Host microhabitat location by Campoletis sonorensis (Cameron) (Hymenoptera: Ichneumonidae), a generalist parasitoid /
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1990.
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| Subjects: | |
| Online Access: | ProQuest, Abstract Link to OAKTrust copy |
| Abstract: | Host microhabitat location by female Campoletis sonorensis was studied in a laboratory wind tunnel flight bioassay. Microhabitat location was influenced by visual cues from the host plant. Parasitoids located a cotton plant (Gossypium hirsutum L.) more readily than a single cotton leaf. Damaged cotton plants provided chemical cues and neither experienced nor naive parasitoids flew to undamaged plants. Experienced females completed equal numbers of flights to mechanically damaged leaves and to naturally damaged leaves either with host frass and Heliothis virescens (F.) larvae (host/plant complex) or without host larvae. Naive parasitoids completed fewer flights than experienced females but exhibited the same specificity. Parasitization experience consisted of oviposition in hosts and exposure to damaged plants and to host frass. Oviposition caused experienced females to complete more flights than naive females and was as effective in stimulating flight as contact with all three factors. Females contacting frass or damaged plants, without oviposition, completed fewer flights than naive females with no contact with kairomones. Cotton seedlings released green leaf chemicals and terpenes. Headspace collections from damaged and undamaged plants were different and may account for the increased attractiveness of damaged plants to C. sonorensis. Undamaged plants produced small amounts of volatiles compared to damaged plants but no new chemicals were detected after damage. Parasitoids reared on hosts fed plant material were no more responsive to host/plant complex odors than were parasitoids reared from hosts fed artificial diet. The diet of the host did not affect the parasitoid's microhabitat preference. Parasitoids given oviposition experience 1 min prior to bioassay completed more flights than did naïve females to two host plants, cotton and sesame (Sesamum indicum L.), and to a nonhost plant, potato (Solanum tuberosum L.). However, after 24 h, only females experienced on potato responded at levels significantly higher than naive females indicating that females learned the novel odor of the nonhost. Parasitoids did not prefer one hose plant over another but did prefer a host to a nonhost plant. A single oviposition experience did not change host microhabitat preference. |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Entomology." |
| Physical Description: | ix, 78 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references. |