The colonization preference and population trends of larval fig psylla, <Emphasis Type="Italic">Homotoma ficus</Emphasis> L. (Hemiptera: Homotomidae)

The colonization preference and population trends of larval fig psylla Homotoma ficus L. were studied in Bursa, northwestern Turkey, from March 2000 to July 2001. Homotoma ficus overwintered at the egg stage on terminal buds and lenticels of shoots. Larval emergence occurred on 30th and 11th March in 2000 and 2001, respectively. Degree-day (DD) accumulations since 1st January indicate that the emergence of first larvae averaged 47 DD based on the larval developmental threshold of 10.9°C. Although the population trends of Homotoma ficus larvae were affected by temperature and rainfall, there was only significant relationship between larval abundance and temperature. The first instar larvae significantly preferred the bottom and the inside stipule of leaves. The second instar larvae distributed not only on expanding green tissues but also on both the upper and lower surface of leaves corresponding to the fig bud development period. Third to fifth instars colonized significantly greater on the bottom of leaves compared with the stipule and upper surface. In addition, significant linear relationship was found between fig phenology and cumulative larval counts. The importance of the colonization preference of larval instars and the use of fig phenology as well as DD for timing of insecticide treatments are discussed.     

Molecular typing and cdt genes prevalence of Campylobacter jejuni isolates from various sources

The genetic diversity of 168 Campylobacter jejuni isolates originating from human (n = 30), cattle (n = 36), sheep (n = 44), dog (n = 35), and poultry (n = 21) and cdt genes prevalence of the isolates were investigated. To determine the genetic diversity of these strains, random amplified polymorphic DNA–polymerase chain reaction (PCR) using a random primer (M13) was performed. The numbers of genotypes determined in human, cattle, sheep, dog, and poultry isolates were 19, 18, 17, 18, and 6, respectively. To find out the prevalence of cdt genes in C. jejuni isolates simultaneously, a multiplex PCR was performed. The prevalence of the separate cdt genes was found to vary from 69% to 100% for cdtA, 92% to 100% for cdtB, and 39% to 98% for cdtC. These rates without host discriminating were 95%, 98%, and 93% for cdtA, cdtB, and cdtC, respectively. The prevalence of all three cdt genes in strains originating from human, cattle, sheep, dog, and poultry were 87%, 67%, 84%, 89%, and 39%, respectively. These results showed the relatively high genetic heterogeneity and variation of cdt genes among C. jejuni isolates from various sources except for poultry isolates. This study gives baseline data on molecular characterization of C. jejuni strains from different sources.     

Estimation of heritability of feeding behaviour traits and their correlation with production traits in Finnish Yorkshire pigs

A major proportion of the costs of pork production is related to feed. The feed conversion rate (FCR) or residual feed intake (RFI) is thus commonly included in breeding programmes. Feeding behaviour traits do not directly have economic value but, if correlated with production traits, can be used as auxiliary traits. The aim of this study was to estimate the heritability of feeding behaviour traits and their genetic correlations with production traits in the Finnish Yorkshire pig population. The data were available from 3,235 pigs. Feeding behaviour was measured as the number of visits per day (NVD), time spent in feeding per day (TPD), daily feed intake (DFI), time spent feeding per visit (TPV), feed intake per visit (FPV) and feed intake rate (FR). The test station phase was divided into five periods. Estimates of heritabilities of feeding behaviour traits varied from 0.17 to 0.47. Strong genetic correlations were obtained between behaviour traits in all periods. However, only DFI was strongly correlated with the production traits. Interestingly, a moderate positive genetic correlation was obtained between FR and backfat thickness (0.1–0.5) and between FR and average daily gain (0.3–0.4), depending on the period. Based on the results, there is no additional benefit from including feeding‐related traits other than those commonly used (FCR and RFI) in the breeding programme. However, if correlated with animal welfare, the feeding behaviour traits could be valuable in the breeding programme.     

Some characteristics of an avocado strain of Tobacco mosaic Virus

An isolate of tobacco mosaic virus (TMV-A) was obtained from healthy and sunblotch-infected avocado (Persea americana) seedlings. TMV-A resembled common TMV in particle morphology, RNA size and coat protein molecular weight. TMV-A coat protein differed from common TMV coat by a minimum of 22 amino acid exchanges including the presence of one methionine, and by the absence of cysteine. Spur formation between the precipitation lines of TMV, TMV-A and a TMV antiserum indicates certain differences among the antigenic determinants of these two strains.     

The role of chicken IL-1β, IL-6 and TNF-α in the occurrence of amyloid arthropathy

In this study, the roles of IL-1β, IL-6 and TNF-α in amyloid arthropathic chickens with variable amounts (severe, moderate and mild) of amyloid accumulation were investigated. The presence and the levels of cytokines were evaluated in serum and in joint tissues by using ELISA and immunohistochemistry, respectively. One hundred brown layer chicks were allocated into four groups and intra-articular injections of Freund’s adjuvant were used to induce amyloid arthropathy in Groups II, III and IV. Vitamin A in group II, and methylprednisolone in Group IV were added to enhance and to reduce the severity of amyloidosis, respectively. At the end of the study, a positive correlation was observed among the incidence and severity of amyloidosis, the serum amyloid A levels and the IL-1β values both in the serum and tissues. Elevation in the tissue TNF-α levels in parallel with the severity of amyloidosis has also been noted. As a conclusion, IL-1β appears to play an important role in avian AA amyloidosis either alone or in combination with TNF-α. Further investigation is needed for understanding the role of the pro-inflammatory cytokines in avian AA amyloidosis.