Petrobia


Petrobia is a genus in Tetranychidae, containing 34 described species. It includes some pest species.

Description

Petrobia mites can be recognised by their reddish-brown cuticle, dark body contents and the first leg pair being very long. Each leg ends in pad-like claws and a hooked empodium with more than 1 pair of tenent hairs. The prodorsum of the body has three pairs of setae and there are no prominent lobes over the gnathosoma. The paranal setae are in a ventral position.
The genus is usually divided into three subgenera: Mesotetranychus, Petrobia and Tetranychina. Mesotetranychus has simple peritremes whereas Petrobia has anastomosing peritremes. Tetranychina usually has long dorsal setae on small tubercles.

Reproduction

Species of Petrobia may reproduce either sexually or asexually.
In P. harti, males make up 10% or less of field populations. Eggs are laid on the ventral surfaces of host plant leaves.
Petrobia latens, on the other hand, has only female individuals. Females lay their eggs parthenogenetically on soil and under stones.

Pests

Several Petrobia species are polyphagous plant pests, meaning they attack a wide range of plants:Petrobia apicalis attacks onions and various legumes in Europe and the United States.Petrobia harti attacks various weeds and also fruit and ornamental plants. It has been dispersed to most of the world.Petrobia latens attacks various fruit, vegetable and grain crops. It is one of the few spider mites proven to transmit barley yellow streak mosaic virus.Petrobia tunisiae attacks grains and chrysanthemum in Iran and the Mediterranean region.

Species

These 34 species belong to the genus Petrobia:Petrobia apicalis Banks, 1917 c gPetrobia barkolensis Wang & Cui, 1992 c gPetrobia brevipes Reck & Bagdasarian, 1949 c gPetrobia californica Baker & Tuttle, 1994 c gPetrobia cardi Chaudhri, 1972 c gPetrobia carthagensis Auger & Flechtmann, 2009 c gPetrobia donnalucatensis Vacante, 1983 c gPetrobia dzhulfaensis Bagdasarian, 1960 c gPetrobia enodis Meyer, 1987 c gPetrobia haematoxylon Meyer, 1987 c gPetrobia harti c g bPetrobia hemerocallis Wang, 1982 c gPetrobia hispaniola gPetrobia jingheensis Ma & Gao, 1991 c gPetrobia latens c gPetrobia layyahensis Sabri & Afzal, 2008 c gPetrobia lippiae Baker & Tuttle, 1994 c gPetrobia lupini McGregor, 1950 c gPetrobia lycopersici Zaher, Gomaa & El-Enany, 1982 c gPetrobia marsai Manson, 1964 c gPetrobia mexicana Baker & Tuttle, 1983 c gPetrobia moutiai Baker & Pritchard, 1960 c gPetrobia nocitus Chaudhri, 1972 c gPetrobia phaceliae Tuttle & Baker, 1964 c gPetrobia prasadi Baker & Tuttle, 1994 c gPetrobia pseudotetranychina Auger & Flechtmann, 2009 c gPetrobia tribulus Chaudhri, 1972 c gPetrobia tunisiae Manson, 1964 c gPetrobia uncata c gPetrobia vachushtii Reck, 1948 c gPetrobia waltheriae Tuttle, Baker & Abbatiello, 1974 c gPetrobia xerophila Mitrofanov, 1975 c gPetrobia xinjiangensis Tan & Wang, 1992 c gPetrobia zachvatkini Reck & Bagdasarian, 1949 c g
Data sources: i = ITIS, c = Catalogue of Life, g = GBIF, b = Bugguide.net

Identification