Labidura Riparia Research Articles

Degradation of Fabric by American Cockroach, House Cricket, and Striped Earwig

Fabrics, cut into 2 × 2-inch pieces, were exposed in a laboratory experiment to American cockroaches, Periplaneta americana (L.); house crickets, Acheta domestica (L.); and striped earwigs, Labidura riparia (Pallas). Selected fabrics included all-cotton; cotton treated with 5 different “easy-care” resin finishes; and synthetic fabrics including acetate, acrylic, nylon, polyester, triacetate, and viscose. Half the fabric pieces were stained with an animal fat, the other half were left untreated. Fabric damage by insects was measured by weight loss and percent visible damage. American cockroaches caused significant damage to acetate, viscose, and triacetate fabrics that had been stained. Damage to cotton fabrics was not apparent. House crickets attacked acetate, viscose, and triacetate to a highly significant degree. Stained and unstained polyester, nylon, and acrylic were attacked to a lesser extent. Striped earwigs slightly nibbled the edges of nylon fabric.

Sense organs on the antennal flagella of earwigs (Dermaptera) with special reference to those of Forficula auricularia.

AbstractFive types of sense organs have been found on the antennal flagellum of Forficula auricularia Linnaeus: (1) tactile hairs; (2) long, thick‐walled chemoreceptors; (3) short, thick‐walled chemoreceptors; (4) thin‐walled chemoreceptors and (5) coeloconic chemoreceptors. Earlier workers have placed the first three of these in a single class. The structural characteristics and distribution of these five kinds of sensilla on the antenna are described. All of the types except the third have been reported previously for other species but short, thick‐walled chemoreceptors have not been described before. They are remarkable for the presence of (1) a broad pad‐Like structure that absorbs dyes readily at the distal end of the peg and (2) a spheroid body, over a micron in diameter, on the dendrite of each olfactory neuron at the point where it narrows to assume the structure of a cilium. The antennal sense organs of a few specimens of Chelisoches morio (Fabricius), Labidura riparia (Pallas) and Euborellia annulipes (Lucas) were also examined.

Independent Development of the Male Gonads and Vasa Deferentia, and the Genitalia of the Australian Earwig, Labidura riparia truncata (Dermaptera : Labiduridae)

L. r. truncata Kirby is the Australian-wide form1 of the cosmopolitan earwig Labidura riparia (Pallas). Snodgrass2 lists literature dealing with the development of the genitalia in several insect orders. His description of the process in the Dermaptera is largely based on the account given by Qadri3 for Forficula auricularia L. (Forficulidae). Snodgrass points out that it is generally held that the genitalia develop from the primary phallic lobes and that the terminal ampullae of the vasa deferentia are commonly associated with the lobes.

The idiochromosomes of an earwig, Labidura riparia

AbstractThe diploid number of chromosomes of a species of Indian earwigs, Labidura riparia, is fourteen; six pairs of autosomes with X and Y idiochromosomes for the male; six pairs of autosomes with X and X for the female.The chromosome distribution is normal, and constant for all the individuals studied.X and Y are derived from a single chromatin nucleolus of the early growth period which assumes a clavate form later, and remains in the same form till the metaphase of the primary spermatocyte is reached.