Effect of host age at parasitization by Aphidius sonchi on the development, survival, and reproduction of the sowthistle aphid, Hyperomyzus lactucae

Nineteen cohorts of Hyperomyzus lactucae (L.) (Homoptera: Aphididae) reared at various temperaturelight regimes were exposed to attack by Aphidius sonchi Marshall (Hymenoptera: Aphidiidae) at different ages of their development. Irrespective of host age at the initial parasitization and rearing conditions, the rates of reproduction, development and survival were unaffected until the parasites within had completed approximately 30, 40 and 55% of their total development respectively. As a result, aphids parasitized in the first or early second instar failed to reach maturity. Thereafter, the numbers of young produced by parasitized aphids increased rapidly as the age of the hosts at initial parasitization increased, and aphids parasitized 3 days after the final moult or later showed similar potential to contribute to future population increase.In comparison with the effects on host moulting, those on wing development of the potentially alatiform nymphs appeared much sooner after the beginning of parasitization, but again with the time lags being more or less independent of host age at the initial parasite attack. Consequently, the extent of wing development depended entirely on the age of the hosts when attacked.These results showed that the age of the host at the initial parasite attack is crucial in determining the consequences of parasitization on the host.

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Résumé Dix-neuf cohortes d'Hyperomyzus lactucae L. (Homoptera: Aphididae), élevées dans différentes conditions de lumière et de température, ont été exposées à différents moments de leur développement aux attaques d'Aphidius sonchi Marsh. (Hym. Aphidiidae). Quels que soient les conditions d'élevage et l'âge des pucerons quand ils ont été parasités, la survie, le développement et la reproduction n'ont été affectés que lorsque les parasites avaient accompli 30, 40 et 55% de leur développement total. Ainsi, les pucerons parasités au premier stade ou au début du second ne parvenaient pas à atteindre la maturité. Par la suite, le nombre de jeunes produits par les pucerons parasités a cru rapidement au fur et à mesure que l'âge de ces derniers au moment où ils avaient été parasités la dernière mue ou plus tard présentaient la même potentialité pour contribuer à l'accroissement ultérieur de la population.Comparés aux effets sur la mue, les effets sur le développement alaire des larves potentiellement ailées apparaissent beaucoup plus tôt après le moment où le puceron a été parasité, mais là aussi avec des délais plus ou moins indépendants de l'âge de l'hôte lors de la première attaque du parasite. Par conséquent, le degré de développement des ailes dépendait totalement de l'âge du puceron lorsqu'ila été parasité.Ces résultats ont montré que l'âge du puceron lors de la première attaque détermine les conséquences du parasitisme de l'hôte.

     

Photoperiodic control of sexual morph production by the currant-sowthistle aphid, Hyperomyzus lactucae

Sexual morph production in Hyperomyzus lactucae (L.) is under photoperiodic control. In southern England oviparae are not produced in night lengths of less than 10 h 40 min at 15 ° C but males are produced in all night lengths between 8 and 14 h with a peak between 10 and 12 h. Old clones produce sexual morphs after fewer generations and via a limited sequence of morphs compared to young clones, but the restraining mechanism in young clones is very variable in the extent of its operation.

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Résumé La production des sexués chez Hyperomyzus lactucae est sous un déterminisme photopériodique, mais les mécanismes qui provoquent la production des ovipares et des mâles sont indépendants et contrôlés par des stimulus photopériodiques différents. La durée de la scotophase pour la production des ovipares est déterminante et d'environ 10 h 40 pour les clones étudiés. Il n'y a pas de production d'ovipares à 15° C en scotophase plus courte. Par contre, des mâles sont produits à toutes les scotophases étudiées entre 8 et 14 h, atteignant un pic entre 10 h 20 et 12 h, mais avec diminution de leur apparition encore plus nette quand les nuits se prolongent.La diversité des conditions tendant à produire des sexués chez les jeunes clones fait contraste avec le nombre limité de possibilités chez les clones plus âgés et prouve qu'un mécanisme réduit dans certains cas la sensibilité à la scotophase tôt dans l'année. Mais, même dans un seul clone, la variation causée par un tel mécanisme est considérable.Il semble que la longueur de la scotophase critique chez cet insecte suffise seule à empêcher la production de sexués au printemps dans le sud de l'Angleterre. Ceci peut donc expliquer les variations du mécanisme restrictif qui, vraisemblablement, ne doit pas être important pour la survie des clones de cette région.

     

光周期和温度对枯叶蛱蝶幼虫生长发育的影响

在人工气候箱中研究不同光周期和温度条件下枯叶蛱蝶Kallima inachus Doubleday幼虫的生长发育情况。结果表明,20℃时,光周期对枯叶蛱蝶幼虫发育历期影响明显,25℃和30℃时无明显影响。20,25和30℃,12.5~14h光照下,幼虫发育历期分别为31.7~36.0,26.3~27.4和21.0~21.5d,最长和最短历期分别相差4.3,1.1和0.5d。随着温度升高,在相同光照下,幼虫发育历期缩短。20,25和30℃12.5~14h光照下幼虫存活率分别为80%~92%、75%~95%和55%~85%,随温度上升,不同光周期下幼虫存活率差异加大。30℃时大部分光周期下存活率较低,已对幼虫生长发育不利,人工养殖时温度不宜超过30℃。     

温度和光周期对斑翅食蚧蚜小蜂发育与繁殖的影响

斑翅食蚧蚜小蜂是橡副珠蜡蚧的重要寄生性天敌之一。研究了温度和光周期对斑翅食蚧蚜小蜂发育、寄生及繁殖等方面的生态学特性。研究表明:温度和光周期对斑翅食蚧蚜小蜂种群增长影响明显。在32℃下不能完成世代发育,在温度为18-27℃范围内随温度升高发育加快,18℃发育历期最长(54.0d),27℃最短(22.8d);世代发育起点温度和有效积温分别为12.76℃和307.62日度。高温和低温均不利于斑翅食蚧蚜小蜂寄生,21℃时寄生率最高为(36.0%),30℃时寄生率最低(4.5%)。结合发育历期、体长、产卵、抱卵、寄生率等参数,该蜂发育繁殖的适宜温度为21-27℃度范围内,30℃以上不利于小蜂的发育及存活。斑翅食蚧蚜小蜂对长光的刺激比较敏感,随光照时间增长,发育加快、产卵量明显增加,长日照条件(LD16∶8h)的发育历期最短(24.8d),短日照条件(LD10∶14h)的最长(27.8d),产卵量在长日照条件(LD16∶8h)时最多(119.6粒),短日照条件(LD10∶14h)时最少(86.2粒)。结合发育、产卵、寄生等参数,长日照条件(LD14∶10-LD16∶8h)有利于种群增长。     

Bionomics and population growth statistics of apterous virginoparae of woolly apple aphid, Eriosoma lanigerum, at constant temperatures

Development, survival, reproduction and population growth statistics of apterous virginoparae of woolly apple aphid, Eriosoma lanigerum (Hausmann) (Hemiptera: Aphididae) at constant temperatures of 10, 13, 15, 20, 25, 30 and 32°C are reported. The developmental times of all life stages were inversely related to temperature ranging from 10 to 30°C. Span of total development (time from birth to adulthood) decreased from 57.8 days at 10°C to 11.7 days at 30°C and increased to 16.8 days at 32°C. A good linear model fit (R²>0.96) between developmental rate and temperature in the range 10–25°C was observed for all life stages. The lower developmental threshold was estimated at 5.8°C for instar I, 4.8°C for instar II, 4.9° for instar III and 4.4°C for instar IV. The lower temperature threshold for total development was estimated at 5.2°C. The upper developmental limit was found to be 32°C. Mean degree-day accumulations required for completion of instars I, II, III, IV and total development were: 125.6, 51.0, 47.7, 50.7 and 267.6, respectively. Fecundity, larviposition period and adult longevity were reduced with increasing temperature. Net reproductive rate was greatest at 15°C whereas intrinsic rate of increase peaked at 25°C. Optimal performance, as measured by fecundity, survival and intrinsic rate of increase, ocurred in the range 13–25°C.     

Influence of temperature on bionomics of cotton aphid, Aphis gossypii, on cotton

Life table parameters of Aphis gossypii Glover (Homoptera: Aphididae) on Gossypium hirsutum L. were determined at six temperatures (10, 15, 20, 25, 30, and 35 ± 0.5°C) in the laboratory. Relationships of life table parameters with temperature were described with mathematical equations. Development was fastest at 30°C, with a pre-larviposition period of 4.6 d. Survival to adult was greatest at 25°C (81%). Fecundity was highest at 25°C, with a total fecundity of 28.3 nymphs per female and a mean reproductive rate of 3.1 nymphs per female per day. Threshold temperatures for development in the first through fourth instar and the adult were 8.2, 8.0, 7.2, 6.2 and 7.9°C, respectively. The durations of these stages, expressed as temperature sums above these thresholds, were 24.2, 23.7, 23.0, 25.5 and 168.8 degree-days (D°), respectively. A. gossypii achieved its maximum net reproductive number (24.4 nymphs per female) and greatest intrinsic rate of increase (0.386 d–1) at 25°C. The high relative rate of population increase at 25°C results in a daily population increase of 47% and a doubling time of only 1.8 d, illustrating the tremendous growth capacity of A. gossypii populations under favourable conditions. Compared to literature sources, our source of A. gossypii, fed on cotton, showed a comparatively great heat tolerance.     

Pathogenic variation and sexual reproduction in Swedish populations of Bremia lactucae

Summary The host-pathogen interaction between lettuce (Lactuca sativa) and downy mildew (Bremia lactucae) is mainly differential and the resistance so far utilized in the host is vertical. As in many other obligate parasites, the introduction of cultivars with new vertical resistance has exerted a strong selection pressure on the pathogen resulting in significant changes in virulence frequencies and in the establishment of races with new combinations of virulence. Genetic diversity in pathogen populations may arise through mutation and gene flow, and new virulence genotypes may then be established through parasexuality and sexual recombination. In Swedish populations of Bremia lactucae, the pattern of variation in the parasite agrees well with that which might be expected in a diploid, outcrossing organism with frequent sexual reproduction. This is supported by: two or more isolates, different in virulence and mating type, may occur together on the same lettuce leaf; zygotes (oospores) are formed in all populations investigated and the frequency varies from 22% to 98%; oospores germinate rather frequently under suitable conditions. To breed for resistance in dynamic host-pathogen systems such as this one is difficult and the program should preferably be based on race-non-specific resistance.     

Influence of temperature and daylength on population development ofAphis gossypii onCucurbita pepo

The life table parameters ofAphis gossypii Glover were evaluated in tow sets of experiments onCucurbita pepo. The first set was conducted at six constant temperatures (5°C increments from 10–35°C) with 12 h photophase. The second set of experiments was conducted at 6, 12, and 18 h photophase at 25°C. Nymphal survivorship was 100% at 15, 20, 25 and 30°C. However, it was 80 and 0% at 10 and 35°C, respectively. The optimum temperature for body length was 10°C, and body length decreased with increasing temperature.A. gossypii attained its optimum growth and reproduction at 25°C. At this temperature, the net reproductive rate (79.7), intrinsic rate of increase (0.496) and finite rate of increase (1.6) were largest while generation time (6.6 d) and population doubling time (1.4 d) were smallest. Temperatures above and below 25°C reduced the net reproductive rate, and the intrinsic and finite rates of increase. The intrinsic and finite rates of increase ofA. gossypii reared at 18 h photophase (0.53 and 1.7) were significantly higher than at 12 (0.43 and 1.5) and 6 h daylength (0.49 and 1.6).     

Effects of diet, photoperiod and temperature on the postdiapause reproduction in the cabbage bug,Eurydema rugosa

InEurydema rugosa Motschulsky (Heteroptera: Pentatomidae), the type of food supplied (i.e. seeds or leaves of the brown mustard,Brassica juncea Hemsel) and photoperiod, which control the induction of adult diapause, do not play a role in the initiation of reproduction after overwintering. A temperature above 13.2°C was required to start reproduction. After its initiation, however, short-day conditions on seeds induced diapause again in some adults. Although a diet of seeds under long-day conditions, in common with short-day conditions, induced diapause in young adults (Numata & Yamamoto, 1990), it did not reinduce diapause in adults after overwintering. Thus,E. rugosa that had overwintered became sensitive to diapause-inducing photoperiod again but not to dietary factors.     

光周期对内蒙古三种草原蝗虫高龄若虫发育、存活、羽化、生殖的影响

研究不同光周期(L8∶D16、L12∶D12及L16∶D8)对毛足棒角蝗Dasyhippus barbipes(F.-W.),亚洲小车蝗Oedaleus decorus asiaticus B.-Bidenko,小翅雏蝗Chorthippus fallax(Zub.)3种草原蝗虫高龄若虫的发育、存活、羽化、生殖的影响。结果表明:在白天温度(28±1)℃,黑夜温度(23±1)℃的恒定温度下,不同光周期对毛足棒角蝗和亚洲小车蝗高龄若虫的发育、羽化、产卵影响不大,但是对其存活率有极显著的影响:毛足棒角蝗和亚洲小车蝗高龄若虫到成虫的发育速度在中光照下(L12∶D12)最快。而在短光照(L8∶D16)下更有利于小翅雏蝗若虫发育,其次是中光照;毛足棒角蝗的羽化在中光照条件下最适宜,而长光照时数(L16∶D8)更有利于亚洲小车蝗和小翅雏蝗的羽化;光周期对亚洲小车蝗产卵影响最为明显,毛足棒角蝗和亚洲小车蝗在中光照和长光照时数条件下有利于它们产卵,而小翅雏蝗在短光照和中光照时数下有利于产卵。     

Life table parameters affecting the population development of the woolly beech aphid, Phyllaphis fagi

A detailed study of the basic biological parameters affecting the population development of the woolly beech aphid, Phyllaphis fagi L. (Homoptera: Drepanosiphidae), was performed under field and laboratory conditions in order to obtain information about factors responsible for outbreak situations in forest nurseries. In the nurseries, the aphid eggs have found to hatch before budburst. The newly hatched nymphs were highly active in searching for feeding places, which resulted in higher nymph mortality in the first generation than in the following generations. Ten aphid generations were recorded in the nursery during one growing season. In the laboratory, development time, nymph mortality, reproduction, and adult lifetimes were assessed for P. fagi at four constant temperatures, i.e., 12, 15, 20, and 25 °C through four successive generations. Both temperature and aphid generation were found to affect life table parameters. The first generation, however, was less susceptible to changing temperatures than the following generations. Phyllaphis fagi reproductive effort was more dependent on temperature than on aphid generation. No significant difference was found in reproductive effort between apterous and alate females. The potential for outbreak situations therefore exists throughout the summer. The formation of winged morphs was not restricted to a few generations but rather continued for several months, with activity peaking in all years in mid-June. This had implications for migration to new seedlings in the nurseries. The highest r_m value was obtained at 20 °C. Nymphs born at higher temperatures were sometimes born deformed and unable to survive.     

pH、食物和光周期对福寿螺生长发育和繁殖的影响

以7.5 g左右的成年福寿螺Pomacea canaliculata为对象,研究p H值(2.5—11.5)、光周期(24 h光照、12 h光照和无光照)和食物(喂食和不喂食)三因子的联合作用下对福寿螺生长发育和繁殖的影响。结果表明,无光照和饥饿条件下,福寿螺在酸性p H值4.5和p H值3.5试验的第24天均达到50%致死率,在碱性p H值10.5试验的第21天死亡率达到53.3%;试验第27天,无光照和饥饿条件下,p H值2.5和p H值11.5的死亡率则分别达到最大为66.7%和80%,产卵量均仅为20粒,孵化率分别低至6.06%和5.97%;24 h光照和喂食条件下,p H值7.5试验的第27天福寿螺体重增长率最高,为17.78%(而12 h光照和无光照条件下则分别仅为7.03%和5.47%),但此时产卵量只有180粒,孵化率仅为8.23%,延长孵化历时到16.6 d,而此酸度下12 h光照(最接近于自然节律),最终产卵量达到1600粒,且卵的孵化率高达84.66%,孵化历时为13.53 d。以上结果说明,福寿螺具有较强的耐酸碱和抗饥饿能力,但过酸(p H值≤3.5)和过碱(p H值≥10.5)的环境,也会严重抑制福寿螺的存活、生长发育和繁殖,特别是在福寿螺缺乏足够食物条件下,抑制作用更强;光周期对福寿螺的生长发育和繁殖影响较大,连续24 h光照会极大地刺激福寿螺的体重增长,但同时会干扰福寿螺繁殖,减少产卵量和卵的孵化率,延长孵化历时;而12 h光照在3种光照条件下最有利于福寿螺的生长发育和繁殖;完全黑暗则会严重抑制福寿螺的生长发育及降低其繁殖能力。     

Role of photoperiod in the development and reproduction of Harmonia axyridis (Coleoptera,Coccinellidae)

To improve the laboratory mass rearing and the winter greenhouse use of the multicoloured Asian lady beetle Harmonia axyridis (Pallas) (Coleoptera, Coccinellidae), the effects of photoperiod on the development and fecundity of H. axyridis were investigated at 20°C and photoperiods ranging from 0L:24D to 24L:0D. We foun'd photoperiod to significantly affect the pre-imaginal development and reproduction of H. axyridis. The development of the pre-imaginal stage was significantly faster at shorter photoperiods (0–14?h) than at longer ones (16–24?h). The proportion of females laying eggs within the first 30 days after eclosion, the mean number of eggs per ovipositing female, and the long axial length of the first oocyte were all lower at shorter photoperiods (6–12?h) than at longer ones (14–24?h). These results suggest that adult H. axyridis may encounter problems in preying and reproducing in the winter conditions of unheated and unilluminated greenhouses in areas with temperatures lower than 20°C and day lengths shorter than 12?h.     

温度对取食芦笋蓟马的巴氏钝绥螨生长发育、存活和繁殖的影响

观察了巴氏钝绥螨Amblyseius barkeri Hughes在5种温度(15、20、25、30和35℃)、食料为芦笋蓟马,相对湿度72%,L∶D=12∶12条件下的发育历期、存活率和繁殖力。结果表明:巴氏钝绥螨卵、幼螨、前若螨、后若螨及世代发育历期在15℃下最长,随着温度的升高而缩短,35℃下最短。产卵前期在15～30℃下,随温度的上升而缩短,35℃下稍有延长。存活率15℃下最低,随温度的上升而提高,30℃下最高。产卵量15℃下最少,其次是35℃,20～30℃下产卵量较多。根据实验结果,组建了巴氏钝绥螨以芦笋蓟马为食料在5种不同温度下的实验种群生命表。     

The role of temperature, photoperiod, crowding and plant quality on the production of alate viviparous females of the bird cherry-oat aphid,Rhopalosiphum padi

Experiments indicated that for offspring of apterousRhopalosiphum padi (L.) (Hemiptera: Aphididae), photoperiod and crowding were the most important determinants of wing development whereas crowding and plant quality were more significant for the next generation. Plant quality became increasingly important as temperature increased while crowding became less so. More alates developed on plants previously infested with aphids, indicating that aphid feeding reduced plant quality. High temperature suppressed alatoid production, but could be overcome by crowding. Temperature appeared to influence wing development indirectly rather than directly by acting on the aphid through the plant. Adult weight and potential fecundity were also reduced for aphids which fed on previously infested plants.     

温度对胡萝卜微管蚜生长发育繁殖的影响

【目标】明确温度对胡萝卜微管蚜Semiaphis heraclei(Takahashi)生长发育和繁殖的影响。【方法】在室内5个温度梯度下(19、22、25、28、31℃)观察并比较胡萝卜微管蚜的发育历期、存活率、存活寿命及产仔量。【结果】在19?31℃范围内,胡萝卜微管蚜各龄期及完整世代的发育历期均随着温度的升高而缩短,完成一个世代分别需要22.17、17.13、12.57、10.03和7.83 d。温度与发育速率呈极显著相关(P<0.01,r>0.8),温度越高发育速率越快。胡萝卜微管蚜4个若蚜期和世代的发育起点分别为14.15、13.87、13.64、15.06、12.92℃,有效积温分别为29.98、29.30、28.54、24.00和144.21日?度。建立了胡萝卜微管蚜各个发育阶段的历期预测式。在5个恒温下胡萝卜微管蚜1?4龄及世代的存活率随温度的变化而小幅波动。在19?31℃范围内,该蚜虫世代的存活率分别为40.0%、52.5%、62.5%、60.0%和47.5%。25℃该蚜虫的存活率相对较高,1?4龄及世代的存活率分别为82.5%、81.8%、92.6%、100%和62.5%。在相同温度条件下该蚜虫不同发育阶段的存活率存在差异。存活寿命随着温度的升高而缩短,19℃时寿命最长,为33.30 d,31℃时寿命最短,为15.40 d。产仔期随着温度的升高而缩短,19℃时产仔期为11.13 d,31℃时为7.57 d。在19?31℃范围内,该蚜虫的单雌产仔总量分别为26.33、27.93、32.53、27.13和17.93头。【结论】温度是影响胡萝卜微管蚜的生长发育、存活和繁殖的重要因素。25℃时胡萝卜微管蚜各龄期及世代的发育历期较短,存活率较高,单雌产仔总量最大。25℃较适合该蚜虫生长发育和繁殖。     

Comparative life table statistics for the ladybeetle Scymnus syriacus reared on the green citrus aphid,Aphis spiraecola,fed on two host plants

Demographic statistics for the ladybeetle Scymnus syriacus Marseul (Coleoptera: Coccinellidae) were investigated when reared on the green citrus aphid, Aphis spiraecola Patch (Homoptera: Aphididae), fed on two host plants: spirea (Spirea sp.) and Thompson orange (Citrus sinensis cv. Thompson) under laboratory conditions (25 ± 1°C, 65 ± 5% relative humidity and 16 h light : 8 h dark). Mean developmental times from egg to adult were 20.32 ± 0.18 and 22.07 ± 0.15 days for spirea and Thompson orange, respectively. The survival rate from egg to adult was higher for spirea (85%) than for Thompson orange (72.5%). The oviposition periods were 41.8 ± 2.47 and 39.71 ± 2.6 days and the total number of eggs per female were 657.6 ± 29.5 and 587.9 ± 32.6 on spirea and Thompson orange, respectively. Fertility life tables were also constructed to compare the effects of host plants. The intrinsic rate of increase (r_m) on spirea was higher than that on Thompson orange. Jackknife estimates of r_m varied from 0.149 on spirea to 0.133 on Thompson orange. The mean population generation times on these host plants were 38.16 and 40.65 days, respectively. These results indicate that spirea‐fed A. spiraecola is more suitable for S. syriacus, producing a higher survival rate and shorter developmental time.     

Effects of pattern and timing of high temperature exposure on reproduction of the rose grain aphid, Metopolophium dirhodum

Metopolophium dirhodum (Walker) (Hemiptera: Aphididae) is one of the three most important cereal aphid species in Germany and central European countries. High temperature is known to play a detrimental role in the reproduction and survival of aphids. Detailed experiments were conducted to assess the effects of high temperatures (27, 29, 31, and 33 °C), exposure pattern (8 h day^?1 for 1, 2, 4, and 6 days), and exposure development stage (2nd, 3rd, 4th instar larvae, and adult) on the reproduction and longevity of M. dirhodum. All three factors have a significant influence on the aphids. Increasing the temperature to over 29 °C significantly decreases their lifetime fecundity and longevity. Mature aphids are more sensitive to high temperatures than younger ones. A high temperature pulse to treat aphids older than 3rd instar larvae greatly shortened their longevity and lessened their lifetime fecundity. Lifetime fecundity and longevity was found to be inversely related to exposure pattern. A high temperature pulse lasting longer than 1 week greatly reduced the lifetime fecundity and longevity. The limitation of the data collected from experiments at constant temperatures for aphid forecasting is discussed.     

温湿度对番茄刺皮瘿螨实验种群的影响

在同一湿度（53%RH）不同温度（14℃、17℃、20℃、23℃、26℃、29℃、32℃、35℃及同一温度（26℃）不同湿度（30%RH、53%RH、75.5%RH、85%RH、92.5%RH、100%RH）组合条件下,测定了温湿度对番茄刺皮瘿螨Aculops lycopersici (Massee)生长发育及繁殖的影响。结果表明,温、湿度对该螨存活率有明显影响,以23℃（53%RH）和75.5%RH（26℃）条件下最高,分别为89.9%和87.1%; 其发育历期较短,在14～35℃和30%～100%RH范围内,历期随温度升高而缩短,随湿度升高而延长; 番茄刺皮瘿螨的发育起点温度较高,卵、若螨和整个世代的发育起点温度分别为10.51、9.02和9.15℃。完成一代需要105.56日·度。温湿度对番茄刺皮瘿螨的繁殖力有明显影响,产卵期随温度升高而缩短,随湿度升高而延长; 产卵量在26℃(53%RH)和53%RH(26℃)下最高,每头雌虫产卵分别为44.3粒和42.2粒; 26℃(53%RH)和53%RH(26℃)条件下种群的内禀增长率最高,分别为0.2645和0.2669。结果表明,适宜的温湿度条件为温度26～29℃、相对湿度53%～75%。     

The influence of temperature, photoperiod and plant type on the predation rate of Macrolophus pygmaeus on Myzus persicae

The effect of temperature and photoperiod on the rate of predation of nymphs and adults of the predator Macrolophus pygmaeus was studied using Myzus persicae prey feeding on egg-plant and pepper plants. The experiments were conducted at three photoperiods (16L:8D, 12L:12D and 8L:16D), three temperatures (20, 25 and 30 °C), and at 65% r.h. The rate of predation increased with temperature. Predation rate was affected by photoperiod on pepper but not on egg-plant. Females and fifth instar nymphs were the most voracious stages followed by third and fourth instar nymphs and males. First and second instar nymphs consumed far fewer aphids. Predation rate was higher on leaves of pepper than egg-plant, especially at 30 °C. Variation in the efficacy of this predator is discussed.