Nigra Scale – Parasaissetia nigra
Nigra Scale (Parasaissetia nigra)
Common Name: Nigra Scale
Latin Name: Parasaissetia nigra
Body oval to elongate oval depending on the host; generally convex in lateral aspect, but less convex in freshly developed females or specimens from various hosts; Body color varies depending on the host, but is usually transparent yellow with brown or red specks; the body becomes brown or black with age; lacks a clear wax coating; ovisac missing. Occurs on plant arboreal sections. Males are frequently missing; eggs are placed beneath the female’s body.
Nigra Scale is found throughout in United States.
Life history and habits:
Mature females have a reticulate pattern on the dorsum, marginal setae that are somewhat larger and fimbriate, no subdiscal or discal setae on the anal plates, and dorsal setae that are often slightly capitate. Other characteristics include: Antennae are usually 8-segmented; there are ventral tubular ducts in a submarginal band around the body margin; the claw lacks a denticle; the claw digitules are equal; there are 3 pairs of prevulvar setae (anal plates often obscure the hindmost pair), and there are 1-21 submarginal tubercles around the body margin. stigmatic setae distinct from other peripheral setae, middle setae noticeably longer than lateral setae; each anal plate with four apical setae, anal fold with six to eight fringe setae; no tibiotarsal sclerosis Multilocular pores typically have 10 loculi; multiloculars are found around the vulvar region and submarginally from segment 2 to segment 8; preopercular pores are present in limited numbers and are visible.