Host feeding in insect parasitoids: why destructively feed upon a host that excretes an alternative?

TY - JOUR

T1 - Host feeding in insect parasitoids: why destructively feed upon a host that excretes an alternative?

AU - Burger, J.S.M.

AU - Reijnen, T.M.

AU - Van Lenteren, J.C.

AU - Vet, L.E.M.

N1 - Reporting year: 2004 Metis note: 3270; CTE; MTI; ; file:///L:/Endnotedatabases/NIOOPUB/pdfs/Pdfs2004/Burger_ea_3270.pdf

PY - 2004

Y1 - 2004

N2 - Host feeding is the consumption of host tissue by the adult female parasitoid. We studied the function of destructive host feeding and its advantage over non-destructive feeding on host-derived honeydew in the whitefly parasitoid Encarsia formosa Gahan (Hymenoptera: Aphelinidae). We allowed parasitoids to oviposit until they attempted to host feed. We either prevented or allowed host feeding. Parasitoids had access to sucrose solution, with or without additional access to honeydew. Parasitoids that were allowed to host feed did not have a higher egg load 20 or 48 h after host feeding than parasitoids prevented from host feeding. Host feeding did not increase the number of eggs matured within these periods, nor did the time spent host feeding positively affect any of these response variables. On the other hand, the presence of honeydew did have a positive effect on egg load 20 and 48 h after host feeding compared with parasitoids deprived of honeydew. Parasitoids with access to honeydew matured more eggs within these periods than honeydew-deprived parasitoids. Host feeding increased life expectancy, but this effect was nullified when honeydew was supplied after the host-feeding attempt. In conclusion, feeding on honeydew could be an advantageous alternative to host feeding in terms of egg quantity and longevity. This applies especially to parasitoids exploiting Homoptera, because these parasitoids can obtain honeydew from the host itself. It is possible that destructive host feeding has evolved to enable females to sustain the production of high-quality anhydropic eggs, which may be important in the parasitoid's natural environment. We argue that future studies should take natural alternative food sources into more consideration. [KEYWORDS: life history host-feeding behaviour honeydew fecundity anhydropic eggs longevity Encarsia formosa Hymenoptera Aphelinidae Trialeurodes vaporariorum Homoptera Aleyrodidae]

AB - Host feeding is the consumption of host tissue by the adult female parasitoid. We studied the function of destructive host feeding and its advantage over non-destructive feeding on host-derived honeydew in the whitefly parasitoid Encarsia formosa Gahan (Hymenoptera: Aphelinidae). We allowed parasitoids to oviposit until they attempted to host feed. We either prevented or allowed host feeding. Parasitoids had access to sucrose solution, with or without additional access to honeydew. Parasitoids that were allowed to host feed did not have a higher egg load 20 or 48 h after host feeding than parasitoids prevented from host feeding. Host feeding did not increase the number of eggs matured within these periods, nor did the time spent host feeding positively affect any of these response variables. On the other hand, the presence of honeydew did have a positive effect on egg load 20 and 48 h after host feeding compared with parasitoids deprived of honeydew. Parasitoids with access to honeydew matured more eggs within these periods than honeydew-deprived parasitoids. Host feeding increased life expectancy, but this effect was nullified when honeydew was supplied after the host-feeding attempt. In conclusion, feeding on honeydew could be an advantageous alternative to host feeding in terms of egg quantity and longevity. This applies especially to parasitoids exploiting Homoptera, because these parasitoids can obtain honeydew from the host itself. It is possible that destructive host feeding has evolved to enable females to sustain the production of high-quality anhydropic eggs, which may be important in the parasitoid's natural environment. We argue that future studies should take natural alternative food sources into more consideration. [KEYWORDS: life history host-feeding behaviour honeydew fecundity anhydropic eggs longevity Encarsia formosa Hymenoptera Aphelinidae Trialeurodes vaporariorum Homoptera Aleyrodidae]

U2 - 10.1111/j.0013-8703.2004.00196.x

DO - 10.1111/j.0013-8703.2004.00196.x

M3 - Article

SN - 0013-8703

VL - 112

SP - 207

EP - 215

JO - Entomologia Experimentalis et Applicata

JF - Entomologia Experimentalis et Applicata

IS - 3

ER -