Life cycle of the lilac pyralid Palpita nigropunctalis (Bremer) (Lepidoptera: Crambidae) on five oleaceous tree species

The seasonal abundance of Palpita nigropunctalis larvae was studied on five oleaceous tree species in Ibaraki, central Japan, for two years. The larval population peaked on some tree species in both spring and autumn while it peaked on other tree species only in autumn. In bimodal populations, the spring peaks consisted of larvae infesting leaves, while the autumn peaks consisted of larvae infesting various tree parts (flowers, fruits and leaves). Larval development was longer and pupal weights were lower on Ligustrum lucidum fruits than on Ligustrum japonicum fruits. Thus, L. japonicum fruits were suitable for larval development in autumn. First-instar larvae appeared to occur three times per year (in late April to early May, mid to late September and early to mid October). Adults were observed from late March to early April, mid May to early June, and early September to mid November at the census sites, showing that P. nigropunctalis had three generations a year. The percentage of females having premature ovaries were 64.3 and 12.5% at 15 °C under 14-h and 15-h photophases, respectively, and 28.6 and 25% at 20 °C under the respective photophases. These temperatures and photoperiods are typical of those in May and June in the census sites. The ovaries of females collected in the field between late May and mid July were premature, in agreement with the laboratory experiments. The pupal duration was prolonged under the short photoperiod, especially at reduced temperatures. We discuss a possible life cycle of P. nigropunctalis in Ibaraki.     

Chemical analysis of the female sex pheromone in Palpita nigropunctalis (Lepidoptera: Crambidae)

The lilac pyralid, Palpita nigropunctalis Bremer (Lepidoptera: Crambidae), is a common pest of Oleaceae plants. A crude extract of the female sex pheromone glands was examined by gas chromatography-electroantennogram detection (GC-EAD) and GC coupled to a mass spectrometer (GC/MS). The GC-EAD analysis revealed three EAG-active components (I–III) in a ratio of 1:0.2:0.01 (I: II: III). GC/MS analysis successfully recorded the mass spectra of I and II. For I, ions at m/z 238 (M⁺) and 220 ([M-18]⁺) indicated the structure of a monoenyl aldehyde with a 16-carbon chain. For II, M⁺ was not detected, but ions at m/z 222 ([M-60]⁺) and 61 ([AcOH+1]⁺) suggested that II was a monoenyl acetate with a 16-carbon chain. Further GC/MS analysis of the extract treated with dimethyl disulfide revealed that the double bonds in both I and II are located at the same position of 11th-carbon. In addition, the pheromone extract was examined by GC/Fourier transform-infrared spectrophotometer (GC/FT-IR). An IR spectrum of I showed characteristic absorption at 1716 and 966?cm^?1, indicating a formyl group and E configuration of the double bond, respectively. In the case of II, absorption at 1745 and 968?cm^?1 indicated an ester carbonyl and E configuration, respectively. Taken together and by comparison with authentic standards, I and II were confirmed as (E)-11-hexadecenal and (E)-11-hexadecenyl acetate, respectively; while III was speculated as (E)-11-hexadecen-1-ol. The synthetic I, II and III all coincided well with those of the natural components in chemical data, and elicited strong electroantennographic activity in male P. nigropunctalis.     

Effect of temperature and relative humidity on the development and fecundity of Chilo partellus (Swinhoe) (Lepidoptera: Crambidae)

The spotted stemborer, Chilo partellus (Swinhoe) (Lepidoptera: Crambidae), is one of the most important insect pests attacking maize and sorghum in Ethiopia. Recent studies have indicated that the pest is spreading to new locations where it was not reported before. In the current study, laboratory investigations were carried out to determine the combined effect of different levels of relative humidity and temperature regimes on the development and fecundity of C. partellus, as these physical factors are known to play an important role in the life cycle of insects and adaptability to local climate. Developmental time, longevity, potential fecundity and realized fecundity of C. partellus were measured under controlled conditions. Three temperature regimes (22°C, 26°C and 30°C) and three relative humidity levels (40%, 60% and 80%) were tested. It was found that temperature, relative humidity (RH) and their interaction significantly affected the developmental time, adult longevity, potential fecundity and realized fecundity of the pest. Developmental time was inversely related to temperature. Mean duration of C. partellus life cycle was 70.2 days at 22°C and 80% RH, whereas it took only 26.5 days to complete its life cycle at 30°C and 40% RH. Male and female longevity were similar in most cases. The adult life span ranged between 6.9-11.1 days at 22°C and 3.1-7.2 days at 30°C for different levels of relative humidity. The most suitable conditions for C. partellus development and fecundity were 26-30°C temperatures regimes and 60-80% RH levels.     

Temperature-dependent development of diapausing larvae of Chilo partellus (Swinhoe) (Lepidoptera: Crambidae)

Temperature-dependent development rate, percent diapause induction (hibernation at low temperature and aestivation at high temperature), and survival of diapausing larvae of Chilo partellus (Swinhoe, 1885) were examined on 13 constant temperatures ranging from 8 to 40 °C. Development of hibernating and aestivating larvae occurred from 10 to 25 °C and 27–38 °C, respectively. However, no development occurred at 8 °C and 40 °C. To determine actual thermal conditions that affect development and trigger both kind of diapause (hibernation and aestivation), various thermal parameters were estimated by fitting the development rate data to two linear (Ordinary equation and Ikemoto & Takai) models and thirteen non-linear models. The lower thermal thresholds (T_min) for development of diapausing larvae of C. partellus were calculated as 9.60 °C and 10.29 °C using the ordinary linear model and Ikemoto & Takai model, respectively. Similarly, the thermal constants (K) estimated using the ordinary linear model was 333.33 degree-days and that estimated with Ikemoto & Takai model was 338.92 degree-days. Among the non-linear models, Lactin-2 followed by Lactin-1 were found to be the best as these models estimated the critical temperatures (T_min, T_max and T_opt) similar to those of observed values. Conclusively, the Ikemoto & Takai linear model and Lactin-2 followed by Lactin-1 non-linear models are useful and efficient for describing temperature-dependent development and estimating the temperature thresholds of diapausing larvae of C. partellus. Our findings provided fundamental information for estimation of thermal requirement and temperature based development models for diapausing larvae of C. partellus. This information will be highly useful for predicting the occurrence, seasonal emergence, number of generations and population dynamics of C. partellus.     

温度对番茄潜叶蛾生长发育和繁殖的影响

【目的】番茄潜叶蛾Tuta absoluta是一种对番茄具有毁灭性危害的世界性入侵害虫,本研究旨在探索温度对入侵番茄潜叶蛾种群生长发育和繁殖的影响,为预测番茄潜叶蛾的分布区域、田间发生动态提供基础。【方法】在室内测定了番茄叶片上番茄潜叶蛾在15, 20, 25, 30和35℃ 5个恒定温度条件下各虫态的发育历期和存活率、繁殖力和种群增长参数,并应用不同模型分析发育速率、内禀增长率和净生殖率与温度的关系,估计发育起点温度、发育极限温度、发育最适温度、有效积温和年发生代数。【结果】在恒温15~30℃范围内,番茄潜叶蛾各虫态的发育历期随温度升高而逐渐缩短。25℃下幼虫期存活率、成虫前期存活率、雌虫总产卵量、净生殖率、内禀增长率和周限增长率均最大。在35℃下,卵的存活率骤降至11%,孵化的幼虫无法正常发育。卵期、幼虫期、蛹期、成虫前期、全世代的有效积温分别为104.17, 232.59, 129.87, 434.78和526.32日·度,该虫在新疆伊宁县和察布查尔锡伯自治县的理论发生代数为4~5代。基于发育速率与温度关系的模型与基于种群增长参数与温度关系的模型所计算的积温需求参数不同,基于内禀增长率求得的番茄潜叶蛾的发育起点温度、发育极限高温和发育最适温度分别为12.46, 30.40和27.36℃。【结论】入侵我国新疆地区的番茄潜叶蛾适温范围广泛,在我国大部分地区具有极高的扩散风险。     

Oviposition preference and development of Maruca vitrata (Fabricius) (Lepidoptera: Crambidae) on different radiofrequency fields

Maruca vitrata is considered as one of the major impediments in boosting up the production of tropical legumes. Since chemical pesticides have an adverse effect on human health and environment, there is an urgent need for developing a non‐chemical based method to replace chemical insecticides for controlling of pests. We investigated the oviposition, development and adult performances of M. vitrata at five radiofrequency levels of 0 (control without frequency), 5, 10, 20, and 30 kHz on artificial diet. In addition, the effects were also studied in three successive generations (Parent, F1‐ and F2‐ generations) of M. vitrata. The results showed that radiofrequency application had significant effects on the life‐variables of M. vitrata. Radiofrequency exposures on M. vitrata not only impacted on oviposition, developmental time, adult longevity, and adult weight but negative effects were also transmitted to the successive generations. Oviposition was found to reduce as generation passed after exposed to radiofrequencies. Total developmental times from egg to adult emergence were longer with shorter longevity in case of radiofrequency treatment than untreated. Decreasing the radiofrequency level further increased time for development of adults as generation passed. The shortest adult longevity occurred at 5 kHz treatment. The outcomes of this study are discussed in terms of targeting susceptibilities to radiofrequency as an alternative to chemical treatments.     

Influence of nutritional substrates on the development of Diaphania hyalinata L. (Lepidoptera: Crambidae)

The aim of this research was to evaluate the biological behaviour of melonworm at different natural and artificial diets. Squash cultivar jacaré, cucumber, summer squash and an artificial diets developed by Hensley & Hammond for the sugarcane borer were tried. The research was carried out in the Laboratório de Entomologia do Centro de Ciências Agrárias of the Universidade Federal do Espírito Santo, in climatized room at 25 +/- 1 masculineC, relative humidity of 70 +/- 10% and 14h photofase. The caterpillars fed on each substrate during the whole life cycle. Differences in duration of the larval period, larvae and pupae survival, adult longevity and number of eggs were registered between the substrates. The results show that the best diet for rearing is the artificial one. Between the natural diets the cucumber showed the best results.     

Effect of temperature on development and survival in Delias nigrina (Fabricius) (Lepidoptera: Pieridae)

Abstract The effect of temperature on rate of development and survival of the immature stages of a subtropical population of the black jezebel, Delias nigrina , was studied under laboratory conditions at a range of constant temperatures. Mean developmental times from first-instar larva to adult varied from 29 days at 27°C to 52 days at 19°C; the development threshold temperature and thermal constant were estimated to be 9°C and 494 degree-days, respectively. Larval developmental rates reached physiological maximum at the higher temperatures tested (25−27°C). Pupal development, by contrast, was not affected in the same way as larvae by higher temperature. Survival of the immature stages varied inversely with temperature: survival was highest at 19°C and significantly reduced at 27°C. Mortality at the higher temperature was attributable mainly to final-instar larvae and pupae. These findings indicate that, compared with other tropical pierids that have been studied, D. nigrina has: (i) a comparatively low temperature threshold; (ii) a slow rate of development; and (iii) a poor tolerance to moderately high temperatures. Physiologically, these features are more characteristic of a temperate butterfly than a tropical one. This physiological response appears to be reflected by the temperate nature of the genus as a whole, which may be related to its period of origin and evolution during past climatic events.     

Effect of environment on resistance to the European corn borer (Lepidoptera: Crambidae) in maize

The European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), is a major pest of maize, Zea mays L., in many temperate parts of the world. Genotype-by-environment interaction effects can make relative performance unpredictable and may hamper selection for resistance to European corn borer. The objective of this study was to determine the effect of environment on genotypic reaction to European corn borer resistance in maize. A set of 12 maize inbred lines was chosen to represent a range of European corn borer responses. Eleven testing environments ranged from Delaware, Ohio, Illinois, Iowa, Nebraska, Missouri, to Mississippi. For length of stalk tunneling, environmental and genotypic main effects (estimated by restricted maximum likelihood) were >20- and 10-fold larger than their interaction effect, respectively. Length of tunneling means for genotypes (across environments) ranged from 10.1 to 35.4 cm. Several putatively resistant genotypes grouped with the susceptible checks, B73 and Mol7. By breaking factors and the interaction into single degree of freedom components, we observed that GEMS-0001 had significant crossover interactions toward less susceptibility in both Mississippi and the Nebraska environments. Environments displaying several crossover interactions indicated that European corn borer screening at these sites would not necessarily apply to other locations, whether due to small differences in experimental conduct and/or environmental effects. The five most resistant genotypes were fairly consistent across environments. Because all environments except Illinois used larvae from the same insectary, and these environments differed in damage intensity and rankings, it is unlikely that insect biotype was a factor contributing to genotype-by-environment effects.     

Effect of temperature on embryonic development and diapause in Chesias legatella (Lepidoptera: Geometridae)

The changing temperature requirements of Chesias legatella Schiffermüller during embryonic development are investigated. The eggs are laid in the autumn and embryogenesis is interrupted by a short diapause at the germ band stage, after which development proceeds slowly throughout the winter. The effects of temperature during the pre-diapause, diapause and post-diapause phases of development are assessed by examination of the rate and variability of morphogenesis through all the embryonic stages. An examination is presented of the effect of temperature during the late autumn on the rate and uniformity of diapause termination, and consequently on the length of the hatching period the following spring.     

Feminizing Wolbachia in an insect,Ostrinia furnacalis (Lepidoptera: Crambidae)

Wolbachia, which forms a group of maternally inherited bacteria in arthropods, often cause reproduction alterations in their hosts, such as cytoplasmic incompatibility, parthenogenesis, male-killing, hybrid breakdown and feminization. To date, Wolbachia-induced feminization has been reported only in isopods. Here we report that a Wolbachia strain feminizes an insect host, Ostrinia furnacalis. Among 79 wild females of O. furnacalis examined, Wolbachia infection was detected in 13 females. Twelve of the 13 infected females produced all-female progenies, and this trait was maternally inherited. Tetracycline treatment of thelygenic matrilines resulted in the production of all-male progenies. The present findings indicate that the Wolbachia infection induces feminization of genetic males in O. furnacalis. Differences in the Wolbachia-induced feminization in O. furnacalis and that in isopods are discussed along with the differences in sex determination mechanisms between insects and isopods. Phylogenetic analysis of the wsp gene sequence of Wolbachia suggests independent evolutionary origins for the Wolbachia-induced feminizations in O. furnacalis and in isopods. Our findings over 5 years suggest that the infection has been maintained at a low prevalence in the O. furnacalis population.     

Effects of temperature on the development of overwintering immature stages of the near‐threatened butterfly Leptalina unicolor (Bremer & Grey) (Lepidoptera: Hesperiidae)

Overwintering larvae of multivoltine and univoltine populations of Leptalina unicolor were reared under various constant and fluctuating temperatures superimposed on a photoperiod of either 12 h of light and 12 h of darkness (LD 12:12) or LD 15:9. Diapause of the larvae terminated in midwinter (by early February). All the larvae of both populations pupated after two molts without feeding and the head capsule width of the final instar larvae was smaller than that of the penultimate instar ones. The photoperiod did not significantly affect larval development, but long‐day conditions (LD 15:9) hastened pupal development. The thermoperiod had a significant effect on the development of the multivoltine population. When multivoltine population larvae were kept under a low fluctuating temperature regime (cryophase/thermophase = 14/20°C), the period until adult eclosion was shorter than that under a constant temperature of 17°C. On the contrary, when larvae were kept under a high fluctuating temperature regime (24/30°C), the period until adult eclosion was longer than that under a constant temperature of 27°C. However, the univoltine population did not show such a reaction to the fluctuating temperature. The durations of final instar larva and pupa of the multivoltine population were shorter than those of the univoltine population. The developmental zeros of penultimate and final instar larvae and pupae of the univoltine population were lower than those of the multivoltine population. The head capsule width of penultimate instar larvae and the forewing length of adults of the univoltine population were larger than those of the multivoltine population for both sexes.     

窗斑野螟属分类学研究（鳞翅目：草螟科：野螟亚科）

窗斑野螟属Discothyris Warren, 1895包含3种：锈斑窗斑野螟D. ferruginata (Moore, 1888),大冠窗斑野螟D. megalophalis Hampson, 1899和痕窗斑野螟D. vestigialis (Snellen, 1890)。本文基于外生殖器特征确认了窗斑野螟属为野螟亚科成员,对该属进行了重新描述,首次记录了痕窗斑野螟在中国的分布,并提供了成虫和外生殖器特征图以及分种检索表。     

Ecology of aquatic Lepidoptera (Crambidae: Nymphulinae) in South Carolina, USA

An ecological study was conducted in May and June of 1995 and 1996 in South Carolina to determine the factors associated with distributions of aquatic Lepidoptera (Crambidae: Nymphulinae). Larvae were found at 65 lotic and lentic sites in three ecoregions (Piedmont, Sandhills, Coastal Plain). Nine species of aquatic Lepidoptera were collected from 12 species of aquatic vascular macrophytes. One to six plant species were used as hosts, depending on the species of lepidopteran; however, the number of host plants used by a lepidopteran was significantly correlated with the lepidopteran's frequency of occurrence. Significant habitat associations were found for five species. Langessa nomophilalis (Dyar) was found under the widest range of temperature and width and occurred in both lotic and lentic habitats. Munroessa icciusalis (Walker) was found in lotic and lentic habitats and had the widest range of recorded depths. Parapoynx maculalis (Clemens) occurred at stream sites with lentic-like conditions. Parapoynx obscuralis (Grote) occupied the widest range of pH and was restricted to lotic habitats, and P. seminealis (Walker) was found in both lotic and lentic habitats. Additional species, collected at fewer than 8% of sites, included M. gyralis, P. allionealis, Synclita obliteralis, and S. tinealis. Overall, the distributions of aquatic Lepidoptera in South Carolina were nonrandom and predictable on the basis of habitat characteristics. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effect of trap type, trap color, trapping location, and pheromone dispenser on captures of male Palpita unionalis (Lepidoptera: Pyralidae)

Field studies were conducted to evaluate the influence of trap design, trapping location, type of pheromone dispenser, and trap color on the capture of Palpita unionalis (Hübner) males, in olive groves. The experiments were carried out in two regions, Alexandria (northern Greece) and Oropos (central Greece), where olives are cultivated. In both regions, the majority of the males (> 70% of the total) were caught from late autumn to early winter, whereas < 1% was caught during July and August. Among the trap types used, the Funnel was significantly more attractive than Delta, Pherocon 1C, and Pherocon II traps. More males were caught in traps placed at the periphery of the groves than those placed in the center. Among the four colored traps tested, white traps were the most effective. However, a significant difference in trap catches was found between white and brown traps. Traps baited with red rubber septa captured more males than those baited with the white one. The use of these parameters in monitoring and managing P. unionalis is discussed.     

Effect of learning on the oviposition preference of field-collected and laboratory-reared Chilo partellus (Lepidoptera: Crambidae) populations

Recent studies show that Vetiver grass, (Vetiveria zizanioides (L.) Nash), may have potential as a dead-end trap crop in an overall habitat management strategy for the spotted stem borer, Chilo partellus (Swinhoe) (Lepidoptera: Crambidae). Vetiver grass is highly preferred for oviposition, in spite of the fact that larval survival is extremely low on this grass. The oviposition behaviour of female Chilo partellus moths was investigated by determining the amount and size of egg batches allocated to maize and Vetiver plants and studying the effect of rearing conditions and oviposition experience on host plant selection. Two-choice preference tests were used to examine the effect of experience of maize (a suitable host plant) and Vetiver plants on the oviposition choice of C. partellus. For both field-collected and laboratory-reared moths, no significant differences were found in the preference distributions between the experienced groups. It is concluded that females do not learn, i.e. that they do not change their preference for Vetiver grass after having experienced oviposition on either maize or this grass, which supports the idea that trap cropping could have potential as a control method for C. partellus. Differences observed between field-collected and laboratory-reared moths in the amount and size of egg batches laid on maize and Vetiver grass indicate that data obtained from experiments with laboratory-reared insects should be treated with caution.     

Effect of multiple mating on the reproductive performance of the rice leaffolder moth,Cnaphalocrocis medinalis (Lepidoptera: Crambidae)

To clarify whether multiple mating of females and males affects the reproductive performance of the rice leaffolder moth, Cnaphalocrocis medinalis (Guenée), we examined the effect of the number of matings (once, twice, or three times) for females (female treatment) and males (male treatment) on the incidence of moth mating, number of eggs laid, egg hatchability, and adult longevity. We also compared the effect of multiple mating imposed on males or females separately with the effect of that imposed on both sexes simultaneously (both sexes treatment). The incidence of mating of females and males that mated three times (3-mated females and males) was significantly lower than for females and males that mated twice or once (2-mated or 1-mated females and males). The incidence of mating of 1-mated moths (both sexes) was significantly higher than for 2-mated or 3-mated moths (both sexes). Two-mated or 3-mated females laid significantly more eggs with significantly higher hatchability than 1-mated females. Females that mated with 1-mated males (second male mating) or 2-mated males (third male mating) laid significantly fewer eggs than those that mated with virgin males (first male mating). Females laid significantly more eggs after the second and third matings for moths of both sexes than after the first mating for moths of both sexes. The mechanisms of improvement and decline of female reproductive performance when multiple mating was imposed on males or females are also discussed in relation to the reproductive biology of C. medinalis.     

温度对荔枝异形小卷蛾发育和繁殖的影响

荔枝异形小卷蛾的蛀梢为害是珍贵树种格木人工林健康发展的主要限制因子。依据其天然分布和潜在推广区的温度范围设置系列温度梯度,探讨温度对荔枝异形小卷蛾发育和繁殖的综合影响。结果显示,温度对荔枝异形小卷蛾各阶段的发育历期具有显著影响,在研究温度范围内,发育历期随温度升高呈显著地下降趋势,世代历期在18℃时为66.87 d,30℃时降至35.77 d。预蛹和蛹的存活率对温度的响应不敏感,而卵、幼虫、成虫的存活率和世代存活率以及产卵量均随温度升高表现为先上升后下降的变化趋势,且繁殖力对温度的反映较存活率敏感,其存活率和繁殖力在18℃时均最低,分别为41.20%和13.90粒,在27℃时发育最适,分别为83.80%和45.40粒,在30℃时虽有下降,分别为66.00%和32.40粒,但仍高于18℃时,即其对低温较高温敏感。荔枝异形小卷蛾完整世代发育起点温度为5.77℃,所需有效积温为876.76 d℃,其中幼虫发育所需有效积温最高,占整个历期的45.23%,发育速率与温度显著正相关。根据荔枝异形小卷蛾为害方式、发育和繁殖特征分析可知,在低温地区其幼虫期长,但世代数少、存活率和繁殖力低,对寄主植物受害部位的单次为害程度严重;在高温地区则幼虫期短,但世代数多、存活率和繁殖力高,对寄主植物受害部位的单次为害程度低,但更为频繁,持续为害程度高。研究结果对于不同地区选择荔枝异形小卷蛾的防治具有借鉴意义,同时有助于指导格木人工林的合理推广和健康发展。     

稻纵卷叶螟幼虫驯化产生的热适应能力的继代效应

摘要: 【目的】在全球不断变暖背景下,昆虫受到热胁迫的频率不断增加。短期内反复受到热胁迫会使昆虫产生热适应性,但是昆虫热驯化所产生的耐热能力的传代效应还不完全清楚。稻纵卷叶螟Cnaphalocrocis medinalis是水稻上的重要害虫,对其幼虫在特定温度下进行几代热锻炼可提高其对高温的适应能力。本研究旨在摸清稻纵卷叶螟热适应的传代能力,为在全球变暖形势下以温度因子预测其种群发展趋势提供指导。【方法】将实验室内分别经39℃和41℃连续锻炼30代建立的稻纵卷叶螟热锻炼品系HA39和HA41以及非锻炼品系HA27的1-5龄期幼虫在不同温度(36℃和41℃)下进行不同时长(1~144 h)的暴露处理,调查幼虫的存活率,确定热锻炼品系幼虫的耐热能力;采用两品系间杂交实验测定HA39和HA27各交配组合的繁殖力及后代3龄幼虫的耐热能力;对HA39停止高温锻炼,并测定停止锻炼2代后3龄幼虫的耐热能力。【结果】稻纵卷叶螟3龄幼虫经历多代次短期热锻炼不仅可提高该龄幼虫的高温适应力,而且可提高其他龄期幼虫对特定高温的耐受能力,表现为HA39和HA41在36或41℃下处理特定时长的存活率显著高于HA27。锻炼高温的不同,幼虫获得的热耐受能力也有差异。39℃下锻炼可提高4龄幼虫在36℃下暴露2和4 d以及5龄幼虫在41℃下暴露5和6 h时的存活率,但41℃下锻炼则不可。HA39和HA27的自交及杂交后代的繁殖力之间均无显著差异,杂交后代3龄幼虫在41℃下处理5和6 h时的存活率与HA39自交后代的相当,并且显著高于HA27自交后代的,幼虫通过热锻炼获得的耐热能力可从亲本遗传给后代。停止热锻炼2代后,在39℃下处理4 h时HA39 3龄幼虫的存活率显著高于HA27的,但39℃下其余处理时间以及36和41℃下处理1~7 h HA39 3龄幼虫的存活率均与HA27的无显著差异,表明幼虫热锻炼产生的耐热能力在停止锻炼后2代仍可部分保持。【结论】稻纵卷叶螟幼虫的热适应能力具有继代效应。经过长期的气候变暖适应后,稻纵卷叶螟种群的热适应能力很可能在不断增强,从而夏季高温对其种群的抑制作用减弱,其种群暴发频率增加。