The biology ofRoptrocerus xylophagorum [Hym.: Torymidae], with a note on its taxonomic status

Samson, PR

doi:10.1007/bf02372116

Cited by 32 publications

(29 citation statements)

References 16 publications

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“…As we did not differentiate between R. xylophagorum and R. mirus, these results are vague. However, there are similar results from other authors (Stephen and Dahlsten 1976;Samson 1984). According to Stephen and Dahlsten (1976), the sex ratio of R. xylophagorum/mirus changes strongly with different localities.…”

Section: Parasitoid Sex Ratiossupporting

confidence: 90%

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Parasitoids of Ips typographus (Col., Scolytidae), their frequency and composition in uncontrolled and controlled infested spruce forest in Bavaria

Feicht

2004

J Pest Sci

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In the Bavarian Forest national park, the spruce bark beetle Ips typographus (Col., Scolytidae) has caused an uncontrolled mass propagation for more than 10 years. To find out if the population of parasitoid species, which can develop in an uncontrolled natural forest, is able to restrict spruce bark beetle gradation, we investigated the parasitoid fauna, their abundance and frequency in the central part of the park (no control), in the protection area and the enlargement area of the park and in a productive forest where the spruce bark beetle is strictly controlled. In 2002 and 2003, the species Coeloides bostrichorum, Roptrocerus xylophagorum/mirus, Rhopalicus tutela, Tomicobia seitneri and Dendrosoter eupterus were identified. C. bostrichorum was the most numerous species before Roptrocerus sp. and Rh. tutela. T. seitneri and D. eupterus were not as numerous. The order of frequency differed. Roptrocerus sp. was the most frequent parasitoid wasp in both years, and Rh. tutela and even T. seitneri were more frequent than C. bostrichorum. C. bostrichorum and Rh. tutela were found to be protandrous, whereas Roptrocerus sp. males and females had different sequences of appearance in different forest types. The average percentages of parasitism increased with time of exposure and was highest in the second generation. We found astonishingly high parasitization rates at sites where attacked trees are regularly removed.

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Section: Parasitoid Sex Ratiossupporting

confidence: 90%

“…Bark beetle density, density of predators and presence of alternative hosts. Parasites prefer hosts which are final instar larvae and pupae (Samson 1984;Samson and Smibert 1986;Kru¨ger and Mills 1990 ). This is also shown here by the higher parasitization of the longer exposed logs.…”

Section: Differences In Parasitizationmentioning

confidence: 57%

Parasitoids of Ips typographus (Col., Scolytidae), their frequency and composition in uncontrolled and controlled infested spruce forest in Bavaria

Feicht

2004

J Pest Sci

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“…Evidence suggests that an interaction between bark beetles and host tree phloem results in production of host location cues that are exploited by the parasitoids. Bark excised from healthy trees does not stimulate attraction or other host finding behaviors in bark beetle parasitoids, but will do so after infestation by bark beetle larvae (Samson, 1984;Mills et al, 1991;Sullivan et al, 2000). For several parasitoid species, infested bark remains attractive after removal of hosts, whereas isolated bark beetle larvae do not elicit parasitoid attraction, arrestment, or oviposition (Mills et al, 1991;Sullivan et al, 2000).…”

Section: Sullivan Andberisfordmentioning

confidence: 99%

“…More than a dozen economically important species of bark beetle in North America and Europe are hosts for this wide ranging and abundant parasitoid (Sullivan et al, 2000). R. xylophagorum prefers late-instar larval hosts but also parasitises pupae (Samson, 1984). Tests of parasitoid attraction to fungicolonized tree tissue were performed exclusively with the beetles' bluestain associates (order Ophiostomatales) because of their reliable association with bark beetles (Upadhyay, 1981) and their ability to grow relatively rapidly into tree tissues in the absence of insects (Bramble and Holst, 1940;.…”

Section: Sullivan Andberisfordmentioning

confidence: 99%

Semiochemicals from Fungal Associates of Bark Beetles May Mediate Host Location Behavior of Parasitoids

Sullivan

Berisford

2004

J Chem Ecol

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Abstract-In laboratory olfactometer bioassays, females of two hymenopteran parasitoid species, Roptrocerusxylophagorum (Ratzeburg) (Hymenoptera: Pteromalidae) and Spathius pallidus (Ashmead) (Hymenoptera: Braconidae), were attracted to odors from bark or bolts of loblolly pine, Pinus taeda L., colonized by bluestain fungi (genus Ophiostoma) associated with the parasitoids' bark beetle hosts. Mock-inoculated bolts and bark were less attractive or unattractive in these bioassays. Bark infested with host larvae that lacked their fungal and other normal microbial associates was attractive to R. xylophugorum females, but was less so than bark infested with larvae possessing their normal complement of associated microbes. In contrast, in oviposition bioassays, R. xylophagorum females spent approximately equal time searching, made similar numbers of oviposition attempts, parasitized similar percentages of hosts, and laid similar numbers ofeggs in bark fragments infested with either associate-free or associate-bearing host larvae. Furthermore, in field bioassays using bluestaininoculated or mock-inoculated loblolly pine bolts as sources of attractants, the numbers of parasitoids attracted by the two treatments did not differ significantly and the two treatments were less attractive than bolts naturally infested with bark beetle larvae. Whereas our laboratory olfactometer data suggest that bark beetle fungal associates may enhance attraction of some parasitoids, our bioassays with associate-free hosts indicate that associate-produced are not required for shortrange host location and parasitization. In addition, our field trials indicated that long-range attraction of parasitoids to the host-fungi-tree complex is not caused simply by an interaction between bluestain fungi and tree tissues.

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“…Its biology has been extensively studied, both in Europe and the USA (e.g. Hedqvist 1963;Samson 1984;Pettersson et al 2000;Sullivan et al 1999). Eggs are laid on bark beetle larvae and, occasionally, on pupae in the galleries.…”

Section: Larval Ectoparasitoidsmentioning

confidence: 99%

Research on Parasitoids and Predators of Scolytidae – A Review

Kenis

Wermelinger

Grégoire

2007

Bark and Wood Boring Insects in Living Trees in Europe, a Synthesis

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The biology ofRoptrocerus xylophagorum [Hym.: Torymidae], with a note on its taxonomic status

Cited by 32 publications

References 16 publications

Parasitoids of Ips typographus (Col., Scolytidae), their frequency and composition in uncontrolled and controlled infested spruce forest in Bavaria

Parasitoids of Ips typographus (Col., Scolytidae), their frequency and composition in uncontrolled and controlled infested spruce forest in Bavaria

Semiochemicals from Fungal Associates of Bark Beetles May Mediate Host Location Behavior of Parasitoids

Research on Parasitoids and Predators of Scolytidae – A Review

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