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Within-tree distribution of an insect pest is useful to determine sample unit, sampling location, and required sample number for this pest within a tree. This study was conducted to characterize the within-tree distribution pattern and determine an efficient sample unit for eggs of Ricania shantungensis (Hemiptera: Ricaniidae) on a chestnut tree. A total of 60 chestnut trees were randomly selected from chestnut fields in Gongju-Si and Buyeo-Gun, Korea in 2019. For each tree, 12 branches were cut at three vertical heights (low, middle, and high) in four cardinal directions (east, west, south, and north). The cut branches were observed for counting the number of egg masses per 10 cm from the branch tip. Coefficient of variation (CV) and coefficient of determination (r2) were calculated and used to determine an optimal sample unit for eggs of R. shantungensis on chestnut trees. Numbers of R. shantungensis egg masses were not significantly different (P > 0.05) vertically and horizontally within a tree. Based on CV and r2 values, the 50 cm branch tip would be the optimal sample unit for R. shantungensis eggs. Using this small sample unit for sampling of R. shantungensis eggs could be economical and efficient.

Two Grapholita species (G. molesta and G. dimorpha) cause serious losses in apple production by means of direct fruit damage and destruction. These two congeners occurred at similar seasons in the same orchards. Furthermore, the two species occurred in similar population sizes in apple orchards, though G. molesta occurred much more in total occurrence density than did G. dimorpha in a pear orchard. The two species share two major sex pheromone components, (Z)-8-dodecenyl acetate (Z8-12:Ac) and (E)-8-dodecenyl acetate (E8-12:Ac), but differ with regard to the relative mixture ratio necessary to create conditions of maximal attraction. To develop a simultaneous mating disruption (SMD), a mass ratio of 95:5 of Z8-12:Ac and E8-12:Ac was selected due to its high cross-calling activity and subsequent high mating disruption against both species. When the mixture was applied to orchards, it resulted in significant mating disruption against both species. However, mating disruption efficacy was slightly higher in G. dimorpha than in G. molesta. Application dose and dispenser type affected efficacy duration of SMD. In addition, the high density occurrence of G. molesta significantly reduced the SMD efficacy. Using a wax-type of dispenser, an application of SMD in 100 g per hectare dispersed in early spring recorded >90% mating disruption efficacy through the entire growing season against both Grapholita species.

The objective of this experiment was to determine the concentration and digestibility of crude protein (CP) and amino acid (AA) in meat meal (MM), and to compare these values with the respective values in soybean meal (SBM). Six barrows (initial body weight = 66.9 +/- 3.8 kg) surgically fitted with a T-cannula at the distal ileum were allotted to a replicated 3x3 balanced Latin square design with 3 diets and 3 periods. Two experimental diets containing test ingredients as the sole source of AA were prepared to estimate the apparent ileal digestibility (AID) for CP and AA by the direct method. An N-free diet was also prepared to estimate basal endogenous losses of CP and AA. All experimental diets contained 5% chromic oxide as an indigestible index. Each period consisted of a 5-d adaptation period and a 2-d of ileal digesta collection period. Heal digesta samples were collected from 0900 to 1700 on d 6 and 7 of each period. The concentrations of CP, Lys, Met, and Trp in MM and SBM were analyzed to be 64.1, 3.5, 1.1 and 0.6, and 45.6, 2.8, 0.8, and 0.3%, respectively. The AID of all AA except Gly in MM was less (p

All tested Korean populations of the diamondback moth, Plutella xylostella, are known to be resistant especially against pyrethroid insecticides by mutation in its molecular target, para-sodium channel. Moreover, P. xylostella is able to develop resistance against most commercial insecticides. This study was performed to develop an efficient control technique against P. xylostella by a combined treatment of an endoparasitoid wasp, Cotesia plutellae, and a microbial insecticide, Bacillus thuringiensis. To investigate any parasitism preference of C. plutellae against susceptible and resistant P. xylostella, five different populations of P. xylostella were compared in insecticide susceptibilities and parasitism by C. plutellae. These five P. xylostella populations showed a significant variation against three commercial insecticides including pyrethroid, organophosphate, neonicotinoid, and insect growth regulator. However, there were no significant differences among five P. xylostella populations in their parasitic rates by C. plutellae. Moreover, parasitized larvae of P. xylostella showed significantly higher susceptibility to B. thuringiensis. As an immunosuppressive agent, viral ankyrin genes (vankyrins) encoded in C. plutellae were transiently expressed in nonparasitized larvae. Expression of vankyrins significantly enhanced the efficacy of B. thuringiensis against the third instar larvae of P. xylostella. Thus an immunosuppression induced by C. plutellae enhanced the insecticidal efficacy of B. thuringiensis. These results suggest that a combined treatment of C. plutellae and B. thuringiensis may effectively control the insecticide-resistant populations of P. xylostella.

This experiment was conducted to evaluate anti-Salmonella enteritidis (anti-SE) bacteriophage as feed additives to prevent Salmonella enteritidis in broilers. The experimental diets were formulated for 2 phases feeding trial, and 3 different levels (0.05, 0.1 and 0.2%) of anti-SE bacteriophage were supplemented in basal diet. The basal diet was regarded as the control treatment. A total of 320 1-d-old male broilers (Ross 308) were allotted by randomized complete block (RCB) design in 8 replicates with 10 chicks per pen. All birds were raised on rice hull bedding in ambient controlled environment and free access to feed and water. There were no significant differences in body weight gain, feed intake and feed conversion ratio (FCR) at terminal period among treatments (p>0.05). Relative weights of liver, spleen, abdominal fat and tissue muscle of breast obtained from each anti-SE bacteriophage treatment were similar to control, with a slightly higher value in anti-SE bacteriophage 0.2%. In addition, a numerical difference of glutamic-oxaloacetic transaminase (GOT), glutamic-pyruvic transaminase (GPT) and LDL cholesterol level was observed in the 0.2% anti-SE bacteriophage application even though blood profiles were not significantly affected by supplemented levels of anti-SE bacteriophage (p>0.05). In the result of a 14 d record after Salmonella enteritidis challenge of 160 birds from 4 previous treatments, mortality was linearly decreased with increasing anti-SE bacteriophage level (p

Three Holstein steers in the growing phase, each with a ruminal cannula, were used to test the hypothesis that the synchronization of the hourly rate of carbohydrate and nitrogen (N) released in the rumen would increase the amount of retained nitrogen for growth and thus improve the efficiency of microbial protein synthesis (EMPS). In Experiment 1, in situ degradability coefficients of carbohydrate and N in feeds including Korean rice wine residue (RWR) were determined. In Experiment 2, three total mixed ration (TMR) diets having different rates of carbohydrate and N release in the rumen were formulated using the in situ degradability of the feeds. All diets were made to contain similar contents of crude protein (CP) and neutral detergent fiber (NDF) but varied in their hourly pattern of nutrient release. The synchrony index of the three TMRs was 0.51 (LS), 0.77 (MS) and 0.95 (HS), respectively. The diets were fed at a restricted level (2% of the animal’s body weight) in a 3×3 Latin-square design. Synchronizing the hourly supply of energy and N in the rumen did not significantly alter the digestibility of dry matter, organic matter, crude protein, NDF or acid detergent fiber (ADF) (p>0.05). The ruminal NH3-N content of the LS group at three hours after feeding was significantly higher (p0.05). In addition, the purine derivative (PD) excretion in urine and microbial-N production (MN) among the three groups were not significantly different (p>0.05). In conclusion, synchronizing dietary energy and N supply to the rumen did not have a major effect on nutrient digestion or microbial protein synthesis (MPS) in Holstein steers.

Electrical conductivity and thermoelectric power (TEP) of poly (2-Butoxy-5-Methoxy-1, 4-Phenylene Vinylene) films doped with iodine and FeCl 3 are investigated. The FeCl 3 doped film stretched to 2.0 times its original length shows maximum conductivity σ ∥ (RT) = 5.7×10 2 S/cm along the stretched direction. The anisotropy at room temperature for this sample is σ ∥ / σ ⊥ = 50 and it increases upon cooling indicating that the interchain hopping conduction is important. The room temperature TEP value varies with the dopant concentrations but it is independent of the stretching ratios. Temperature dependence of TEP is quasi-linear for all doped samples characteristic to be metallic. The change of ionization potential due to the substituted rings on PPV chain seems to be the origin for the conductivity enhancement when the polymer is doped.