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Diversity of grasshoppers (Caelifera) recorded on the banks of a Ramsar listed temporary salt lake in AlgeriaOriginal articleSarah MAHLOUL, Abboud HARRAT, Daniel PETITEur. J. Entomol. 113: 158-172, 2016 | DOI: 10.14411/eje.2016.020 The chotts in Algeria are temporary salt lakes recognized as important wintering sites of water birds but neglected in terms of the diversity of the insects living on their banks. Around a chott in the wetland complex in the high plains near Constantine (eastern Algeria), more than half of the species of plants are annuals that dry out in summer, a situation that prompted us to sample the vegetation in spring over a period of two years. Three zones were identified based on an analysis of the vegetation and measurements of the salt content of the soils. Surveys carried out at monthly intervals over the course of a year revealed temporal and spatial variations in biodiversity and abundance of grasshoppers. The inner zone is colonized by halophilic plants and only one grasshopper species (Dericorys millierei) occurs there throughout the year. Two polyphagous species of Calliptamus, which can feed on halophilic plants migrate from adjacent areas into the inner zone in August to feed on the plants growing there. The other species of grasshoppers remain in outer zones as they are unable to feed on halophilic plants. The greatest abundance of grasshoppers from August to winter was recorded in the inner zone and in spring and early summer in the outer zones. The dependence of D. millierei on bushes of Amaranthaceae and its moderate flight ability, features of the family Dericorytidae, limit this species ability to colonize neighbouring chotts. |
Sibling species delimitation and nomenclature of the Merodon avidus complex (Diptera: Syrphidae)Dunja POPOVIĆ, Jelena AČANSKI, Mihajla DJAN, Dragana OBREHT, Ante VUJIĆ, Snežana RADENKOVIĆEur. J. Entomol. 112 (4): 790-809, 2015 | DOI: 10.14411/eje.2015.100 A study of the relationships between 21 southern European, Moroccan and Turkish populations of the Merodon avidus species complex was carried out. Based on a parallel study of type material from several museums, documented diagnostic morphological characters, season of adult activity and geographical distribution, we justify the use of the following names for three closely related taxa in this complex: M. avidus (Rossi, 1790), M. moenium (Wiedemann, 1822), and M. ibericus Vujić nom. n. (new name for M. bicolor Gil Collado, 1930, preoccupied by M. bicolor Walker, 1852). Neotypes of Merodon avidus, M. spinipes (Fabricius, 1794) and M. quadrilineatus Lioy, 1864 are designated. Lectotype of Merodon moenium (Wiedemann in Meigen, 1822) is designated here. A cluster analysis of DNA barcoding sequences clearly separated M. ibericus, but not M. avidus and M. moenium, even though the lack of shared haplotypes, analysis of molecular variance (AMOVA), pairwise Φst values together with allozyme and ecological niche analyses revealed statistically significant percentage of variation among all three species in the Merodon avidus complex. Analysis of 5 diagnostic enzyme loci revealed the presence of genetic differentiation among the M. avidus/moenium complex populations investigated (Fst = 0.654) and species-specific alleles were found at the AAT locus. The presence of two separate related taxa within the M. avidus/moenium complex was further supported by an UPGMA tree based on Nei's (1978) genetic distances. The value of Nei's measure of genetic identity (I = 0.520) between two large (meta) populations of M. avidus and M. moenium suggest that these taxa are sibling species. Populations from Djerdap (Serbia) confirmed the presence of temporal divergence between these species at a locality where they occur sympatrically, while spring and autumn populations from Umag (Croatia) provide an example of morphological plasticity within the species M. avidus. Ecological niche analysis contributed to the species delimitation. Review of the available genetic and ecological data confirmed our hypothesis that the M. avidus species complex, in addition to M. ibericus Vujić nom. n. from the Iberian Peninsula, consists of two sibling species in the rest of Europe and indicated their recent speciation. |
Indochinese Polydictya lanternflies: Two new species from Vietnam, identification key and notes on P. vietnamica (Hemiptera: Fulgoromorpha: Fulgoridae)Original articleJérôme CONSTANT, Hong-Thai PHAMEur. J. Entomol. 114: 279-290, 2017 | DOI: 10.14411/eje.2017.034 Two new species of Polydictya Guérin-Méneville, 1844 from Vietnam, P. grootaerti sp. n. from Central Vietnam and P. drumonti sp. n. from North Vietnam, are described and compared with the closest species, P. chantrainei Nagai & Porion, 2004 and P. kuntzi Nagai & Porion, 2004. The male genitalia are described and illustrated for the two new species as well as for P. vietnamica Constant & Pham, 2008 for the first time. Habitus details and photographs, a distribution map and photographs of specimens in nature when available, are provided. The occurrence of P. vietnamica from Thailand and Northeast India, noted here for the first time based on photographs taken in nature, requires confirmation based on the examination of specimens. An identification key to the species of Polydictya from the Indochinese region is provided. |
Intraguild predation of Orius niger (Hemiptera: Anthocoridae) on Trichogramma evanescens (Hymenoptera: Trichogrammatidae)Original articleSerkan PEHLİVAN, Alican KURTULUŞ, Tuğcan ALINÇ, Ekrem ATAKANEur. J. Entomol. 114: 609-613, 2017 | DOI: 10.14411/eje.2017.074 Intraguild predation of a generalist predator, Orius niger Wolff (Hemiptera: Anthocoridae) on Trichogramma evanescens Westwood (Hymenoptera: Trichogrammatidae), was determined in choice and no-choice experiments using a factitious host, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae), under laboratory conditions. Choice and no-choice experiments were conducted in order to assess the level of intraguild predation of O. niger on E. kuehniella eggs parasitized by T. evanescens. In no-choice experiments, approximately 50 sterile (1) non-parasitized, (2) 3-day-old parasitized, or (3) 6-day-old parasitized E. kuehniella eggs were offered to 24-h-old females of O. niger in glass tubes. In choice experiments approximately 25 eggs of two of the three groups mentioned above were offered to 24-h-old O. niger females. In both choice and no-choice experiments, O. niger consumed more non-parasitized eggs of E. kuehniella. However, intraguild predation occurred, especially of 3-day-old parasitoids, but very few 6-day-old parasitized eggs were consumed. The preference index was nearly 1 indicating O. niger preferred mainly non-parasitized E. kuehniella eggs. A lower level of intraguild predation is expected under field conditions but needs to be investigated using further experiments. |
Effects of ultraviolet-C and microwave irradiation on the expression of heat shock protein genes in the maize weevil (Coleoptera: Curculionidae)Original articleJatuporn TUNGJITWITAYAKUL, Nujira TATUN, Boongeua VAJARASATHIRA, Sho SAKURAIEur. J. Entomol. 113: 135-142, 2016 | DOI: 10.14411/eje.2016.017 The maize weevil, Sitophilus zeamais (Motschulsky), is a major pest of stored grain kernels. Irradiation is an established technique for controlling insects in stored grain and is a major stress factor affecting these insects. Since heat shock protein (hsp) genes respond to this stress, we proposed that hsps may be associated with irradiated stress tolerance in S. zeamais. The responses of the maize weevil to exposure to ultraviolet-C (UV-C) and microwave irradiation were assessed at four developmental stages: egg, larva, pupa and adult. The results revealed that exposure to UV-C (254 nm, < 8 h) did not affect the survival of the maize weevils; however, Szhsp70, Szhsc70 and Szhsp90 mRNA levels significantly increased during the first 1 h of UV-C exposure. The median lethal time (LT50) of exposure to microwave irradiation indicated that the adult stage was more tolerant of microwave irradiation than the other developmental stages. Microwave irradiation enhanced the expression of the three hsps, but the intensity of up-regulation differed among the three genes, with Szhsp70 the most highly up-regulated. Our experiments revealed that UV-C and microwave irradiation influenced the expression profile of hsp genes in S. zeamais. At the tissue level, the gene responses to UV-C and microwave irradiation varied greatly in different tissues. |
Invasive ant Tapinoma melanocephalum (Hymenoptera: Formicidae): A rare guest or increasingly common indoor pest in Europe?Petr KLIMEŠ, Jan OKROUHLÍKEur. J. Entomol. 112 (4): 705-712, 2015 | DOI: 10.14411/eje.2015.089 The ghost ant (GA), Tapinoma melanocephalum (Fabricius, 1793), is one of the most common invasive species of ants (Hymenoptera: Formicidae) in the world. While in its native tropical region it is both an ordinary indoor and outdoor pest, it occurs only indoors in the temperate zone, where increasingly more records of this species have been published since 1887. In this study, the current distribution of GA in Europe, including the new records published since Wetterer (2009), is reviewed. Furthermore, we report the first record of GA in the Czech Republic, where a large colony of GA was discovered in a block of flats in České Budějovice in 2014, and present a case study of its eradication. The revised distribution of GA shows that despite previous concerns about the threats posed by this new pest only three other European countries (including Czech Republic) reported the presence of this species after 2009. Although GA is currently documented as occurring in 18 European countries, which were invaded mainly after 1990, there is only a single (or dubious) record for ten of these countries. Abundance of workers was monitored in two flats in an infested building using traps baited with yolk-honey and GA were subsequently eradicated with imidacloprid (0.01% w/w). The pre-treatment revealed abundances that ranged up to 524 workers per trap (mean = 99, S.D. = 142, 80% of baits occupied). Despite the initial success of the treatment (no ants observed after 3 weeks), monitoring of the building a year later revealed it was still infested with GA and in a similar rate. We suggest alternative methods of eradicating GA in the temperate zone based on studies carried out in the tropics. Our study indicates the difficulty of eradicating the species from buildings when its colony is already established. Furthermore, it highlights the bias in the discovery-probability of GA as a household pest probably due to the species cryptic appearance and lack of attention to it outside of the scientific community. |
Partial consumption of different species of aphid prey by the predator Macrolophus pygmaeus (Hemiptera: Miridae)Original articleDionyssios LYKOURESSIS, Dionyssios PERDIKIS, Ioannis MANDARAKASEur. J. Entomol. 113: 345-351, 2016 | DOI: 10.14411/eje.2016.045 The partial consumption of prey refers to when a predator does not consume all the digestible biomass of an animal it has killed. The frequency of partial consumption of prey by the polyphagous predator Macrolophus pygmaeus (Hemiptera: Miridae) was recorded for different species of prey and prey population structures, in single and mixed prey species patches. All the instars of the aphid, Aphis gossypii, were provided as prey alone or together with Myzus persicae or Macrosiphum euphorbiae. Numbers killed were determined when equal (10 nymphs of each instar, 40 in total) or unequal numbers (higher numbers of young nymphs but again 40 in total) of nymphs were placed on an eggplant leaf in a plastic Petri dish. In each dish a single 5th instar nymph of the predator was introduced and the numbers killed and numbers of partially consumed aphids were recorded after 24h, at 25 ± 1°C. The numbers of A. gossypii killed were higher than those of the other species of prey used. The frequency of partially consumed prey was highest when A. gossypii was offered alone in equal numbers of each instar, followed by when A. gossypii was provided together with M. persicae in unequal numbers of instars (23.6% and 11.2%, of the total mortality, respectively). Killed but not consumed prey was also recorded, at frequencies that reached 10.7% of the total mortality when A. gossypii was provided alone in equal numbers of each instar. For M. persicae and M. euphorbiae, these percentages were significantly lower. The higher frequency of this behaviour when A. gossypii was the prey may be related to its lower nutritional quality for the predator. The effect of prey instar was not significant. These results indicate that in determining the numbers killed by a predator, partially consumed prey may make up a significant part of the total kill and thus should be taken into consideration. |
Do the arthropod communities on a parasitic plant and its hosts differ?Original articleAlba LÁZARO-GONZÁLEZ, José A. HÓDAR, Regino ZAMORAEur. J. Entomol. 114: 215-221, 2017 | DOI: 10.14411/eje.2017.026 Parasitic plants growing on tree branches may be a novel niche and phytoresource for arthropods. The spatial continuity between hosts and their parasites in canopies might provide a homogeneous environment for arthropod communities, but differences in mistletoe leaves and host needles could be exploited by different species of arthropods. Therefore, it is important to determine insect-community assemblages in order to discover the role of parasitic plants as a different habitat for arthropods. Thus, we aim to evaluate the level of similarity between the arthropod community on mistletoe (Viscum album) and that on its two principal pine hosts, Black pine (Pinus nigra) and Scots pine (P. sylvestris), on a Mediterranean mountain. Our results reveal that, irrespective of the species of pine host, V. album has a stable, independent and simple arthropod trophic web, composed mainly of two specialist hemipteran herbivores, Cacopsylla visci (Psyllidae) and Pinalitus viscicola (Miridae), and a hemipteran predator, Anthocoris visci (Anthocoridae). Despite this, the composition of the arthropod communities differed significantly on both host species, with a greater richness and diversity on Scots than Black pine and these differences are not reflected in the community on mistletoe. Overall, we conclude that, although Viscum album is considered to be a pest of pine, its presence increases the heterogeneity of the forest canopy by providing a novel habitat for a new and specific community of arthropods. In addition, this is a new record for and most probably an extension of the southernmost limit of the known geographical distribution of the arthropod community inhabiting V. album. |
Chromosome mapping of 28S ribosomal genes in 11 species of Cassidinae (Coleoptera: Chrysomelidae)Original articleAmália T. LOPES, Flávia R. FERNANDES, Marielle C. SCHNEIDEREur. J. Entomol. 114: 546-553, 2017 | DOI: 10.14411/eje.2017.069 In this study, we examined for the first time the distribution of the 28S ribosomal genes in beetles of the subfamily Cassidinae. More than 55% of the species in this subfamily have a similar karyotype, 2n = 16 + Xyp. For this work, we selected species belonging to the tribes Cassidini and Mesomphaliini, which have, respectively, the most conserved and diversified karyotype characteristics within the Cassidinae. An analysis of 11 species revealed that rDNA sites on one pair of autosomes is the most frequent pattern, occurring in 10 species. This condition occurs in the seven genera examined and in species of both of the tribes, Cassidini and Mesomphaliini. Nevertheless, the differences in the locations of 28S rDNA were more pronounced in the tribe Cassidini and among species with similar karyotype characteristics. On the other hand, in Mesomphaliini, the increase in the diploid number was not accompanied by an increase in the number of ribosomal sites. Moreover, the comparison of the number and localization of major rDNA sites with the distribution of constitutive heterochromatin indicates that there is no direct correlation between the dispersion of constitutive heterochromatin and 28S rDNA genes in Cassidinae. |
Host condition effects upon Agrilus planipennis (Coleoptera: Buprestidae) captures on decoy-baited branch trapsOriginal articleMichael J. DOMINGUE, Jennifer BERKEBILE, Kim STEINER, Loyal P. HALL, Kevin R. CLOONAN, David LANCE, Thomas C. BAKEREur. J. Entomol. 113: 438-445, 2016 | DOI: 10.14411/eje.2016.057 We deployed branch traps in an ash (Fraxinus) plantation to investigate how Agrilus planipennis behavior is associated with Fraxinus pennsylvanica condition and dispersal patterns. Data were collected from traps with or without the presence of beetle visual decoys, and from a yearly survey of exit holes. The traps were placed on trees that were either clearly declining, with most foliage arising from epicormic sprouting, or on apparently healthy trees, with little evidence of damage or decline. We calculated correlations of exit holes among neighboring tree rings and also between exit holes and male trap captures. The damaged trees the traps were hung upon had more cumulative exit holes observed than the corresponding healthy trees. However, there was otherwise no evidence that the experiment was biased by differences in exit hole patterns of the surrounding trees. Male captures were greater on decoy-baited traps than controls and this decoy effect was most clearly apparent late in the season when traps were placed on healthy trees. There were also patterns of correlations between male captures and exit hole numbers that may be indicative of short-range mate finding-and dispersal behaviors. Female captures were sparser, but were positively affected by decoys on healthy and declining trees early in the season. Thus, the results suggest that the placement of such traps on healthier trees will maximize detection, and the branch traps also show promise for further use in dispersal studies. |
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. |
Book review: Miller K.B. & Bergsten J. 2016: Diving Beetles of the World. Systematics and Biology of the Dytiscidae.Book reviewJiří HÁJEK, David S. BOUKALEur. J. Entomol. 114: 332-333, 2017 | DOI: 10.14411/eje.2017.041 Miller K.B. & Bergsten J. 2016: Diving Beetles of the World. Systematics and Biology of the Dytiscidae. John Hopkins University Press, Baltimore, 320 pp. ISBN 978-1-4214-2054-7 (printed); 978-1-4214-2055-4 (electronic). Price USD 150.00. |
Pharmacological analysis of the feeding response of codling moth (Cydia pomonella; Lepidoptera: Tortricidae) neonates to bitter compoundsOriginal articleMaciej A. PSZCZOLKOWSKIEur. J. Entomol. 114: 500-506, 2017 | DOI: 10.14411/eje.2017.063 Feeding in codling moth neonate caterpillars was inhibited by 0.67 mM and 2.24 mM concentrations of denatonium benzoate. This inhibitory effect was abolished by phospholipase C inhibitor, U-73122 and the phosphodiesterase inhibitor, Rolipram. Quinine and quinidine did not have inhibitory effects at concentrations as high as 1.64 mM and 0.43 mM, respectively. The inhibitory effect of denatonium was partially reversed in the presence of the calcium ion chelator, EGTA, at concentrations ranging from 2.5 µM to 250 µM. These results indicate that transduction of the taste of denatonium in codling moth neonates relies on signalling pathways that involve phospholipase C, phosphodiesterase and calcium ion influx into cells. |
Electrophysiological and behavioural responses of female Isoceras sibirica (Lepidoptera: Cossidae) to volatiles produced by the plant, Asparagus officinalisOriginal articleHongxia LIU, Zhixiong LIU, Haixia ZHENG, Zerong JIN, Jintong ZHANGEur. J. Entomol. 114: 101-105, 2017 | DOI: 10.14411/eje.2017.014 In herbivorous insects plant volatiles have an important role in locating mates and oviposition sites. The aim of this study was to test the antennal and behavioural responses of females of Isoceras sibirica Alpheraky (Lepidoptera: Cossidae) to the volatiles produced by Asparagus officinalis L. Electroantennographs (EAG) revealed that the antennae of I. sibirica respond in a dose dependent way to hexanal, limonene, 2-ethyl-2-hexenal, linalool and α-terpineol. In flight tunnel experiments, 2-ethyl-2-hexenal, α-terpineol, hexanal, ρ-cymene and geraniol were significantly more attractive to females of I. sibirica than other chemicals. These findings indicate that host volatiles are important for host recognition in I. sibirica. |
Biological parameters of Duponchelia fovealis (Lepidoptera: Crambidae) reared in the laboratory on two dietsNoteMaria A.C. ZAWADNEAK, Rodrimar B. GONÇALVES, Alex S. POLTRONIERI, Bráulio SANTOS, Adélia M. BISCHOFF, Aline M. BORBA, Ida C. PIMENTELEur. J. Entomol. 114: 291-294, 2017 | DOI: 10.14411/eje.2017.035 Duponchelia fovealis Zeller is a polyphagous insect that has been recently reported attacking strawberry plants (Fragaria x ananassa Duchesne). Despite its economic importance there are few studies on this pest because it is difficult to rear it in the laboratory. With a constant supply of insects, studies on alternative methods of pest control can be conducted. This study aimed at developing an artificial diet for rearing D. fovealis with biological characteristics similar to those reared on their natural diet. This study was carried out in a climate-controlled room (25°C ± 2°C, RH 70% ± 10%, and 14L : 10D). The natural diet consisted of 'San Andreas' strawberry leaves (D1), while the artificial diet (D2) was developed in which beans, casein, soy protein, yeast and wheat germ are used as sources of protein. Five instars were identified. D. fovealis completed its life cycle in 38 and 40 days when fed D1 and D2, respectively. Survival was highest for the larvae fed the artificial diet. Females fed D1 lay a mean of 300.2 ± 62.3 eggs, while those fed D2, 220.3 ± 41.8 eggs. The artificial diet is suitable for the continuous rearing of D. fovealis in the laboratory. |
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. |
Mycobiota in the brood cells of the European beewolf, Philanthus triangulum (Hymenoptera: Crabronidae)Original articleTobias ENGL, Bettina BODENSTEIN, Erhard STROHMEur. J. Entomol. 113: 271-277, 2016 | DOI: 10.14411/eje.2016.033 Mass provisioning insects have to cope with microbial spoilage of their food supplies. As their fitness is directly linked to the availability of high quality food for their offspring, they have evolved various mechanisms for preserving these resources. The European beewolf, Philanthus triangulum, uses several mechanisms to not only preserve the food for their larvae, paralyzed workers of the European honeybee, Apis mellifera, but also protect the larvae that develop on the stored food. To assess the spectrum of fungi that pose a threat to beewolf brood cells, we manipulated brood cells by removing the insect defenses. We monitored the subsequent fungal infestations that would have been prevented by the beewolf defense mechanisms and isolated and identified the mold fungi. The cosmopolitan and highly competitive species of Aspergillus, in particular A. flavus, dominated the mold in beewolf brood cells. All other infestations could also be attributed to generalist mold fungi that are commonly found in soil and also on insects. Our findings indicate that beewolf brood cells can be colonized by a broad range of opportunistic soil mold fungi. Thus, it seems highly adaptive that beewolves employ general, broad spectrum defense mechanisms. |
Factors limiting the northern distribution of the blueberry maggot, Rhagoletis mendax (Diptera: Tephritidae) in Eastern CanadaOriginal articleCharles VINCENT, Pierre LEMOYNE, Sonia GAUL, Kenna MACKENZIEEur. J. Entomol. 113: 143-149, 2016 | DOI: 10.14411/eje.2016.018 Until recently, the Canadian distribution of the blueberry maggot, Rhagoletis mendax Curran (Diptera: Tephritidae), was restricted to Nova Scotia, Prince Edward Island and New Brunswick. The insect was first mentioned in southern Quebec in 1996 and, to date, it has not reached the Lac St-Jean region, where 34% of Canadian blueberry acreage is located. Two questions concerning the northern limit of distribution of the blueberry maggot in Quebec were addressed. First, are wild plants suitable hosts for larval development? We collected the fruit of five wild plants, (e.g. Vaccinium corymbosum, Vaccinium angustifolium, Vaccinium myrtilloides, Gaylussacia baccata, and Aronia melanocarpa) growing in southern Quebec and allowed larvae to complete their development into pupae. Blueberry maggot pupae were recovered from Vaccinium corymbosum, Vaccinium angustifolium, and Gaylussacia baccata, indicating that these plants are suitable for larval development. Second, are harsh winter temperatures a factor limiting the northern distribution of the blueberry maggot? Pupae collected in Quebec and Nova Scotia were put in the soil in the fall and were brought back to the laboratory to determine their supercooling points at different times during winter. The supercooling points of pupae collected in Quebec and Nova Scotia averaged -22.6°C. In natural conditions, air temperatures <-20°C are frequently observed in Quebec in January, February and March. However, due to snow cover, soil temperatures are rarely <-12°C. If -22.6°C constitutes the lower limit for the survival, then winter temperatures are probably not a limiting factor to its northern distribution in Quebec, because blueberry maggot pupae overwinter in the soil. |
Seasonal polyphenism in Eristalis pertinax (Diptera: Syrphidae)Original articleLukasz E. MIELCZAREK, Andrzej OLEKSA, Katarzyna MEYZA, Adam TOFILSKIEur. J. Entomol. 113: 489-496, 2016 | DOI: 10.14411/eje.2016.064 Eristalis pertinax varies seasonally, with the spring morph more hairy than the summer morph. We measured the size and the venation of the wings of the seasonal morphs. Wings of the spring morph were significantly larger than those of the summer morph and those of females were larger than those of males. There were also significant differences between the morphs in wing venation and their allometric relationship. The differences between sexes were larger than differences between seasonal morphs. The allometry can account for the sexual dimorphism but not seasonal dimorphism. The differences between seasonal morphs in wing shape were relatively large with very few intermediate individuals. The differences were comparable to those between two related species of Syrphidae. Genetic analyses based on markers in nuclear and mitochondrial genomes unequivocally revealed that spring and summer morphs of E. pertinax form a single population and should not be regarded as separate taxa. Thus seasonal variability in this species is a rare example of polyphenism in Diptera. |
Fitness traits of Drosophila melanogaster (Diptera: Drosophilidae) after long-term laboratory rearing on different dietsOriginal articleJelena TRAJKOVIĆ, Vukica VUJIĆ, Dragana MILIČIĆ, Gordana GOJGIĆ-CVIJOVIĆ, Sofija PAVKOVIĆ-LUČIĆ, Tatjana SAVIĆEur. J. Entomol. 114: 222-229, 2017 | DOI: 10.14411/eje.2017.027 Nutrition is one of the most important environmental factors that influence the development and growth in Drosophila. The food composition strongly affects their reproduction, welfare and survival, so it is necessary for flies to search for a mixture of macronutrients that maximizes their fitness. We have five D. melanogaster strains, which were reared for 13 years on five different substrates: standard cornmeal-agar-sugar-yeast medium and four substrates modified by adding tomato, banana, carrot and apple. This study was aimed at determining how such long-term rearing of flies on substrates with different protein content affects fitness traits (dynamics of eclosion, developmental time and egg-to-adult survival). Further, we determined how transferring flies reared on fruit/vegetable substrates to a standard laboratory diet affected their fitness. Results indicate that strains reared on the diet with the lowest content of protein and the highest C/N ratio had the slowest eclosion and developmental time, and lowest egg-to-adult survival (apple diet). The flies reared on the diet with the highest protein content and the lowest C/N ratio had the highest survival (tomato diet). Flies reared on the carrot diet, which is quite similar in protein content and C/N ratio to the standard cornmeal diet, had the fastest development. Transferring flies to the standard cornmeal diet accelerate eclosion and developmental time, but did not affect survival. |
Host specificity of the tribe Chrysidini (Hymenoptera: Chrysididae) in Estonia ascertained with trap-nestingMadli PÄRN, Villu SOON, Tuuli VALLISOO, Kristiina HOVI, Jaan LUIGEur. J. Entomol. 112 (1): 91-99, 2015 | DOI: 10.14411/eje.2015.012 Cuckoo wasps (Chrysididae) are a medium-sized and widespread family of Hymenoptera whose species are generally parasitoids or cleptoparasites of solitary wasps and bees. The identities of the hosts are known from various studies and occasional records; however the utility of such data is often low due to unstable taxonomy of the species and the inappropriate methods used to determine the host species. Therefore, despite numerous publications on the subject, the host-parasite relationships of cuckoo wasps are poorly understood. Moreover, a revision of existing literature reveals that cuckoo wasps are often unreasonably considered to be unspecialized (i.e., sharing host species). In this study we use an accurate method (trap-nests) to determine the host relationships of Estonian cuckoo wasps of the genera Chrysis and Trichrysis and determine their level of specialization. 568 trap nest bundles (each containing 15-20 single reed stems) were established at 361 locations across Estonia during the vegetation periods of 2009-2011. Nests built in traps were opened and the order of cells documented in order to determine the host-parasite relationships of mason wasps and cuckoo wasps. Altogether, 5386 insects were recorded, including 12 species of Chrysidini. Hosts of all 12 cuckoo wasp species were determined and included some not previously recorded. Analysis of host-parasite relationships revealed that Estonian species of Chrysidini exhibit a greater degree of host specialization than previously thought, with only a minimal overlap in hosts between species. Such a high degree of specialization accounts for the high species diversity of cuckoo wasps, as the diversity of parasitic insects is often associated with narrow host specialization. |
Development and survival of the spruce bark beetle, Ips typographus (Coleoptera: Curculionidae: Scolytinae) at low temperatures in the laboratory and the fieldOriginal articleKristýna ŠTEFKOVÁ, Jan OKROUHLÍK, Petr DOLEŽALEur. J. Entomol. 114: 1-6, 2017 | DOI: 10.14411/eje.2017.001 The European spruce bark beetle (Ips typographus) is a highly destructive pest of spruce monocultures. Adult spruce bark beetles are well-adapted to survive over winter however, the ability of sub-adult stages to overwinter has not been clearly established. The increase in average temperature recorded over the last three decades has resulted in an increase in voltinism by one generation, but due to insufficient time the last generation may not complete its development. It is crucial to investigate the survival and development of sub-adult stages at low temperatures in order to predict the effect of increased voltinism on the population dynamics of this species. We measured the development and survival of larvae and pupae (over 12 weeks) in logs kept at winter temperatures outdoors (in shade and exposed to sunlight) and in the laboratory (at 0 and 5°C), with 10°C as a control, at which normal development was expected. Overall, findings revealed that development continued at low temperatures, although it was slower than at high temperatures. Importantly, after 12 weeks significant numbers of spruce bark beetles were present, including newly emerged adults. We demonstrate, for the first time, that sub-adult spruce bark beetles can mature over winter and the percentage survival was significant, indicating that some of the beetles that did not complete their development before the onset of winter can complete their development during winter and potentially adversely affect forests and pose problems for their management. |
White plant shoots, wax-producing insects and other white structures made by arthropods: A mimicry complex?Point of viewKazuo YAMAZAKIEur. J. Entomol. 114: 343-349, 2017 | DOI: 10.14411/eje.2017.043 Many insects masquerade as parts of plants, such as bark or leaves, or mimic poisonous organisms in order to defend themselves against predators. However, recent studies indicate that plants may mimic insects and other arthropods to deter herbivores. Here, I report visually similar white structures of plants and arthropods in Japan and suggest they are part of a mimicry complex. Young shoots covered with white trichomes or waxy substances may mimic wax-producing insects, such as woolly aphids, coccids and caterpillars, potentially resulting in reduced herbivory. Since wax-producing insects would reduce plant quality and quantity, be distasteful and attract natural enemies, herbivorous insects and mammals may avoid such white shoots. Furthermore, fungus-infected insects, gregarious braconid cocoons, spider egg sacs and froth made by froghopper nymphs or blasticotomid sawfly larvae are also conspicuously white and impose risks for herbivorous insects. Thus, these white structures may be mimicry models for white shoots and are likely to be part of a defensive mimicry complex. Although this study focuses on defence against herbivores, there are simultaneous physiological roles for white colouration that will not be discussed in depth here. |
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. |
Morphological and molecular characterization of common European species of Adialytus (Hymenoptera: Braconidae: Aphidiinae) based on the mtCOI barcoding gene and geometric morphometrics of forewingsSaša S. STANKOVIĆ, Andjeljko PETROVIĆ, Marijana ILIĆ MILOŠEVIĆ, Petr STARÝ, Nickolas G. KAVALLIERATOS, Vladimir ŽIKIĆ, Željko TOMANOVIĆEur. J. Entomol. 112 (1): 165-174, 2015 | DOI: 10.14411/eje.2015.007 In this study three common European species of the genus Adialytus Förster, 1862 were examined: Adialytus ambiguus (Haliday, 1834), Adialytus salicaphis (Fitch, 1855) and Adialytus thelaxis (Starý, 1961). Molecular analysis involved the DNA barcoding of a region of the mitochondrial gene cytochrome oxidase I (COI). The genetic difference based on Kimura s two-parameter model for computing pairwise distances showed that A. thelaxis differs from both A. ambiguus and A. salicaphis by 4.9 and 6% on average, respectively. The genetic distance between A. ambiguus and A. salicaphis was 1.5% on average, suggesting that barcodes based on the COI gene are insufficiently informative for separating these two species. Geometric morphometrics analysis of forewing size and shape revealed statistically significant differences. The R1 vein on the forewing of A. ambiguus is more elongated than on the wings of A. salicaphis and A. thelaxis. The geometric morphometrics analysis of the forewings also revealed that A. salicaphis and A. thelaxis have much broader forewings, suggesting strong flight ability associated with their parasitizing arboricolous aphids. The distal part of the forewing of Adialytus ambiguus is narrower, which in this case suggests poor flight ability associated with parasitizing Sipha aphids on grasses. An illustrated key for identifying the European species of Adialytus is provided. |
Tri-trophic interaction involving host plants, black legume aphid, Aphis craccivora (Hemiptera: Aphididae) and the predator, Cheilomenes sexmaculata (Coleoptera: Coccinellidae)Original articleSnehasish ROUTRAY, Karnam V. HARI PRASADEur. J. Entomol. 113: 551-557, 2016 | DOI: 10.14411/eje.2016.075 Interactions involving host plants (cowpea, groundnut, cotton, sunflower, greengram, blackgram) an insect herbivore, black legume aphid Aphis craccivora Koch (Hemiptera: Aphididae) and a predator, the zigzag beetle Cheilomenes sexmaculata (Fabricius) (Coleoptera: Coccinellidae) were investigated during 2014-2015. The preference of the aphid A. craccivora for host plants measured in terms of growth and multiplication was cowpea > groundnut > greengram > blackgram > sunflower > cotton (most preferred to least preferred). Cowpea was the most preferred host plant for growth and multiplication of A. craccivora. Aphid's oviposition period was longest, fecundity greatest; adult longevity longest (188.40 ± 28.87 h; 52.00 ± 10.92; 231.60 ± 40.41 h), and nymphal mortality was lowest (0%) when reared on cowpea followed by groundnut, greengram and blackgram. Aphids had highest nymphal mortality (100%), with very few or no live adults produced, when reared on sunflower and cotton, the least preferred host of A. craccivora in this study. At the third trophic level, both the larvae and the adults of the coccinellid, Cheilomenes sexmaculata, consumed more of the aphids reared on groundnut than of those reared on blackgram, greengram, cowpea, sunflower and cotton. The biochemical constituents (phenols) present in cotton and sunflower, which contributed to the aphid's nymphal mortality, also affected the feeding behaviour of the coccinellid. |
Response of the reduviid bug, Rhynocoris marginatus (Heteroptera: Reduviidae) to six different species of cotton pestsOriginal articleKitherian SAHAYARAJ, Subramanian MUTHU KUMAR, Annie ENKEGAARDEur. J. Entomol. 113: 29-36, 2016 | DOI: 10.14411/eje.2016.003 Abstract. In Indian agro-ecosystems Rhynocoris marginatus (F.) is one of the most abundant predatory arthropods and feeds on a wide range of insect pests. We investigated the responses of R. marginatus to six species of cotton pests: Spodoptera litura (F.), Sylepta derogata (F.), Pericallia ricini (F.), Mylabris indica (Thunberg), Mylabris pustulata (Thunberg) and Dysdercus cingulatus (F.), in terms of its predatory behaviour (approach and handling times), weight gain, macromolecular profile (content of carbohydrates, proteins, free aminoacids and lipids) and haemocytic profile. We also determined the predator's reliance on kairomones from different species of prey. Larvae of the species of Lepidoptera studied were approached and captured more quickly than adults of the two meloid coleopteran and one heteropteran pest and were more beneficial to the predator in terms of weight gain. Predators had a higher total protein content when reared on larvae of the three lepidopteran species, higher lipid content when reared on adults of the two meloid coleopteran species and a higher carbohydrate content when reared on adults of one heteropteran species. The number of haemocytes was greater in predators reared on larvae of the Lepidoptera studied, followed by those reared on adults of the heteropteran and lowest in those reared on adults of the two meloid coleopterans. Response to kairomones was strongest for S. litura followed by S. derogata and M. pustulata. We conclude that the Lepidoptera studied tended to be, for this predator, superior prey, with S. litura being especially beneficial and the prey species for which R. marginatus has the highest kairomonal preference. Moreover, we propose that R. marginatus may be useful as a biocontrol agent against lepidopteran cotton pests. |
Settling moths as potential pollinators of Uncaria rhynchophylla (Rubiaceae)NoteDaichi FUNAMOTO, Shinji SUGIURAEur. J. Entomol. 113: 497-501, 2016 | DOI: 10.14411/eje.2016.065 Nocturnal pollinators such as moths have received less attention than diurnal insects. To elucidate whether nocturnal moths are important pollinators, we observed both the diurnal and nocturnal visitors to the flowers of Uncaria rhynchophylla (Rubiaceae) in a warm-temperate forest in central Japan. The diurnal visitors included various taxonomic groups (e.g., bees, hoverflies and butterflies). The nocturnal visitors were exclusively moths (Geometridae, Erebidae, Noctuidae and Crambidae). Pollen grains of U. rhynchophylla were attached to both diurnal and nocturnal visitors. Although diurnal flower visitors carried pollen grains of other plant species, nocturnal moths did not carry heterospecific pollen grains. These results suggest that nocturnal moths, as well as diurnal insects, are important pollinators of U. rhynchophylla. |
Acceptance of alien queens by the ruby ant Myrmica rubra (Hymenoptera: Formicidae): Gene flow by queen flowOriginal articleJouni SORVARIEur. J. Entomol. 114: 230-234, 2017 | DOI: 10.14411/eje.2017.028 Social insect colonies, especially of ants, often include several egg-laying queens that are not always closely related to each other. At least in some cases, the ants seem to accept non-related queens into their colonies. Here I test whether the colony queen status (with or without a queen), genetic and geographic differences between source and recipient nests and the average relatedness of the workers in the recipient colony affect the acceptance of alien queens. I used field collected ruby ant Myrmica rubra colonies as a model system. Only the queen status significantly affected the acceptance process. Colonies without queens accepted alien queens more frequently than colonies with a queen. The nests without queens and nest fragments may act as vectors for gene flow by the movement of queens between nests, i.e., queen flow. |
Detailed morphological descriptions of the immature stages of the ant parasite Microdon mutabilis (Diptera: Syrphidae: Microdontinae) and a discussion of its functional morphology, behaviour and host specificityOriginal articleGiulia SCARPARO, Pierfilippo CERRETTI, Maurizio MEI, Andrea DI GIULIOEur. J. Entomol. 114: 565-586, 2017 | DOI: 10.14411/eje.2017.071 The myrmecophilous immature stages of hover flies of the genus Microdon Meigen, 1803 (Diptera, Syrphidae) are still poorly known and only about 15 species were previously incompletely described and/or illustrated using light microscopy based on occasional findings mainly of pupae and third instar larvae. The exceptional finding of a large number of second and third instar larvae and pupae (159 specimens) of Microdon mutabilis (Linnaeus, 1758) inside the nest of a new host species, Formica cunicularia Latreille,1798, enabled us to rear them and obtain a great number of eggs and first instar larvae. We filmed and described the feeding behaviour and locomotion of these highly derived slug-like larvae. Combining light, fluorescence and scanning electron (SEM) microscopy, we describe in detail and illustrate the external features of all the immature stages of M. mutabilis (eggs, larvae and pupae). Covering the entire chorion of the egg is a peculiar microsculpture composed of volcano-like processes. The three larval instars strongly differ from each other, especially at the level of the shape of the body, the posterior spiracular tubercle and the cephaloskeleton. SEM microscopy was used to describe in detail the microsculpture, sensorial structures, spiracles and cephalic appendages of larvae and pupae. Fluorescence microscopy was used to reveal the exceptional presence of resilin in the external layer of the posterior spiracular tubercle in first instar larvae. The possible functional significance of these structures is discussed. |



