Phenology and laboratory rearing procedures of an Asian longicorn beetle, Glenea cantor (Coleoptera: Cerambycidae: Lamiinae)

Clenea cantor (F.) (Coleoptera: Cerambycidae: Lamiinae) is an Asian longicorn beetle whose larvae bore under the bark of living trees of at least seven plant families and enter the wood for pupation. Here, we determined the phenology of this beetle on its natural host, kapok [Bombax ceiba L. = Cossampinus malabaricus (DC.) Merr], in an uncontrolled insectary at ambient environmental conditions, and we compared the efficiency of four larval rearing procedures at 25 +/- 2 degrees C, 75 +/- 5% RH, and a photoperiod of 14:10 (L:D) h in the laboratory. It had five generations, including an overwintering generation, a year in southern China, with overlaps between generations and no diapause. Adults were present in early March-early December; eggs in early April-early December; larvae almost year-round, and pupae in mid-February-mid-April as well as mid-May-late November. All larvae of the overwintering generation and the larvae of the fourth generation that hatched in and after mid-November overwintered. The longevity of females and males was 71.94 +/- 1.21 d and 46.87 +/- 1.11 d, respectively, and mean fecundity was 106.65 +/- 3.61 eggs. Four larval rearing procedures using kapok twigs were tested: (1) 10 neonate larvae were left in the original host twig, (2) 10 neonate larvae were removed from the original bark and transferred to a new host twig, 3) 10 neonate larvae embedded in the original bark were transferred to a new host twig, and 4) a single neonate larva embedded in the original bark was transferred to a new host twig. We observed the survival of 300 neonate larvae for each rearing procedure. Approximately 81-85% of neonate larvae successfully developed to adult stage when neonate larvae were transferred together with the original bark to new host twigs; when neonate larvae were transferred without the original bark, only approximately 38% of the inoculants became adults, and when larvae were left in original twigs, approximately 52% of them reached adult stage. Resulting adults from different rearing methods and collected from the field had similar body weight and sex ratio. In terms of time, labor, and the number of resulting adults, procedure 3 is the most effective method for maintaining a laboratory colony.     

Olive fruit fly (Diptera: Tephritidae) populations in relation to region, trap type, season, and availability of fruit

Olive fruit fly, Bactrocera oleae (Gmelin), was monitored with adult captures by season and trap type, and was related to fruit volume and nonharvested fruit to elucidate the occurrence of the newly introduced pest in California. The highest numbers of adults captured in ChamP traps in olive trees, Olea europaea, were in October in an inland valley location, and in September in a coastal location. Comparisons of trap types showed that the number of olive fruit fly adults captured in Pherocon AM traps in a commercial orchard was significantly greater than in ChamP traps. A significantly greater number of females were captured in Pherocon AM traps with bait packets and pheromone lures than traps with pheromone lures alone, while a significantly greater number of adults and males were captured in traps with pheromone lures alone. Significantly more adults were captured in ChamP traps with bait packets and pheromone lures versus traps with bait packets alone. Fruit volume increased by four times from mid-June to mid-November. Olive fruit fly was found to oviposit on small olive fruit <1 cm3 shortly after fruit set, the maximum number of ovipositional sites per fruit occurred in October, and the greatest number of pupae and adults were reared from fruit collected in September and October. The highest numbers of pupae were collected from nonharvested fruit in March when high numbers of adults were captured in the same orchard.     

北京地区杨潜叶跳象生物学特性及药物防治效果

杨潜叶跳象Rhynchaenu sempopulifolis Chen是杨树的重要食叶害虫之一。该虫在北京密云1年发生1代,以成虫越冬。翌年3月下旬越冬成虫开始出蛰上树危害。4月上旬成虫交尾,4月中旬开始产卵,卵产于叶片背面,孵化后即开始潜入叶肉内为害,4月下旬化蛹。5月上旬成虫羽化,然后继续上树取食叶片,直到10月下旬进入枯枝落叶内、石缝、表土中进行越冬。发现2种重要的寄生性天敌:杨跳象金小蜂Pteromalus miyunensis和三盾茧蜂Triaspissp.。它们对害虫种群起着较大的控制作用。用5%高效氯氰菊酯1000倍液进行土壤处理,杨潜叶跳象成虫和蛹的平均校正死亡率分别达到94.05%和66.5%。     

宽索鳃金龟的研究

宽索鳃金龟是为言猕猴挑的重要食叶害虫．该虫在福建建宁县一年发生一代,以成虫在土中越冬,翌年4月上旬开始出土为害,4月下旬至5月下旬为害盛期,成虫可整夜取食猕猴桃叶片和花器,成虫出土及人土的时间较为整齐．5月上旬雌虫开始在土中产卵,5月下旬开始孵化．幼虫3龄,在土中1-20cm处活动,以8-10cm处占绝大多数,幼虫取食土壤中腐植质和根皮,截根．9月上旬开始化蛹,10月中旬成虫开始羽化。但当年不出土,逗留在土中。并越冬．采用50％辛硫磷1000—2000倍液防治幼虫：80％敌敌畏乳油1000倍．帅％乐果800-1000倍、25％溴氰菊酯5000倍等药液毒杀成虫均有良好效果,亦可人工捕杀和灯光诱杀成虫．     

Field releases of two genetic sexing strains of the Mediterranean fruit fly (Ceratitis capitata Wied.) in two isolated oases of Tozeur governorate, Tunisia

The recent development of medfly genetic sexing strains (GSS) enables only male adults to be produced and released for area-wide control using the sterile insect technique (SIT). Before these strains can be incorporated into large operational field programmes, information is required on all aspects of field performance.
In a pilot project in Tunisia, medfly pupae from GSS SEIB-40 [based on a pupal colour mutation ( wp ) and VIENNA-43/44 [based on a temperature sensitive lethal mutation ( tsl ) were shipped from the FAO/IAEA Agriculture and Biotechnology laboratory (Seibersdorf, Austria) and the emerged sterile males released weekly from the ground in oases of the Tozeur Governorate from mid-February until October 1994. During that period, flies emerging from an average of 5000 pupae per hactare were released weekly throughout 105 hectares. Transportation problems were encountered which resulted in damage to the pupae. Nevertheless, the monitoring of the wild population through a trapping network using Jackson and McPhail traps showed that both strains performed equally well inducing a three- to five-fold decrease of the wild population compared with the control oasis (10 wild flies per Jackson trap per day in October in Ain-El-Karma, five in Tamerza and 30 in Bir Kastilia control oasis). Considering the economical and technical benefits inherent in the use of these new strains in the field and as a result of their good field performance, similar strains have been introduced into mass-rearing facilities in Guatemala (1994), Argentina (1995) and Madeira (1996).     

Population dynamics of the white pine weevil, Pissodes strobi, infesting jack pine, Pinus banksiana, in Ontario, Canada

1. Eight generations of white pine weevil, Pissodes strobi (Peck) , infesting the terminal shoots of young jack pine trees, were sampled as larvae, pupae, and adults between 1988 and 1995.
2. The density of adult weevils increased rapidly for the first 3 years of the study, then declined in the next 4 years. Between-generation rates of change in density of weevils were related to mean number of weevils produced per terminal shoot of the host tree. Net increases in population density followed years in which a relatively high number of weevils emerged per terminal shoot and vice versa.
3. The mean number of weevils emerging per terminal shoot was determined by survival of weevils between the end of the larval stage and the successful emergence of adult weevils.
4. There was no clear relationship between survival of the post-feeding stages of the weevil and rates of parasitism or bird predation on these same stages. There was, however, a strong negative relationship between survival of weevils within the terminal shoot and the abundance of the facultative dipteran predator Lonchaea corticis Taylor.
5. The relationship among generational rates of change in populations, survival, and predation was evident irrespective of the age of the trees infested, suggesting that population dynamics of the weevil may be influenced as much by local predation pressure as by physical and biotic changes associated with growth of the young host trees.     

POPULATION STUDIES ON HYLOBIUS ABIETIS (L.) (COLEOPTERA, CURCULIONIDAE

Populations of third-stage larvae, pupae and adults of Hylobius abietis in the stumps of pine trees, Pinus sylvestris L., have been assessed. On a felled area the relative numbers of adults have been obtained by trapping; the most reliable estimate of absolute numbers was obtained from the stump sampling data.     

宁夏灵武市沟眶象发生特点

系统调查沟眶象Eucryptorrhynchus chinensis(Olivier)在宁夏灵武市的发生情况和特点发现:沟眶象以成虫和幼虫在土壤中越冬,成虫有2个发生高峰期,越冬结束后以成虫越冬的沟眶象出土出现第1个高峰期,以幼虫越冬的沟眶象经化蛹羽化出土出现第2个高峰期;幼虫危害臭椿根部形成的瘤状物可以作为鉴别沟眶象危害的特征;沟眶象幼虫在土壤中垂直分布范围集中在0～45 cm深土层,约占80%;成虫出土孔集中在距臭椿树干基部75 cm范围内,占88%。据此建议土壤施药化学防治沟眶象时,施药深度不宜低于45 cm,施药点距树干基部水平距离不得少于75 cm,且树周各个方向均需施药。每年10月末沟眶象开始"入土"、翌年4月末开始"出土",在沟眶象"入土"结束后但未冻土之前的11中旬和土壤解冻之后但尚未"出土"前的4月中旬,这两个时期土壤施药防治效果较好;防治沟眶象的同时,还应适时采取打孔注药、熏蒸等措施防治臭椿(Ailanthus altissima(Mill.)Swingle)树干内的臭椿沟眶象Eucryptorrhynchus brandti(Harold)。     

Effects of a juvenoid, DPE-28, on biology and behaviour of Culex quinquefasciatus, the human filariasis vector

Studies on the effect of a juvenoid, DPE-28 (2,4-dinitrophenyl-2',6'-di-tertiarybutyl phenyl ether) on biology and behaviour of Cx. quinquefasciatus showed that the developmental duration, sex ratio, mating success and blood feeding were considerably affected by the exposure of larvae and pupae to the compound. Exposure of fourth instar larvae to 0.007 (EI90) and 0.0019 (EI50) ppm of DPE-28 prolonged the duration of pupation by 58.6 and 52.4 hr and delayed the adult emergence by 35.4 and 17.7 hr in males and 36.8 and 21.1 hr in females respectively. Exposure of freshly ecdysed pupae to 10 and 5 ppm delayed the adult emergence with respect to the control by 54.3 and 32.4 hr in males and 55.2 and 33.2 hr in females respectively. The sex ratio of the adults emerged from treated larvae and pupae was also affected. The female mosquitoes that survived from the exposed fourth instar larvae and pupae exhibited a low blood engorgement ratio. This depression in blood feeding was more pronounced in adults emerged from treated pupae than that of treated fourth instar larvae. A significant proportion of adults emerged from treated larvae and pupae were able to feed only partially. Mating success of the treated populations declined considerably when crosses were made between the males and females emerged from treated fourth instar larvae and pupae. The adults emerged from treated larvae and pupae showed a significant reduction in the oviposition.     

STUDIES ON SOIL POPULATION OF CONTARINIA PISI WINN. IN 1957 IN YORKSHIRE AND LANCASHIRE

For studying the population of pea-midge cocoons, larvae and pupae in the soil, a new method of examining the 'float' obtained from washing soil through the wet-extraction apparatus is described.
Examination of soil samples in the summer of 1957 from fields which carried heavily attacked pea crops in 1956 indicated that pupae were present at depths of 0–3, 3–6, 6–9 in., respectively, from 18 June onwards, and that the peak emergence of midges was in the period 28 June-2 July; observations on adult activity in pea fields confirmed this. Small numbers of pupae were recovered throughout July.
Similar studies on pea fields in 1957 showed the build-up of the cocoon population and the rate of pupation of this generation of larvae. The first flight of 1957 was composed of individuals from the 1956 generation and was far larger than the second flight, which was composed of some 1956 generation and part of the first 1957 generation.
There were indications that increases of temperature might accelerate pupation with a resulting earlier emergence of adults.
The size of midge populations recorded from soil from green pea and dry-harvesting pea fields tended to be similar and appeared to be related to sowing date.     

Host status of fresh prunes by potential quarantine pests in laboratory tests and evaluation of packinghouse culls.

The status of fresh prunes, Prunus domestica L., as a host for codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae); peach twig borer, Anarsia lineatella Zeller (Lepidoptera: Gelechiidae); omnivorous leafroller, Platynota stultana Walshingham (Lepidoptera: Tortricidae); oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae); navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae); and walnut husk fly, Rhagoletis completa Cresson (Diptera: Tephritidae), was investigated in laboratory tests and by examination of packinghouse culls. In laboratory no-choice tests, the mean number of adults reared per fruit was 0.01 for codling moth, 0.08 for omnivorous leafroller, 0 for oriental fruit moth, and 1.6 for navel orangeworm. In choice tests the mean number of adults reared per apple or fresh prune was for codling moth, 0.78 and 0.02 (significantly different); for omnivorous leafroller, 0.05 and 0.02; and for oriental fruit moth, 2.07 and 0 (significantly different), respectively. Walnut husk fly oviposited in fresh prunes in no-choice tests but pupae did not develop from the fruit. In choice tests, walnut husk fly did not oviposit in fresh prunes when caged with its normal host, green walnuts, in which large numbers of pupae developed. Inspection of packinghouse culls for immature insects showed that fresh prunes with possible larval feeding sites in the form of frass or fruit gum extrusions were lighter in weight, significantly less firm, similar in color, and had significantly higher soluble solids than noninfested fruit. Based on packinghouse cull samples, 1 fresh prune per 133 harvested fruit would be expected to show possible insect damage. Eleven peach twig borer larvae were found in fresh prune cull samples (213.9 kg) removed from a 16,744.5-kg harvest. The calculated level of infestation was 1 infested fruit per 8,501.8 fruit harvested or per 21.7 cartons of medium-sized packed fruit. Based on our results, the risk of infestation of fresh prunes by the insects in this study would be minimal in fruit exported from the San Joaquin Valley of California.     

Biology of Hylobitelus xiaoi (Coleoptera: Curculionidae), a new pest of slash pine, Pinus elliottii

The biology of the weevil Hylobitelus xiaoi Zhang was studied in both field and laboratory in Shangyou, Jiangxi Province, China. This species required 2 yr to complete one generation with overwintering by adults in pupal chambers and larvae in galleries in the bark of host trees. Adults emerged from early March to early April and fed on the inner bark of branches of the trees. Adults fly little. Adults exhibited a diel periodicity, climbing up the trees around sunset and returning to the tree base the next morning. The mean preovipostion period was 46 d. Oviposition commenced in early May and ended in late August. The average fecundity per female was 36 eggs. Overwintered adult females and males lived 208 and 227 d, respectively. At 25 degrees C, the mean egg incubation period was 13 d. In the field, egg hatch occurred in 12-15 d with 83% survival. There were five to seven instars. At 25 degrees C, duration of the larval stage averaged 129 d. Pupation commenced in late August. At 25 degrees C, pupation averaged 20 d. In the field, pupation required 20-26 d. Transformation to adults occurred from late September to October. New adults remained in the pupal chambers until the next year. Infection by Beauveria bassiana Vuill. occurred in 0.8% of the pupae and 8.8% of the overwintered adults.     

哈尔滨地区大猿叶虫发育历期与生物学特性

在哈尔滨对白菜上的大猿叶虫Colaphellus bowringi Baly的生活史和生物学习性进行观察研究。结果表明,大猿叶虫在哈尔滨地区绝大多数个体1年发生1代,少部分个体1年发生2代。主要以成虫入土在2～27cm土层中滞育越冬。越冬成虫翌年4月下旬开始出土活动。第1代发生在5上旬至7月上旬,第2代发生于6月中旬至7月中旬。所有成虫在7月下旬以后均滞育越冬。在25℃条件下,雌虫产卵期为6～55d,平均为30.95d,单雌平均产卵量为454.9粒。在25℃各虫态的发育历期为:卵(4.46±0.33)d,幼虫(8.22±0.26)d,蛹(4.17±0.22)d。各虫态发育起点温度卵为10.80℃,幼虫为10.95℃,蛹为9.79℃;有效积温卵为64.82日.度,幼虫为117.37日.度,蛹为64.36日.度。     

Temperature-dependent post-diapause development and prediction of spring emergence of the pine needle gall midge (Dipt., Cecidomyiidae)

Abstract:  We determined the influence of temperature on post-diapause development of overwintered Thecodiplosis japonensis Uchida et Inouye (Dipt., Cecidomyiidae) under various treatments (12, 15, 18, 21, 24, 27 and 30°C) in an effort to predict its spring emergence. Survival and developmental period for the overwintered larvae and pupae were significantly influenced by temperature. Linear and nonlinear regression models quantitatively described temperature-dependent development and survival of T. japonensis . The survival models exhibited right-skewed bell shape patterns for all stages, indicating a more detrimental impact on survival at high temperatures. Theoretical optimum temperatures with highest survival were 22.3, 24.0 and 24.0°C for the overwintered larvae, pupae and total post-diapause development (the larvae to adults) respectively. Pupal mortality was higher at all temperatures than larval mortality and the suitable range of temperature for pupae was narrower than that of larvae. The nonlinear Briere model estimated that optimum temperatures with the fastest development were 29.1°C for larvae, 27.6°C for pupae and 27.0°C for larvae to adults. In a linear model, the lower threshold temperatures were 5.1, 7.1 and 5.9°C for larvae, pupae, and larvae to adults respectively. A predictive degree-day model was developed using trap catches of T. japonensis adult emergence during 1991–1995. The model accounted for 84.6% of year-to-year variation in adult emergence and predicted accurately the median emergence time in 1996.     

喙尾琵甲（鞘翅目：拟步甲科）形态记述及生物学特性观察

记述了喙尾琵甲Blaps rhynchopetera Fairmaire各虫态特征,观察了其生物学特性.实验种群1月下旬至12月上旬产卵,卵期为8～15 d;幼虫期141～213 d,共9～13龄,第9龄以后,龄期较长;蛹前期8～14 d;蛹期12～24 d.成虫羽化24～92 d后性成熟,开始交配产卵活动,成虫期超过18个月.自然种群在昆明和曲靖1年发生1～1.5代,世代重叠严重;以不同龄期幼虫和成虫越冬,越冬幼虫于次年4月上旬开始化蛹,新羽化成虫于4月下旬至12月上旬交配产卵,成虫全年都能活动、产卵.该虫为夜出型、暂栖性土壤昆虫,喜潮湿阴暗的环境.成虫具有夜出习性、防御性和群聚性.     

Vertical distribution of Culicoides larvae and pupae

This study was carried out in the northeast region of Konya in Turkey, between April and December 2004, to determine the vertical distribution of Culicoides (Diptera: Ceratopogonidae) larvae and pupae. Larvae and pupae were collected using the saturated sugar flotation technique in mud samples taken from a range of depths of up to 20 cm. In total, 282 adult Culicoides were obtained. The number of larvae and pupae decreased as the depth increased; at 2.5 cm, 97 Culicoides larvae and 73 Culicoides pupae were found. Larvae and pupae of C. nubeculosus (Meigen) and C. puncticollis (Becker) were mostly found in organic matter-rich breeding sites, while larvae and pupae of C. gejgelensis Dzhafarov and C. festivipennis Kieffer were mostly found in organic matter-poor breeding sites. Culicoides larvae and pupae were obtained largely in July and August.     

The effects of temperature, diet, and other factors on development, survivorship, and oviposition of Aethina tumida (Coleoptera: Nitidulidae)

Developmental rate and survivorship of small hive beetle, Aethina tumida Murray (Coleoptera: Nitidulidae), life stages were measured across different temperatures (21, 25, 28, 32 and 35 degrees C) and diets, which included natural and artificial pollen, honey, and bee pupae. Temperature affected hatch success, time to hatching, and larval growth. Eggs hatched in 61 h at 21 degrees C but in < 22 h at 35 degrees C. Larvae achieved peak weight in < 8 d at 35 degrees C but needed 17 d at 21 degrees C. Diet had comparatively little effect on larval survivorship or maximum weight, although larvae fed only bee pupae had lower survivorship. Access to soil influenced pupation success. Duration of the life stage spent in the soil, during which pupation occurs, was also affected by temperature: adults emerged after 32.7 d at 21 degrees C but after only 14.8 d at 35 degrees C, albeit with high mortality. Minimum temperature for development was estimated at 13.5 degrees C for eggs, and 10.0 degrees C for larvae and pupae. Temperature influenced adult longevity and oviposition: on a honey and pollen diet average adult lifespan was 92.8 d at 24 degrees C but only 11.6 d at 35 degrees C. Beetles lived longer at 28 degrees C or lower but produced the most eggs per female, regardless of diet, at 32 degrees C. Beetle density influenced fecundity: beetles kept at three pairs per vial laid 6.7 times more eggs per female than those kept as single pairs. Overall, beetles fared best at 28-32 degrees C with mortality of all stages highest at 35 degrees C.     

Phenology ofHippodamia undecimnotata (Col.: Coccinellidae) in Greece

Hippodamia (Semiadalia) undecimnotata (Coleoptera: Coccinellidae), collected from central Greece and reared in cages during 1993–1994 and in vials during 1994–1995 outdoors at Kifissia, Athens, completed 5 generations per year. In both cases, adults of the 1^st, 2^nd and 3^rd generations reproduced, completing their egg laying in the same year; 4^th and 5^th generation adults reproduced both in the year they emerged and the following year. In both cases, adults of the 1^st and 2^nd generations died before winter; in 1993, adults of the 3^rd generation died before winter, in 1994, they survived until April 1995. Adults of the 4^th and 5^th generations overwintered successfully. The greatest numbers of eggs were laid by females of the 1^st and 2^nd generations. Field observations and timed counts of specimens (30 minutes per location) made on the tops of Mounts Chlomo and Kitheron and on the neighboring plain of Kopais between 1991 and 1994 revealed that most adults arrived on the mountains between late June and early September and left between the end of March and beginning of May.H. undecimnotata were not found on the plain of Kopais during the winter. Overwintered adults arrived between the end of March and beginning of May; 1^st generation adults emerged in June. The presence of a few eggs, larvae, pupae and newly-emerged adults observed on the plain during August-September 1993 suggests that at least a portion of theH. undecimnotata population in central Greece completes 2 or more overlapping generations per year.     

松墨天牛成虫雌雄体型差异及蛹和成虫大小与越冬幼虫体重的关系

【目的】本研究旨在明确松墨天牛 Monochamus alteratus 成虫及越冬幼虫体型大小的差异,探讨该虫越冬后成虫体型大小和越冬幼虫体重大小关系及原因。【方法】于2014年5月1日至10月31日在浙江富阳野外诱捕松墨天牛,通过测量野外诱捕到的松墨天牛成虫体长、体宽,确定林间松墨天牛成虫体型的差异;松墨天牛越冬幼虫的采集和称重测量明确越冬幼虫的组成和体重大小差异;进而通过对越冬幼虫单头跟踪饲养至化蛹、羽化,确定越冬幼虫体重大小与发育所得蛹和成虫大小的关系,阐明林间松墨天牛成虫体型差异的原因。【结果】浙江富阳野外诱捕发现,松墨天牛的活动期间很长,从5月中旬到10月初一直能诱捕到松墨天牛成虫,高峰期在6和7月份。松墨天牛雌雄成虫体型差异很大,雌虫平均体长和体宽分别为20.59±0.19和6.59±0.06 mm;雄虫平均体长和体宽分别为19.90±0.26 和6.44±0.08 mm; 雌虫的平均体长明显高于雄虫,但二者体宽没有显著差异;并且雌雄成虫体长和体宽呈显著正相关。越冬幼虫的头宽测定表明头宽的变化很大,最小为2.20 mm,最大为4.24 mm,经比对越冬幼虫由4龄和5龄幼虫组成;幼虫体重差异大,平均体重为304.2 mg, 介于71.6~858.0 mg之间,其中5龄越冬幼虫显著重于4龄越冬幼虫。进一步将越冬幼虫单管饲养跟踪研究发现,越冬幼虫体重大小决定蛹和羽化后的成虫的大小,二者存在显著的正相关,并且由4龄越冬幼虫发育所得的蛹和成虫显著轻于由5龄幼虫发育所得的蛹和成虫。【结论】松墨天牛成虫体型差异很大,这与越冬幼虫体重差异相关;越冬幼虫的体重大小决定了其化蛹后的蛹重和羽化后成虫的体型和体重的大小;造成越冬幼虫体重差异的可能原因包括松墨天牛成虫扬飞周期长导致的产卵期长而使得天牛发育进度不一致以及寄主不同部位营养的差异。     

High temporal variation in the assemblage of Lepidopteran larvae on a constant resource

We studied variation in the assemblage of lepidopteran larvae between individual trees, and temporal variation in the diversity and species composition of the assemblage in a medium‐altitude rainforest in Kibale National Park, Uganda. Monthly samples of lepidopteran larvae were collected from the leaves of Neoboutonia macrocalyx Pax. between January 1995 and December 1996. During this period, a total of 1961 specimens representing 76 lepidopteran morphospecies were found. The numbers of individuals within species varied enormously, ranging from one to 707 individuals. Assemblages of individual trees were highly similar and dominated by geometrid larvae. Temporal variation in herbivore abundance was high. The number of individuals peaked during the major rainy season in 1995 but not in 1996 and was not correlated significantly with rainfall within these 2 years. In contrast, a negative correlation was found between lepidopteran diversity and rainfall that seems to cause a semi‐annual trend in diversity with one or two peaks per year. Furthermore, there was seasonality in the similarity of the assemblage. Consequently, the same species were found in the assemblage during certain times of the year. Our study shows that short‐term biodiversity assessments can give a skewed picture of the diversity of tropical forests.