Madarococcus Hoy, 1962

Hodgson, Chris & Miller, Dug, 2010, A Review of the Eriococcid Genera (Hemiptera: Sternorrhyncha: Coccoidea) of South America 2459, Zootaxa 2459 (1), pp. 1-101 : 58-59

Madarococcus Hoy

Madarococcus Hoy 1962: 15 , 21, 151–163, 200.

Type species: Rhizococcus pulchellus Maskell 1890: 143–144 .

Generic diagnosis. Adult female. Body variable in shape; anal lobes variable but all with 3 dorsal setae, an apical seta and a ventral seta. Dorsum. Dorsal derm usually nodulose; setae variable, ranging from minute and digitate to enlarged and spinose. Macrotubular ducts present or absent; when present variable in structure. Microtubular ducts small, generally with 1–5 at base of enlarged dorsal setae. Loculate pores generally absent. Cruciform pores absent. Margin. With or without marginal setal fringe. Venter. Setae flagellate or spinose. Suranal setae spatulate on most species. Macrotubular ducts present or absent. Microtubular ducts present along margin or absent. Loculate pores, each with 3 or 5 loculi, present on abdomen. Anal ring well developed, with pores and 3 or 4 pairs of setae. Antennae 6 or 7 segmented. Frontal lobes perhaps absent but antennal tubercles sometimes present. Labium either 3 segmented or composed of 2 fused segments. Metathoracic coxae, femur and tibia often with translucent pores. Vulva present between abdominal segments VII and VIII. (Modified after Hardy et al., 2008).

Apparently restricted to Nothofagaceae .

Comment. The genus Madarococcus has recently been revised by Hardy et al. (2008) based on nucleotide sequence data and morphology. As part of this review, they transferred 4 South American species previously included in Eriococcus to Madarococcus , namely E. chilensis Miller and González (from Chile), E. eurythrix Miller and González (from Argentina and Chile), E. navarinoensis Hoy (from Argentina and Chile) and E. rhadinothrix Miller and González (from Chile). All of these species are known only from Nothofagus (Nothofagaceae) . We suspect that 1 of the species recently described by González ( González, 2008a) from Argentina on Nothofagus ( Eriococcus dombeyi ) will eventually also be transfered to Madarococcus . Hardy et al. also included species in this genus from New Zealand and Australia.

Recent molecular data have demonstrated that previous concepts of genera such as Acanthococcus , Eriococcus , Gossyparia, Greenisca , Rhizococcus , etc. need careful re-analysis, because species that are similar morphologically differ considerably using molecular characters ( Cook & Gullan, 2004; Kondo et al., 2006; Hardy et al., 2008). The lack of diagnostic morphological characters for characterizing Madarococcus ( Hardy et al., 2008) adds further confusion to the status of these genera. Until more definitive analyses are undertaken, we will adhere to the current classification except where more detailed analyses have been undertaken, as is the case in the paper by Hardy et al. (2008).

We note, however, that 3 of the 4 South American Madarococcus species mentioned above, i.e., M. chilensis , M. navarinoensis , and M. rhadinothrix could just as easily be placed in a taxon separate from Madarococcus based on the morphological phylogeny of Hardy et al. (2008), with only M. eurythrix placed outside of the lineage, separated by M. occultus Hardy & Gullan. The molecular phylogeny could also be interpreted so that the South American species of “ Madarococcus ” would be placed in a separate taxon, but in this case M. eurythrix and M. navarinoensis would be included. Apparently, no specimens of M. chilensis , M rhadinothrix , or M. occultus were available for DNA analysis. Hardy et al. (2008) point out that the morphological, DNA, and combined morphological and DNA trees are variable in the placement and support of the South American Madarococcus species. Their classification strategy was to minimize disruption to the generally accepted system and still be consistent with their phylogenetic results, but this has left a lack of diagnostic morphological characters for characterizing Madarococcus . It appears that more research is needed to clearly understand the species composition of Madarococcus , particularly in South America.