Effects of some abiotic factors on the exit of poppy root weevils (Ethelcus denticulatus Schrank) (Coleoptera: Curculionidae) from overwintering area

With this study, it is aimed to determine the effects of some abiotic factors on the exit of poppy root weevils (Ethelcus denticulatus Schrank) (Coleoptera: Curculionidae) from their overwintering area. Poppy root weevils is the most important harmful pest of poppy fields (Papaver somniferum L.) (Rhoedales; Papaveraceae). According to the findings, the first adults were seen on the soil on March 10, 2014. It has been observed that as the temperature of the air increases, the number of adults on the soil surface also increases. Thus, it was determined that the number of adults in square meters reached the highest level on April 21, 2014. After this date, it was determined that the number of wintering adults decreased gradually. While the first insect on the surface of the field was caught on March 09, 2015 in the second year. It was determined that the number of highest poppy root weevils caught on the soil surface and in the traps was on April 13, 2015. After this date, it was determined that both the trapped insects and their numbers in m2 decreased. There were significant (P£0.05) correlations between the poppy root weevil exit from their overwintering area and soil temperature (r=0.648, r2=0.461, n=84 P=0.000) and temperature (r=0.59, r2=0.277, n=84, P=0.004) whereas there was no significant correlation between it and soil moisture (r=0.310, r2=0.021, n=84, P=0.466), humidity (r=0.32, r2=0.108, n=84, P=0.87) and rain (r=0.38, r2=0.101, n=84, P=0.73).

Feeding by grey seals on endangered stocks of Atlantic cod and white hake

High natural mortality is preventing the recovery of collapsed stocks of Atlantic cod and white hake in the southern Gulf of St Lawrence, Canada. Predation by grey seals has been proposed as an important cause of this high mortality. We determined the contribution of cod and hake to the diet of grey seals collected along the west coast of Cape Breton Island and in the Cabot Strait, an area where overwintering cod aggregate. Along the coast of Cape Breton Island, the contribution of hake and cod to the diet was 30 and 17%, respectively, by weight using stomach contents and 13 and 9%, respectively, based on intestine contents. In the Cabot Strait, when overwintering aggregations of cod were present, cod accounted for 68% (range 57–80%) of the male diet from stomachs, and 46% (range: 31–64%) of the diet determined from intestines. Among females, cod represented 14% (range: 0–34%) and 9% (range: 3–54%) of the diet from stomachs and intestines, respectively. In Cabot Strait, white hake accounted for up to 17% of the diet by weight from stomachs, and up to 6% of the diet determined from intestines. The mean length of cod consumed by seals was 28 cm (SD = 8.6) along the coast of Cape Breton Island, and 39 cm (SD = 5.7) in Cabot Strait. The mean length of hake consumed by seals was 29 cm (SD = 7.0) along the coast of Cape Breton Island, and 35 cm (SD = 5.6) in Cabot Strait. Cod and hake are more important to the diet of males than that of females. The contribution of cod to the diet of grey seals foraging in the cod overwintering area is much greater than has been reported elsewhere.

Diurnal fluxes of CO2 and N2O from cattle-impacted soil and implications for emission estimates

Short-term diurnal changes in emissions of CO₂ and N₂O were determined in a cattle overwintering area during three specific periods of the year. Production of both N₂O and CO₂, as determined with gas chambers buried in soil and spatially distributed changed rapidly, and the general course of fluxes of the two gases was different. CO₂emissions were basically controlled by temperature, and most gas chambers showed the same trends in CO₂ flux, indicating low spatial heterogeneity. In contrast, N₂O emissions were much more spatially heterogeneous and each chamber had its own time course of emission; therefore, the relationship between flux and temperature was more complicated for N₂O than CO₂. For estimating gas emissions over long periods, we strongly recommend the use of frequent emission measurements during periods of high gas fluxes.