| 1. |
- Ahlbäck Widenfalk, Lina, et al.
(author)
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The effect of landscape structure and habitat composition on the presence of the threatened parasitic sand-living beetle Apalus bimaculatus (Coleoptera: Meloidae)
- 2013
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In: Canadian Entomologist. - : Cambridge University Press (CUP). - 0008-347X .- 1918-3240. ; 145, s. 626-638
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Journal article (peer-reviewed)abstract
- Apalus bimaculatus (Linnaeus) (Coleoptera: Meloidae) is a beetle currently managed for conservation in Sweden. The species inhabits at-risk ephemeral and patchily distributed sandy habitats. However, little is known about its ecology and the factors important for its distribution. We censused 158 discrete sand patches within 31 potential sites for A. bimaculatus and examined which environmental variables predicted the probability of finding the beetle. Apalus bimaculatus was found at 17 sites, its presence at sand-patch scale was positively correlated with sand-patch area, sand temperature, and medium-sized sand grains. Although the beetle is assumed to be a parasite on the solitary bee, Colletes cunicularius (Linnaeus) (Hymenoptera: Colletidae), presence of the bee was a very weak predictor for A. bimaculatus, while other sand-living Hymenoptera were a strong predictor. At site-level scale, the beetle was positively correlated with total amount of sandy habitat and presence of sand-living Hymenoptera. Our study suggests that management strategies for this species should not consider sandy habitats equally. Rather, management efforts should focus on maintaining sites with larger total sandy areas, creating larger sand patches with medium-grained sand and a high degree of sun exposure. We also highlight that biotic interactions between the beetle and sand-living Hymenoptera are still poorly understood but potentially important for successful A. bimaculatus management.
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| 2. |
- Back, C, et al.
(author)
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High-dosage treatment of a Quebec stream with Bacillus thuringiensis serovar. israelensis : efficacy against black fly larvae (Diptera, Simuliidae) and impact on nontarget insects
- 1985
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In: Canadian Entomologist. - 0008-347X .- 1918-3240. ; 117:12, s. 1523-1534
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Journal article (peer-reviewed)abstract
- A typical lake outlet of the Canadian Shield was treated for 15 min with a high dose (5.28 g/L s−1 of discharge) of Teknar®, a commercial formulation of Bacillus thuringiensis serovar. israelensis. Efficacy on Simuliidae larvae and impact on non-target aquatic insects of this stream were monitored using drift nets, counting plates, and artificial turf substrates along a 1000-m section downstream of the site of application. Compared with a 4-day pre-treatment average for 12-h sampling periods, drift of Simuliidae increased from 64 to 92 ×, with shorter peaks of 133–184 ×, 2–6 h after treatment. There was no evident drift increase in larvae of Ephemeroptera, Plecoptera, Trichoptera, Chironomidae, or dipterous pupae, but larvae of Blephariceridae (Diptera) were severely affected as their drift was increased by up to 50 × and remained high for 3 days. After 30 h the mortality of Simuliidae on counting plates ranged from 95 to 82% in the first 300 m, with detachment rates of 78.5–46.5%. Densities of non-target insect larvae were not reduced on the artificial substrates, except for 2 genera of Chironomidae (Eukiefferella and Polypedilum) which were reduced 26 to 39% of their original density. Drifting larvae of 1 chironomid genus (Phaenopsectra) also showed symptoms of toxemia by B.t.i. The main impact of the treatment was thus seen in 2 Nematocera families (Chironomidae and Blephariceridae) which were mainly exposed to B.t.i. sedimented on the bottom of the stream or attached to periphyton growing on rocks.
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| 3. |
- Back, C, et al.
(author)
-
High-dosage treatment of a Quebec stream with Bacillus thuringiensis serovar. israelensis : efficacy against black fly larvae (Diptera, Simuliidae) and impact on nontarget insects
- 1985
-
In: Canadian Entomologist. - : Cambridge University Press. - 0008-347X .- 1918-3240. ; 117:12, s. 1523-1534
-
Journal article (peer-reviewed)abstract
- A typical lake outlet of the Canadian Shield was treated for 15 min with a high dose (5.28 g/L s−1 of discharge) of Teknar®, a commercial formulation of Bacillus thuringiensis serovar. israelensis. Efficacy on Simuliidae larvae and impact on non-target aquatic insects of this stream were monitored using drift nets, counting plates, and artificial turf substrates along a 1000-m section downstream of the site of application. Compared with a 4-day pre-treatment average for 12-h sampling periods, drift of Simuliidae increased from 64 to 92 ×, with shorter peaks of 133–184 ×, 2–6 h after treatment. There was no evident drift increase in larvae of Ephemeroptera, Plecoptera, Trichoptera, Chironomidae, or dipterous pupae, but larvae of Blephariceridae (Diptera) were severely affected as their drift was increased by up to 50 × and remained high for 3 days. After 30 h the mortality of Simuliidae on counting plates ranged from 95 to 82% in the first 300 m, with detachment rates of 78.5–46.5%. Densities of non-target insect larvae were not reduced on the artificial substrates, except for 2 genera of Chironomidae (Eukiefferella and Polypedilum) which were reduced 26 to 39% of their original density. Drifting larvae of 1 chironomid genus (Phaenopsectra) also showed symptoms of toxemia by B.t.i. The main impact of the treatment was thus seen in 2 Nematocera families (Chironomidae and Blephariceridae) which were mainly exposed to B.t.i. sedimented on the bottom of the stream or attached to periphyton growing on rocks.
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| 4. |
- Björklund, Niklas
(author)
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Non-destructive tree-trunk funnel trap for capturing Hylobius warreni (Coleoptera: Curculionidae) ascending stems of trees
- 2009
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In: Canadian Entomologist. - : Cambridge University Press (CUP). - 0008-347X .- 1918-3240. ; 141, s. 422-424
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Journal article (peer-reviewed)abstract
- A simple and inexpensive non-destructive trap to catch insects as they ascend tree boles is described. The trap was tested in a capture-mark-recapture experiment on the Warren root collar weevil, Hylobius warreni Wood. A high percentage (77%) of marked H. warreni were recaptured at least once during a 12-day period and 54% were recaptured more than once, with one weevil recaptured eight times.
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| 5. |
- Drotz, Marcus K., et al.
(author)
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The genetic population structure of lotic and lentic mayflies of the Baetis vernus group (Ephemeroptera: Baetidae)
- 2012
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In: Canadian Entomologist. - : Cambridge University Press (CUP). - 0008-347X .- 1918-3240. ; 144:5, s. 679-690
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Journal article (peer-reviewed)abstract
- Nymphs of lotic mayflies live in environments that are expected to give rise to different degrees of population structuring. Here we investigate two taxa adapted to different lifestyles. Baetis macani Kimmins (Ephemeroptera: Baetidae) lives in flowing water; brooks that may periodically dry out in the summer or freeze to the bottom in winter. Baetis jaervii Savolainen is mostly found in sedge belts along the shores of lakes. Most insects living in flowing water show low levels of among-population genetic differentiation within and among catchments. Levels of differentiation in the lotic species are therefore assumed to be lower than in lentic B. jaervii. Here we test this hypothesis. Mitochondrial DNA and allele frequencies of nuclear genes were used to detect population structure in specimens originating from an extensive area from northern Finland. The genetic differentiation among populations of the lotic B. macani is more than twice the corresponding value for the lentic B. jaervii (F-ST 0.33 versus 0.15, while the mean F-ST between species was 0.33 and significant). The result is congruent within the cytochrome c oxidase subunit I gene (COI) partial gene frequencies. We argue that the significant genetic population structure, which only was found in the lotic B. macani, is differentiated as a consequence to the unpredictable environment as contrasted to the stable environment in standing bodies of water.
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| 6. |
- Ekbom, Barbara, et al.
(author)
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Consumption of flea beetles (Phyllotreta, Coleoptera: Chrysomelidae) by spiders in field habitats detected by molecular analysis
- 2014
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In: Canadian Entomologist. - : Cambridge University Press (CUP). - 0008-347X .- 1918-3240. ; 146, s. 639-651
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Journal article (peer-reviewed)abstract
- Flea beetles, Phyllotreta Chevrolat (Coleoptera: Chrysomelidae) species, are often found in oilseed rape (OSR), Brassica napus Linnaeus (Brassicaceae). Among predators in the generalist predator complex present in agricultural fields, wolf spiders (Araneae: Lycosidae) are found on the ground and cobweb spiders (Araneae: Theridiidae) build webs in the foliage. We present group-specific primers developed for five flea beetle species within the genus Phyllotreta and study the incidence of predation of flea beetles by these spider groups using DNA-based gut-content analysis. Wolf spiders of the genus Pardosa Koch and the cobweb spider, Phylloneta impressa (Koch), were collected in three winter OSR fields. Flea beetle densities as well as the occurrence of predators and alternative prey were monitored. In total 19.4% of the collected Pardosa tested positive for flea beetle DNA in the polymerase chain reaction analyses, whereas 10% P. impressa were positive. Pardosa were more likely to be positive for flea beetle DNA when Pardosa activity density was low. Phylloneta impressa were more likely to be positive for flea beetle DNA if they were positive for pollen beetle DNA. Implications of these results for conservation biological control and future studies of food webs in OSR are discussed.
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| 7. |
- Faraone, Nicoletta, et al.
(author)
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Collection of host-marking pheromone from Rhagoletis mendax (Diptera : Tephritidae)
- 2016
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In: Canadian Entomologist. - : Cambridge University Press (CUP). - 0008-347X .- 1918-3240. ; 148:5, s. 552-555
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Journal article (peer-reviewed)abstract
- Blueberry fruit fly, Rhagoletis mendax Curran (Diptera: Tephritidae), females deposit a host-marking pheromone (HMP) on the surface of fruit immediately after oviposition that deters oviposition by female conspecifics. We collected this HMP from artificial oviposition devices and faeces. In subsequent two-choice bioassays, gravid females showed a strong preference for untreated oviposition devices as compared to those treated with extracts from either of these two sources. The methods described for collecting HMP of R. mendax will be useful for its eventual identification and synthesis, with potential applications in R. mendax management.
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| 8. |
- Savolainen, Eino, et al.
(author)
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Baetis bundyae (Ephemeroptera: Baetidae), described from Arctic Canada is found in northernmost Europe
- 2014
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In: Canadian Entomologist. - : Cambridge University Press (CUP). - 0008-347X .- 1918-3240. ; 146:6, s. 621-629
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Journal article (peer-reviewed)abstract
- The taxonomy and identification of mayflies of the Baetis vernus group (Ephemeroptera: Baetidae) represents a major challenge in both Europe and North America. The recent description of B. jaervii Savolainen from Finland, a species taxonomically close to the Palaearctic taxon Baetis macani Kimmins and the Nearctic B. bundyae Lehmkuhl, called for clarification of the status and distribution of these species in northernmost Europe. We generated mtDNA COI sequences for establishing the identity of the collected samples. Based on these data we conclude that B. bundyae does occur in northeastern Finland in sympatry with B. macani. Accordingly, this taxon shows a highly interesting distributional pattern across the Nearctic and western Palaearctic regions.
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| 9. |
- Sevcik, Jan, et al.
(author)
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Revision of Speolepta (Diptera: Mycetophilidae), with descriptions of new Nearctic and Oriental species
- 2012
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In: Canadian Entomologist. - : Cambridge University Press (CUP). - 1918-3240 .- 0008-347X. ; 144:1, s. 93-107
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Journal article (peer-reviewed)abstract
- The cave-living and monobasic fungus gnat genus Speolepta Edwards is reviewed with a description of the first Nearctic species, Speolepta vockerothi sp. nov., from Canada (caves in Ontario and British Columbia) and the United States (Alaska). Its morphology, life history, and biology are documented and compared with the single European species Speolepta leptogaster (Winnertz). A further new species, Speolepta orientalis sp. nov., is described based on a single male from northern Vietnam, representing the first record of this genus from the Oriental Region.
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| 10. |
- Tessier, Louis, et al.
(author)
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Characterization of Hydropsyche slossonae (Trichoptera: Hydropsychidae) capture net polypeptides
- 2000
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In: Canadian Entomologist. - 0008-347X .- 1918-3240. ; 132:1, s. 59-68
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Journal article (peer-reviewed)abstract
- A laboratory study on the sublethal effects of malathion on the net-spinning behavior of the caddisfly larvae Hydropsycheslossonae was conducted in order to assess the potential of net anomalies as an indicator of chronic exposure to organophosphorus insecticides. Two anomalies were identified after chronic exposure to 0.01, 0.05, 0.1, 0.5 and 1.0 μg l−1 malathion. The first was a distortion of the midline meshes where the normal diamond shape structure was disrupted and the meshes were separated by extra strands (called ‘midline’ anomaly). The second aberration observed was a significant decrease in net symmetry. Both anomalies were highly correlated to the toxic action of malathion, i.e. inhibition of the acetylcholinesterase enzyme (AChE). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analyses of capture nets did not show any modification of silk polypeptides after exposure to malathion, indicating that net distortions were not related to silk composition. Both anomalies seem to represent the symptoms of the specific toxic action of malathion; nevertheless, they can serve as an index of the physiological condition of the larvae, especially the midline anomaly. The symmetry of the nets decreased significantly after exposure to 0.5 and 1.0 μg l−1. However, the toxicity curves (EC50) showed that the sensitivity threshold for the midline anomaly ranged from 0.11 to 0.28 μg l−1, which reflect more realistic exposure to concentrations expected to occur in the field. Hence, the use of capture net anomalies of hydropsychid larvae could represent a valuable indicator of sublethal toxicity induced by malathion and other organophosphorus insecticides in running waters.
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