Erling Jirle | Lund University (original) (raw)

Papers by Erling Jirle

Journal of Chemical Ecology, 2000

Under an artificial light:dark cycle, females of Lampronia capitella were observed calling, with ... more Under an artificial light:dark cycle, females of Lampronia capitella were observed calling, with extended terminal abdominal segments, during the first 2 hr of the photoperiod. Extracts of terminal abdominal segments from females elicited large electroantennographic responses from male antennae. Gas chromatography with electroantennographic detection revealed three active peaks. Based on comparison of retention times and mass spectra of synthetic standards, these compounds were identified as (Z ,Z )-9,11-tetradecadienol and the corresponding acetate and aldehyde. The electroantennographic activity of the four geometric isomers of all three compounds was investigated, and the respective (Z ,Z )-isomer was found to be the most active in all cases. Aldehydes generally elicited larger antennal responses than alcohols, whereas acetates were the least active compounds. A subtractive trapping assay in the field, Plenum Publishing Corporation 644 LÖFSTEDT ET AL. based on a 13:26:100 µg mixture of (Z ,Z )-9,11-tetradecadienal, (Z ,Z )-9,11tetradecadienyl acetate, and (Z ,Z )-9,11-tetradecadienol confirmed that all three compounds are pheromone components. Subtraction of (Z ,Z )-9,11-tetradecadienol from the blend completely eliminated its attractiveness, whereas the other two-component blends showed reduced activity. This is the first pheromone identification from the monotrysian superfamily Incurvarioidea, confirming that the common pheromones among ditrysian moths (long-chain fatty acid derivatives comprising alcohols, acetates, and aldehydes with one or more double bonds) is not an autapomorphy of Ditrysia, but a synapomorphy of the more advanced heteroneuran lineages.

Journal of Applied Entomology, 2014

The sex pheromone of the cloaked pug moth, Eupithecia abietaria G€ otze, an important cone-feedin... more The sex pheromone of the cloaked pug moth, Eupithecia abietaria G€ otze, an important cone-feeding pest in spruce seed orchards in Europe, was investigated. Chemical and electrophysiological analyses of pheromone gland extracts of female moths and analogous analyses of synthetic hydrocarbons and epoxides of chain length C 19 and C 21 revealed (3Z,6Z,9Z)-3,6,9-nonadecatriene (3Z,6Z,9Z-19:H) and 3Z,6Z-cis-9,10epoxynonadecadiene (3Z,6Z-cis-9,10-epoxy-19:H) as candidate pheromone components, which were found in a gland extract in a ratio of 95 : 5. In field trapping experiments, conspecific males were only attracted to a combination of 3Z,6Z,9Z-19:H and the (9S,10R)-enantiomer of 3Z,6Z-cis-9,10-epoxy-19:H. The (9R,10S)-enantiomer was not attractive, which is in agreement with studies on other Eupithecia species, for which males have only been attracted by the (9S,10R)-enantiomer of epoxides. Subsequent experiments showed that E. abietaria males were attracted to a wide range of ratios of the two active compounds and that trap catches increased with increasing dose of the binary blend. A twocomponent bait containing 300 lg 3Z,6Z,9Z-19:H and 33 lg of the (9S,10R)-enantiomer of 3Z,6Z-cis-9,10-epoxy-19:H was efficient for monitoring E. abietaria in spruce seed orchards in southern Sweden, where this species has probably been overlooked as an important pest in the past. With sex pheromones recently identified for two other moths that are major pests on spruce cones, the spruce seed moth, Cydia strobilella L., and the spruce coneworm, Dioryctria abietella Denis & Schifferm€ uller, pheromone-based monitoring can now be achieved for the whole guild of conefeeding moths in European spruce seed orchards.

Journal of Insect Behavior, 1999

Females of the European pine sawfly, Neodiprion sertifer (Geoffr.) (Hymenoptera: Diprionidae), we... more Females of the European pine sawfly, Neodiprion sertifer (Geoffr.) (Hymenoptera: Diprionidae), were released and observed inside and outside ( = control) of areas treated with their sex pheromone for the purpose of mating disruption. In 1992 and 1993, respectively, 0 and 2.5% of the females were observed mating in the pheromone treated area during the first day, compared with 28 and 26% in the control area. Of the females that mated, approximately 50% stayed on their twigs and oviposited, while the remaining 50% disappeared. Significantly more females disappeared from their twigs inside the treated area compared to the control area in both years. No difference was found in the proportion of unmated females ovipositing (2-12%) between the treated and the control area. Predation was responsible for much of the disappearance, but deliberate dispersal was also noted. Mating and dispersal in female N. sertifer are discussed in relation to population density and overall fitness.

Journal of Chemical Ecology, 2008

In the caddisfly Molanna angustata, females produce a sex pheromone in glands with openings on th... more In the caddisfly Molanna angustata, females produce a sex pheromone in glands with openings on the fifth sternite. Gas chromatographic analyses of pheromone gland extracts with electroantennographic detection revealed four major compounds that stimulated male antennae. These compounds were identified by means of gas chromatography-mass spectrometry and enantioselective gas chromatography as heptan-2-one, (S)-heptan-2-ol, nonan-2-one, and (S)-nonan-2-ol in the approximate ratio of 1:1:4:10, respectively. Field tests showed that the mixture of the two alcohols was attractive to males whereas addition of the corresponding ketones reduced trap catches. The sex pheromone of M. angustata, a species in the family Molannidae within the suborder Integripalpia, is similar to the pheromones or pheromone-like compounds previously reported from six other trichopteran families, including members of the basal suborder Annulipalpia. This suggests that minimal evolutionary change of the pheromone chemistry has taken place within the leptoceroid branch of integripalpian Trichoptera compared to the ancestral character state.

Journal of Chemical Ecology, 2010

The spruce seed moth, Cydia strobilella L., is a serious pest on cones of spruce (Picea spp.) in ... more The spruce seed moth, Cydia strobilella L., is a serious pest on cones of spruce (Picea spp.) in the Holarctic region. Previous studies from different parts of its area of distribution have reported conflicting results on the composition of its sex pheromone. By gas chromatography with electroantennographic detection, coupled gas chromatography-mass spectrometry, a Y-tube olfactometer bioassay, and field trials, the sex pheromone of Swedish populations of the species was identified as (8E,10E)dodecadienyl acetate and (8E,10Z)-dodecadienyl acetate. About 0.5 pg of each pheromone component was extracted per female. The most attractive blend of EE-and EZ-isomers was about 6:4, respectively, and 0.3 µg of the blend per rubber septum was the most attractive dosage for field trapping. Monounsaturated components previously reported as sex pheromone components/attractants for C. strobilella, (E)-8-dodecenyl acetate in Canadian populations and (Z)-8dodecenol in Polish and Dutch populations, did not attract any C. strobilella in this study. Large numbers of C. jungiella Clerck were trapped by using (8E,10Z)-dodecadienyl acetate alone, whereas (Z)-8-dodecenol attracted Pammene splendidulana Guenée and P. rhediella Clerck. Keywords Sex pheromone . Cydia strobilella . Tortricidae . Lepidoptera . (8E,10E)-dodecadienyl acetate . (8E,10Z)-dodecadienyl acetate . Spruce seed orchard . Monitoring

Journal of Applied Entomology, 2006

The currant shoot borer, Lampronia capitella (Lep., Prodoxidae), is an important pest of currants... more The currant shoot borer, Lampronia capitella (Lep., Prodoxidae), is an important pest of currants, Ribes spp., in northern Europe. Oviposition was studied in cage experiments and the flight period was monitored in field studies using pheromone-baited traps. Blackcurrant, Ribes nigrum, was the host species in both studies. The total egg supply of females was on average 107 eggs and oviposition started 2-5 days after emergence. About 60% of the eggs were laid during the first day of the oviposition period. Eggs were laid in currant fruitlets, in batches comprising several, usually four to seven eggs. The flight period started shortly after the end of the flowering period of blackcurrant, and lasted for about 3 weeks.

Journal of Applied Entomology, 2012

Combining pheromone trapping and genetic analyses can be useful when trying to resolve complexes ... more Combining pheromone trapping and genetic analyses can be useful when trying to resolve complexes of closely related insect taxa that are difficult to distinguish based on morphological characters. Nearctic and Palearctic populations of the spruce seed moth, Cydia strobilella L., have been considered taxonomically synonymous since 1983, but more recent work revealing distinct sex pheromones for Canadian and Swedish moths suggest that populations in the two regions belong to different species. In order to test this hypothesis, we performed field trapping using different pheromone lures at ten sites in North America, Europe and Asia, and reconstructed phylogenetic relationships among trapped moths using mitochondrial (cytochrome oxidase subunit I ) and nuclear (elongation factor 1 alpha) DNA sequence data. Trapping data and tree topologies for both genes revealed distinct pherotypes in North America and Eurasia. A genetically distinct population from China was investigated further with respect to its sex pheromone. Electrophysiological data indicated that Chinese females produce a deviant ratio of the sex pheromone components (dienic acetates) compared to Swedish females. However, trapping experiments in both areas revealed a similar broad response profile in males to a wide range of acetate ratios, and these populations should be considered taxonomically synonymous. A previous suggestion of an agonistic effect on the attraction of C. strobilella males in Sweden when adding the corresponding alcohols to the binary acetate blend was also tested in Sweden as well as in China, with no observed effect on attraction of males. In

Journal of Chemical Ecology, 2000

Under an artificial light:dark cycle, females of Lampronia capitella were observed calling, with ... more Under an artificial light:dark cycle, females of Lampronia capitella were observed calling, with extended terminal abdominal segments, during the first 2 hr of the photoperiod. Extracts of terminal abdominal segments from females elicited large electroantennographic responses from male antennae. Gas chromatography with electroantennographic detection revealed three active peaks. Based on comparison of retention times and mass spectra of synthetic standards, these compounds were identified as (Z ,Z )-9,11-tetradecadienol and the corresponding acetate and aldehyde. The electroantennographic activity of the four geometric isomers of all three compounds was investigated, and the respective (Z ,Z )-isomer was found to be the most active in all cases. Aldehydes generally elicited larger antennal responses than alcohols, whereas acetates were the least active compounds. A subtractive trapping assay in the field, Plenum Publishing Corporation 644 LÖFSTEDT ET AL. based on a 13:26:100 µg mixture of (Z ,Z )-9,11-tetradecadienal, (Z ,Z )-9,11tetradecadienyl acetate, and (Z ,Z )-9,11-tetradecadienol confirmed that all three compounds are pheromone components. Subtraction of (Z ,Z )-9,11-tetradecadienol from the blend completely eliminated its attractiveness, whereas the other two-component blends showed reduced activity. This is the first pheromone identification from the monotrysian superfamily Incurvarioidea, confirming that the common pheromones among ditrysian moths (long-chain fatty acid derivatives comprising alcohols, acetates, and aldehydes with one or more double bonds) is not an autapomorphy of Ditrysia, but a synapomorphy of the more advanced heteroneuran lineages.

Journal of Applied Entomology, 2014

The sex pheromone of the cloaked pug moth, Eupithecia abietaria G€ otze, an important cone-feedin... more The sex pheromone of the cloaked pug moth, Eupithecia abietaria G€ otze, an important cone-feeding pest in spruce seed orchards in Europe, was investigated. Chemical and electrophysiological analyses of pheromone gland extracts of female moths and analogous analyses of synthetic hydrocarbons and epoxides of chain length C 19 and C 21 revealed (3Z,6Z,9Z)-3,6,9-nonadecatriene (3Z,6Z,9Z-19:H) and 3Z,6Z-cis-9,10epoxynonadecadiene (3Z,6Z-cis-9,10-epoxy-19:H) as candidate pheromone components, which were found in a gland extract in a ratio of 95 : 5. In field trapping experiments, conspecific males were only attracted to a combination of 3Z,6Z,9Z-19:H and the (9S,10R)-enantiomer of 3Z,6Z-cis-9,10-epoxy-19:H. The (9R,10S)-enantiomer was not attractive, which is in agreement with studies on other Eupithecia species, for which males have only been attracted by the (9S,10R)-enantiomer of epoxides. Subsequent experiments showed that E. abietaria males were attracted to a wide range of ratios of the two active compounds and that trap catches increased with increasing dose of the binary blend. A twocomponent bait containing 300 lg 3Z,6Z,9Z-19:H and 33 lg of the (9S,10R)-enantiomer of 3Z,6Z-cis-9,10-epoxy-19:H was efficient for monitoring E. abietaria in spruce seed orchards in southern Sweden, where this species has probably been overlooked as an important pest in the past. With sex pheromones recently identified for two other moths that are major pests on spruce cones, the spruce seed moth, Cydia strobilella L., and the spruce coneworm, Dioryctria abietella Denis & Schifferm€ uller, pheromone-based monitoring can now be achieved for the whole guild of conefeeding moths in European spruce seed orchards.

Journal of Insect Behavior, 1999

Females of the European pine sawfly, Neodiprion sertifer (Geoffr.) (Hymenoptera: Diprionidae), we... more Females of the European pine sawfly, Neodiprion sertifer (Geoffr.) (Hymenoptera: Diprionidae), were released and observed inside and outside ( = control) of areas treated with their sex pheromone for the purpose of mating disruption. In 1992 and 1993, respectively, 0 and 2.5% of the females were observed mating in the pheromone treated area during the first day, compared with 28 and 26% in the control area. Of the females that mated, approximately 50% stayed on their twigs and oviposited, while the remaining 50% disappeared. Significantly more females disappeared from their twigs inside the treated area compared to the control area in both years. No difference was found in the proportion of unmated females ovipositing (2-12%) between the treated and the control area. Predation was responsible for much of the disappearance, but deliberate dispersal was also noted. Mating and dispersal in female N. sertifer are discussed in relation to population density and overall fitness.

Journal of Chemical Ecology, 2008

In the caddisfly Molanna angustata, females produce a sex pheromone in glands with openings on th... more In the caddisfly Molanna angustata, females produce a sex pheromone in glands with openings on the fifth sternite. Gas chromatographic analyses of pheromone gland extracts with electroantennographic detection revealed four major compounds that stimulated male antennae. These compounds were identified by means of gas chromatography-mass spectrometry and enantioselective gas chromatography as heptan-2-one, (S)-heptan-2-ol, nonan-2-one, and (S)-nonan-2-ol in the approximate ratio of 1:1:4:10, respectively. Field tests showed that the mixture of the two alcohols was attractive to males whereas addition of the corresponding ketones reduced trap catches. The sex pheromone of M. angustata, a species in the family Molannidae within the suborder Integripalpia, is similar to the pheromones or pheromone-like compounds previously reported from six other trichopteran families, including members of the basal suborder Annulipalpia. This suggests that minimal evolutionary change of the pheromone chemistry has taken place within the leptoceroid branch of integripalpian Trichoptera compared to the ancestral character state.

Journal of Chemical Ecology, 2010

The spruce seed moth, Cydia strobilella L., is a serious pest on cones of spruce (Picea spp.) in ... more The spruce seed moth, Cydia strobilella L., is a serious pest on cones of spruce (Picea spp.) in the Holarctic region. Previous studies from different parts of its area of distribution have reported conflicting results on the composition of its sex pheromone. By gas chromatography with electroantennographic detection, coupled gas chromatography-mass spectrometry, a Y-tube olfactometer bioassay, and field trials, the sex pheromone of Swedish populations of the species was identified as (8E,10E)dodecadienyl acetate and (8E,10Z)-dodecadienyl acetate. About 0.5 pg of each pheromone component was extracted per female. The most attractive blend of EE-and EZ-isomers was about 6:4, respectively, and 0.3 µg of the blend per rubber septum was the most attractive dosage for field trapping. Monounsaturated components previously reported as sex pheromone components/attractants for C. strobilella, (E)-8-dodecenyl acetate in Canadian populations and (Z)-8dodecenol in Polish and Dutch populations, did not attract any C. strobilella in this study. Large numbers of C. jungiella Clerck were trapped by using (8E,10Z)-dodecadienyl acetate alone, whereas (Z)-8-dodecenol attracted Pammene splendidulana Guenée and P. rhediella Clerck. Keywords Sex pheromone . Cydia strobilella . Tortricidae . Lepidoptera . (8E,10E)-dodecadienyl acetate . (8E,10Z)-dodecadienyl acetate . Spruce seed orchard . Monitoring

Journal of Applied Entomology, 2006

The currant shoot borer, Lampronia capitella (Lep., Prodoxidae), is an important pest of currants... more The currant shoot borer, Lampronia capitella (Lep., Prodoxidae), is an important pest of currants, Ribes spp., in northern Europe. Oviposition was studied in cage experiments and the flight period was monitored in field studies using pheromone-baited traps. Blackcurrant, Ribes nigrum, was the host species in both studies. The total egg supply of females was on average 107 eggs and oviposition started 2-5 days after emergence. About 60% of the eggs were laid during the first day of the oviposition period. Eggs were laid in currant fruitlets, in batches comprising several, usually four to seven eggs. The flight period started shortly after the end of the flowering period of blackcurrant, and lasted for about 3 weeks.

Journal of Applied Entomology, 2012

Combining pheromone trapping and genetic analyses can be useful when trying to resolve complexes ... more Combining pheromone trapping and genetic analyses can be useful when trying to resolve complexes of closely related insect taxa that are difficult to distinguish based on morphological characters. Nearctic and Palearctic populations of the spruce seed moth, Cydia strobilella L., have been considered taxonomically synonymous since 1983, but more recent work revealing distinct sex pheromones for Canadian and Swedish moths suggest that populations in the two regions belong to different species. In order to test this hypothesis, we performed field trapping using different pheromone lures at ten sites in North America, Europe and Asia, and reconstructed phylogenetic relationships among trapped moths using mitochondrial (cytochrome oxidase subunit I ) and nuclear (elongation factor 1 alpha) DNA sequence data. Trapping data and tree topologies for both genes revealed distinct pherotypes in North America and Eurasia. A genetically distinct population from China was investigated further with respect to its sex pheromone. Electrophysiological data indicated that Chinese females produce a deviant ratio of the sex pheromone components (dienic acetates) compared to Swedish females. However, trapping experiments in both areas revealed a similar broad response profile in males to a wide range of acetate ratios, and these populations should be considered taxonomically synonymous. A previous suggestion of an agonistic effect on the attraction of C. strobilella males in Sweden when adding the corresponding alcohols to the binary acetate blend was also tested in Sweden as well as in China, with no observed effect on attraction of males. In