松毛虫光周滞育的研究

在敏感的虫龄内，松毛虫对短光周的反应，随着幼虫发育进度的不同而不同，初龄对短光周最敏感，2龄开始减弱，到4龄时，幼虫基本上就丧失了对短光周的反应。在脱皮时，幼虫对短光周刺激的反应较明显，在两次脱皮之间，幼虫的反应较弱，短光周处理时间越长，幼虫在3－4龄时进入滞育的比率也越高，这可能与昆虫体内保幼激素含量的变化有关。     

白蜡窄吉丁幼虫的龄数和龄期测定

采用林间定期调查取样的方法，测定白蜡窄吉丁幼虫的龄数以及各龄的龄期；分别测量不同发育阶段幼虫的体长、体宽(第7腹节最宽处)、前胸背板宽、口缘宽、尾又长和尾叉前缘宽等6项指标，以期找出区分和判定幼虫虫龄的最佳形态特征及指标。结果表明：白蜡窄吉丁幼虫有4龄，尾又及其长度可作为理想的分龄特征和分龄指标；幼虫的口缘宽度也可作为指标之一；体长、体宽、前胸背板宽和尾又前缘宽变异较大，不宜用于分龄。研究还发现：幼虫尾叉内侧的形态特征是区分幼虫虫龄的简洁而方便的方法。利用种群众数龄期法测定各龄的平均龄期分别为：1龄18．1d，2龄11．2d，3龄10．7d，4龄261．2d，幼虫期共为301．3d。     

The colonization preference and population trends of larval fig psylla, <Emphasis Type="Italic">Homotoma ficus</Emphasis> L. (Hemiptera: Homotomidae)

The colonization preference and population trends of larval fig psylla Homotoma ficus L. were studied in Bursa, northwestern Turkey, from March 2000 to July 2001. Homotoma ficus overwintered at the egg stage on terminal buds and lenticels of shoots. Larval emergence occurred on 30th and 11th March in 2000 and 2001, respectively. Degree-day (DD) accumulations since 1st January indicate that the emergence of first larvae averaged 47 DD based on the larval developmental threshold of 10.9°C. Although the population trends of Homotoma ficus larvae were affected by temperature and rainfall, there was only significant relationship between larval abundance and temperature. The first instar larvae significantly preferred the bottom and the inside stipule of leaves. The second instar larvae distributed not only on expanding green tissues but also on both the upper and lower surface of leaves corresponding to the fig bud development period. Third to fifth instars colonized significantly greater on the bottom of leaves compared with the stipule and upper surface. In addition, significant linear relationship was found between fig phenology and cumulative larval counts. The importance of the colonization preference of larval instars and the use of fig phenology as well as DD for timing of insecticide treatments are discussed.     

Continuous nondestructive monitoring of larval feeding activity and development of the bamboo powderpost beetle <Emphasis Type="Italic">Dinoderus minutus</Emphasis> using acoustic emission

The life history and feeding biology of the bamboo powderpost beetle Dinoderus minutus remain poorly understood because the beetles’ oviposition, development, and feeding take place inside bamboo culms. In this study, acoustic emission (AE) monitoring was applied for continuous nondestructive analysis of larval feeding activity and development from the first instar to adult eclosion. Newly hatched larvae were inoculated individually into pieces of madake (Phyllostachys bambusoides) culms. AE hits were recorded using single AE sensors fixed onto the bamboo pieces. Generation of AE hits indicated that larval feeding activity had begun after inoculation. Based on the time course of the hourly AE hit rate, the larvae were feeding constantly during each instar, and feeding activity only ceased during periods of ecdysis and pupation. Half of the individuals examined underwent seven instars and the other half underwent eight instars. The time course of AE hit rate per 5 min exhibited periodic cycles, where continuous meals were separated by inactive phases of ca. 5 min, with an average dominant period of each instar ranging between 0.76 and 2.19 h. After correcting the AE data based on distance attenuation of AE waves, the tendency that AE amplitude increased as the larvae developed through ecdysis events became more apparent. AE monitoring continued after adult eclosion, and the feeding activity of the newly emerged adults continued almost ceaselessly during the Reifungsfrass period.     

乌柏金带蛾生物生态学研究

乌桕金带蛾(Eupterote sapivora Yang)属鳞翅目带蛾科,是乌桕(Sapium sebiferum Roxb.)树上重要的害虫,还为害22种重要的经济林和用材林。幼虫取食叶片、嫩枝及花萼。该虫在贵州常年成灾,受害面积达30多万亩,可使乌桕籽减产20％,出油率下降8％—15％。为开展防治技术研究,我们于1986—1988年在正安县、遵义县对其生物生态学作了研究,现将结果报道如下。     

无瓣海桑主要害虫绿黄枯叶蛾的取食行为研究

绿黄枯叶蛾Trabala vishnou Lefebure是红树林植物无瓣海桑Sonneratia apetala Buch-Ham的重要害虫,为制定科学的防治指标和防治策略,对该虫的取食行为和取食量进行了初步的研究。结果表明:绿黄枯叶蛾幼虫喜食无瓣海桑、尾巨桉,拒食秋茄、桐花树;幼虫5龄,1～3龄幼虫具有聚集性,4龄幼虫开始分散取食;1～2龄幼虫取食量少,3～5龄取食量占整个幼虫期取食量的98.12%,其中5龄幼虫的取食量占整个幼虫期取食量的74.52%;幼虫期平均取食无辨海桑叶片178.94 cm2/头,确定防治指标为9.8头/千叶。     

Biological traits and life history of Pagiophloeus tsushimanus(Coleoptera: Curculionidae), a weevil pest on camphor trees in China

Cinnamomum camphora(L.) J.Presl.(Laurales:Lauraceae) is widely cultivated as an important landscape tree species in many urban areas in South China,especially in Shanghai City.Pagiophloeus tsushimanus Morimoto has become a destructive insect pest of C.camphora plantations in Shanghai,but the biological and ecological traits of this pest remain largely unknown.In this study,we investigated the damage and life history and determined the larval instar of P.tsushimanus.The results indicated that P.tsushimanus is a monophagous weevil pest,and C.camphora is the unique host tree species.C.camphora plantations in all administrative districts of Shanghai have been seriously damaged by P.tsushimanus.Adults often aggregate for feeding on the tender bark of twigs and occasionally on newly emerged buds.After experiencing damage,the twigs shrink and crack and the buds will shrink.Adults tend to repeatedly mate and oviposit,and all females lay single eggs at a time.Eggs will be covered with a mixture of secretions and wood chips by female adults.Larvae(1 st-2 nd instar)feed on the phloem,while 3 rd-5 th instar can bore into the phloem and the cambium.Massive tunnels,including three shapes(inverted "L",inverted "T",and inverted "Z"),were observed in the trunk of each tree,and resulted in swelling of the outer bark.P.tsushimanus has one life cycle per year in Shanghai.Both adults and larvae(3 rd-5 th instar) overwinter from early November to early April.Adults overwinter in grooves on the underside of branches or at branch nodes,and larvae overwinter in tunnels.Five larval instars of P.tsushimanus were determined according to Dyar's and Crosby's rules.The biological traits and life history of P.tsushimanus have been identified and can provide guidance in terms of pest control and plantation management.     

Studies on morphology and biology of immature stages of the predator Rhyzobius lophanthae Blaisdell (Col.: Coccinellidae)

Morphological characteristics of immature developmental stages of Rhyzobius lophanthae Blaisdell (Col.: Coccinellidae), predator of scale insects of the family Diaspididae (Homoptera), are described. Data about the morphology of eggs, the four larval instars, and the pupa is presented. Larval instars are described in more detail: size of head capsule, length of tibia, distribution of dorsal and lateral setae of abdomen segments for each larval instar is reported. Distribution of spiracles is also given. Study on the biology concerns the influence of prey on the duration of instar periods. The diaspidids Aspidiotus nerii and Aonidiella aurantii were used as food. The mean duration of the developmental period from egg to adult was 27.1 days, and no mortality was observed (0?%) when A. nerii was used as prey. The respective numbers when the prey was A. aurantii were 48.8 days and 84?%.     

银杏大蚕蛾的生物学和防治技术研究

银杏大蚕蛾在湖北一年发生一代。幼虫5龄;4、5龄幼虫有绿色型和黑色型。幼虫取食38种植物,天敌有53种。本文还叙述了该虫发生与环境的关系。防治试验表明:喷洒2.5％溴氰菊酯5000倍液、2×10~8孢子/ml白僵菌液、25％苏脲一号500倍液、1×10~8PIB/mlDjNPV虫尸液效果均很好。