|Crop Knowledge Master|
Eutetranychus banksi (McGregor)
|Texas Citrus Mite|
Jayma L. Martin Kessing, Educational Specialist
Ronald F. L. Mau, Extension Entomologist
Department of Entomology
Plant hosts of this pest in Hawaii include: breadfruit (Artocarpus altilis), castor bean, Citrus, croton (Codiaeum variegatum), lima bean (Phaseolus limensis), papaya (Carica papaya), plumeria (Plumeria acuminata), and lablab bean leaves. Outside of Hawaii, this mite attacks cotton and grapefruit.
This mite is present in Citrus growing areas in the south eastern US, especially Texas and Florida. It has also been collected in Costa Rica and Mexico (McGregor, 1950). In Hawaii, this mite is present on the islands of Lanai, Maui and Oahu. It probably occurs on all inhabited islands.
The Texas citrus mite is one of several species of red spider mites that occurs in Hawaii. It is among the most destructive pests of citrus fruits (Metcalf, 1962). The mite feeds primarily on the upper surface of the leaves and causes them to turn yellow-brown and abscise prematurely. Like the citrus red mite, their feeding results in a silvery, speckled effect on leaves by removing chlorophyll (Metcalf, 1962). Infested areas are somewhat heavier on the upper surfaces of the leaves and on the sunny side of the host plant (Muma, et. al., 1953).
Detailed biological studies of the Texas citrus mite are not present in the literature. However, information is available for another red spider mite species, the citrus red mite, which has a similar life cycle as observed by Muma, et. al. (1953). The citrus red mite, Panonychus citri (McGregor), lays from 20 to 50 eggs, at a rate of 2 to 3 a day. It has a six legged larval stage, and eight-legged protonymph and deutonymph stages before becoming an adult. The entire life cycle for the red citrus mite requires from 3 to 5 weeks, temperature dependent, with as many as 12 to 15 generations per year (Metcalf, 1962). Populations are hampered by high humidity and rainfall (Dean, 1962). Life cycle information of the citrus red mite should be viewed as approximate times for the Texas citrus mite. The descriptions given below are for the Texas citrus mite below only.
The flat and disc-like eggs have a fine, rolled rim around the edge. The eggs are light yellow when first laid. They vary from tan and green to reddish-brown just prior to hatching (Muma, et. al., 1953). Eggs are laid primarily along the midrib, near the lateral margins of the leaves (Muma, et. al., 1953) and branching veins (Dean, 1952).
Newly hatched mites are lemon yellow (McGregor, 1935). The nymphs are similar in appearance to the adult females except for their smaller size.
The adult female body is broad, robust and flattened and ranges from light yellow to tan to greenish brown with dark brown to greenish spots and bars near the lateral margins (Muma et al., 1953). Sometimes the dark markings on the back form the letter "H" (Dean, 1952). Dead and dried specimens are reddish (Dean, 1952). This species has strong legs, four pointing forward and four towards the rear, that are pale in color.
Males have a smaller, more triangular shaped body and vary from tan to light brown with darker, greenish spots and bars on the lateral margins of the body (Muma, et. al., 1953). Their legs are slightly longer and light tan in color.
This mite disperses rapidly when it is disturbed.
This mite is not associated with extensive webbing like other mite species (McGregor, 1935).
Because the Texas citrus mite usually feeds on the upper surface of leaves, rain often washes this mite off of the leaf surface and is at times important in reducing population densities (Sandhu, et. al., 1982).
Very little information is known on the biological control agents of the Texas citrus mite. Dean (1962) suggested that the predatory mite, Iphidulus finlandicus Oudms., might have given some reduction based on its large numbers in Texas citrus groves where heavy Texas citrus mite and rust mite infestations existed. He also observed the large red predatory mite, Allotrombidium spp., feeding on the eggs, nymphs and adults of the Texas citrus mite. Other predatory mites that prey on the Texas citrus mite are Tydeus spp., Pronenatus spp., Balaustium spp., Amblyseius spp., Bdella spp., and Typhlodromus finlandicus Oudms. (Dean, 1962).
The Texas citrus mite has developed some resistance to the commonly used miticides (Reinking, 1971)
Dean, H. A. 1952. Spider Mites of Citrus and Texas Citrus Mite Control in the Lower Rio Grande Valley of Texas. J. Econ. Entomol. 45(6): 1051-1056.
McGregor, E. A. 1935. The Texas Citrus Mite, A New Species. 1935. Proc. Ent. Soc. Wash. 37(8): 161-165.
McGregor, E. A. 1950. Eutetranychus clarki (McGregor), new combination. Midland Nationalist. 44(2): 270-271.
Metcalf, R. L. 1962. Destructive and Useful Insects Their Habits and Control. McGraw-Hill Book Company; New York, San Francisco, Toronto, London. 1087 pages.
Muma, M. H., H. Holtzberg and R. M. Pratt. 1953. Eutetranychus banksi (McG.) Recently Found on Citrus in Florida (Acarina: Tetranychidae). The Florida Entomologist. 36(4): 141-144.
Pritchard A. E. and E. W. Baker. 1955. Eutetranychus banksi (McGregor). pp. 115-123. In: A revision of the Spider Mite Family Tetranychidae. The Pacific Coast Entomological Society; San Francisco. 472 pages.
Reinking, R. B. 1971. Plictran Miticide for Texas Citrus Mite Control. Down to Earth. 27(3): 6-7.
Sandhu, M. S., G. S. Gatoria, S. S. Sandhu and S. Singh. 1982. Chemical Control of Tetranychid Mite (Eutetranychus banksi McGregor) Infesting Cotton in Punjab. J. Res. Punjab Agric. Univ. 19(2): 127-129.