A New Species of Aleurodicus Douglas and Two Close Relatives (Homoptera: Aleyrodidae)

Abstract

This paper provides a name for a whitefly that occurs on diverse plants of economic importance. The insect is of concern in Florida, where it has been collected from numerous plants, including avocado, citrus, guava, and palm, and where it is suspected of being associated with the destructive lethal yellows disease of coconut palms. It is here recorded from 38 genera belonging to 27 plant families. Its known distribution includes southern Florida, portions of Central and South America, the West Indies, and the Canary Islands. Two previously described species are discussed briefly because of their close relationship to the new species. Harold A. Denmark, Chief of the Entomology Section, Division of Plant Industry, Florida Department of Agriculture, asked me to describe the new species, and I am happy to do so. Through his efforts. and those of his associate, Howard V. Weems, Jr., and of their Department Inspectors, much useful material has been collected in Florida since 1957. Specimens from other areas have accumulated over a period of nearly 60 years and have been furnished by many people. I extend my sincere appreciation to the collectors and to all persons who have contributed to this study. Aleurodicus coccolobae Quaintance and Baker (1913), Aleurodicus fiavus Hempel (1922), and Aleurodicus dispersus Russell, new species, are closely allied and form a group that is set apart from other species of Aleurodicus by the characteristics of its so-called pores. Before discussing the species further, it is desirable to describe the wax secreting organs on the dorsal surface of the immature forms. Glands found in the pupae of Aleurodicus were called compound pores and simple pores by Quaintance and Baker (1913). Most subsequent workers have followed their terminology and it is, used here. Although the compound pores were well described by Quaintance and Baker, the simple pores have received little attention from them or other workers. Since both compound and simple pores vary, and are of value in differentiating the species under consideration, they are discussed in some detail. Compound pores occur in seven or fewer subdorsal pairs. They are comparatively large and conspicuously invaginated, and have several to many distinct loculi at the bottom, arranged in a circle around the base of a central process that rises above the top of the pore. Cylindrical, or cylindrical and thimble shaped, compound pores occur in the species treated here. In contrast, simple pores are fairly tovery numerous and occupy various positions. They are minute to small, are slightly or not at all invaginated, and lack well-defined loculi and an elongate central process. Though the structure of the pores is apparent only under optimum optical conditions, their size and location are readily discernible. Disk pores and their associated porettes, which are not included in the category of simple pores, are scattered sparsely in the median and submedian areas. The disk pores are very minute and have thin dark rims, and the porettes are nearly or quite indistinguishable. They appear to be similar to the pores and