Excessive acid deposition causes soil acidification, and changes the soil microhabitat, thus affecting the survival and reproduction of soil organisms. Folsomia candida (Collembola, Isotomidae), as a model organism, is widely used to assess the chemical toxicity in soil, and its avoidance response can indicate the environmental changes. In this study, we used Folsomia candida to assess the risks of acid deposition on soil ecosystems. Different pH (3.0, 3.5, 4.0, 4.5, 5.0, and 5.5) treatments were set up in petri dish experiments, and the avoidance behavior of Folsomia candida was measured after 12, 24, and 48 h exposure to the pH conditions. The results indicated that (1) both the exposure duration and pH level influenced avoidance behavior of collembolan. (2) After 12 h exposure, most of the individuals showed avoidance behavior but without significant differences among the treatments. (3) After 24 h exposure, significant avoidance behavior was observed at pH 3.0, 3.5, and 4.0. (4) After 48 h exposure, avoidance behavior was found in all treatment conditions except for pH 5.5. This study clarified the direct responses of soil fauna to acid deposition, and indicated that both pH and length of exposure influenced the avoidance behavior of Folsomia candida. During the experimental period, the collembolan reacted negatively and showed consistent avoidance behavior at pH 3.0, 3.5, and 4.0. Reversed avoidance behavior was apparent between pH 4.5 and 5.0 and not observed at pH 5.5, indicating that the latter was the preferred pH environment.

土壤微塑料污染已引起国内外学者的广泛关注.但关于次生微塑料在土壤动物食物链上的迁移及其毒理效应的研究较少.为探究次生微塑料的生物传递效应,本试验以同步化14 d(幼虫)和28 d(成虫)的土壤白符跳(Folsomia Candida)为供试生物,将废料(塑料类废料混合物)、保温棉、麦麸保温棉混合和细保温棉经黄粉虫(Tenebrio molitor Linnaeus)降解后形成的4种不同次生微塑料产物作为处理因子,研究次生微塑料对土壤跳虫生物学的影响.结果发现:1)第7天,所有跳虫开始蜕皮,喂食保温棉、麦麸保温棉和细保温棉组的幼虫死亡率分别为1.67％、1.67％和5％;2)第14天,跳虫蜕皮量增多,保温棉和细保温棉组的幼虫死亡率分别为6.67％和5％,各组成虫产卵量剧增,喂食酵母菌的对照组产卵率显著高于处理组;3)第28天,蜕皮量增势趋缓,除废料组外,各组幼虫开始产卵且无死亡现象发生;4)与处理组相比,对照组中跳虫的蜕皮量、产卵量和生物量都是最高的,且体长变化显著(P＜0.05).综上,研究结果将进一步完善次生微塑料对土壤动物毒理效应的基础数据,为土壤环境中的次生微塑料的生态风险评价提供理论依据.

为了找出较为适宜上海青生长的栽培基质,利用腐叶土、泥炭土、蛭石、珍珠岩、椰糠5种材料混配成不同的基质类型,并设置添加或不添加微生物菌剂处理,比较试验基质理化性质的差异及其与微生物菌剂协同作用对上海青生长的影响.结果显示:不同基质之间除通气孔隙度外,理化性质均存在显著差异,且其对上海青生长指标有极显著影响(p<0.001);添加菌剂对基质理化性质没有显著影响,但同一基质类型中添加菌剂使上海青鲜重提高了24％～153％,能显著促进上海青的生长.上海青的生长指标与基质pH值和EC值显著正相关,与总孔隙度、持水孔隙度显著负相关.本研究认为较适合上海青生长的栽培基质为腐叶土+菌剂、腐叶土+泥炭土+菌剂.

为探索防治桔小实蝇的新途径,开展了辽细辛提取物对桔小实蝇成虫的引诱作用研究及田间防治试验.结果表明:辽细辛提取物对桔小实蝇成虫有强烈的引诱作用;辽细辛提取物能有效降低杨桃园桔小实蝇成虫种群数量,与对照区相比,防治区虫果率大大降低,防治效果达90％以上;用GC-MS方法测定辽细辛提取物的化学成分,其中左旋-β-蒎烯、左旋-α-蒎烯、杜仲酮、3,5-二甲氧基甲苯、黄樟脑、甲基丁香酚、3,4,5-三甲氧基甲苯、肉豆蔻醚等8种成分的相对含量较高,均大于2％.

[目的]初步了解惠州地区桔小实蝇的野生寄主植物.[方法]以象头山、罗浮山等为中心,调查该地区内自然生长的植物上桔小实蝇的为害情况,将发现的桔小实蝇成虫或虫果带回实验室进行镜检,为害程度则根据受害率进行分级.[结果]桔小实蝇的寄主植物19科41属68种;其中桃金娘科和芸香科寄主植物受害程度最高,桑科寄主植物种类最多.各种植物的受害期不同,并在其中转移为害,世代繁衍.[结论]该研究为桔小实蝇防控提供理论依据.