| 1. |
- Dejene Biasazin, Tibebe, et al.
(författare)
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Detection of Volatile Constituents from Food Lures by Tephritid Fruit Flies
- 2018
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Ingår i: Insects. - : MDPI AG. - 2075-4450. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Tephritid fruit flies require protein for sexual and gonotrophic development. Food-based lures are therefore widely used in strategies to detect and control fruit flies in the Tephritidae family. However, these baits are attractive to a broad range of insect species. We therefore sought to identify volatiles detected by the fly antennae, with the goal to compose lures that more specifically target tephritids. Using gas chromatography-coupled electroantennographic detection (GC-EAD) we screened for antennal responses of four important tephritid species to volatile compounds from five commercially available protein-based baits. Antennal active compounds were reconstituted in synthetic blends for each species and used in behavioral assays. These species-based blends were attractive in olfactometer experiments, as was a blend composed of all antennally active compounds from all the four species we observed (tested only in Bactrocera dorsalis, Hendel). Pilot field tests indicate that the blends need to be further evaluated and optimized under field conditions.
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| 2. |
- Karlsson, Miriam Frida
(författare)
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Effect of fruit and host fly species on the associative learning by Fopius arisanus
- 2019
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Ingår i: Bulletin of Entomological Research. - 0007-4853 .- 1475-2670. ; 109, s. 649-658
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Tidskriftsartikel (refereegranskat)abstract
- Parasitoids, released in augmentative biological control programmes, which display a rapid host-location capacity, have a higher likelihood of successfully controlling target pest species. By learning to associate sensory cues to a suitable oviposition site, might parasitoids used as biological control agents, locate hosts more rapidly, and perhaps increase the efficacity of e.g. Tephritidae fruit fly management. We studied associative learning of Fopius arisanus (Hymenoptera: Braconidae) and tested its range of learning in natural and conditional hosts and host fruits, i.e. Bactrocera dorsalis, Zeugodacus cucurbitae, Ceratitis capitata and Ceratitis cosyra (Diptera: Tephritidae) and on fruits (papaya, tomato, banana). Naive female F. arisanus were compared with experienced wasps, which had been offered infested and non-infested fruit, and been allowed to oviposit. Preferences for olfactory cues from infested fruits were thereafter assessed in a two-choice olfactometer. Naive and trained parasitoids preference differed in general and non-responders to infested fruits were higher among naive parasitoids. The trained wasps preferred the fruit infested in the training more than the control fruit, for all combination, except when C. cosyra infested the fruits, hence avoidance behavioural response was observed towards the odour of the infested fruit. Fopius arisanus was capable of behaviourally respond to the learned information, e.g. associative odour learning was achieved, yet limited depending on interaction level, fruit fly and fruit combination. To create F. arisanus preference of an associated odour, it might hence be needed to ensure oviposition in perceived suitable host and host fruit, for the parasitoid learning to become favourable in a biological control setup.
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| 3. |
- Karlsson, Miriam Frida
(författare)
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Exotic or Native? Interspecific Competition in the Parasitization of the Fruit Fly Ceratitis cosyra
- 2017
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Konferensbidrag (refereegranskat)abstract
- Fopius arisanus Sonan and Fopius caudatus Szèpligeti (Hymenoptera: Braconidae) are two solitary endoparasitoids of tephritid fruit flies that parasitize eggs of fruit flies infesting the same fruits. We studied intraspecific competition between these two parasitoids species in the mango fruit fly Ceratitis cosyra (Walker) (Diptera: Tephritidae). Based on previous documentation of the equal chance of survival between F. arisanus and Fopius ceratititvorus Wharton (Hymenoptera: Braconidae) while co-parasitizing (Bokonon-Ganta et al., 2005), we hypothesized that we would not find a superior competitor between the two parasitoids.
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| 4. |
- Karlsson, Miriam Frida
(författare)
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First report of Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) in the Republic of Benin
- 2018
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Ingår i: BioInvasions Records. - : Regional Euro-Asian Biological Invasions Centre Oy (REABIC). - 2242-1300. ; 7, s. 463-468
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Tidskriftsartikel (refereegranskat)abstract
- Tomato leafminer Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a serious pest of tomato Solanum lycopersicum L. (Solanaceae) originating from South America. Due to previous outbreaks in neighbouring West African countries, surveillance was ongoing since 2014 in Benin. Tomato plants were regularly inspected and pheromone traps placed in tomato-producing localities in northern, southern and central Benin, including fields close to the border with Niger and Nigeria. In late 2017 and beginning of 2018 Gelechiidae moths were obtained from both the traps and the reared plant material. Morphological examination and molecular analysis of the gained specimens allowed to confirm the presence of the pest in the northern and central regions of Benin. We hence confirm the presence of T. absoluta in yet another West African country.
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| 5. |
- Karlsson, Miriam Frida, et al.
(författare)
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Host-plant location by the Guatemalan potato moth Tecia solanivora is assisted by floral volatiles
- 2017
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Ingår i: Chemoecology. - : Springer Science and Business Media LLC. - 0937-7409 .- 1423-0445. ; 27, s. 187-198
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Tidskriftsartikel (refereegranskat)abstract
- Insects locate their host plants using mainly visual and olfactory cues, generally of the exploited plant structure. However, when the resource is difficult to access, it could be beneficial to utilise indirect cues, which indicates the presence of reward (e.g., oviposition site or mate). In the present study, we investigated the host-plant location strategy of the monophagous Guatemalan potato moth Tecia solanivora (Lepidoptera: Gelechiidae). The larva of the moth feed exclusively on potato Solanum spp. (Solanaceae) tubers usually hidden below ground. Using electrophysiological and behavioural tests, we characterised the olfactory cues mediating the attraction of the moth towards their host plant. Odour blends were made to represent different potato structures: tubers, foliage, and flowers. Synthetic blends were created by combining potato-emitted compounds that were antennal active which showed positive dose-response. Attraction to these blends of compounds in relation to the mating status of males and females was tested in dual-choice Y-tube assays. Both males and females, virgin and mated, were attracted to a three-compound blend representing flower odour, while foliage and tuber blends attracted neither sexes. Oviposition bioassays indicated additionally that the floral blend enhances oviposition. We show that potato flower odour might indicate the presence of an oviposition site for the female and possibly an increased mating opportunity for both sexes. Our results provide one of the few examples of the use of floral odour as a reliable indicator of host and probably mating possibility for phytophagous insects exploiting a site spatially separated from the flower.
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| 6. |
- Karlsson, Miriam Frida
(författare)
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Host species and vegetable fruit suitability and preference by the parasitoid wasp Fopius arisanus
- 2017
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Ingår i: Entomologia Experimentalis et Applicata. - : Wiley. - 0013-8703 .- 1570-7458. ; 163, s. 70-81
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Tidskriftsartikel (refereegranskat)abstract
- Parasitoids that oviposit in a concealed host inside a plant part need to be able to find both the plant and the host. Egg parasitoids of fruit-infesting Tephritidae need to assess the oviposition site based both on the host egg and the infested fruit. Infestation by Tephritidae fruit flies threatens fruit and vegetable production. Management methods have been implemented including biological control, using Fopius arisanus Sonan (Hymenoptera: Braconidae). The parasitism by F. arisanus in three Tephritidae flies in vegetable fruits was investigated. Laboratory assays were conducted to assess the parasitoid's preference and survival. Zucchini, sweet pepper, and tomato were artificially infested with eggs of Bactrocera dorsalisHendel, Ceratitis capitata Wiedemann, and Ceratitis cosyraWalker (all Diptera: Tephritidae), then exposed tomated naive F. arisanus females in a 20: 1 egg: parasitoid ratio. Parasitoid behavioral activities (resting, antennating, probing, ovipositing) were observed on the infested fruits. Parasitism rate was determined by dissection of fruit fly eggs under a stereomicroscope. Behavioral activities of F. arisanus differed between all the fruits when infested with B. dorsalis or C. cosyra eggs but differed only between some of the fruits when infested with C. capitata. Fopius arisanus preferred B. dorsalis over C. capitata and C. cosyra, with a parasitism rate 29 higher on B. dorsalis compared to the Ceratitis species. Preference for fruits was dependent on the infesting fruit fly. The emergence of F. arisanus was higher with B. dorsalis than with Ceratitis spp. Although B. dorsalis completed its development earlier than Ceratitis spp., host fly species did not affect the developmental time of F. arisanus. We discuss the significance of F. arisanus preference in relation to naturally occurring Tephritidae infestations. We also discuss whether some fruits might constitute a refuge for Tephritidae flies and whether this will affect the current biological control efforts against B. dorsalis.
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| 7. |
- Karlsson, Miriam Frida
(författare)
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Interspecific competition between egg parasitoids: Native Fopius caudatus and exotic Fopius arisanus, in Ceratitis cosyra
- 2018
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Ingår i: Biological Control. - : Elsevier BV. - 1049-9644 .- 1090-2112. ; 117, s. 172-181
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Tidskriftsartikel (refereegranskat)abstract
- Tephritidae fruit flies are parasitized by Braconidae wasps, of which some are used in biological control programs. Releases of exotic parasitoids might affect, or be affected by, native species exploiting a common host. We studied interspecific competition between the native African parasitoid Fopius caudatus (Szepligeti) and the exotic Asian parasitoid Fopius arisanus (Sonan) (both Hymenoptera: Braconidae) in African native Ceratitis cosyra Walker (Diptera: Tephritidae). Wasp behaviour on infested fruits and dissection of fruit fly eggs assessed acceptance, oviposition performance and suitability for egg development, parasitism, and effect of parasitism by heterospecific species. While F. arisanus outcompeted F. caudatus in parasitization of relatively younger eggs, chased away F. caudatus, and oviposited more, F. caudatus survived better than F. arisanus. Fopius caudatus parasitized more in 2-day-old C. cosyra eggs than in 1 or 3-day-old egg. More oviposition by F. caudatus was found in fruits previously exposed to F. arisanus, coinciding with presence of more developed host eggs, while such difference was not observed for F. arisanus. Fopius caudatus was an inferior competitor than F. arisanus in C. cosyra-infested African mango Irvingia gabonensis (Irvingiaceae).
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