Andricus pseudoflos ( Monzen, 1954 ) Abe, 2007

Abe, Yoshihisa, 2007, Parallelism in secondary loss of sex from a heterogonic life cycle on different host plants in the Andricus mukaigawae complex (Hymenoptera: Cynipidae), with taxonomic notes, Journal of Natural History 41 (5 - 8), pp. 473-480 : 478

Andricus pseudoflos ( Monzen, 1954) comb. n.

Cynips pseudoflos Monzen 1954, p 25 .

Adleria pseudoflos: Kovalev 1965 .

Andricus targionii: Abe 1986 .

The examined specimens of A. targionii (s. lat.) collected from Q. dentata by Abe (1986) are identified as A. pseudoflos .

Lectotype designation

I examined the type specimens of A. pseudoflos kept in the Entomological Laboratory, Kyushu University. One, labelled ‘‘ Cynips pseudoflos Monzen, Okunakayama, Dec. 1953 ’’ is hereby designated as the lectotype, and labelled as such in order to fix the status of this specimen as the sole name-bearing type of this species. Left flagellar segments, all legs, and metasoma are lost in the lectotype. The other three specimens, labelled ‘‘Okunakayama, Dec. 1953, Suzuki leg.’’, have been labelled by me as paralectotypes. Okunakayama is located in northern Iwate Prefecture, Japan.

Secondary loss of sex from heterogonic life cycle

Secondary loss of the bisexual generation from a heterogonic life cycle is known to have occurred in some groups of heterogonic animals ( Hebert 1987). Among oak gallwasps, a univoltine thelytokous life cycle occurs also in Plagiotrochus suberi Weld , A. quadrilineatus Hartig , and Dryocosmus kuriphilus Yasumatsu. As reviewed by Melika and Abrahamson (2002), P. suberi is heterogonic in Europe, but the introduced population in the USA is univoltine and thelytokous. Folliot (1964) revealed that unisexual females of A. quadrilineatus produce both bisexual and unisexual generations. Yasumatsu (1951) described a univoltine thelytokous species, D. kuriphilus , which is a serious pest of chestnut trees in Japan. Although this species has been studied by many applied entomologists, a candidate for the ancestral heterogonic species has not been found. In the A. mukaigawae complex, I consider that secondary loss of sex occurred in parallel on different host plants ( Figure 3 ). Whether or not such a loss occurred on the same host plant species more than once could be resolved by using molecular markers.

In another heterogonic insect group, aphids, transition from heterogony to permanent thelytoky appears to have occurred frequently ( Moran 1992). Structural difference in karyotype between thelytokous and the extant heterogonic relatives are revealed in some aphids ( Blackman 1980). In many animals and plants, permanent thelytoky is accompanied by polyploidy (Suomalainen et al. 1987), but change in ploidy level has not been detected in such aphids. In the present study, no structural difference was found in karyotype between bivoltine heterogonic A. kashiwaphilus and univoltine thelytokous A. pseudoflos . The phenotypic potential for the bisexual generation of A. kashiwaphilus may have been retained in the genome of A. pseudoflos .

Figures

Figure 3. The life cycles, gall shape of unisexual generation, and suggested changes in the Andricus mukaigawae complex.