A Parasitic Wasp (Eretmocerus mundus Mercet) Can Exploit Chemically Induced Delays in the Development Rates of Its Whitefly Host (Bemisia tabaci Genn.)

Authors: Devine G.J.¹; Wright D.J.²; Denholm I.¹

Source: Biological Control, Volume 19, Number 1, September 2000 , pp. 64-75(12)

Publisher: Academic Press

Abstract:

Sublethal plant defences, resulting in impaired growth of insect herbivores, may increase the impact of natural enemies upon those herbivores. This study examined whether such effects could be reproduced by chemically altering host growth rates. Fresh residues of piperonyl butoxide (a compound which slows growth in nymphs of the whitefly, Bemisia tabaci (Gennadius)) showed relatively little toxicity to adults and larvae of the parasitoid Eretmocerus mundus (Mercet), and once residues were 48 h old, they caused no discernible lethal or behavioral effects on adult wasps. Piperonyl butoxide had lethal effects on whitefly nymphs, but immature parasitoids continued to develop successfully in those hosts that survived. The hypothesis that slowing the growth rate of hosts might lead to increased parasitism by E. mundus was tested on large host populations in controlled temperature cabinets over two generations. On host populations of comparable size, highly significant increases in parasitism (7–8%, P < 0.0001) were observed. This work provides unique evidence that host growth rates can be artificially manipulated to confer advantage to parasitoids. The implications for biological control strategies and an understanding of plant allelochemical effects are discussed. Copyright 2000 Academic Press.

Keywords: slow growth; increased parasitism; parasitoid; host; piperonyl butoxide; Bemisia tabaci; Eretmocerus mundus

Language: English

Document Type: Research article

Affiliations: 1: Department of Biological and Ecological Chemistry, IACR-Rothamsted, Harpenden, Hertfordshire, AL5 2JQ, United Kingdom 2: Department of Biology, Imperial College at Silwood Park, Ascot, Berkshire, SL5 7PY, United Kingdom

Publication date: 2000-09-01

• In this: publication
• By this: publisher
• In this Subject: Plant Culture
• By this author: Devine G.J. ;  Wright D.J. ;  Denholm I.

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