Yellow mite

Description. In Lorryia formosa, like all Acariformes mites, the capitulum is the head segment and the idiosoma is the body segment. The idiosoma is further subdivided into the propodosoma, metapodosoma, and opisthosoma. The Tydeinae subfamily, to which Lorryia formosa belongs, is characterized by having three pairs of lyrifissures (grooves that encircle the surface of an appendage) and a pair of primitive eyes (oculi) which commonly occur laterally on the propodosoma, the middle body segment to which the first two pairs of legs are attached. The genital region includes a progenital aperture flanked by setae. Specimens are generally less than 250 µm long.
Life Cycle. Life cycles of Lorryia formosa are characterized by six distinct developmental stages: egg, larva, protonymph, deutonymph, tritonymph, and adult. The average lifetime is 37 days, of which 60% is considered adulthood. The females of the species use an asexual form of reproduction where the growth and development of embryos occurs without fertilization by a male; this type of parthenogenesis, where females are produced from unfertilized eggs, is called thelytoky. It is not known whether the intracellular endosymbiont bacterium Wolbachia is responsible for the alteration in reproductive capability. Wolbachia, a genus of inherited bacteria common in insects, are known to alter the sex ratio in arthropods and mites. The sex ratio is also greatly influenced by the host plant: one study found that on citrus, 30% of the population were males, compared to 62% males when reared on grapefruit. Reared on rubber trees, the percentage of males in the population drops to very low, or nothing.