Cales (Hymenoptera: Chalcidoidea): morphology of an enigmatic taxon with a review of species

Systematic Entomology (2011), 36, 267–284 DOI: 10.1111/j.1365-3113.2010.00557.x Cales (Hymenoptera: Chalcidoidea): morphology of an enigmatic taxon with a review of species J A S O N L . M O T T E R N , J O H N M . H E R A T Y and E M I L Y H A R T O P Department of Entomology, University of California, Riverside, CA, U.S.A. Abstract. Calesinae is a small group of Chalcidoidea (Hymenoptera) that are parasitoids of whiteflies (Hemiptera: Aleyrodidae). One species, Cales noacki Howard, has been introduced from South America into citrus-growing regions of North America, the Mediterranean and Africa for biological control. The remaining species are found in Australia and New Zealand: a classic Gondwanan disjunction. The subfamily consists of a single genus, Cales, which is currently unplaced within Chalcidoidea. Its taxonomic position has historically been unstable, although most often Cales is associated with Aphelinidae. Here, we present a detailed morphological study of the group with an emphasis on Australian species. Although Cales shares many characteristics with Aphelinidae, especially Coccophaginae and Eretmocerus, more studies of character systems across Chalcidoidea are needed to determine which features may be synapomorphic. Consequently, we leave Cales incertae sedis within Chalcidoidea. We also describe a new species from New Zealand, Cales berryi sp.n., reared from the whitefly Asterochiton pittospori on lemonwood, Pittosporum eugenioides, and we present a key and review the four known species of Cales. Introduction Although the monophyly of some chalcidoid groups is strongly supported by morphological or molecular synapomorphies, many higher-level relationships within the superfamily remain uncertain. Establishing relationships within Chalcidoidea is hindered by a lack of comprehensive morphological studies, either across character systems or across taxa. Some detailed studies are available (e.g. Darling, 1988; Gibson, 1989; Heraty et al., 1994, 1997; Basibuyuk & Quick, 1995; Heraty & Schauff, 1998; Krogmann & Vilhelmsen, 2006), but more information is needed to determine the utility of various morphological features for phylogenetic reconstruction. Wide diversity of form and function, resulting in uncertainty regarding sister-group relationships, has left some chalcidoid groups unplaced into higher taxonomic categories, and several families are regarded as either paraphyletic or polyphyletic (Gibson et al., 1999; Campbell et al., 2000). The genus Cales Howard is an economically important and easily defined Correspondence: Jason L. Mottern, Department of Entomology, University of California, Riverside, CA 92521, U.S.A. E-mail: jmott002@student.ucr.edu © 2010 The Authors Systematic Entomology © 2010 The Royal Entomological Society group that currently defies placement into any family within Chalcidoidea. Taxonomic history. The taxonomic history of Cales and its higher classification is complex, and reflects the uncertainty various workers have encountered when trying to classify the group. Cales noacki was first described from specimens reared from Orthezia sp. (Hemiptera: Pseudococcidae) in Campinas, Brazil (Howard, 1907). Howard placed this species in the tribe Pteroptricini (now Aphelinidae: Coccophaginae), which was then included in the subfamily Aphelininae. Br`ethes (1914) described Diaspidophilus pallidus from specimens reared from the white peach scale, Pseudaulacaspis pentagona (Targioni) (Hemiptera: Diaspididae), in Argentina, and placed it in the family Mymaridae. Mercet (1929) synonymized Diaspidophilus with Cales and erected the new subfamily Calesinae within Aphelinidae. Dozier (1933) placed Cales within Trichogrammatidae while studying whitefly parasitoids in Haiti. Paranthemus spenceri Girault was described from Australia and placed in Mymaridae (Girault, 1915), but Paranthemus was later synonymized with Cales by Viggiani (1981). A third species was reared from an Australian whitefly, Orchamoplatus citri (Takahashi) (Hemiptera: Aleyrodidae),