温湿度对松墨天牛越冬幼虫寿命的影响

松墨天牛不仅是一种重要的森林害虫,还是松材线虫病的主要传播者。不同温湿度条件对松墨天牛寿命有较大的影响,实验结果表明:当相对湿度为40%时,在25℃的寿命要长于30℃时的寿命,在30℃的羽化率(20.6±4.9)%和25℃的羽化率(14.8±4.3)%无显著差异;当温度为25℃时,相对湿度90%的寿命要长于相对湿度40%的寿命,相对湿度40%的羽化率(14.8±4.3)%和相对湿度90%的羽化率(24.0±4.9)%差异不显著,说明高湿可以增加越冬幼虫的羽化率。     

Age and growth in southern bluefin tuna, Thunnus maccoyii (Castelnau): Direct estimation from otoliths, scales and vertebrae

In the early 1990s, the spawning biomass of the southern bluefin tuna (SBT) population was estimated to be less than 10% of its historical level. However, major uncertainties surrounding the age composition of the catch confounded the virtual population analysis assessment models. To eliminate these uncertainties, validated estimates of the age composition of the catch were required.We examined scales, caudal vertebrae and sagittal otoliths to determine which structure produced the most accurate age estimates in SBT. Scales proved useful for estimating ages of SBT only up to 4 years. Marginal increment analysis verified that the zones of dense circuli visible on the scales were deposited annually up to this age. In larger fish, the compression of circuli on the margin of scales and high incidence of regenerated scales made estimation of age very difficult. Obvious increments were present on both the vertebrae and otoliths. Age estimates from the two structures matched closely for the first 10 years of life. However, in larger (older) fish the counts diverged, otoliths consistently providing higher age estimates. We determined that annual increments are formed on sagittal otoliths throughout life but that this is not the case in vertebrae, where bands are formed less frequently. Thus, vertebrae were unreliable for estimating age beyond 10 years, which corresponds approximately to the age-at-first maturity.Ages were estimated from otoliths of 1121 fish from throughout the species’ size range. These data indicate that SBT live to at least 40 years of age, twice the longevity previously accepted; that age at recruitment is 1 year, not 2; and that mean age-at-maturity is approximately 11 years, not 7.The age distribution of SBT catches by the Japanese longline fishery in the Tasman Sea indicate that a significant proportion of the SBT population in this area is over 25 years of age and that cohorts spawned in the late 1970s and early 1980s are markedly under-represented in the population. The latter is thought to result from intense exploitation on these cohorts by the Australian surface fishery soon after recruitment.     

Effect of temperature on the developmental time,survival of immatures and adult longevity of Aganaspis daci (Hymenoptera: Figitidae), a natural enemy of Ceratitis capitata (Diptera: Tephritidae)

Longevity, developmental time and offspring survival of parasitoid wasps are decisive in their effective performance as biocontrol agents. Optimum temperature range determines parasitoid survival, development and reproduction. Thus, controlling this abiotic factor is a key to the success of pest management programs. Adult longevity, developmental time from egg to adult and survival of immatures of Aganaspis daci were assessed in the laboratory under different constant temperatures; adult longevity without hosts, but with the provision of water and honey, and developmental time and survival of immatures from host pupae, whose larvae had been exposed to parasitoids. Results showed that longevity depended on temperature decreasing in the range 15–20 °C (36 – 25 days), but was lower in the range 25–35 °C (10 – 7 days). Regarding developmental time from egg to adult and survival of immatures, our results showed that 20 and 25 °C are the most suitable temperatures. At 15 and 30 °C mortality of the immature stages was very high (>90%) or developmental time to adult was very slow (>3 months). Immatures did not survive at 35 °C. We found no significant differences in developmental time to adult or survival of immatures between 20 and 25 °C. The sex ratio of parasitoid progeny was female biased at 25 °C; the proportion of females increased at all cases with temperature. The t_o and K for total development were 8.5 °C and 500 DD, respectively. Our findings provide some guidance for future inundative or inoculative field releases of this parasitoid for the management of Ceratitis capitata in Spain.     

Effect of feeding regime, growth intensity and age at first insemination on performances and longevity of Holstein heifers born during autumn

An experiment was performed on 113 heifers born during three successive autumns (1987, 1988, and 1989) and aimed to study the effect of rearing strategy on performances and longevity. From 4–12 mo of age, heifers were grazing (G) or fed indoors with two levels of a corn-silage based diet (CS) with a high (CSH) or low (CSL) level concentrate. Age at first calving was 24 months (AFC24), but, because of seasonal calving management, some animals calved at 36 months of age (AFC36). From 4–12 mo of age, average daily weight gain (ADG) of G, CSL and CSH heifers was 874, 736 and 890 g/d, respectively. G and CSH heifers had the same ADG from 4–12 mo of age, whereas G and CSL heifers had the same ADG from 4 mo of age until puberty. Puberty was detected for 106 heifers, occurring at 269 (SD = ± 28) d of age at a weight of 286 (± 36) kg. On average, CSH heifers were 28 d younger at puberty (P < 0.001). In AFC24 heifers, fertility after one insemination was higher for CS heifers than for G heifers (77 and 55%, respectively). When heifers were adults, it corresponded to 77 and 96%, respectively. During their 1st lactation, AFC24 (G and CSL) heifers tended to have a higher milk peak than CSH heifers (27.3, 28.8 and 24.7 kg/d, respectively). On average, each cow completed 2.64 lactations (range = 0–7), but this parameter varied significantly (P < 0.05): 2.81 (G), 2.67 (CSL), 2.30 (CSH). Productive life was 852 d long, with significant differences between groups (945, 890 and 663 d for G, CSL and CSH groups, respectively). Culling rate during the first four lactations was around 38%. A deleterious effect of an excessive growth rate between 120 and 300 d, corresponding to body weight varying between 150 and 260 kg, was noted. In practice, this indicates that growth rates should be controlled before puberty, but a high growth rate is possible between puberty and first insemination without major problems.     

Estimation of some productive and reproductive effects on longevity of beef cows using survival analysis

Longevity of beef cows defined as the length of productive life from first calving to culling was estimated in this study. Data from 1800 cows belonging to Hereford, Angus, Simmental, Charolais, Limousin and Blonde d' Aquitaine breeds were analysed using survival method. The results indicate effects of breed, calving season, and calving difficulty on longevity (P < 0.05); however, herd, age of the cow at first calving, sex and weaning weight of their calves did not affect (P > 0.05) the length of productive life. Hereford had significantly greater (10.3 years) estimated length of productive life than Angus (8.1 years), Simmental (7.9 years), and Charolais (7.1 years), which had similar estimated longevity. Limousin (5.9 years) and Blonde d' Aquitaine (5.2 years) were similar in estimated longevity, but less than the other breeds studied. Cows that calved first in spring or summer were estimated to have longer productive life (7.2 years and 9.9 years) and less risk of early culling than those calving in autumn (5.7 years) and in winter (5.1 years). Longer productive life (6.2 years) was estimated across breeds for cows calving without assistance or with a little assistance (6.9 years) compared to those needing veterinary assistance (2.8 years) or having stillbirth (4.6 years). The results highlight that breed, calving season and calving difficulty of beef cows may have important effects on length of productive life. Special attention should be devoted to these effects.     

Development and reproduction of Sancassania polyphyllae (Acari: Acaridae) feeding on entomopathogenic nematodes and tissues of insect larvae

We studied the effect of different food sources, infective juveniles of the entomopathogenic nematodes, Steinernema feltiae and Heterorhabditis bacteriophora (Rhabditida: Steinernematidae, Heterorhabditidae), and tissues from the insect larva, Polyphylla fullo (Coleoptera: Scarabaeidae) or Galleria mellonella (Lepidoptera: Pyralidae), on the development, reproduction and longevity of Sancassania polyphyllae (Acari: Acaridae). We showed that the immature mite stages - protonymph and tritonymph - could develop to the next developmental stage on living or sonicated (i.e., ruptured) S. feltiae or H. bacteriophora. However, the mite larval stage could only develop to the next developmental stage on sonicated infective juveniles of the nematodes. Subsequently, we demonstrated that S. polyphyllae completed development from protonymph to adult on live S. feltiae or H. bacteriophora, whereas all immature stages of S. polyphyllae completed their development from larva to adult on insect tissues. The total developmental period of S. polyphyllae that fed on insect tissues was significantly shorter than those that fed on live infective juveniles. The pre-oviposition, oviposition, and post-oviposition periods and female longevity were not significantly different among the food sources. The total and daily fecundity of S. polyphyllae feeding on P. fullo and G. mellonella was significantly higher than those feeding on S. feltiae and H. bacteriophora, although there was no significant difference observed between P. fullo and G. mellonella or between S. feltiae and H. bacteriophora. The net reproductive rate (R₀) was highest (588.3♀/♀) when S. polyphyllae fed on P. fullo. The longest mean generation time (T₀) occurred on H. bacteriophora (12.6 days) and the shortest occurred on P. fullo (10.5 days). S. polyphyllae, which fed on P. fullo (r_m=0.61) and G. mellonella (r_m=0.55) had the highest intrinsic rate of increase (r_m) compared to mites that fed on S .feltiae (r_m=0.45) and H. bacteriophora (r_m=0.41).     

柑桔潜叶蛾雌成虫寿命,产卵量及产卵行为的研究

在实验室条件下，温度与柑桔潜叶蛾雌成虫寿命的关系可用方程ｙ＝１１．３５１７ＥＸＰ拟合。在１５℃时平均寿命为３２．１天，高温３３℃为９．２天，２０－２５℃为１８．９－１２．１天。２０－２５℃温度范围内，平均每雌成虫产卵量为３８粒上下，３３℃为１１。８粒，１５℃仅可产少量的卵。     

引发处理对番茄种子保存和寿命的影响

用30%PEG溶液和3%KNO3溶液分别对番茄种子进行引发处理,引发处理提高了种子的发芽速度和整齐度。PEG引发处理的种子在室温下保存5.5 a依然保持明显的引发效果,没有表现出比未引发的对照种子衰老快的趋势。对引发种子进行加速老化试验,结果表明:PEG引发种子比未引发的对照种子和KNO3引发种子表现出明显的抗老化能力。与先老化再引发处理相比,先引发再老化处理对种子活力影响较小。     

Serum lipid levels and ApoB gene Xba I and 3'-VNTR polymorphisms in longevous elderly Han population in Zhejiang

AIM: To study the levels of serum lipids and the effects of apolipoprotein B (ApoB) gene Xba I-restriction fragment length polymorphism (RFLP) and 3'-variable-number tandem repeat (VNTR) polymorphism on serum lipid and apolipoprotein levels in longevous elderly Han population in Zhejiang. METHODS: Physical and laboratory examinations were performed on longevous elders, children of longevous elders, normal control people and children of non-longevous elders, and the Xba I-RFLP and 3'-VNTR polymorphism in ApoB gene were genotyped. RESULTS: The serum levels of triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and ApoB were negatively correlated with longevity (P<0.05), while the level of high-density lipoprotein cholesterol (HDL-C) was positively correlated with longevity (P<0.01). The levels of total cholesterol (TC), LDL-C and ApoB were higher and the HDL-C level was lower in the people with Xba I-RFLP X⁺X^- genotype than those in the people with Xba I-RFLP X^-X^- genotype (P<0.01). The levels of TC, TG, LDL-C and ApoB were higher and the HDL-C level was lower in the people with 3'-VNTR large allele than those in the people with 3'-VNTR minor allele (P<0.01). CONCLUSION: High TG, LDL-C and ApoB levels and low HDL-C level are not conductive to longevity. Serum lipid levels in the people with Xba I-RFLP X^-X^- genotype or 3'-VNTR minor allele are healthy and conductive to longevity.