A portable, power-driven sifter for soil insect studies

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A note on the acceptability of leaf macerates on filter paper of plants from peat bogs by adult black vine weevils, Brachyrhinus sulcatus (F.)

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Wildland fire effects in silviculturally treated vs. untreated stands of New Mexico and Arizona

Stand-replacement fires, particularly in ponderosa pine (Pinus ponderosa) forests, have replaced high frequency, low-intensity historical fire regimes. We examined whether forest stands treated recently using silvicultural practices would be (1) less susceptible to stand-replacing crownfires, and (2) more ecologically and functionally resilient compared to untreated stands following extreme wildland fire. Reports detailing wildland fire behavior in treated stands remain largely anecdotal. We compared fire severity indices, fireline intensity (btu/ft/s), stand characteristics including canopy bulk density (kg/m3), and post-fire recovery indices in silviculturally treated vs. untreated forest stands in New Mexico and Arizona. Results indicated fire severity in pine-grassland forests was lowered when surface and aerial fuel loads were reduced. Specifically, as density (stems/ac) and basal area (ft2/ac) decreased and mean tree diameter (in) increased, fire severity and fireline intensity decreased. The more aggressive the treatment (i.e., where the canopy bulk density was reduced), the less susceptible forest stands were to crownfire. However, mechanical treatments where slash was scattered rendered stands susceptible to near stand-replacement type damage when wildfire occurred within 4 years of treatment. On our study sites, mechanical treatment followed by prescribed fire had the greatest impact toward mitigating fire severity (i.e., aerial and surface fuels were reduced). Treated stands were also more ecologically and functionally resilient than untreated forest stands following wildland fire

Fecundity of the black vine weevil, Brachyrhinus sulcatus (F.), fed on foliage of blueberry, cranberry and weeds from peat bogs

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Effects of early-life competition and maternal nutrition on telomere lengths in wild meerkats

Early-life adversity can affect health, survival and fitness later in life, and recent evidence suggests that telomere attrition may link early conditions with their delayed consequences. Here, we investigate the link between early-life competition and telomere length in wild meerkats. Our results show that, when multiple females breed concurrently, increases in the number of pups in the group are associated with shorter telomeres in pups. Given that pups from different litters compete for access to milk, we tested whether this effect is due to nutritional constraints on maternal milk production, by experimentally supplementing females’ diets during gestation and lactation. While control pups facing high competition had shorter telomeres, the negative effects of pup number on telomere lengths were absent when maternal nutrition was experimentally improved. Shortened pup telomeres were associated with reduced survival to adulthood, suggesting that early-life competition for nutrition has detrimental fitness consequences that are reflected in telomere lengths. Dominant females commonly kill pups born to subordinates, thereby reducing competition and increasing growth rates of their own pups. Our work suggests an additional benefit of infanticide may be that it also reduces telomere shortening caused by competition for resources, with associated benefits for offspring ageing profiles and longevity.The Kalahari Meerkat Project is supported by the Universities of Cambridge, Zurich and Pretoria. Components of this research were supported by grants to TC-B from the Natural Environment Research Council (grant no. NE/G006822/1) and the European Research Council (grant no. 294494). PM was supported by the European Research Council (grant no. 268926)

The effect of root weevils (Coleoptera: Curculionidae) on yield of five strawberry cultivars in British Columbia

To determine the effect of root weevils on strawberry yield, 5 strawberry cultivars: Totem, Shuksan, Northwest, Cheam and BC-25 were infested in the field with 2 or 8 adults per plant of 1 of 4 species of root weevils: the black vine weevil, Otiorhynchus sulcatus (F.); the strawberry root weevil, O. ovatus L.; the obscure strawberry root weevil, Sciopithes obscurus Horn; and the woods weevil Nemocestes incomptus (Horn). There were no significant differences in yield between weevil infestations in the first cropping season. In the second year plants in the plot infested with 8 O. sulcatus per plant produced significantly less fruit than those in all other infestations. Within this plot Totem and Cheam produced significantly more fruit than the other cultivars. In the third year most of the other weevil-infested plots produced significantly less fruit than the uninfested plot. The plot with 2 N. incomptus per plant was the most severely damaged in the third season. The cultivars Totem and Cheam were usually the most tolerant to all weevils. Northwest and BC-25 were the most susceptible to all weevils. The tolerance of Totem to attack by the main root weevil species, O. sulcatus, is probably related to the ability of the plant to produce and regenerate a large supply of roots

Fecundity of the black vine weevil, Otiorhynchus sulcatus (Coleoptera: Curculionidae), fed foliage from some current cultivars and advanced selections of strawberry in British Columbia

Adults of the black vine weevil, Otiorhynchus sulcatus (F.), kept individually in plastic vials in the laboratory were fed foliage picked from strawberry cultivars or selections in one field of the British Columbia strawberry breeding program at Abbotsford. The source of foliage had no significant influence of preoviposition period, weight gain, or amount of foliage consumed. However, there were significant differences in the number of eggs laid during a ten-week period and in the number of larvae that hatched. The fewest eggs were laid and larvae hatched when weevils fed on the new cultivar Tyee and the selection BC 73-9-79. The other foliage sources in order of increasing numbers of eggs were BC 70-22-82, Totem, BC 69-5-34, Shuksan, and BC 70-20R-15

A note on the acceptability of leaf macerates on filter paper of plants from peat bogs by adult black vine weevils, Brachyrhinus sulcatus (F.)

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Acceptability of cultivars of highbush Blueberry at varying temperatures by adult black vine weevils (Col.: Curculionidae)

Adults of the black vine weevil,Otiorhynchus (Brachyrhinus) sulcatus  (F.), fed and oviposited at normal, expected rates when fed excised foliage of the acceptable highbush blueberry cultivars, June and Stanley, in variable temperature regimes of 7 to 15, mean 10; 12 to 19, mean 15; and 16 to 29, mean 22C. However, on the unacceptable cultivars, Cabot and Weymouth, they laid some eggs at the high and very few eggs at the medium regimes, whereas in earlier work they laid no eggs at a constant 20C. These results indicate that Cabot and Weymouth provide barely adequate nutrition to the weevils and that environmental stresses such as a constant 20C demand more nutrients than the unacceptable cultivars can provide. Variable conditions, probably due to a lower turn-over rate during the cool periods, allow the insect to obtain the nutrients necessary for fat body development and some oviposition

A portable, power-driven sifter for soil insect studies

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