Submitted to: Experimental and Applied Acarology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 9, 2003
Publication Date: June 9, 2003
Citation: Welbourn, W.C., Ochoa, R., Kane, E.C., Erbe, E.F. 2003. Morphological observations on brevipalpus phoenicis (geijskes) (acari: tenuipalpidae) including comparisons with b. californicus (banks) and b. obovatus donnadieu.. Experimental and Applied Acarology. 30: 107-134
Interpretive Summary: Flat mites are cosmopolitan and include more than 600 plant-feeding species in 30 genera. The importance of flat mites to citrus increased when they were associated with citrus leprosis virus. There is a concern that species on citrus represent a very complex group of species. Because these mites are small, slow moving, have cryptic coloration, and have stationary behavior, field recognition, collection, and control are very difficult. There is a necessity for a very meticulous molecular study in coordination with a careful morphological study of the species. To study body morphology, the use of low temperature scanning microscope techniques is used for these species. The objective of this study is to discuss the major characters of mite morphology and compare them with related species that also are associated with citrus. This paper will be important to extension personnel, farmers, integrated pest management specialists, citrus growers, ecologists, and persons involved in mite systematics.
The genus Brevipalpus has over 300 species worldwide. The three most important agricultural species in the genus, B. californicus (Banks), B. obovatus Donnadieu and B. phoenicis (Geijskes), have been consistently confused and misidentified for more than fifty years. The present study provides a discussion of the characters and character states used to separate these mites. Low-temperature scanning electron microscopy and traditional light microscopy techniques are used to illustrate the subtle morphological differences between these three species. Morphology of the dorsal propodosoma, opisthosoma and leg chaetotaxy of all three species was examined and compared. The number of dorsal setae, the number of solenidia (omega) on tarsus of leg II, and dorsal cuticular patterns are most important characters in the identification of Brevipalpus species. Brevipalpus phoenicis is similar to B. californicus in having two omega on tarsus leg II and different from B. obovatus which has only one omega on tarsus leg II. Brevipalpus phoenicis is similar to B. obovatus in having only one pair of F setae (f3), but differs from B. californicus with two pairs of F setae (f2-3). The dorsal opisthosomal and propodisomal cuticular patterns frequently used to distinguish between these three species are useful but one must be aware that age, feeding and mounting techniques can make some difficult to find.