Host‐feeding of three parasitoid species on Bemisia tabaci biotype B and implications for whitefly biological control

Abstract

Parasitoids in the genera Encarsia and Eretmocerus (Hymenoptera: Aphelinidae) are important biological control agents of whiteflies through their reproductive as well as host-feeding activities.The feeding capacities of female parasitoids of three species with different reproductive strategies [ Encarsia sophia (Girault & Dodd), Encarsia formosa Gahan, and Eretmocerus melanoscutus Zolnerowich & Rose] on their host, sweetpotato whitefly, Bemisia tabaci (Gennadius) biotype B (Homoptera: Aleyrodidae), were evaluated on cabbage in a single-instar no-choice experiment in the laboratory and a mixed-instar choice experiment in the greenhouse. In both single-and mixed-instar experiments, significant differences in host-feeding capacities were found among the three parasitoid species. Encarsia sophia exhibited superior capacity of host-feeding compared to E. formosa and E. melanoscutus . In the single-instar experiment, parasitoids fed more on younger (smaller) hosts than older (larger) hosts. In the mixed-instar experiments, all three parasitoid species exhibited a clear preference for feeding on older hosts compared to younger hosts. Total number of whitefly nymphs fed on by E. sophia was approximately three times that of the other two parasitoid species. Whitefly mortality accounted for by host-feeding by E. sophia was up to 59.7%, and, thus, equivalent to parasitization. The significance of host-feeding of E. sophia for biological control of B. tabaci is discussed.

Biological pest management by predators and parasitoids in the greenhouse vegetables in China

“…The oligophagous predator, Delphastus cataliae exhibits good bio-control effectiveness, especially under high density of whitefly nymphs (Zang and Liu, 2007). Recently, Zang and Liu (2008) found that E. sophia, a heteronomous hyperparasitoid, is also an effective biological control agent of B. tabaci. These parasitoid species can suppress whiteflies through parasitism and host feeding better than E. formosa, if the release of numbers of male adults could be controlled (Zang et al, 2011a).…”

Model selection and averaging in the estimation of population parameters of Bemisia tabaci (Gennadius) from stage frequency data in sweet pepper plants

“…The level of parasitism due to E. mundus in the N4 instar may be high (González-Zamora et al 1996;Téllez et al 2003;Stansly et al 2005). Predation by E. mundus adults on different instars of the whitefly B. tabaci is well known and has been evaluated (Gerling and Fried 2000;Urbaneja et al 2007), and is considered an important factor in population regulation (Téllez et al 2003;Zang and Liu 2008).…”

Eretmocerus warrae prefer to attack mid-aged hosts to gain fitness for both adults and their offspring

“…However, some studies give controversial conclusions, for example, in E. melanoscutus Liu (2007) reports that females lay most eggs under the third instar nymphs while Zang and Liu (2008) indicate that they prefer the first and second instar nymphs for oviposition. With regard to feeding, Zang and Liu (2008) demonstrate that E. melanoscutus feed more on younger than older hosts in the single-instar experiment but more on older than younger hosts in the mixed-instar experiments. Therefore, oviposition vs. host-feeding strategy of these parasitoid females may vary depending on parasitoid life history and the availability of host resources (Yang et al, 2012).…”

“…General models predict that a foraging parasitoid should select lower quality hosts for feeding and higher quality ones for oviposition (Kidd and Jervis, 1991;Chan and Godfray, 1993;Heimpel and Rosenheim, 1995;Lauzière et al, 2001). However, female parasitoids prefer hosts of similar stages for both feeding and oviposition in E. melanoscutus Zolnerowich and Rose (Zang and Liu, 2008) and E. hayati Zolnerowich and Rose (Yang and Wan, 2011). Hanan et al (2012) and Yang et al (2012) suggest that host-feeding vs. oviposition strategy of these parasitoid females may vary depending on parasitoid life history strategies and the availability of host resources.…”