Laboratory selection of resistance by the Red Flour Beetle,Tribolium castaneum (Herbst), To a carbon dioxide-enriched atmosphere

Background: The red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) is one of the world’s most serious stored grain insect pests. A method of early and rapid identification of red flour beetle in stored products is urgently required to improve control options. Specific chemical signals identified as Volatile Organic Compounds (VOCs) that are released by the beetle can serve as biomarkers. Methods: The Headspace Solid Phase Microextraction (HS-SPME) technique and the analytical conditions with GC and GCMS were optimised and validated for the determination of VOCs released from T. castaneum. Results: The 50/30 μm DVB/CAR/PDMS SPME fibre was selected for extraction of VOCs from T. castaneum. The efficiency of extraction of VOCs was significantly affected by the extraction time, temperature, insect density and type of SPME fibre. Twenty-three VOCs were extracted from insects in 4 mL flask at 35 ± 1°C for four hours of extraction and separated and identified with gas chromatography-mass spectroscopy. The major VOCs or chemical signals from T. castaneum were 1-pentadecene, p-Benzoquinone, 2-methyl- and p-Benzoquinone, 2-ethyl. Conclusion: This study showed that HS-SPME GC technology is a robust and cost-effective method for extraction and identification of the unique VOCs produced by T. castaneum. Therefore, this technology could lead to a new approach in the timely detection of T. castaneum and its subsequent treatment.

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Woot, an Active Gypsy-Class Retrotransposon in the Flour Beetle, Tribolium castaneum, is Associated With a Recent Mutation

Genetics ◽

10.1093/genetics/143.1.417 ◽

1996 ◽

Vol 143 (1) ◽

pp. 417-426

Author(s):

Richard W Beeman ◽

M Scott Thomson ◽

John M Clark ◽

Marco A DeCamillis ◽

Susan J Brown ◽

...

Keyword(s):

Sequence Analysis ◽

Tribolium Castaneum ◽

Frameshift Mutation ◽

Open Reading Frames ◽

Red Flour Beetle ◽

Intron Sequence ◽

Coding Region ◽

Long Terminal Repeats ◽

Flour Beetle ◽

Reading Frames

Abstract A recently isolated, lethal mutation of the homeotic Abdominal gene of the red flour beetle Tribolium castaneum is associated with an insertion of a novel retrotransposon into an intron. Sequence analysis indicates that this retrotransposon, named Woot, is a member of the gypsy family of mobile elements. Most strains of T. castaneum appear to harbor ~25-35 copies of Woot per genome. Woot is composed of long terminal repeats of unprecedented length (3.6 kb each), flanking an internal coding region 5.0 kb in length. For most copies of Woot, the internal region includes two open reading frames (ORFs) that correspond to the gag and pol genes of previously described retrotransposons and retroviruses. The copy of Woot inserted into Abdominal bears an apparent single frameshift mutation that separates the normal second ORF into two. Woot does not appear to generate infectious virions by the criterion that no envelop gene is discernible. The association of Woot with a recent mutation suggests that this retroelement is currently transpositionally active in at least some strains.

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Rating knockdown of flour beetles after exposure to two insecticides as an indicator of mortality

Scientific Reports ◽

10.1038/s41598-020-78982-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Christos G. Athanassiou ◽

Nickolas G. Kavallieratos ◽

Frank H. Arthur ◽

Christos T. Nakas

Keyword(s):

Tribolium Castaneum ◽

Concrete Surface ◽

Mortality Rates ◽

Red Flour Beetle ◽

Flour Beetle ◽

Insecticidal Effect ◽

Testing Period ◽

Flour Beetles ◽

Confused Flour Beetle ◽

Contact Insecticides

AbstractKnockdown and mortality of adults of the red flour beetle, Tribolium castaneum (Herbst) and the confused flour beetle, Tribolium confusum Jacquelin du Val, were assessed after exposure to two contact insecticides, chlorfenapyr and cyfluthrin, on a concrete surface. Individuals were rated on a scale for knockdown of exposed adults according to their mobility from 1, representing immobilized adults to 5, representing normally moving (similar to the controls). Only cyfluthrin gave immediate knockdown. Adults were rated at 1, 3 and 7 days post-exposure. After the final assessment, adults were discarded and the same procedure was repeated for 5 consecutive weeks with new adults exposed on the same treated surfaces. Despite initial knockdown, many individuals did not eventually die after exposure to cyfluthrin. In contrast, adults exposed to chlorfenapyr were not initially knocked down after exposure but most died after 7 days. These trends were similar during the entire 5-week residual testing period. The storage of the treated dishes in illuminated or non-illuminated conditions did not affect the insecticidal effect of either insecticide. The results of the present study can be further implemented towards the design of a “lethality index” that can serve as a quick indicator of knockdown and mortality rates caused after exposure to insecticides.

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