金霉素和灭蚁灵的几种合剂对五种常见白蚁的毒力对比

通过三种抗生素对几种常见白蚁毒力的实验室生物测定,综合结果发现盐酸金霉素对白蚁肠内原生动物的毒力相对较优,可以用作杀白蚁剂配方中的有效组成成份。本试验的目的在于从一些金霉素和灭蚁灵的合剂中选择可用于防治白蚁的含抗生素成份的最佳有效配方。     

两种水生植物对抗生素污染水体的修复作用

采用水培方法,通过检测水样中氨苄青霉素（Ampicillin）、盐酸四环素（Tetracycline）、盐酸土霉素（Oxytetracycline）和盐酸金霉素（Chlortetracycline）含量的动态变化,确定水生植物大漂（Pistia stratiotes）和凤眼莲（Eichhornia crassipes）对水体中抗生素的清除作用。结果显示：①在系列高浓度（10～50 μg/mL）抗生素的条件下,凤眼莲去除水中盐酸金霉素与盐酸土霉素的效果优于大漂;②对于采集的污水（抗生素浓度＜2.5 μg/mL）,培养72 h后,大漂和凤眼莲对盐酸四环素的去除率分别达80%和90%以上,对氨苄青霉素的去除率分别达80%和70%以上。大漂和凤眼莲对4种抗生素污染的水体均表现出不同程度的修复功能,特别是凤眼莲效果更佳,可作为去除水体抗生素污染的首选材料。     

黑胸散白蚁和台湾乳白蚁对镇江地区几种常见木材品种的取食偏好性研究

【目的】本文研究了黑胸散白蚁Reticulitermes chinensis和台湾乳白蚁Coptotermes formosanus对镇江几种常见木材树种的取食偏好性,分析了白蚁种类和木材品种对白蚁取食偏好性和死亡率的影响,以期为本地区白蚁治理及预防提供科学依据。【方法】采取白蚁非选择性取食试验,研究两种白蚁分别取食香樟Cinnamonum campora、银杏Ginkgo biloba、水杉Metasequoia glyptostrodoides、垂柳Salix babylonica、广玉兰Magnolia grandiflora、枇杷树Eriobotrya japonica、马尾松Pinus massoniana 7种树种食料的取食偏好和死亡率,取食偏好采用白蚁取食率,即每克白蚁每天取食量(mg)评价。试验数据采用多因素方差分析。【结果】方差分析结果表明,白蚁种类和不同木材对白蚁取食率和死亡率均影响显著。在供试的7种木材中,黑胸散白蚁最喜食垂柳和马尾松,其取食率分别为31.46和30.59 mg;台湾乳白蚁最喜食马尾松、水杉和银杏,其取食率分别为26.53、21.82和21.81 mg。两种白蚁对银杏、垂柳、广玉兰这3种木材的取食率有显著差异,而对其他4种木材的取食率差异不显著。【结论】白蚁取食率和死亡率受白蚁种类和木材品种影响明显。7种供试木材中,两种白蚁都对马尾松显示出明显偏好,且死亡率最低。     

混合稀土及化学药物添加剂与抗生素联合应用的抗菌效果测定

采用试管液体法在测定混合稀土及2种化学药物添加剂喹乙酸、阿散酸单独抗菌活性的基础上将它们与常用抗生素金霉素、土霉素进行组合联用,测定其联用后的抗菌效果。结果表明,混合稀土、阿散酸与金霉素、土霉素联合应用后呈相加作用或无拮抗作用。喹乙酸与金霉素、土霉素联合作用后有较好的协同抗菌作用。试验结果对于畜牧业生产中将化学药物添加剂与抗生素配合使用具有一定参考价值。     

六种常见抗生素对小白菜种子萌发及生理特性的影响

以小白菜为受试生物,研究了6种常用抗生素(四环素、土霉素、金霉素、强力霉素、氯霉素和磺胺二甲嘧啶)对小白菜种子萌发、根(芽)伸长、可溶性蛋白及抗氧化酶系统的毒理效应。结果表明,0.5~5 mg·L-1抗生素胁迫下,小白菜种子的发芽率无显著变化,随着抗生素暴露浓度的增加,小白菜种子的发芽率受到了显著抑制;抗生素暴露浓度与小白菜根(芽)伸长抑制率之间具有良好的剂量效应关系。由抗生素对小白菜根长的半抑制效应浓度(EC50)可知,6种抗生素对小白菜种子萌发的毒性大小依次为:磺胺二甲嘧啶氯霉素金霉素四环素强力霉素土霉素。实验浓度范围内的抗生素对小白菜幼苗体内可溶性蛋白含量具有显著的诱导效应,且各处理组间差异显著。此外,抗生素的胁迫破坏了小白菜幼苗体内的抗氧化防御系统的平衡。     

金针虫室内毒力测定方法筛选

【目的】为了探索适用于金针虫的防治药剂室内毒力测定方法。【方法】笔者以细胸金针虫Agriotes fusicollis Miwa 3龄幼虫为试虫,分别采用浸虫法、土壤混药法和食料浸渍法,测定了多种杀虫剂对试虫的室内毒力。并从试验方法的灵敏性、试验结果的规律性和可重复性,以及试验操作过程的简便性等方面,全面分析和比较了3种毒力测定方法的优、缺点,评价了3种毒力测定方法在地下害虫金针虫室内毒力测定方面的应用前景。【结果】3种方法各有其优、缺点。土壤混药法灵敏性高,但操作过程复杂,试虫死亡与否不易辨别;食料浸渍法结果可靠,但对食料的要求非常严格;浸虫法灵敏性稍低,但可重复性强,操作简便易行,死亡标准易确定,并可同时处理较大量试虫。【结论】3种毒力测定方法均可用于该虫的毒力测定,而从应用前景方面来看,浸虫法更易得到推广应用。但还应根据试验目的和供试药剂的不同选择不同的毒力测定方法。     

三株螺原体对抗生素敏感性的体外测定

对我国新分离的两个螺原体和典型的柑桔僵化病螺原体,在体外条件下对10种抗生素的敏感性进行了测定;其敏感程度用最小生长抑制浓度(MIC)和最小致死浓度(MBC)表示。结果表明,红霉素、四环素、土霉素等有较强的生长抑制和致死作用;其次是氯霉素、夹竹桃霉素、庆大霉素;作用较弱的有链霉素,新霉素、卡那霉素;青霉素在试验浓度范围内(0.01—2000μg/ml)无作用。三株供试菌中,以柑桔僵化病螺原体(Sc189)对10种抗生素最敏感,新分离的两个螺原体CH-1和CB-2的敏感性相似。同时,不同培养时间对MIC测定     

三株螺原体对抗生素敏感性的体外测定

对我国新分离的两个螺原体和典型的柑桔僵化病螺原体,在体外条件下对10种抗生素的敏感性进行了测定;其敏感程度用最小生长抑制浓度(MIC)和最小致死浓度(MBC)表示。结果表明,红霉素、四环素、土霉素等有较强的生长抑制和致死作用;其次是氯霉素、夹竹桃霉素、庆大霉素;作用较弱的有链霉素、新霉素、卡那霉素;青霉素在试验浓度范围内(0.01—2000μg/ml)无作用。三株供试菌中,以柑桔僵化病螺原体(Sc189)对10种抗生素最敏感,新分离的两个螺原体CH-1和CB-2的敏感性相似。同时,不同培养时间对MIC测定     

烯啶虫胺肠衣饵剂对黑翅土白蚁的防治效果

[目的]为了开发一种高效环保型白蚁饵剂.[方法]选定烯啶虫胺和溴虫腈对黑翅土白蚁Odontotermes formosanus进行室内毒力测定,根据室内毒力测定结果筛选毒力较高药剂进行驱避试验,并制备3种不同剂量的肠衣饵剂,开展室内白蚁毒杀效果试验和园林白蚁防治效果试验;选用合适剂量肠衣饵剂进行堤坝黑翅土白蚁诱杀试验,并用挖巢法检测肠衣饵剂对堤坝黑翅土白蚁的诱杀效果.[结果]1.6tg/mL烯啶虫胺处理黑翅土白蚁72 h后校正死亡率达100％,16 μtg/mL溴虫腈处理72 h后黑翅土白蚁校正死亡率也达到100％.室内毒力测定结果表明烯啶虫胺对黑翅土白蚁的LC5o值低于溴虫腈,100 μtg/mL烯啶虫胺处理8h后对黑翅土白蚁无显著驱避作用.3种剂量烯啶虫胺肠衣饵剂处理72 h后,黑翅土白蚁校正死亡率均在60％以上.将不同剂量的烯啶虫胺肠衣饵剂投放到园林中45 d后,肠衣饵剂基本被食空,施药点周围无白蚁及活动迹象.在福建省水库大坝周围投放60 μtg/g烯啶虫胺肠衣饵剂,3个月后肠衣饵剂未发霉且基本被食空,6个月后挖巢发现蚁道内无黑翅土白蚁活动,白蚁巢体出现死亡和坍塌情况.[结论]60 μg/g烯啶虫胺肠衣饵剂对园林和堤坝中的黑翅土白蚁具有良好的诱杀效果,是一种高效环保型白蚁肠衣饵剂.     

不同药剂防治园林植物家白蚁试验

用五种杀白蚁药剂对家白蚁进行室内毒力测定结果表明,锐劲特、毒死蜱、溴氰菊酯、辛硫.灭扫利对家白蚁的直接毒杀效果优于氯丹,且前三种药剂的传递毒杀效率也优于氯丹;而室外抗虫蛀蚀试验结果显示,毒死蜱对林木被蛀蚀的保护能力最强。     

The effect of aureomycin on the growth and metabolism of the pig

The effect of dietary aureomycin on the growth of the pig has been studied under conditions of full-feeding and equalized feed intake. The growth response to aureomycin appeared to be dependent upon an increased daily feed intake. Such factors as hemoglobin level, efficiency of feed utilization, nitrogen balance, and energy balance did not seem to be influenced by feeding aureomycin under the conditions imposed by this experiment.     

Laboratory evaluation of bistrifluron, a benzoylphenylurea compound, as a bait toxicant against Coptotermes formosanus (Isoptera: Rhinotermitidae)

Bistrifluron, a benzoylphenylurea compound, was evaluated with regard to its efficacy against workers of Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae) by using three laboratory tests. In the no-choice feeding test, the mortality of bistrifluron-treated worker termites was significantly higher than that of termites exposed to the same concentrations of hexaflumuron (e.g., 6 wk at 500 ppm, 4 wk at 5,000 ppm, and 2 wk at 50,000 ppm) and untreated controls. Bistrifluron showed higher dose dependence and a faster speed of action than hexaflumuron. Both bistrifluron and hexaflumuron had feeding-deterrent effects at 5,000 ppm in the two-choice feeding test, although the mortality of worker termites exposed to bistrifluron or hexaflumuron at 5,000 ppm was not significantly different from untreated controls. In the allogrooming inhibition test, to examine effects of bistrifluron on allogrooming behavior of termites, termite movement was affected at 1 wk before termites died when exposed to 5,000 ppm bistrifluron. These results indicate bistrifluron is effective as a bait toxicant at 5,000 ppm; however, bistrifluron may cause some feeding repellency at > or = 5,000 ppm.     

Utilizing rabbit immunoglobulin G protein for mark-capture studies on the desert subterranean termite, Heterotermes aureus (Snyder)

Mark-capture dispersal studies were conducted to investigate the feasibility of marking the southwestern desert subterranean termite, Heterotermes aureus (Snyder) with rabbit immunoglobulin G (IgG). In turn, short-range dispersal patterns of H. aureus were measured across a 20-m diameter desert landscape at three distinct field locations. Each location consisted of 51 termite feeding stations containing corrugated cardboard. The central feeding station (CFS) at each location was impregnated with rabbit IgG. A circular grid was then constructed around each CFS that consisted of 50 additional unmarked cardboard feeding stations strategically placed around the CFS at distances of 1.5, 2.0, 4.0, 7.0 or 10.0 m. Termites self-marked with rabbit IgG by feeding on the marked bait. The CFS and the 50 peripheral feeding stations were sampled for marked termites twice at each location 17–65 days after the marked bait was placed at the CFS to determine the spatial dispersal patterns of H. aureus within each research grid. Termites that self marked by feeding on rabbit IgG marked bait were detected by an anti-rabbit IgG enzyme-linked immunosorbent assay (ELISA). Generally, the CFSs contained the highest frequency of marked termites with 28.0% of the individuals assayed from the CFSs containing rabbit IgG. Over the course of the study, 39 of the unmarked peripheral feeding stations contained at least one marked termite. Of the termites assayed from the peripheral stations (n = 2,955), 124 or 4.2% of the individuals contained the mark. The average distance traveled by the marked termites collected at the peripheral feeding stations was 5.7 ± 3.3 m from the CFSs. We also examined single nucleotide polymorphisms (SNPs) from termites collected at each field site. Data indicated that each field site were genetically distinct and therefore non-related termites. We discuss the advantages and limitations of marking termites with rabbit IgG for dispersal studies.     

Formyltetrahydrofolate synthetase gene diversity in the guts of higher termites with different diets and lifestyles

In this study, we examine gene diversity for formyl-tetrahydrofolate synthetase (FTHFS), a key enzyme in homoacetogenesis, recovered from the gut microbiota of six species of higher termites. The "higher" termites (family Termitidae), which represent the majority of extant termite species and genera, engage in a broader diversity of feeding and nesting styles than the "lower" termites. Previous studies of termite gut homoacetogenesis have focused on wood-feeding lower termites, from which the preponderance of FTHFS sequences recovered were related to those from acetogenic treponemes. While sequences belonging to this group were present in the guts of all six higher termites examined, treponeme-like FTHFS sequences represented the majority of recovered sequences in only two species (a wood-feeding Nasutitermes sp. and a palm-feeding Microcerotermes sp.). The remaining four termite species analyzed (a Gnathamitermes sp. and two Amitermes spp. that were recovered from subterranean nests with indeterminate feeding strategies and a litter-feeding Rhynchotermes sp.) yielded novel FTHFS clades not observed in lower termites. These termites yielded two distinct clusters of probable purinolytic Firmicutes and a large group of potential homoacetogens related to sequences previously recovered from the guts of omnivorous cockroaches. These findings suggest that the gut environments of different higher termite species may select for different groups of homoacetogens, with some species hosting treponeme-dominated homoacetogen populations similar to those of wood-feeding, lower termites while others host Firmicutes-dominated communities more similar to those of omnivorous cockroaches.     

Effect of a lignin-degrading fungus on feeding preferences of Formosan subterranean termite (Isoptera: Rhinotermitidae) for different commercial lumber

The feeding preferences of the Formosan subterranean termite, Coptotermes formosanus Shiraki, for commercial lumber Alaska yellow cedar, Chamaecyparis nootkatensis (D. Don) Spach; yellow birch, Betula alleghaniensis Britton; northern red oak, Quercus rubra L.; redwood, Sequoia sempervirers (D. Don) Endl; and spruce (Picea spp.) were examined to determine whether the presence of the lignin-degrading basidiomycete Marasmiellus troyanus (Murrill) Singer could alter the relative preference of termites for these wood species. In paired choice tests with fungus-inoculated sawdust versus control sawdust, termites showed a strong preference for the fungus-inoculated sawdust for all wood species tested, except for Alaska yellow cedar. In a multiple-choice test using sawdust without fungus, termites showed a very strong preference for red oak sawdust over the other three species. In a paired choice test using fungus-inoculated sawdust, termites showed a preference for redwood over red oak sawdust. In a feeding test using autoclaved wood blocks without fungal decay, there was no difference in termite consumption of birch, red oak, or redwood. The relative preference of termites for redwood increased when blocks were decayed by M. troyanus for 3 and 8 wk. These results indicate that chemical modifications due to fungal decay affected the feeding preference of termites for different commercial lumber.     

Tunnel specificity and forager movement in subterranean termites (Isoptera: Rhinotermitidae and Termitidae)

The movement of foragers of two species of Australian, subterranean, mound-building termites, Coptotermes lacteus (Froggatt) (Rhinotermitidae) and Nasutitermes exitiosus (Hill) (Termitidae), was investigated in their natural habitat using artificial feeding sites along trenches dug to mimic natural forager tunnels that radiate out from the central mound-nests. Termites were dyed by self-feeding on cardboard soaked with histological fat-stains on one or two trenches and then termites were collected from other feeding sites at two and four weeks after the fat-stains were placed. At two and four weeks after marking commenced, 60-75% of marked termites were found in trenches containing the marked paper, and 2-16% were found in trenches on the opposite side of the nest. The proportion of marked termites in a sample was three to eight times greater in the trenches containing the marked paper relative to other trenches. Although difficulties with fat-stains used as markers might explain some of the observed patterns, it is evident that C. lacteus and N. exitiosus foragers do not move randomly between feeding sites in their natural habitat.     

Feeding preference of Coptotermes formosanus (Isoptera: Rhinotermitidae) for gamma-irradiated wood impregnated with benzoylphenylurea compounds under laboratory conditions

The feeding preference of Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae) for 200-kGy gamma-irradiated Cryptomeria japonica D. Don (Japanese cedar) sapwood impregnated with benzoylphenylurea compounds such as hexaflumuron and noviflumuron was examined by three laboratory tests. Although termites were not deterred from feeding on gamma-irradiated wood samples that had been impregnated with hexaflumuron or noviflumuron, termite mortality was significantly higher compared with solvent controls in the no-choice test. All live termites were transferred to paper disks immediately after the no-choice test to investigate changes in mortality with time, and this test also confirmed the effects of hexaflumuron and noviflumuron on worker termites, which showed a significant feeding preference for gamma-irradiated wood. Only the 1480 ppm noviflumuron-impregnated gamma-irradiated wood specimens showed significant differences in mortality in the two-choice test. These results suggest that gamma-irradiated C. japonica wood, which is locally abundant in Japan, may have potential as a bait substrate for benzoylphenylurea compounds.     

A test of seasonal responses to sugars in four populations of the termite Reticulitermes flavipes

Several studies have shown that Reticulitermes termites prefer food with certain types of sugars. However, the specific sugars that were preferred by the termites in each study differed. The difference between the results of these studies might be explained by differences between populations or changes in feeding responses during the active season. To address these variables, we examined the feeding response to a food source food containing glucose, sucrose, or xylose versus a food source without sugar in several populations of termites and observed whether these responses changed during the year. Termites were collected from colonies from four field sites in Missouri during the spring (May and June), summer (July and August), and fall (September and October) and tested for their response to all three sugars under laboratory conditions. Results show there are distinct differences in response to sugars between populations but only a slight seasonal effect.     

Trophic interactions among invertebrates in termitaria in the African savanna: a stable isotope approach

Abstract 1. Termites (Isoptera) in tropical savannas are known as ecosystem engineers, affecting the spatial and temporal distribution of water, carbon, cations, and nutrients through their mound structures. Their mounds, however, also offer habitation to diverse taxa and feeding guilds of other invertebrates; a keystone role that has not been properly quantified. 2. The aim of this study was to explore the ecosystem role of termitaria in determining invertebrate diversity and their potential trophic interactions. We used stable isotopes to distinguish termite‐feeding invertebrates from invertebrates merely living in termite mounds under field conditions. 3. The results suggest that inquiline spiders (Arachnida) do not feed on termites directly, but on other invertebrates within the termitaria that are termitophagous, elevating the spiders three trophic levels higher than the termites. 4. This study is the first to demonstrate food web interactions among inquiline invertebrates with a stable isotope approach. It provides evidence that termites play a keystone role in the system by providing habitat for various, trophically interacting invertebrates. These results illustrate a rather unexplored ecosystem property of savanna termites.     

Termite Feeding by <Emphasis Type="Italic">Gorilla gorilla gorilla</Emphasis> at Bai Hokou,Central African Republic

Though insectivory by large-bodied gorillas may be unexpected, researchers have reported it in all populations of gorillas studied to date. Our study of 2 well monitored groups of western gorillas (Gorilla gorilla gorilla) at Bai Hokou in Dzanga-Ndoki National Park, Central African Republic provides information on frequency and variability of termite consumption (the most commonly eaten insect) as well as some of the first direct observations of the behavior. Pooled data from both groups indicate termite feeding on 34% and 83% of days, through fecal analysis and feeding trails, respectively. Direct observations revealed that termite feeding occurred on 91% of the days for 1 group, in which the silverback fed on termites during 13% of all feeding scans, making termites the most commonly observed food item. The group that had a higher density of termite mounds in its home range consumed termites more frequently than the other group did. A higher proportion of fecal samples from the silverbacks contained termite remains than the ones from adult females and juveniles. Termite consumption was lower during the dry season, but it does not correlate with rainfall, measures of fruit availability, or fruit consumption. Displacements at termite mounds occurred more than expected, indicating that they are a patchy, sought-after food resource. Gorillas did not use tools to extract termites, but they used 2 different techniques to remove them from the cells. Though culture or social traditions may cause the variation in termite consumption across sites, further investigation of termite availability and consumption is necessary to rule out ecological and methodological explanations for observed variations.