体重与寄主植物对棉铃虫同类相残行为的影响

对棉铃虫Helicoverpa armigera(Hübner)的同类相残进行行为学观测,以分析体重在胜负中作用,以及不同寄主植物情况下,同类相残导致的数量变化。结果表明:棉铃虫同类相残包括试探性攻击、反击、追击、嘶咬、缠绕、取食等过程,其中能否成功缠绕对方是成功的关键。体重在同类相残过程中起到重要的作用,同一龄期,体重大的个体获胜可能性显著大于体重较小的个体。寄主植物的营养状况对同类相残有着显著影响,不适宜寄主植物环境下,同类相残在低龄期即可降低种群数量。     

寄主植物对乌桕黄毒蛾取食量及生长发育的影响

【目的】研究乌桕黄毒蛾Euproctis bipunctapex(Hampson)对5种不同科寄主植物(天仙果Ficus erecta var.beecheyana、拐枣Hovenia acerba、苦槠Castanopsis sclerophylla、杨梅Myrica rubra和杜英Elaeocarpus decipiens)叶片的取食量以及不同寄主植物对乌桕黄毒蛾生长发育和繁殖的影响。【方法】在恒定条件[温度(26±1)℃,相对湿度80%,光周期12L︰12D]下,设置5个处理组,每处理分别投喂不同寄主植物叶片,测定取食量、幼虫历期、存活率、繁殖力等指标。【结果】乌桕黄毒蛾对不同寄主植物的取食量差异显著,苦槠饲喂组最高(2 588.15 mg),杜英饲喂组最低(1 971.33 mg);但对不同植物的日取食量总体趋势相同,随时间呈指数增长,4龄起进入暴食期,4龄、5龄和6龄幼虫取食量占总取食量的80.68%~85.91%。取食不同寄主植物的乌桕黄毒蛾生长发育差异显著,天仙果饲喂组的个体幼虫历期(34.35 d)最短,存活率(60.20%)最高,产卵量(281.33粒/雌)最多,而杜英饲喂组的个体幼虫历期(41.36d)最长,存活率(38.78%)最低,产卵量(215.83粒/雌)较少。【结论】乌桕黄毒蛾虫害防治适期是4龄之前,苦槠和杨梅受乌桕黄毒蛾取食最多,天仙果是乌桕黄毒蛾生长发育的最适寄主植物。     

福寿螺对饵料的选择性研究

研究福寿螺对 8种饵料的选择性 ,结果表明福寿螺对浮萍具有很强的嗜好性 ,对水稻秧苗、狗尾草为负选择 ,其余饵种为正选择 .     

不同寄主植物对马铃薯甲虫的引诱作用

随着马铃薯甲虫不断扩展其分布范围,其对寄主的适应性也在发生变化。在我国,马铃薯甲虫的主要寄主植物是马铃薯、茄子、番茄和天仙子。为进一步明确马铃薯甲虫对不同寄主植物的嗜食程度,研究了以上4种寄主植物对马铃薯甲虫的引诱作用,以及取食量的影响,同时进行了田间寄主选择性的调查。选择性试验结果表明:不同寄主植物对马铃薯甲虫的引诱作用差异显著,其中马铃薯、天仙子引诱作用显著高于茄子和番茄;取食量研究结果表明:马铃薯甲虫各龄期对不同寄主24 h取食量的大小依次为:马铃薯>茄子>天仙子>番茄;1—2龄幼虫取食量小,3—4龄幼虫及成虫暴食寄主叶片,是马铃薯甲虫造成危害的主要阶段。     

草地螟对寄主植物的选择性及其化学生态机制

田间自然条件下,草地螟成虫产卵对不同植物具有明显的选择性,其中灰菜上落卵量最多,占调查总卵量的50%以上;甜菜、大豆上次之,玉米和马铃薯上最少。在室内条件下,草地螟成虫产卵对灰菜、大豆、玉米和马铃薯的选择性与田间调查结果完全吻合。而且,草地螟幼虫的嗜食性与成虫产卵对寄主的选择性是一致的。吸附、收集上述植物的挥发物后进行GC-MS测定,并利用风洞进行了生测。其中灰菜和大豆的主要挥发物成分为反-2-己烯醛、青叶醇、青叶酯、1-十八烯等;玉米和马铃薯的挥发物性成分包括青叶酯、芳樟醇、香叶醇、紫罗酮、1-十八烯。生测结果表明,灰菜的挥发物对草地螟雌蛾引诱力最大,选择系数为78%;大豆苗挥发物对其也有较高的诱虫活性;但玉米和马铃薯几乎无引诱作用。自然生长的4种植物的诱虫结果与其挥发物的诱虫结果相似。这些生测结果与成虫和幼虫选择寄主的一致性反映了草地螟选择寄主行为的化学机制。     

草地贪夜蛾对三种寄主植物的取食选择性及其适应性研究

为了解草地贪夜蛾对玉米、甘蔗和水稻的取食选择性及适应性,分别采用叶碟法和叶面积法在有选择和非选择条件下测定草地贪夜蛾各龄幼虫对3种寄主植物的取食偏好,并通过测定幼虫体重增长速率和蛹重,初步明确草地贪夜蛾对3种寄主植物的适应性。结果表明,草地贪夜蛾在有选择条件下和非选择条件下均表现出对玉米的偏好。但随着龄期的增长对玉米的取食偏好会逐渐减弱,在有选择条件下6龄幼虫在玉米和水稻上的选择取食率无显著差异,分别为32%和23%,在非选择条件下6龄幼虫取食3种寄主植物的叶面积无显著差异。取食3种寄主植物后幼虫体重增长均能与Logisitic生长模型较好拟合,取食玉米的幼虫体重增长速率最快,蛹重也最重。表明了当前新入侵广西地区的草地贪夜蛾种群对玉米的取食偏好要高于对甘蔗和水稻。     

寄主植物对荔枝蒂蛀虫产卵的引诱作用

试验观察荔枝蒂蛀虫Conopomorpha sinensisBradley对寄主植物品种、器官及器官部位的产卵选择性规律。结果表明,与老梢相比,荔枝蒂蛀虫明显倾向于选择嫩梢产卵;4个荔枝品种果枝中以妃子笑上落卵数最多,在淮枝、糯米糍荔枝果实上较少,桂味荔枝上最少;不同的荔枝品种果实气味引诱雌虫产卵的能力不同,其中妃子笑引诱力最强,淮枝、糯米糍引诱力较低,桂味最低;在同一荔枝果实不同部位的落卵量,以果皮上、下两部分较大,全果明显低于果皮上部,而荔枝肉和荔枝核上没有落卵。     

椰子木蛾的产卵节律及其对寄主植物的产卵选择性

【背景】椰子木蛾是近年来新入侵我国棕榈科植物的害虫,研究其产卵习性可为监测和防治该虫提供参考。【方法】在室内条件下,观察、记录了椰子木蛾雌成虫的产卵节律及其对不同寄主植物的产卵选择性。【结果】椰子木蛾最高日产卵量可达34.4粒·头-1,且主要集中在羽化后4 d内产卵,占总产卵量的54.1%;产卵活动主要发生在夜间23:00到次日8:00;在椰子、蒲葵、大王棕、槟榔和散尾葵等寄主植物上的产卵量无显著差异,为89.3~147.7粒·头-1,但产卵位置存在差别。【结论与意义】椰子木蛾雌成虫具有较强的繁殖能力和产卵节律性,且在不同寄主植物上的产卵量一致。     

南方小花蝽对寄主植物的产卵选择性及其卵的保存条件

室内研究南方小花蝽Orius similis Zheng在9种产卵寄主植物(辣椒,豇豆,长寿花,迎春花,黄荆,绿豆芽,棉花,石莲花,太阳花)的嫩茎上的产卵量、孵化率及繁殖系数。结果表明,南方小花蝽对不同产卵植物具有显著的选择差异性。从产卵量看,对辣椒嫩枝选择性最强,其产卵量占总产卵量的23.4%;从孵化率看,产在迎春花嫩茎上的卵的孵化率最高;从繁殖系数看,辣椒嫩枝和迎春花嫩茎作为产卵植物的繁殖系数较高,分别为7.6和12.8;从辣椒嫩枝和迎春嫩茎上的繁殖系数的构成看,两者明显属于2种不同的类型,前者属于高着卵量、低存活率类型,后者属于低着卵量、高存活率类型。对南方小花蝽不同虫态进行了抗寒能力的测定,结果表明南方小花蝽卵的抗寒能力最强,成虫次之,1~2龄若虫最弱。在此基础上做了卵的低温保藏实验,结果表明要保证80%以上的孵化率,最佳保藏条件为8℃下保藏9天。     

寄主植物叶片物理性状对潜叶昆虫的影响

潜叶昆虫广泛分布于鳞翅目、双翅目、鞘翅目和膜翅目中,其幼虫潜入叶片内部生活和取食,是一类用于研究植物-昆虫-天敌种间关系和协同进化的重要模式生物。有些潜叶昆虫是重要农林害虫。相比外食性昆虫,在叶内取食的潜叶昆虫幼虫更易受到叶片物理性状的直接影响。叶片的着生位置、朝向、大小、颜色和表皮毛等直接决定潜叶虫成虫的取食和产卵选择,从而影响幼虫的空间分布和寄主适应。叶片的某些物理性状也会直接影响幼虫的取食行为、生长发育和被寄生率。研究叶片物理性状的防御作用以及潜叶昆虫对这些防御的适应,有助于了解潜叶昆虫-寄主植物的协同进化。另一方面,外界环境和遗传育种都有可能改变植物叶片的物理特性,而对潜叶害虫产生抗性,从而实现潜叶害虫的可持续生态控制。     

Effects of macrophytes on feeding and life-history traits of the invasive apple snail Pomacea canaliculata

1. Biological invasions have become a serious threat to ecosystems worldwide. Various factors can contribute to the success of biological invasion. We examined how different macrophyte food affected feeding and life‐history traits of the invasive herbivorous snail Pomacea canaliculata, and whether differences in snail life‐history traits could explain its successful infestation of agricultural and non‐agricultural wetlands in Asia. 2. We tested five cultivated and five wild semi‐aquatic macrophytes. Snail daily feeding rate varied substantially with plant species, ranging from 1.3% to 22% of its body mass. Snails fed with four (Amaranthus gangeticus, Apium graveolens dulce, Ipomoea aquatica and Nasturtium officinale) of the five cultivated macrophyte species exhibited high survivorship, fast growth and high fecundity. Snails fed with Colocasia esculenta, however, grew poorly, did not reproduce and eventually died. 3. Of the five wild species (Eichhornia crassipes, Ludwigia adscendens, Murdannia nudiflora, Myriophyllum aquaticum and Polygonum hydropiper), M. nudiflora supported a high snail survival, but snails had slower growth and lower fecundity than those reared on the four palatable cultivated species. Snails fed with L. adscendens grew substantially slower than those fed with M. nudiflora, and produced only a small clutch of eggs. Snails fed with E. crassipes, M. aquaticum and P. hydropiper had very low survivorship, grew very little and did not reproduce. 4. We determined six plant properties and their correlation with the feeding, growth and reproduction of the apple snails. Cultivated macrophytes in general had a higher nutritional value and lower physical and chemical defences. Phenolic content was negatively correlated with snail feeding rate, while plant nitrogen and phosphorus contents were positively correlated with snail egg production and growth, respectively. 5. These results indicate that, due to their higher nutritional value and lower chemical and physical defences, cultivated macrophytes are in general desirable for the apple snail which may partly explain its successful invasion into wet agricultural areas in Asia. This snail may also selectively graze poorly defended wild macrophytes in non‐agricultural wetlands, leading to changes in floral diversity and wetland functioning. Management of this and other apple snails with similar life‐history traits should thus focus on the prevention of their further spread.     

不同生境福寿螺(Pomacea canaliculata)的营养成分及其利用价值

为比较不同生境和不同肉色福寿螺的营养成分组成差异以探讨其在综合防治中的潜在利用价值,分析了鱼塘、沟渠和水田3种生境福寿螺以及黑白肉色福寿螺的一般营养成分和氨基酸组成。结果表明:鱼塘福寿螺的水分和粗脂肪含量最高,沟渠福寿螺的灰分含量最高,水田福寿螺的水分、粗脂肪和粗蛋白含量最低,沟渠和鱼塘福寿螺的粗蛋白含量都高于13%,鱼塘福寿螺的总氨基酸、必需氨基酸、呈味氨基酸含量和必须氨基酸指数均最高,但必需氨基酸的比例最低;水田福寿螺的必需氨基酸和呈味氨基酸含量高于沟渠福寿螺,必需氨基酸指数依次是鱼塘>水田>沟渠,白肉福寿螺的总体营养价值较黑肉福寿螺高,福寿螺的总体必需氨基酸组成与鱼粉(CP53.5%)较为接近;在利用中应充分考虑不同生境和不同肉色福寿螺营养组成存在的差异。     

Herbivory on aquatic vascular plants by the introduced golden apple snail (<Emphasis Type="Italic">Pomacea canaliculata</Emphasis>) in Lao PDR

The effect of naturally found densities of the exotic and herbivorous golden apple snail (Pomacea canaliculata) on three dominant aquatic plants – duckweed (Lemna minor), water hyacinth (Eichhornia crassipes) and morning glory (Ipomoea aquatica) – was assessed in a wetland survey and quantified in a field experiment in Laos in southeast Asia. Snail grazing reduced plant biomass, but plant species were differently affected by grazing. Duckweed had almost disappeared after 6 and water hyacinth after 21 days, whereas morning glory remained at 80% of initial biomass after 32 days. Snail growth was lowest on morning glory and, when all plant species were simultaneously presented to snails, this plant was not preferred. We suggest that the negative effect the golden apple snail had on the growth of these plant species in field enclosures is present in the natural environment as well. This new and intense herbivory could have serious negative effects on invaded freshwater ecosystems in this region.     

饥饿胁迫下福寿螺的存活和产卵情况及器官组织损伤观察

【背景】福寿螺是首批被列入我国外来入侵物种黑名单的生物。近年来,有关福寿螺的研究主要集中在生物学特性、农业危害及防控等方面。其中,关于饥饿胁迫对福寿螺的影响亦有报道,但饥饿胁迫造成其器官组织损伤后的表观结构变化尚未见报道。【方法】本文研究了饥饿胁迫下福寿螺的存活和产卵情况,并通过扫描电镜对福寿螺头部和肝脏表面结构进行观察。【结果】福寿螺在饥饿25 d后存活率达90%以上;饥饿组在25 d内平均每缸产卵量为4.00块,明显低于对照组的24.33块,且福寿螺在饥饿12 d后停止产卵。通过扫描电镜观察可见,头部皱缩并有侵蚀絮状物堆叠,肝脏螺旋结构松散,并伴有深浅不一的裂痕和侵蚀状损伤。【结论与意义】短期饥饿（25 d）对福寿螺存活影响不大,但其产卵量受到明显影响,且头部和肝脏存在明显的外表破损。该结果为研究福寿螺入侵机制及防控策略提供了一定的参考。     

A preliminary investigation into the use of the invasive golden apple snail,Pomacea canaliculata (Lamarck, 1822), as a water purifier and food source in the breeding ponds of the oriental weatherloach Misgurnus anguillicaudatus (Cantor, 1842)

This study investigated the feasibility of using an invasive snail, Pomacea canaliculata, as a food source and water purifier for the commercial breeding of the loach Misgurnus anguillicaudatus. The predatory potential of M. anguillicaudatus (3.5–5.5?g) against hatchling snails was evaluated in aquaria and simulated paddy fields. Some hatchling snails left the water to avoid being preyed upon by the loaches, and approximately 10 hatchlings died per day in the presence of five loaches in aquaria, whereas a weaker snail control effect was observed in the simulated paddy fields. The growth of rice seedlings (Oryza sativa) was not reduced by the presence of hatchling snails alone, but the shoot biomass of seedlings coexisting with snails was promoted after introducing the loaches. Additionally, the presence of P. canaliculata adults improved the aquatic environment in the short term for loach breeding by decreasing the turbidity of the water. Importantly, M. anguillicaudatus (12–18?g) mortality decreased and its weight increased in the presence of adult snails.     

Allometric and trophic effects on shell morphology of Pomacea canaliculata (Caenogastropoda,Ampullariidae) from a geometric morphometrics viewpoint

Pomacea canaliculata, an invasive apple snail native to South America, is a serious pest of aquatic crops in several parts of the world. The origin of inter-population variation in shell shape is thought to be both genetic and environmental but the reaction norms to specific environmental factors are still poorly understood. Our aims were to analyze the existence of direct and indirect (allometric) effects of food availability (FA) on the shape of young adults of P. canaliculata. Full sibling hatchlings were reared under different levels of FA. Nine landmarks and 10 semi-landmarks were determined on photographs of mature shells and analyzed using geometric morphometrics. In both sexes significant allometry was found: a decrease in the spire height in both sexes, and an increase of the aperture size in males and of the last whorl in females. When this allometric component was removed a relationship between size-corrected shape and FA was found only in females, which were more globose and had a larger aperture when grown under high FA. This effect may be explained by the faster growth of the reproductive organs and the thinner shells of the best fed females.     

Changes in chemical components in the freshwater apple snail, Pomacea canaliculata (Gastropoda: Ampullariidae), in relation to the development of its cold hardiness

The apple snail, Pomacea canaliculata, is an invasive freshwater snail. It increases its cold hardiness before winter. However, the physiological mechanism of cold hardiness in molluscs is poorly understood, especially in freshwater molluscs. In this study, we examined the changes in low molecular weight compounds, glycogen and lipids, in the body of P. canaliculata in association with the development of cold hardiness. When snails without cold hardiness were experimentally cold-acclimated, the amount of glycerol, glutamine, and carnosine increased, while glycogen and phenylalanine decreased. Overwintering cold-tolerant snails collected from a drained paddy field in November also showed increased glycerol in their bodies with decreasing glycogen concentration, compared to summer snails collected from a submerged field. Water content also decreased during the cold acclimation, although the water loss was minimal. These results indicate that the freshwater snail, P. canaliculata enhances cold hardiness by accumulation of some kinds of low molecular weight compounds in its body as some insects do. However, the actual function of each low molecular compound is still unknown.     

Angiostrongylus cantonensis: experimental study on the susceptibility of apple snails, Pomacea canaliculata compared to Pila polita

Six groups (15 snails/group) of Pomacea canaliculata and Pila polita were infected orally with 0 (control), 200, 400, 800, 1600 and 3200 first-stage Angiostrongylus cantonensis larvae (L1). The respective mean+/-SD third stage larvae (L3) worm recovery 1-month post-infection (p.i.) for P. canaliculata was 0, 1.4+/-5.42 (0.7%), 0.13+/-0.35 (0.03%), 0.07+/-0.26 (0.009%), 0.07+/-0.26 (0.004%), 0, and for P. polita 0, 64.33+/-21.38 (32.25%), 115.36+/-36.82 (28.93%), 265.33+/-90.01 (33.27%), 471.33+/-92.98 (29.60%) and 849.00+/-243.23 (26.61%). The susceptibility of A. cantonensis in P. polita was dose-dependent (p<0.001). In the three groups (nine snails/group) of P. polita given 500 L1, we studied the distribution of L3 in the internal organs (i.e., foot, head+esophagus, kidney, albumin gland, mantle, intestine, digestive gland) and found the highest density after 1, 2 and 3 months p.i. in the mantle at 29.37%, 31.09% and 37.45%. The infection rate in P. canaliculata was too low to study distribution rates.     

Dealing with a hyper-successful neighbor:effects of the invasive apple snail Pomacea canaliculata on exotic and native snails in South America

Pomacea canaliculata is a successful invader and also a competitor and predator of other snails and may play a key role in structuring freshwater snail communities both in its native and invaded range. In the present study we evaluated the contact and distant effects of P. canaliculata in its native range on exotic (Melanoides tuberculata and Physa acuta) and native snails (Heleobia parchappii, Biomphalaria peregrina, and Chilina parchappii). Habitat use was affected in P. acuta, H. parchappii, and B. peregrina by contact effects of P. canaliculata, whereas survival was only affected in P. acuta through combined con tact and dista nt effects. Fee undity was reduced in P. acuta and B. peregrina by combined con tact and distant effects;evidence of egg mass predation was also observed in both species. Melanoides tuberculata was not affected at all by P. canaliculata. The snail species with higher withdrawal resp on ses to con tacts with P. canaliculata were those that suffered less mortality by corporal contact, whereas snails with high crawling away responses suffered from higher mortality. The effects of P. canaliculata seem to be highly negative to small non operculate sn ails that lay gelati nous egg masses, whereas large operculate ovoviviparous snails are not affected in their survival and reproducti on. This apple snail may exert biotic resista nee agai nst P. acuta but could favor the establishme nt of M. tuberculata and other function ally similar species in new habitats in South America.