Petiole (insect anatomy) a pedicel, but in entomology, that term is more correctly reserved for the second segment of the antenna; while in arachnology, 'pedicel' is the accepted term to define the constriction between the cephalothorax and abdomen of spiders. The plump portion of the abdomen posterior to the petiole (and postpetiole in the Myrmicinae) is called the gaster. The structure of the petiole is an easy way to visually classify ants, because the major subfamilies of Formicidae have structural differences: some ants have two-segmented petioles, while others have a single-segmented petiole. Petiole may also be used in the context of wing veins,
RID Insect Repellent against mosquitoes, biting flies, chiggers, fleas and ticks. These insect repellents slowly evaporate into the air, producing an invisible chemical barrier around the areas on the body and clothes where it is applied, repelling incoming insects.<ref name="Repellents/AMCA"></ref> RID was invented in 1956, after 3,000 hours of field research by inventor Doug H. Thorley. A bottle of RID is exhibited at the Queensland Museum in Australia. RID insect repellents are used to repel insects which may carry a number of diseases, including; Ross River Virus, Dengue Fever, West Nile Virus, Malaria, Yellow Fever, Japanese B Encephalitis, Filariasis, Lyme Disease, Leishmaniasis, Typhus