Developmental Biology and Effects of Adult Diet on Consumption,Longevity, and Fecundity of Colaspis crinicornis (Coleoptera: Chrysomelidae)

The chrysomelid beetle Colaspis crinicornis Schaeffer (Coleoptera: Chrysomelidae) occurs primarily in the Great Plains region of the United States. Little is known about the biology and ecology of this species, but over the last decade, it has become increasingly common in the corn, Zea mays L., and soybean, Glycine max (L.) Merrill, agroecosystem of southeastern Nebraska. As part of a larger comprehensive project to understand the natural history and pest potential of this species, laboratory experiments were conducted to study the developmental biology, morphological characters of immature stages, and the effect of adult diet on consumption, longevity, and fecundity. Females readily deposited egg clusters in the soil, and percentage egg hatch was high under laboratory conditions. Larvae and pupae were confirmed to be soil-dwelling stages. C. crinicornis has relatively short egg, pupal, and adult stages with the majority of its life cycle spent in the larval stage. Results of choice and no-choice adult feeding experiments indicate that diets of corn or soybean leaves did not significantly affect consumption, longevity, or fecundity of adult C. crinicornis, suggesting that corn and soybean leaves are similarly suitable food sources for adults. The ability to effectively utilize tissues from very different plant families as adult food sources suggests that C. crinicornis is polyphagous in the field.     

Measurement of ammonia volatilization loss using a dynamic chamber technique: A case study of surface-incorporated manure and ammonium sulfate in an upland field of light-colored Andosol

The present study aimed to elucidate ammonia (NH₃) volatilization loss following surface incorporation (0–15 cm mixing depth) of nitrogen (N) fertilizer in an upland field of light-colored Andosol in central Japan. A dynamic chamber technique was used to measure the NH₃ effluxes. Poultry manure, pelleted poultry manure, cattle manure, pelleted cattle manure and ammonium sulfate were used as N fertilizers for basal fertilization to a bare soil with surface incorporation. All three experiments in summer and autumn 2007 and in summer 2008 showed negligible NH₃ volatilization losses following the application of all N fertilizers with the same application rate of 120 kg N ha⁻¹ as total N; these negligible losses were primarily ascribed to chemical properties of the soil, that is, its high cation exchange capacity (283 mmol_c kg⁻¹ dry soil) and relatively low pH(H₂O) (5.9). In addition, the surface incorporation, the very small ratio of ammoniacal N to total N for the manure, and the decrease in soil pH to ≤5.5 following applications of ammonium sulfate were also advantageous to the inhibition of NH₃ volatilization loss from the field-applied N fertilizers.     

Airborne nitrogen load in Japanese and Chinese agroecosystems

The objective of this review is to make current knowledge on the nitrogen (N) load throughout the atmosphere (airborne N load) available to readers, with special emphasis on Japanese and Chinese agroecosystems. Key species of airborne N are ammonia, nitrogen dioxide, nitrogen oxide, nitric acid, nitrous acid and particulate ammonium and nitrate. Organic N also exists in the atmosphere. The main processes in terms of the airborne N load involve emission, atmospheric transportation and transformation, atmospheric deposition and environmental impacts. Agricultural activities are the largest emitters of ammonia through emissions mainly from livestock waste and field-applied N fertilizers. The ammonia emissions in China in 1995 from chemical fertilizers and organic fertilizers, such as animal excreta, were estimated to be 3.56 and 2.04 Tg N year⁻¹, respectively, and the emissions in Japan were 0.059 and 0.069 Tg N year⁻¹, respectively. The most fundamental causes of the airborne N load in relation to Japanese and Chinese agriculture were intensive livestock farming in Japan and over use of N fertilizers in China. However, agroecosystems are also a sink for airborne N. Atmospheric N deposition was up to 20 and 60 kg N ha⁻¹ year⁻¹ in Japan and China, respectively. The unrelenting load of airborne N continues in Japan and China. The development of a simple, but accurate method to determine the dry deposition flux that is applicable to simultaneous and multipoint observations would be valuable. The establishment of cross relationships among in situ observations, remote sensing and numerical modeling is also needed to cope with the issue by assessing the actual status, predicting the future status and working out effective measures.     

Temperature determines growth rates of larval round herring Etrumeus teres in the Pacific coastal waters off southern Japan

Seasonal variation in daily growth rates in the early and middle larval stages of round herring Etrumeus teres were largely determined by the sea temperatures experienced by hatch-date cohorts in the Pacific coastal waters off southern Japan. Round herring larvae were collected by purse seining in the coastal waters of central Tosa Bay. A total of 451 larvae were aged by reading daily rings in otoliths. Individuals within a range of 2–5 hatch dates were grouped as hatch-date cohorts. We selected 16 cohorts that hatched during September 2000 and March 2002 and calculated mean widths of otolith growth increments for each cohort during the first feeding stage (W _FF, increments 1–5) and the maximum increment width in the middle larval stage (W _MAX). Seasonal variation in mean W _FF and W _MAX among the 16 cohorts was largely (80–90 %) explained by the sea temperature in the bay. These results indicate that temperature was a predominant determinant of larval growth rates; other environmental factors, such as food availability, did not substantially affect growth rates of round herring larvae in coastal waters along the subtropical Kuroshio Current off southern Japan.     

Experimental infection of enterotoxemic Escherichia coli associated with porcine edema disease and its pathologic characteristics in the intestine

Edema disease (ED) has become frequent in Japan, but no effective method for experimental infection has been developed. We report here the use of a capsule that resistant against gastric digestion to induce the ED in piglets. Four 21-day-old piglets were used. Shiga toxin 2e-producing Escherichia coli (STEC) cell pellet was encapsulated and administered orally. Two pigs received 1.0x10(10) CFU for two days, and the others received 3.9x10(8) CFU for three days. The high-dose group caused the typical clinical ED signs (palpebral edema or neurologic impairment). Eosinophil infiltration, swollen lymphoid follicles, and edema were observed in the ileum. The kidney had the thrombus in the glomerulus.     

Decreasing traits of fecal immunoglobulin A in neonatal and weaning piglets

The concentration of fecal secretory immunoglobulin A (sIgA) in neonate and weaning piglets was measured daily from 1 day after birth to 50 days of age. The concentration of fecal sIgA started from the level of 10(4) microg/g wet feces 1 day after birth and then increased to a maximal value of up to 10(5) microg/g within a few days of birth. The values constantly declined to between 10(1) and 10(2) microg/g for the next 10 days and were relatively constant until weaning. The level of sIgA in the feces remained very low until at least 50 days of age. The vulnerability of pre- or post-weaning piglets can be explained, at least in part, by this low level of sIgA in the intestine.     

The effect of colostrum ingestion during the first 24 hours of life on early postnatal development of piglet immune systems

It has been suggested that colostrum is important not only for direct protection from pathogens but also for proper development of immune systems in piglets. In this study, we focused on the effect of colostrum ingestion during the first 24 h of life on early postnatal development of piglet immune systems. Thirty‐six piglets from five litters were divided into colostrum‐fed (CoF) and colostrum‐deprived (CoD) groups. The former group was allowed to suckle normally while formula milk was fed to the latter group during the first 24 h of life. At the weaning period, the concentrations of fecal immunoglobulin (Ig) A and plasma IgG as well as the number of blood leukocyte subsets were analyzed. Fecal IgA and plasma IgG concentrations in the CoF group were more than twice as high as those in the CoD group (P < 0.01). In addition, the number of blood B cells was significantly higher in the CoF group than that in the CoD group (P < 0.05). This study demonstrates that colostrum ingestion during the first 24 h plays a significant role in early postnatal development of both mucosal and systemic immunity of piglets.     

Probiotic supplementation improves reproductive performance of unvaccinated farmed sows infected with porcine epidemic diarrhea virus

We investigated if probiotic supplementation could improve the health and reproductive performance of unvaccinated lactating sows infected with porcine epidemic diarrhea (PED) virus. Twenty unvaccinated pregnant sows were equally allocated to probiotic‐supplemented (P) and control (C) groups. For the experiment, 15 g/day of probiotic compound BIO‐THREE PZ was given to P sows. Reproductive performance was checked daily. The number of neonates fostered by each sow was maintained at eight throughout the experiment. Individual milk production post‐parturition was measured twice. Milk protein and fat ratios were determined by a milk analyzer. Total immunoglobulin (Ig) A and G concentrations were measured by ELISA. At day 7 post‐parturition, the body weight of P sows was 10 kg higher than that of C sows, and at day 3 post‐parturition, P sows produced more milk (+2 kg) and had a higher IgA concentration in whey than did C sows (p < .05). Finally, unlike C sows, P sows tended to return to estrus faster, and had larger piglets at birth with a lower mortality percentage during early days of suckling. In conclusion, probiotic compound BIO‐THREE PZ helped strengthen the immune system of unvaccinated, PED‐infected sows and improved their reproductive performance.