Overview and future research needs for development of effective biocontrol strategies for management of Bactrocera dorsalis Hendel (Diptera: Tephritidae) in sub‐Saharan Africa

Abstract

Infestation of fruits by native and invasive fruit flies causes significant economic losses. In most cases, incidence of ‘regulated’ dangerous fruit flies in orchards results in restrictions on export of fruits from such places to international markets. Unfortunately, use of insecticides applied on foliage and fruits does not kill the fruit‐to‐soil stages of fruit flies. However, diverse biological control agents (BCAs) do so. Thus, prevalence of native and invasive fruit flies in orchards will require that a combination of BCAs is included in integrated pest management (IPM) programmes. In the case of Bactrocera dorsalis Hendel and other economically important fruit flies found in sub‐Saharan Africa (SSA), use of classical biocontrol approach involves concomitant releases of two exotic parasitoids (Fopius arisanus Sonan and Diachasmimorpha longicaudata Ashmead). These non‐native wasps may have complemented the indigenous parasitoids in combination with application of entomopathogenic fungi (EPFs) and conservation of predatory ants (Oecophylla longinoda Latreille, with O. smaragdina) in fruit fly IPM plans. Consequently, some levels of decline in fruit infestation have been observed. Although interspecific interactions between BCAs against several insect pests have produced varying results, including threatening the survival of other BCAs, the prevalence of B. dorsalis in orchards across SSA requires further research to investigate effects of coalescing biocontrol approaches in IPM strategies. Therefore, future research into combining parasitoids, EPFs and entomopathogenic nematodes, in addition to conservation of predatory ants (O. longinoda, O. smaragdina and others) in IPM plans may improve the effectiveness of currently used strategies for the management of fruit‐infesting tephritids. © 2021 Society of Chemical Industry.

Review of entomopathogenic fungi and nematodes as biological control agents of tephritid fruit flies: current status and a future vision

“…However, application of B. bassiana in combination with release of C. haywardii for management of A. obliqua was not effective (Martínez-Barrera et al, 2020). Comparing the effectiveness of combined B. bassiana and C. haywardii in controlling A. obliqua to that of EPFs against B. dorsalis in sub-Saharan Africa (SSA), it can be concluded that the use of EPF species in IPM programs has been effective against B. dorsalis and economically less important fruit flies in SSA, where diverse parasitoids have established (Heve et al, 2021).…”

“…Solenopsis spp. may prey on EPN-killed pupae of fruit flies to kill developing EPN-IJs in cadavers in soils (Heve et al, 2021). On the other hand, Solenopsis spp.…”

Correlation between Irradiation Treatment and Metabolite Changes in Bactrocera dorsalis (Diptera: Tephritidae) Larvae Using Solid-Phase Microextraction (SPME) Coupled with Gas Chromatography-Mass Spectrometry (GC-MS)

“…Because they have a wide range of hosts, primarily fruits, and are highly invasive. The fruit fly was initially recorded in Taiwan in 1912, and it has since widely distributed throughout the Asia-Pacific region and much of sub-Saharan Africa [ 1 , 2 ]. Through its larvae, which feed on fruit, the species can cause massive direct crop losses to agricultural production.…”

Assessment of attractancy and safeness of (E)‐coniferyl alcohol for management of female adults of Oriental fruit fly, Bactrocera dorsalis (Hendel)

“…2,[4][5][6] Therefore, it is difficult to use pesticides to control fruit fly stages that are hidden in fruits and soil, thereby making insecticides unsuitable in this case. 7 Moreover, resistance against synthetic pyrethroids, organophosphates, and abamectin insecticides is now prevalent among wild B. dorsalis populations. 8,9 Controlling adult flies is one of the methods used to reduce the damage of this pest on fruits and vegetables.…”

“…Females of B. dorsalis oviposit eggs into ripening fruits, where the newly hatched larvae feed on the pulp until they migrate from fallen fruits on the ground to pupate in the soil 2,4–6 . Therefore, it is difficult to use pesticides to control fruit fly stages that are hidden in fruits and soil, thereby making insecticides unsuitable in this case 7 . Moreover, resistance against synthetic pyrethroids, organophosphates, and abamectin insecticides is now prevalent among wild B. dorsalis populations 8,9 .…”