Response to conspecific and heterospecific semiochemicals by Sesamia nonagrioides (L.) (Lepidoptera: Noctuidae) gravid females

2015 ◽  
Vol 105 (3) ◽  
pp. 347-354 ◽  
Author(s):  
D. Cruz ◽  
M. Eizaguirre

AbstractThe Mediterranean corn borer, Sesamia nonagrioides, occurs sympatrically in the northeast of Spain with other lepidopteran pests such as Ostrinia nubilalis and Mythimna unipuncta. In this study, we evaluated the electrophysiological and behavioural response of mated and unmated females and males of S. nonagrioides to their own complete pheromone blend, to its own four components separately, and to the pheromone components of the sympatric species O. nubilalis and M. unipuncta. Results of the electroantennogram recordings revealed that females of S. nonagrioides can detect their own pheromone blend and its individual components. Moreover, our results show that unmated females and males of S. nonagrioides are more sensitive to the female pheromone, showing higher electrophysiological response than the mated females and males. Electroantennogram recordings showed that males and females can detect the major sexual pheromone component of O. nubilalis (Z)-11-tetradecenyl acetate and the minor component of the pheromone of M. unipuncta (Z)-9-hexadecenyl acetate. When the sex pheromone stimulus was presented in the dual-choice assays, gravid females of S. nonagrioides were attracted to both their own complete pheromone blend and one of their own minor pheromone components, (Z)-11-hexadecenal, but the major sexual pheromone component of O. nubilalis acts as a behavioural antagonist to the females.

2000 ◽  
Vol 132 (6) ◽  
pp. 951-963 ◽  
Author(s):  
G. Birgersson ◽  
M.J. Dalusky ◽  
C.W. Berisford

AbstractThe aggregation pheromone of Pityogenes hopkinsi Swaine was identified; it is a three-component mixture, comprising chalcogran, cis-verbenol, and ethyl dodecanoate. Ethyl dodecanoate is new as a bark beetle pheromone component. Chemical analyses (GC–MS) were made on hindgut extracts from unmated and mated males and mated females collected in the field during colonization of Pinus strobus L. (Pinaceae). Aerations from the naturally colonized logs were also analyzed to quantify the released amounts of the pheromone components, a necessary preliminary step to making up biologically relevant doses for field bioassay. Beetles reared from infested host material in the laboratory were introduced into logs of P. strobus, and the production and release of pheromone components in relation to attack phase and "mating status" were described. In general, unmated males increased their production of chalcogran and ethyl dodecanoate until females were admitted, after which production ceased. A field subtractive bioassay showed that chalcogran was the key pheromone component, synergized by different compounds for the two sexes. Females exhibited their strongest response to a mixture of chalcogran and ethyl dodecanoate, whereas cis-verbenol was the synergist for male response. Male-produced 1-hexanol had an inhibitory effect on male attraction to the aggregation-pheromone blend.


1988 ◽  
Vol 43 (11-12) ◽  
pp. 918-928 ◽  
Author(s):  
Ernst Priesner ◽  
Hermann Bogenschütz ◽  
Christer Löfstedt

The alkenyl acetates E9-12:Ac, Δ11-12:Ac and Zll-14:Ac were identified as minor components of the C. murinana female pheromone blend by chemical analyses of volatile pheromone gland constituents and potential pheromone precursors, electrophysiological recordings from single receptor cells, and field trapping tests. Gland washes from virgin females contained these compounds at 3%, 10% and 5%. respectively, the amount of the primary pheromone component Z9-12:Ac already reported. A 0.3% addition of either Δ11 - 12 : Ac or Z11-14:Ac significantly raised trap captures over Z9-12:Ac alone and a 3-30% addition of either minor component revealed maximum captures, not increased further by including both synergists within the same blend. A functional role of the E9-12: Ac could not be established during this study; 3% of it when combined with the pheromonal ratio mixture of the three other components tended to increase trap captures further whereas in various other mixture combinations the E9-12:Ac strongly reduced captures. These inhibitory effects were more pronounced with attractant blends based on Δ11-14:Ac rather than Δ11-12:Ac. Each blend component activated its own type of antennal receptor cell.


1997 ◽  
Vol 77 (2) ◽  
pp. 775-781 ◽  
Author(s):  
Thomas A. Christensen ◽  
John G. Hildebrand

Christensen, Thomas A. and John G. Hildebrand. Coincident stimulation with pheromone components improves temporal pattern resolution in central olfactory neurons. J. Neurophysiol. 77: 775–781, 1997. Male moths must detect and resolve temporal discontinuities in the sex pheromonal odor signal emitted by a conspecific female moth to orient to and locate the odor source. We asked how sensory information about two key components of the pheromone influences the ability of certain sexually dimorphic projection (output) neurons in the primary olfactory center of the male moth's brain to encode the frequency and duration of discrete pulses of pheromone blends. Most of the male-specific projection neurons examined gave mixed postsynaptic responses, consisting of an early suppressive phase followed by activation of firing, to stimulation of the ipsilateral antenna with a blend of the two behaviorally essential pheromone components. Of 39 neurons tested, 33 were excited by the principal (most abundant) pheromone component but inhibited by another, less abundant but nevertheless essential component of the blend. We tested the ability of each neuron to encode intermittent pheromonal stimuli by delivering trains of 50-ms pulses of the two-component blend at progressively higher rates from 1 to 10 per second. There was a strong correlation between 1) the amplitude of the early inhibitory postsynaptic potential evoked by the second pheromone component and 2) the maximal rate of odor pulses that neuron could resolve ( r = 0.92). Projection neurons receiving stronger inhibitory input encoded the temporal pattern of the stimulus with higher fidelity. With the principal, excitatory component of the pheromone alone as the stimulus, the dynamic range for encoding stimulus intermittency was reduced in nearly 60% of the neurons tested. The greatest reductions were observed in those neurons that could be shown to receive the strongest inhibitory input from the second behaviorally essential component of the blend. We also tested the ability of these neurons to encode stimulus duration. Again there was a strong correlation between the strength of the inhibitory input to a neuron mediated by the second pheromone component and that neuron's ability to encode stimulus duration. Neurons that were strongly inhibited by the second component could accurately encode pulses of the blend from 50 to 500 ms in duration ( r = 0.94), but that ability was reduced in neurons receiving little or no inhibitory input ( r = 0.23). This study confirms that certain olfactory projection neurons respond optimally to a particular odor blend rather than to the individual components of the blend. The key components activate opposing synaptic inputs that enable this subset of central neurons to copy the duration and frequency of intermittent odor pulses that are a fundamental feature of airborne olfactory stimuli.


2005 ◽  
Vol 31 (3) ◽  
pp. 621-646 ◽  
Author(s):  
A. M. El-Sayed ◽  
A. R. Gibb ◽  
D. M. Suckling ◽  
B. Bunn ◽  
S. Fielder ◽  
...  

1997 ◽  
Vol 200 (7) ◽  
pp. 1073-1087 ◽  
Author(s):  
S Anton ◽  
C Löfstedt ◽  
B S Hansson

Antennal lobe neurones were investigated in the pyralid moth Ostrinia nubilalis using intracellular recording and staining techniques. Response characteristics of antennal lobe neurones from males in the so-called E and Z strains, in F1 hybrids and in parental backcrosses were studied. The antennal lobe of a male O. nubilalis comprises approximately 30 ordinary glomeruli and three enlarged glomeruli making up the macroglomerular complex (MGC). Receptor neurones enter the antennal lobe via the antennal nerve and arborize in single glomeruli. Intracellularly stained, pheromone-responding projection neurones in both parental strains arborized in different glomeruli within the MGC, irrespective of their response characteristics. Neurones were grouped according to their specificity to single pheromone components and to pheromone blends. Component-specific, blend-specific and generalist neurones were found. Specificity only occurred at low stimulus concentrations and disappeared as concentrations increased. Although all neuronal types were present in both pheromone strains and crossings, differences in abundance and sensitivity were found. In the parental strains, neurones responding to the major pheromone component and to the respective strain-specific blend were more abundant than neurones responding to the minor component and the blend produced by the other strain. Neurones investigated in ZxE hybrids responded similarly to those of E-strain males, whereas neurones in EZxZ paternal backcrosses responded similarly to those of Z males. In the hybrids and paternal backcrosses, hybrid-blend-specific neurones were present that were not found in parental-strain males.


2001 ◽  
Vol 73 (7) ◽  
pp. 1157-1162 ◽  
Author(s):  
J. S. Yadav ◽  
M. Y. Valli ◽  
A. R. Prasad

Diacrisia obliqua is a polyphagous pest especially on oil seed crops. Adult female sex pheromone blend consists of five pheromone components, which include (3Z,6Z)-cis-9,10-epoxyl,3,6-henicosatriene and (3Z,6Z)-cis-9,10-epoxy3,6-henicosadiene. Synthesis of these enantiomers was achieved through alkylative epoxide rearrangement and stereoselective Wittig olefination reactions as key steps. Bioefficacy experiments both at laboratory and minifield were very positive.


Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 192 ◽  
Author(s):  
Qing-Hua Chen ◽  
Feng Zhu ◽  
Zhihua Tian ◽  
Wan-Min Zhang ◽  
Rong Guo ◽  
...  

Several lepidopteran species share the same pheromone blend consisting of (Z)-11-hexadecenal (Z11-16:Ald) and (Z)-9-hexadecenal (Z9-16:Ald) at different ratios and active doses. In rice pest Chilo suppressalis, (Z)-11-hexadecenol, (Z11-16:OH) and octadecanal (18:Ald) were identified as minor components in the pheromone gland of female moths, and these components were previously not considered as part of the sex pheromone of C. suppressalis. Z11-16:Ald, Z9-16:Ald and (Z)-13-octadecenal (Z13-18:Ald) frequently trapped other lepidopteran species, such as rice pests Scirpophaga incertulas and Mythimna separate, corn and vegetable pests Helicoverpa armigera in the field, suggesting a lack of specificity in the pheromone blend. Our data showed that the minor component Z11-16:OH did not have a synergistic effect on the attractiveness of the blend to C. suppressalis; however, pheromone mixtures containing Z11-16:OH failed in trapping male H. armigera moths. We confirmed the identity and specificity of the C. suppressalis sex pheromone and demonstrated that Z11-16:OH plays a key role in the reproductive isolation of C. suppressalis, M. separata, and H. armigera moths, and a similar role of Z9-18:Ald in that of S. incertulas and C. suppressalis. This phenomenon could be more widely applicable to interspecific interactions in the pheromone communication between insects, which is crucial to developing the electronic automatic counting device for automatically monitoring the pest population by pheromone trapping based on its species specificity.


1994 ◽  
Vol 49 (7-8) ◽  
pp. 516-521 ◽  
Author(s):  
M. Tóth ◽  
G. Szőcs ◽  
W. Francke ◽  
F. Schmidt ◽  
P. Philipp ◽  
...  

In pheromone extracts of calling female Chiasma clathrata L. (Lepidoptera: Geometridae), a defoliator pest of alfalfa, (Z,Z,Z)-3,6,9-heptadecatriene and (Z,Z)-6,9-cis-3,4-epoxyheptadecadiene was identified. Chiral gas chromatography using a modified cyclodextrin and synthetic reference samples proved the natural epoxide to show (3R, 4S)-configuration. In field trapping tests, only the pure (3R, 4S)-enantiom er of the epoxide attracted males. The addition of the triene component was synergistic. Males of the sympatric species Tephrina arenacearia Hbn. (Lepidoptera: Geometridae) were caught only in traps with baits containing the (3S, 4R)-enantiomer [together with a previously described minor component, (Z,Z)-3,9-cis- 6,7-epoxyheptadecadiene]. In trapping tests conducted in a different biotope, Abraxas grossulariata L. (Lepidoptera: Geometridae) males were attracted by the (3S, 4R)-enantiomer, whereas the (3R, 4S)-enantiomer attracted a close relative, Abraxas sylvata Scop. (Lepidoptera: Geometridae). The present results suggest that one of the key mechanisms responsible for pheromone specificity among both the two alfalfa geometrids and the two A braxas species in their respective biotops, may be the use of different enantiomers of the same polyenederived epoxide as a sex pheromone component. It is probable that this discrimination mechanism is widespread among moth species utilizing epoxide pheromone components


2019 ◽  
Vol 113 (2) ◽  
pp. 712-719 ◽  
Author(s):  
Donald C Weber ◽  
William R Morrison ◽  
Ashot Khrimian ◽  
Kevin B Rice ◽  
Brent D Short ◽  
...  

Abstract The brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) is attracted to its male-produced aggregation pheromone, a ~3.5:1 mixture of (3S,6S,7R,10S)- and (3R,6S,7R,10S)-10,11-epoxy-1-bisabolen-3-ol (SSRS and RSRS respectively), and also to the pheromone of its Asian sympatric species Plautia stali Scott (Hemiptera: Pentatomidae), methyl (2E,4E,6Z)-2,4,6-decatrienoate (MDT). A stereoisomeric mixture of (7R) 10,11-epoxy-1-bisabolen-3-ols (= mixed murgantiols) is used together in commercialized products with MDT because the latter is a synergist for H. halys attraction to mixed murgantiols. However, the optimal ratio for MDT combination with mixed murgantiols, and the sensitivity of bug captures to variation in ratio of the two pheromone components, have not been tested to date. Using black pyramid traps at two sites (in Maryland and West Virginia, United States), different ratios of mixed murgantiols to MDT were tested over two entire seasons. Also, captures using various ratios of the two active pheromone stereoisomers were undertaken in month-long trials with and without MDT. Results showed that H. halys adult and nymphal captures were relatively insensitive to the ratio of synthetic pheromone (mixed murgantiols) to MDT, as long as each was present in the trap. Captures of adults and nymphs were responsive to the lure loading of the SSRS isomer, but relatively insensitive to levels of the minor component, RSRS. The relative insensitivity of H. halys to these attractant ratios gives flexibility to development of more cost-efficient synthesis and trapping as well as other semiochemical-based management tactics.


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