Depth of pupation and survival of the Oriental fruit fly, Bactrocera dorsalis (Diptera: Tephritidae) pupae at selected soil moistures

Abstract

Estimates of pupation depth and survival of the Oriental fruit fly, Bactrocera dorsalis (Hendel), are important for optimizing soil control and for better understanding its natural mortality in the agricultural system of Guangzhou, China. Late third-instar larvae were placed in soils having relative moistures of 0-100% for pupation. No pupae were found on the surface at soil moistures of 0-70%. Instead, more than 50% of the larvae pupated on the surface at soil moistures of 80, 90, and 100%. Most of the larvae preferred to pupate in less than 4 cm of the soils, while relatively few larvae moved more than 4 cm when the soils received too little water or too much water. The survival rate of pupae at 70% moisture level was low, and the pupae were unable to survive at soil moistures of 0, 80, 90, and 100%, while emergence rates exceeded 90% at the conditions of 10-60% moisture levels. Moreover, soil moistures had an influence on the average time to emergence (average time between the larvae release and the emergence of adults). Adult flies at 30% moisture level emerged earlier than those at the other moisture levels, whereas the average time to emergence at 70% moisture level was the longest.

Mulch type and moisture level affect pupation depth of Rhagoletis mendax Curran (Diptera: Tephritidae) in the laboratory

“…The range of pupation depths recorded in this study, 0-50 mm, is comparable to depths found by others, 5-40 mm, in laboratory tests using tropical tephritids (Dimou et al 2003;Hennessey 1994;Hou et al 2006;Jackson et al 1998;Tsitsipis and Papanicolaou 1979). The depths are also similar to those reported in the field for other tephritids, including Rhagoletis spp.…”

“…The authors suggested that the dense layer of blueberry roots probably impeded deeper pupation. In other studies, tropical tephritid flies, i.e., Anastrepha suspensa (Loew) and Bactrocera oleae (Gmelin), Caribbean and olive fruit flies, responded to increased moisture and soil density or compactness by pupating closer to the surface (Hennessey 1994; Tsitsipis and Papanicolaou 1979), and Bactrocera dorsalis (Hendel), Oriental fruit fly, pupated on the surface of saturated soil (Hou et al 2006). In other studies, however, pupation depth increased when soil or sand moisture levels were increased, i.e., Bactrocera spp.…”

Short-term anoxic conditioning hormesis boosts antioxidant defenses, lowers oxidative damage following irradiation and enhances male sexual performance in the Caribbean fruit fly, Anastrepha suspensa

“…SIT programs for some other tephritid pests, such as medflies, irradiate and ship pupae in sealed bags so that they experience hypoxic or anoxic conditions for 24-36h (FAO/IAEA/USDA, 2003), albeit at low temperatures (4°C). Like other tephritid fruit flies, caribflies pupate in the soil and their pupae are expected to regularly experience hypoxia or anoxia for several hours when inundated by rainfall (Hou et al, 2006;Montoya et al, 2008). This history of exposure to environmental hypoxia during the soil-bound immobile pupal stage may contribute to the anoxia tolerance in caribfly pupae, which are known to survive well even after 60h of anoxia (Benschoter et al, 1981).…”

Site-specific temporal and spatial validation of a generic plant pest forecast system with observations of Bactrocera dorsalis (oriental fruit fly)

“…Mortality (LD 90 ) was 2.49 d for third instar B. dorsalis larvae in flooded conditions at 25 °C (Xie and Zhang 2007); however, no information for the pupae was available, so it was assumed that pupae would respond similarly to flooding like larvae. Bactrocera dorsalis pupae did not survive at soil moisture greater than 80% (Hou et al 2006), although the survival time in saturated soils is unknown. A study with Mediterranean fruit fly showed that survival under similar conditions were 4 and 3 days for larvae and pupae, respectively (Eskafi and Fernandez 1990).…”