Pachycrepoideus vindemmiae (Rondani, 1875)

Shimbori, Eduardo Mitio, Costa, Valmir Antonio & Zucchi, Roberto Antonio, 2020, Annotated checklist and illustrated key to parasitoids (Hymenoptera: Diapriidae Eulophidae and Pteromalidae) of fruit flies (Diptera, Tephritidae) in Brazil, Zootaxa 4858 (1), pp. 53-70 : 62

Pachycrepoideus vindemmiae (Rondani, 1875)

( Figs 6–8 )

Diagnosis. Small wasps, black with slight metallic-green iridescence; head and mesosoma densely punctate to mostly reticulate, including mesopleuron; antennae with basal 2 or 3 segments of flagellum annular, subsequent funicular segments nearly as wide as long; metasoma appearing sessile, smooth, with petiole bordered on either sides by flange extending anteriorly from first sternite; marginal vein uniformly thickened, proportion of marginal: stigmal:posmarginal veins = 1:1:2; legs yellowish beyond coxae.

Taxonomy. This species is treated in modern taxonomic revisions that include well-illustrated keys, such as those of Rueda & Axtell (1985) and Bouček & Heydon (1997). Pachycrepoideus vindemmiae is the only species of the genus known to occur in Brazil ( Costa 2019).

Biology. Pupal idiobiont ectoparasitoid, recorded in a wide range of Diptera species (at least 60 species in several families). It may also act as a facultative hyperparasitoid ( Wang & Messing 2004). In Brazil, it is frequently associated with fruit flies ( Tephritidae ), namely A. fraterculus , A. obliqua and A. sororcula ( Aguiar-Menezes & Menezes 2002; Aguiar-Menezes et al. 2003; Marchiori et al. 2000), although parasitism on species of other families is also common.

Biological control. This parasitoid has been used as a biological control agent for filth flies ( Diptera : Muscidae ) (e.g. Meyer et al. 1990; Wharton 1989), and introduced in several countries in the Americas for classical and augmentative biological control of fruit-infesting tephritids (e.g. Gilstrap & Hart 1987; Purcell 1998), but usually established populations prior to intentional introductions. The efficacy of this species in augmentative programs is criticized, since it has been used for decades without evidence of success ( Ovruski et al. 2000). Even though natural parasitism may aid in regulating population levels of some pests observed rates are usually low, and efforts on introducing or mass-rearing P. vindemmiae are discouraged, due to its polyphagy, resulting in negative effects on non-target species, and lack of efficacy ( Ovruski et al. 2000; Wang & Messing 2004; Lee et al. 2019).

Distribution. Cosmopolitan. The introduction of P. vindemmiae in Brazil, as in many other countries, is not well documented. For instance, Ovruski & Schliserman (2012) comment that occurrence in 11 American countries could be a result of intentional or unintentional introduction, or even of the natural distribution of P. vindemmiae . The first well documented introduction is reported for Hawaii, in 1914, for specimens brought from the Philippines by Mr. D. T. Fullaway ( Pemberton & Willard 1918). The same researcher, working as an employee of the Bureau of Entomology and Plant Quarantine of Puerto Rico, was responsible for sending parasitoid specimens from Brazil to Puerto Rico, including P. vindemmiae , between years 1935 and 1937 ( Bartlett 1941). Additionally, there are some reports of specimens of P. vindemmiae being redistributed from Hawaii to Latin American countries (e.g. Purcell 1998, for Costa Rica). Therefore, this species could have been introduced in Brazil between years 1914 and 1937, from Hawaii, by Mr. D. T. Fullaway, a possibility that we could not confirm by the lack of historical records. The first citation of P. vindemmiae in Brazil is given by Souza (1943), as a parasitoid in pupae of Billaea claripalpis (Wulp) (formerly Paratheresia brasiliensis Townsend ) ( Diptera , Tachinidae ), which in turn was parasitizing Diatraea saccharalis (Fabricius) ( Lepidoptera , Crambidae ) in sugarcane. The specimens were obtained from samples taken in 1940-1941 ( Souza 1943), but P. vindemmiae has possibly established populations in Brazil before 1937 (see Bartlett 1941).

Distribution in Brazil (associated with tephritid species). CE and RN ( Silva et al. 2020), GO ( Marchiori et al. 2000), RJ ( Aguiar-Menezes & Menezes 2002; Aguiar-Menezes et al. 2003), RS ( Salles 1996), SP ( Montes et al. 2011).

Figures

FIGURES 1–8. 1, 2, Trichopria sp. aff. anastrephae, head; 3, Spalangia simplex, head; 4, 5, Tetrastichus giffardianus: 4, mesosoma dorsal and 5, fore wing; 6–8, Pachycrepoideus vindemmiae: 6, head, 7, mesosoma dorsal and 8, fore wing. Arrows indicating: point of insertion of the antenna (Figs 1–3, 6); submedian grooves on scutellum (Fig. 4); thickened marginal vein (Fig. 8). (bar = 0.1 mm)