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- Arnaud, Ludovic, et al.
(författare)
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Preliminary observations of sperm storage in Adalia bipunctata (Coleoptera : Coccinellidae): sperm size and number
- 2003
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Ingår i: Applied Entomology and Zoology. - : Japanese Society of Applied Entomology & Zoology. - 1347-605X .- 0003-6862. ; 38:3, s. 301-304
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Tidskriftsartikel (refereegranskat)abstract
- Sperm storage in Adalia bipunctata (L.) (Coleoptera, Coccinellidae) was examined and compared between diapausing and non-diapausing females. We observed that non-diapausing females store on average 13,688 (+/-722, S.E.) sperm in their spermatheca and that every female examined had sperm in storage (n = 16). In contrast, most diapausing females had empty spermatheca and only two had sperm in storage (n = 15). Mean sperm number in diapausing females was 250 (+/-112, S.E.). The mean length of the spermatozoa stored by non-diapausing females was 2,068.5 mum (+/-9.8, S.E.), ranging from 1,530.8 to 3,171.7 mum. Sperm length in diapausing females was only measurable in one female and was of 2,102.9 mum (+/-22.4, S.E.).
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| 2. |
- Verheggen, F, et al.
(författare)
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Electrophysiological and Behavioral Activity of Secondary Metabolites in the Confused Flour Beetle, Tribolium confusum
- 2007
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Ingår i: Journal of Chemical Ecology. - : Springer Science and Business Media LLC. - 0098-0331 .- 1573-1561. ; 33:3, s. 525-539
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Tidskriftsartikel (refereegranskat)abstract
- Several previous studies have addressed pheromone communication in various flour beetles (Coleoptera: Tenebrionidae), including the confused flour beetle, Tribolium confusum (du Val). Different stereoisomers of 4,8-dimethyldecanal (DMD) were reported as the only components of an aggregation pheromone, but the behavioral activity of DMD is low. In the present study, additional previously reported secondary metabolites (benzoquinones and hydrocarbons) were tested for electrophysiological activity (EAG) with both sexes of T. confusum. Two benzoquinones and three monoenic hydrocarbons elicited significant EAG activity from both male and female antennae. There was an elevated male EAG response (vs. the females) to two out of the three hydrocarbons and for both quinones. The EAG-active compounds were subsequently investigated for behavioral activity in a walking bioassay. Benzoquinones are considered toxic and have been assigned a function as alarm substances in flour beetles, but we found that methyl-1, 4-benzoquinone in intermediate concentrations was attractive to both male and female beetles and could therefore act as an aggregation pheromone component. Males were also attracted to ethyl-1,4-benzoquinone. The corresponding hydroquinones, presumed precursors of the benzoquinones, did not elicit any electrophysiological response and were not tested for behavioral activity. The unsaturated hydrocarbons (1-tetradecene, 1-pentadecene, and 1-hexadecene) elicited significant EAG responses from both male and female antennae and were also attractive in the behavioral assay. Our results show that several beetle-produced compounds, in addition to 4,8-dimethyldecanal, may be part of a complex pheromone system in flour beetles and play a role in mediating aggregation in T. confusum.
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