in laboratory reared generations. These results suggest that inbreeding depression caused a reduction in offspring survival and the male-biased sex ratio in the laboratory. The sex-ratio difference could result either from the difference in host size in the field and laboratory or from the production of diploid males in the laboratory. |
Host-plant leaf-surface preferences of young caterpillars of three species of Pieris (Lepidoptera: Pieridae) and its effect on parasitism by the gregarious parasitoid Cotesia glomerata (Hymenoptera: Braconidae)Original articleTomoko WATANABE, Keiji NAKAMURA, Jun TAGAWAEur. J. Entomol. 115: 25-29, 2018 | DOI: 10.14411/eje.2018.004 Preferences of young caterpillars of three species of Pieris (P. rapae crucivora Boisduval, P. melete Ménétriès, and P. napi japonica Shirôzu) (Lepidoptera: Pieridae) for the upper and lower surfaces of the leaves of their host plants (Brassicaceae) were investigated in the laboratory. On horseradish Armoracia rusticana Gaertn. Mey. et Scherb., which was provided as a common food for three species, second and third instar larvae of the respective species preferred the lower to the upper surface of horizontally placed leaves, irrespective of whether they hatched on the upper or lower surface. First instar larvae seemed to remain on the surface on which they hatched. However, first instar larvae of P. melete on Rorippa indica (L.), a natural food of P. melete in the field, and first instar larvae of P. napi japonica on Arabis flagellosa Miq., a natural food of P. napi japonica, preferred the lower to the upper surface, just as second and third instar larvae did. To elucidate the effects of leaf-surface preference, the percentage parasitism of P. rapae crucivora on Arm. rusticana and Ara. flagellosa by the parasitoid Cotesia glomerata (L.) (Hymenoptera: Braconidae) was investigated. On Arm. rusticana, the percentage parasitism of the larvae on the upper surface was higher than that of larvae on the lower surface. On Ara. flagellosa, however, percentages parasitism were nearly equal on both surfaces. Leaf-surface preference by the larvae of Pieris is discussed in terms of avoidance of parasitism by the parasitoid C. glomerata. |
Diversity of ground beetles (Coleoptera: Carabidae) and spiders (Araneae) in roadside verges with grey hair-grass vegetationJinze NOORDIJK, André P. SCHAFFERS, Karlè V. SÝKORAEur. J. Entomol. 105 (2): 257-265, 2008 | DOI: 10.14411/eje.2008.036 Roadside verges in densely populated areas are often a significant addition to the total semi-natural area and as such may contribute to the conservation of biodiversity. Furthermore, they can enhance the ecological cohesion of a region, especially when the existing nature reserves are small and/or highly fragmented. We investigated the occurrence of ground beetles and spiders in six highway verges with grey hair-grass vegetation in the Veluwe region, The Netherlands. Total species number in the verges was similar to the values found in nearby nature reserves with comparable vegetation, but the ground beetles tended to be more abundant in the reserves. Many stenotopic species were present in the verges, confirming the significant conservation value of this habitat. However, compared with the nature reserves, there were fewer species of stenotopic ground beetles and the stenotopic spiders were less abundant in the verges. From our knowledge of the biology and ecology of the species captured it seems likely that this is attributable to differences in "habitat quality". In the verges, species preferring bare sand are scarcer, and the weighted mean body length of ground beetles is shorter than in nature reserves. This suggests that the sward in the road verges is too dense and the suitable vegetation too patchy to sustain some of the stenotopic species. Habitat analyses support this contention: Compared with the nature reserves, the verges had proportionally less bare sand, more herb and tree cover and the vegetation patches were smaller. The strategy suggested to promote stenotopic species entails removing encroaching trees and shrubs from the verges in order to expand the nutrient-poor zone and (re-)create pioneer conditions. Subsequent management should aim at further improving the road verges as extensions of nutrient-poor habitat. |
Do flower mixtures with high functional diversity enhance aphid predators in wildflower strips?Original articleSéverin HATT, Roel UYTTENBROECK, Thomas LOPES, Pierre MOUCHON, Julian CHEN, Julien PIQUERAY, Arnaud MONTY, Frédéric FRANCISEur. J. Entomol. 114: 66-76, 2017 | DOI: 10.14411/eje.2017.010 Among the semi-natural elements in agricultural landscapes, wildflower strips sown at field margins or within fields are potential habitats for the natural enemies of insect pests. As insects are sensitive to a variety of flower traits, we hypothesized that mixtures with high functional diversity attract and support a higher abundance and species richness of aphid flower visiting predators than mixtures with low functional diversity. During a field experiment, repeated over two years (2014 and 2015) in Gembloux (Belgium), aphid predators (i.e., lacewings, ladybeetles and hoverflies) were pan-trapped in five sown flower mixtures (including a control mixture, with three replicates of each mixture) of low to high functional diversity based on seven traits (i.e., flower colour, ultra-violet reflectance and pattern, start and duration of flowering, height and flower class, primarily based on corolla morphology). In both years, the species of flowering plants in the sown mixtures (i.e., sown and spontaneous flowers) were listed, and the realized functional diversity in each plot calculated. Over the two years, a high functional diversity was not associated with high abundance and richness of aphid predators. Moreover, ladybeetles, which made up the majority of the predators trapped, were more abundant in mixtures with very low or intermediate functional diversity at sowing, especially in 2014. We hypothesize that certain flowers, which were abundant in certain mixtures (and not in those exhibiting the highest functional diversity), attracted predators and were sufficiently abundant to support them. Our results present novel information that could be used for developing flower mixtures that provide effective ecosystem services, such as pest control. |
To fly or not to fly: Factors influencing the flight capacity of carabid beetles (Coleoptera: Carabidae)ReviewStephen VENNEur. J. Entomol. 113: 587-600, 2016 | DOI: 10.14411/eje.2016.079 This review considers factors affecting the flight capacity of carabid beetles and the implications of flight for carabids. Studies from the Dutch polders in particular show that young populations of carabids consist predominantly of macropterous species and macropterous individuals of wing-dimorphic species. Also populations of wing-dimorphic carabid species at the periphery of their geographical range contain high proportions of macropterous individuals. However, studies from Baltic archipelagos show that older populations of even highly isolated island habitats contain considerable proportions of brachypterous species and individuals. This suggests that macroptery is primarily an adaptation for dispersal and that there exists a mechanism for subsequently reducing the ratio of macropterous to brachypterous species under stable conditions, due to the competitive advantage of brachyptery. Populations in isolated habitats, such as islands and mountains, have high proportions of brachypterous species. Many macropterous species do not possess functional flight muscles. Species of unstable habitats, such as tree canopies and wet habitats, are mostly macropterous. Brachypterous species tend to disappear from disturbed habitats. There is uncertainty regarding the extent to which carabid dispersal is directed and how much passive. Both Den Boer and Lindroth recognized that mostly macropterous individuals of macropterous and wing-dimorphic species disperse and found new populations, after which brachyptery tends to rapidly appear and proliferate in the newly founded population. It is most likely that the allele for brachyptery would arrive via the dispersal of gravid females which had mated with brachypterous males prior to emigration. Whilst many studies consider wing morphology traits of carabid beetles to be species-specific and permanent, a number of studies have shown that the oogenesis flight syndrome, whereby females undertake migration and subsequently lose their flight muscles by histolysis before eventually regenerating them after reproducing, has been reported for a growing number of carabid species. Wing morphology of carabid beetles clearly offers strong potential for the study of population dynamics. This field of study flourished during the 1940's to the late 1980's. Whilst a considerable amount of valuable research has been performed and published, the topic clearly holds considerable potential for future study. |
Comparison of gut morphology and distribution of trehalase activity in the gut of wood-feeding and fungus-growing termites (Isoptera: Termitidae)Original articleNujira TATUN, Chutamas SAWATNATHI, Suwakan TANSAY, Jatuporn TUNGJITWITAYAKULEur. J. Entomol. 114: 508-516, 2017 | DOI: 10.14411/eje.2017.065 Termites are important decomposer due to their ability to digest cellulose and their diverse feeding habits. Trehalase is an enzyme that hydrolyzes trehalose to glucose in insects and has an important biological role. Gut morphology of wood-feeding termites (Globitermes sulphureus, Termitinae; Microcerotermes crassus, Termitinae and Bulbitermes prabhae, Nasutitermitinae) and fungus-growing termites (Macrotermes annandalei, Macrotermitinae) that belong to the family Termitidae was determined in this study. Results indicate that wood-feeding termites have a similar gut morphology, which consists of a foregut, midgut and elongated hindgut, which is divided into four segments. More specifically the enlarged segment in the hindgut, called a paunch, is prominent in wood-feeding termites, whereas fungus-growing termites have a simpler tubular gut with a very small paunch. Trehalase activity was high in the midgut of wood-feeding termites (G. sulphureus, Mi. crassus and B. prabhae), but in the fungus-growing termite (Ma. annandalei) the highest level of activity was recorded in the hindgut. Cellulase activity (endo-β-1,4-glucanase) was detected in all gut segments with very high levels in the hindguts of B. prabhae and Ma. annandalei. Differences in the distribution of trehalase and gut morphology correspond to the phylogenetic analyses of Termitidae, which indicate that Macrotermitinae is the sister group of Termitinae and Nasutitermitinae. In addition, validamycin suppressed trehalase activity in termites in vitro and in vivo, resulting in a high mortality in wood-feeding and fungus-growing termites, indicating that trehalase inhibitors could be useful tools for termite control. |
More complex than expected: Cold hardiness and the concentration of cryoprotectants in overwintering larvae of five Erebia butterflies (Lepidoptera: Nymphalidae)Original articlePavel VRBA, Oldřich NEDVĚD, Helena ZAHRADNÍČKOVÁ, Martin KONVIČKAEur. J. Entomol. 114: 470-480, 2017 | DOI: 10.14411/eje.2017.060 Understanding the factors restricting the distribution of some insect species to high altitudes is hindered by poor knowledge of temporal changes in their cold hardiness during overwintering. We studied overwintering larvae of five species of Erebia butterflies (Lepidoptera: Nymphalidae: Satyrinae) differing in altitudinal distribution: lowland E. medusa, submountain E. aethiops, subalpine E. pronoe, alpine E. cassioides, and subnivean E. pluto. We subjected them to three treatments, AutumnWarm (13/8°C), imitating conditions prior to overwintering; AutumnCold (5/0°C), imitating late autumn conditions; and WinterCold (5/0°C), differing from AutumnCold by a shorter photoperiod and longer exposure to zero temperatures. Supercooling points (SCP) did not differ between species in the AutumnWarm treatment, despite large differences in the concentrations of cryoprotectants (CrPC; lowest in E. medusa and E. aethiops). Lowland E. medusa was freeze-tolerant, the subalpine, alpine and subnivean species were freeze-avoidant, whereas submountain E. aethiops displayed a mixed strategy. SCPs diverged in the AutumnCold treatment: it increased in the lowland E. medusa (from -16.5 to -10.8°C) and reached the lowest value in E. cassioides (-21.7°C). In WinterCold, SCP increased in subalpine E. pronoe (from -16.1°C in AutumnWarm and -18.7°C in AutumnCold to -12.6°C). E. medusa decreased and E. aethiops increased their CrPCs between autumn and winter; the highest CrPC was recorded in subnivean E. pluto. CrPC did not correlate with SCP across species and treatments. Cryoprotectant profiles corroborated the difference between lowland and freeze-tolerant E. medusa and the three high altitude freeze-avoidant species, with E. aethiops in an intermediate position. Glycerol was surprisingly rare, trehalose was important in all species, and such rare compounds as monopalmitin and monostearin were abundantly present in E. pronoe, E. cassioides and E. pluto. |
Double strand RNA-mediated RNA interference through feeding in larval gypsy moth, Lymantria dispar (Lepidoptera: Erebidae)Original articleSaikat Kumar B. GHOSH, Dawn E. GUNDERSEN-RINDALEur. J. Entomol. 114: 170-178, 2017 | DOI: 10.14411/eje.2017.022 RNA interference (RNAi) technology uses dsRNAs to silence specific targeted genes by downregulating their expression. It has become a potent tool for functional and regulatory studies of insect genes and has potential to be applied for insect control. Though it has been challenging to generate effective RNAi in lepidopteran insects, in the current study this technology was applied to develop specific RNAi-based molecular tools that could be used to negatively impact the invasive lepidopteran forest pest, gypsy moth (GM). GM midgut-specific genes were selected for dsRNA design from larval transcriptome profiles. Two methods were used to produce specific dsRNAs, bacterial expression and in vitro synthesis, which were then fed per os to GM larvae. Depletion of uncharacterized gene targets known as locus 365 and locus 28365, or their stacked combination, depleted target transcripts in a sequence specific manner and resulted in 60% reduction in body mass. Treated GM females that were able to moult to the adult stage displayed an approximately two-fold reduction in egg masses. These have potential to be developed as molecular biopesticides for GM. |
Book Review: Löbl I. & Löbl D. (eds) 2017: Catalogue of Palaearctic Coleoptera. Archostemata-Myxophaga-Adephaga. Vol. 1. Revised and updated edition.Book reviewA. BEZDĚKEur. J. Entomol. 115: 641, 2018 | DOI: 10.14411/eje.2018.062 Löbl I. & Löbl D. (eds) 2017: Catalogue of Palaearctic Coleoptera. Archostemata-Myxophaga-Adephaga. Vol. 1. Revised and updated edition. Brill, Leiden, Boston, xxxiv + 1443 pp. ISBN: 978-90-04- 33028-3 (print book), 978-90-04-33029-0 (e-book). Price USD 260.00 (print book), USD 236.00 (e-book). |
The central-marginal hypothesis in acridid Orthoptera: A critique of Colombo's (2012) articleClaudio J. BIDAU, Dardo A. MARTÍEur. J. Entomol. 110 (2): 181-185, 2013 | DOI: 10.14411/eje.2013.028 We discuss and criticise the contention of Colombo (2012) that the central-marginal model does not apply to three species of chromosomally polymorphic acridid grasshoppers, and that chromosomal clines in these species are a consequence of temperature gradients. We also discuss Colombo's interpretation of our own results on the South American melanopline grasshopper, Dichroplus pratensis Bruner. |
Gut microbiota influences female choice and fecundity in the nuptial gift-giving species, Drosophila subobscura (Diptera: Drosophilidae)Original articleBenjamin S. WALSH, Chloe HEYS, Zenobia LEWISEur. J. Entomol. 114: 439-445, 2017 | DOI: 10.14411/eje.2017.056 Recently, there has been rapidly growing interest in the effects of the microbiota on host physiology and behaviour. Due to the nutritional value of bacteria, gut microflora may be particularly important in species that present nuptial gifts during courtship. Here, we explore whether the presence or absence of gut microbiota in males and females of the nuptial gift-giving species Drosophila subobscura (Collin, 1936) alters mating behaviour in terms of female preference, male investment, and female fecundity. We found that females that had been fed antibiotics, compared to females with intact gut bacteria, were more willing to mate with a male that had been fed normally. However female fecundity was higher when both males and females lacked gut bacteria compared to both individuals having a full complement of gut bacteria. This implies that the presence of the microbiota acts to reduce female fecundity in this species, and that male gut bacterial content influences female fecundity. Our results provide further evidence to the growing consensus that the microbiota of an individual may have important effects on both reproductive behaviour and physiology, and suggest that it may also contribute to the nutritional value of the nuptial gift in this system. |
Population dynamics of Coccinella septempunctata (Coleoptera: Coccinellidae) in the region of Edremit Gulf in West Anatolia (Mount Ida)NoteAli ÖZPINAR, Ali Kürşat ŞAHİN, Burak POLATEur. J. Entomol. 115: 418-423, 2018 | DOI: 10.14411/eje.2018.041 This study reports seasonal presence of Coccinella septempunctata L. (Coleoptera: Coccinellidae) in Southeast Turkey, in 2008, 2009 and 2010. Samples were collected from crops in agricultural areas at altitudes of 10 m, 800 m and 1400 m from stands of wild herbaceous plants , and at 1750 m from stone debris fields. First C. septempunctata adults were collected at the beginning of June at Tentcamp (800 m) and Tozlu (1400 m), early in July at Sarikiz (1700 m) when the mean air temperature reached 30°C. Adults became active in spring, after aestivating around Sarikiz and overwintering there under snow. First adults emerged on 2nd April in 2009 around Edremit Gulf when mean air temperature reached 14.8°C. Adult and immature stages of C. septempunctata were recorded attacking aphid populations till the end of June. C. septempunctata was present there for only one period each year during which they completed one generation. Adult individuals of this generation returned to Mount Ida to aestivate. Maximum numbers of adults present on Mount Ida in the first week of August in 2009 and 2010 were recorded. C. septempunctata adults aestivate and overwinter at Sarikiz on Mount Ida after completing their development on aphids in April, May and June around Edremit Gulf. |
Effect of host species on larval growth differs between instars: The case of a geometrid moth (Lepidoptera: Geometridae)Helen VELLAU, Siiri-Lii SANDRE, Toomas TAMMARUEur. J. Entomol. 110 (4): 599-604, 2013 | DOI: 10.14411/eje.2013.081 Although the effects of host plant quality on the performance of polyphagous herbivores are largely uniform across insect taxa, there are various exceptions to this rule. In particular, there are scattered reports of cases in which the relative quality of different hosts differs among larval instars of a single insect species. Such cases are explained either in terms of differences in the susceptibility of different aged larvae to plant defences or, alternatively, age-specific nutritional demands. Here we report the results of experiments that show that young larvae of the polyphagous common heath moth Ematurga atomaria (Lepidoptera: Geometridae) consistently attain higher weights on common heather Calluna vulgaris than bilberry Vaccinium myrtillus, whereas the rank order of these host plants is reversed in the final larval instar. Phytochemical analyses showed that differences in nutrient content of these plants are not likely to explain the observed pattern. Instead, the results are more consistent with the idea that the greater chemical defence of bilberry has a relatively stronger influence on young than old larvae. |
Juvenile hormone analogue, fenoxycarb, modulates ecdysone-triggered transcriptional hierarchy during programmed cell death of midgut in silkworm, Bombyx mori (Lepidoptera: Bombycidae)Original articleEbru GONCU, Ramazan URANLI, Osman PARLAKEur. J. Entomol. 114: 235-248, 2017 | DOI: 10.14411/eje.2017.029 Steroid hormone 20-hydroxyecdysone and the sesquiterpenoid juvenile hormone are the main regulators of insect development; however, it is unclear how they interact in the regulation of metamorphic events. Using the silkworm, Bombyx mori, we show that the juvenile hormone analogue fenoxycarb affects the cascade of ecdysone regulated genes that control the programmed cell death in the larval midgut. Morphological changes that occur during cell death were investigated by studying cross-sections of the midgut stained with hematoxylin and eosin. Apoptosis-specific DNA fragmentation was detected using TUNEL assay. Expression patterns of genes ATG8 and ATG12, which were used as indicators of autophagy, and genes of the ecdysone-regulated gene cascade were examined using real-time quantitative polymerase chain reaction. Fenoxycarb application on day 0 of the 5th larval instar extended the feeding period and postponed programmed cell death in mature larval midgut. This effect was probably due to a delay in ecdysone secretion and associated changes in gene expression were mostly not a direct response to the fenoxycarb. However, differences in the gene expression patterns in the control and fenoxycarb treated insects during the prepupal and early pupal stages indicated that fenoxycarb may also exert a more direct effect on some genes of the ecdysone regulated gene cascade. |
The effect of pitfall trap construction and preservative on catch size, species richness and species composition of ground beetles (Coleoptera: Carabidae)Michal KNAPP, Jan RŮ®IČKAEur. J. Entomol. 109 (3): 419-426, 2012 Pitfall trapping is the most frequently used sampling technique for epigeal arthropods. Trap design could significantly affect the catch so the results of studies using different trap designs may be difficult to compare. Although species composition is frequently investigated in ecological studies, however when pitfall trapping is employed, the effect of trap design on the recorded species composition is rarely considered. In the present study, we investigated the effect of trap construction (funnel or cup trap) and the preservative used (formaldehyde or propylene glycol) on total catch, catch of particular species, species richness and species composition of the ground beetle assemblage sampled. We were interested in the extent to which trap design could bias these characteristics. Total catch was significantly affected by trap construction and preservative used, with the effect of the latter being the stronger. Species richness was only slightly affected by trap design when assemblages caught by traps of a particular type were corrected for unequal sample size. Moreover, we show that the traps of different designs differ in their efficiency for catching particular species of carabid and thus the composition of assemblages recorded using pitfall traps is affected by trap construction and the preservative used. We conclude that to assess the full significance of the effect of pitfall trap design on the results of ecological studies on epigeal arthropods it is necessary to simultaneously use traps of various designs. |
Preliminary evidence of the horizontal transmission of Wolbachia between Crioceris leaf beetles (Coleoptera: Chrysomelidae) and their Asparagus host plantsOriginal articleMichał KOLASA, Matteo MONTAGNA, Valeria MEREGHETTI, Daniel KUBISZ, Miłosz A. MAZUR, Łukasz KAJTOCHEur. J. Entomol. 114: 446-454, 2017 | DOI: 10.14411/eje.2017.057 Intracellular bacteria of the genus Wolbachia (α-Proteobacteria) are the most widespread endosymbionts of insects. Host infection is usually associated with alterations in reproduction, such as cytoplasmic incompatibility, the induction of parthenogenesis and offspring sex ratio bias: all phenomena that may influence host speciation. In the present study, by using well-established molecular tools, we investigated the presence of Wolbachia in leaf beetles of the genus Crioceris and their host plants, which are various species of Asparagus. Multilocus sequence typing of bacterial genes showed that despite their occurrence in the same habitat and feeding on the same plant, two species of Crioceris, C. quinquepunctata and C. quatuordecimpunctata, are infected by two different strains of Wolbachia. C. asparagi, C. paracenthesis and C. duodecimpunctata, which are sympatric with the infected species, do not harbour the bacterium. Interestingly, DNA of Wolbachia was detected in host plant tissues that are exploited by the beetles, providing evidence for the horizontal transmission of the bacterium between beetles and their host plants. Moreover, Wolbachia was detected in species of Crioceris that are not closely related. |