The potential of novel African isolates of Phthorimaea operculella granulovirus for the control of Tuta absoluta

Abstract

Phthorimaea operculella granulovirus (PhopGV) is infectious for larvae of different Gelechiidae insect species, including Tuta absoluta and Phthorimaea operculella. As these are major economic pests in North and sub‐Saharan Africa as well as in the Mediterranean area, the development of locally suitable biocontrol agents is essential. We have studied five isolates of PhopGV from Tunisia (Tns16, Tu1.11 and Tu2.11), Kenya (Ken13) and Yemen (Ym14) for their biological activity and the sequence polymorphism of their granulin and ecdysteroid UDP‐glucosyltransferase (egt) genes and allocated the isolates to two different egt types. Infection experiments with neonate larvae of T. absoluta and P. operculella demonstrated their pathogenicity to both host species. The isolate PhopGV Tu1.11 was the most virulent one for T. absoluta but had a relatively low infectivity to two P. operculella populations originating from Italy and Tunisia.

The History of Baculovirology in Africa

“…The virus is known to infect at least six species within the family Gelechiidae, some of which are important pests of solanaceous crops worldwide. These are the potato tuber moth, Phthorimaea operculella (Zeller); the Guatemala potato tuber moth, Tecia solanivora (Povolny); the tomato leaf miner, Phthorimaea absoluta (Meyrick); Eurysacca quinoa (Povolny); Symmetrischema tangolias (Gyen); and Paraschema detectendum (Povolny) [ 156 , 157 , 158 , 159 , 160 ].…”

“…Substantial genetic analyses have been conducted on PhopGV, with partial sequence data available for most isolates and complete genome sequence data available for at least 12 isolates, including two from Africa [ 156 , 159 , 161 ]. These studies have resulted in each PhopGV isolate being assigned to either one of five groups based on partial egt gene sequences or one of four groups based on whole-genome sequence analysis.…”

“…This excludes PhopGV-SA, which did not cluster within the four groups. At least 10 African PhopGV isolates have been reported, all of which originated from infected P. operculella larvae [ 155 , 156 , 156 , 161 , 162 , 163 , 164 ].…”

Few indirect effects of baculovirus on parasitoids demonstrate high compatibility of biocontrol methods against Tuta absoluta

“…A member of the genus Betabaculovirus ( lepidopteran granuloviruses ), Phthorimaea operculella granulovirus (PhopGV), has been considered for the management of different lepidopteran pest species of the Gelechiidae family such as Phthorimaea operculella (Zeller), Tecia solanivora (Povolny), and T. absoluta 15–19 . Recently, a microbial insecticide based on PhopGV was commercially developed against T. absoluta (Tutavir©, Andermatt Biocontrol, Switzerland).…”

“…13,14 A member of the genus Betabaculovirus (lepidopteran granuloviruses), Phthorimaea operculella granulovirus (PhopGV), has been considered for the management of different lepidopteran pest species of the Gelechiidae family such as Phthorimaea operculella (Zeller), Tecia solanivora (Povolny), and T. absoluta. [15][16][17][18][19] Recently, a microbial insecticide based on PhopGV was commercially developed against T. absoluta (Tutavir©, Andermatt Biocontrol, Switzerland). The product is registered for use in Brazil and has been granted emergency approval in different European countries such as Greece, Cyprus, Germany, and Switzerland (Andermatt, personal communication).…”