南方水稻黑条矮缩病对褐飞虱和白背飞虱体内三种保护酶活性的影响

为探寻植物感染病毒病后对刺吸性害虫体内生化酶活性的影响,本文研究了感染南方水稻矮缩病毒(Southern rice black-streaked dwarf virus,SRBSDV)的水稻对褐飞虱Nilaparvata lugens和白背飞虱Sogatella furcifera成虫及若虫体内三种保护酶活性的影响。结果表明,取食染病水稻的白背飞虱和褐飞虱成虫及若虫体内超氧化物歧化酶(superoxide dismutase,SOD)、过氧化物酶(peroxidase,POD)和过氧化氢酶(catalase,CAT)的活性均随取食时间的延长而增加。在带毒水稻上取食12 h后,白背飞虱成虫、褐飞虱成虫、若虫体内SOD活性与对照比差异不显著外,其他均显著高于对照;取食24 h后,白背飞虱若虫体内SOD、POD活性和褐飞虱若虫SOD活性虽高于对照但未达显著水平;取食5 d后,白背飞虱若虫、褐飞虱成虫、若虫POD活性未达显著外,其他均显著高于对照。以上研究结果可为进一步研究植物-病毒-寄主三种之间的关系提供参考。     

外源激素对褐飞虱翅型分化的影响

该文报道外源蜕皮激素(ED)和保幼激素类似物(JHA)对褐飞虱Nilaparvata lugens (Stal)翅型分化及体内酯酶活性、可溶性糖和游离氨基酸含量等的影响。褐飞虱在3、4龄若虫期经JHA处理后,所羽化出的成虫短翅型比例明显升高;而在5龄若虫期处理,所羽化出成虫的短翅型比例无明显变化。ED处理能增加3、4龄若虫体内酯酶活性、可溶性糖及游离氨基酸含量,而JHA处理则能有效地抑制ED的这些生物活性,这可能是JHA处理后褐飞虱成虫短翅型比例提高的生理生化基础。     

三种杀虫剂对褐飞虱海藻糖含量和海藻糖酶活性的影响

为了解农药处理导致褐飞虱Nilaparvata lugens (Stål）飞行能力增强的生理机制, 本文采用蒽酮法和酶促反应终止法, 研究了吡虫啉、 三唑磷和溴氰菊酯3种杀虫剂亚致死剂量对褐飞虱3龄、 5龄若虫及长、 短翅型雌雄成虫体内海藻糖含量和海藻糖酶活性的影响。结果表明： 杀虫剂处理的褐飞虱3龄若虫海藻糖含量和海藻糖酶活性与对照相比没有显著差异（P>0.05）。40 mg/L三唑磷处理的褐飞虱5龄若虫体内海藻糖含量显著低于对照（P<0.05）, 比对照降低了24%; 而20和40 mg/L三唑磷处理的褐飞虱5龄若虫海藻糖酶活性显著高于对照（P<0.05）, 分别比对照高出了100%和129%。10 mg/L吡虫啉, 20 和40 mg/L三唑磷以及3和6 mg/L溴氰菊酯处理的褐飞虱短翅雌成虫和雄成虫体内海藻糖含量显著低于对照（P<0.05）, 雌成虫体内海藻糖含量比对照分别降低了36%, 53%, 67%, 58%和69%, 雄成虫体内海藻糖含量比对照分别降低了59%, 71%, 65%, 70%和77%; 而40 mg/L三唑磷以及3和6 mg/L溴氰菊酯处理的褐飞虱短翅型雌成虫和雄成虫体内海藻糖酶活性显著高于对照（P<0.05）, 雌成虫体内海藻糖酶活性比对照分别高出了124%, 100%和88%, 雄成虫体内海藻糖酶活性比对照分别高出了146%, 132%和118%。10 mg/L吡虫啉, 40 mg/L三唑磷和3 mg/L溴氰菊酯处理的褐飞虱长翅型雌成虫和雄成虫海藻糖含量显著低于对照（P<0.05）, 雌成虫海藻糖含量比对照分别降低了44%, 34%和37%, 雄成虫体内海藻糖含量比对照降低了48%, 54%和43%; 而5和10 mg/L吡虫啉处理的长翅型雌成虫和雄成虫海藻糖酶活性显著高于对照（P<0.05）, 雌成虫体内海藻糖酶活性比对照分别高出了317%和300%, 雄成虫体内海藻糖酶活性比对照分别高出了170%和97%。这些结果说明这3种杀虫剂亚致死剂量处理可以增强褐飞虱体内海藻糖酶活性, 并导致海藻糖含量下降。本研究结果对深入阐明农药诱导褐飞虱再猖獗及杀虫剂处理增强其飞行能力的生理机制具有一定的科学价值。     

高温对稻褐飞虱发育与生殖的影响

通过高温处理及交配产卵实验,探讨了高温对稻褐飞虱Nilaparvata lugens (Stal)发育与生殖的影响。研究了不同高温条件对褐飞虱若虫发育历期、产卵量、产卵前期、寿命等生物学特性的影响。34℃以上高温导致褐飞虱若虫发育历期延长。高温处理4龄若虫使羽化后的雌成虫产卵量减少。高温处理不同日龄雌成虫也致使其产卵量减少,其中以1日龄短翅型、3日龄长翅型的产卵量影响最大。高温处理后褐飞虱寿命缩短。高温恒温处理,对短翅型雌成虫的产卵前期影响不大,但能延长长翅型雌成虫的产卵前期;而高温变温处理致使短、长翅型雌成虫的产卵前期均延长。高温变温对褐飞虱生殖的影响程度大于高温恒温。高温处理组雌、雄成虫与对照组相应的成虫交配试验表明,高温对雌性的影响大于雄性。实验初步确定34℃为对褐飞虱发育与生殖产生影响的临界温度。     

水稻麦黄酮对褐飞虱的抗性潜力

使用石油醚、乙酸乙酯、无水乙醇和水依次对抗性水稻品种IR36乙醇提取物进行萃取,并测试了4种萃取物对褐飞虱的活性。结果发现乙酸乙酯萃取物处理后3d的活性最强,褐飞虱1～2龄若虫和3～4龄若虫的死亡率分别是26．0％和48．0％。乙酸乙酯萃取物经柱层析分离得到麦黄酮。将麦黄酮定量加入人工饲料中饲养褐飞虱3龄若虫15d。结果表明,褐飞虱3、4龄若虫的排蜜露量随着麦黄酮在饲料中浓度（50～500μg／ml）的增加而减少,褐飞虱3、4龄若虫的死亡率却随着麦黄酮在饲料中浓度的增加而显著提高。当饲料中麦黄酮的浓度为500μg／ml时,褐飞虱3、4龄若虫的死亡率分别为58．21％和31．75％。麦黄酮50～500μg／ml浓度处理,褐飞虱3龄和4龄若虫的发育历期和相对生长量与对照之间没有明显的差异,表明麦黄酮有拒食作用。用500μg／ml的麦黄酮溶液涂抹到对褐飞虱敏感的水稻品种TN1植株上对褐飞虱雌成虫有明显的拒食作用和忌避产卵作用。本项研究结果表明水稻源的麦黄酮在水稻对褐飞虱的抗性中有重要的作用。     

黄龙病病菌在柑橘木虱体内的分布及感染动态

【目的】柑橘木虱Diaphorina citri Kuwayama是传播黄龙病病菌唯一的自然媒介昆虫,本文研究了黄龙病病菌在柑橘木虱各个发育阶段体内的分布以及感染动态,为有效防控柑橘木虱提供科学数据。【方法】利用常规PCR检测柑橘木虱若虫体内的黄龙病病菌,利用q RT-PCR和荧光原位杂交技术分别检测黄龙病病菌在柑橘木虱不同发育虫态体内的含量与分布形式。【结果】常规PCR可以在3-5龄若虫以及成虫体内检测到黄龙病病菌,而q RT-PCR除了3-5龄若虫外,还可以在2龄若虫体内检测到黄龙病病菌。卵和各龄期若虫中黄龙病病菌的含量是随着龄期的变大而不断增多。产卵盛期的成虫木虱体内黄龙病病菌的含量最高,显著高于产卵前期以及产卵后期。荧光原位杂交技术可以检测到4龄、5龄若虫及成虫体内的黄龙病病菌分布形态,病菌在若虫主要分布在U型含菌体内,而在雌雄成虫体内均是散布型分布。【结论】柑橘黄龙病在柑橘木虱的2-5龄若虫及成虫中都有感染,但其含量与分布形式因发育阶段不同而有显著差异。     

越南斧瓢虫对烟粉虱的捕食作用

【目的】烟粉虱Bemisia tabaci(Gennadius)是一种外来入侵性的重大农业害虫,越南斧瓢虫Axinoscymnus apioides Kuznetsov&Ren是其重要的捕食性天敌之一,本文系统研究了越南斧瓢虫对烟粉虱的捕食作用。【方法】在温度误差为±1℃,相对湿度为75%,光照周期为L︰D=14︰10条件下,测定瓢虫成虫对烟粉虱各虫态的功能反应和不同温度下对烟粉虱4龄若虫的功能反应以及测定瓢虫成虫取食烟粉虱4龄若虫个体间的干扰反应。【结果】结果表明,越南斧瓢虫对烟粉虱的功能反应呈HollingⅡ型,随着猎物龄期的增加,越南斧瓢虫成虫的寻找效率(a)逐渐降低,处置时间(Th)基本依次延长。温度对瓢虫的捕食效应影响显著,试验所设温度为15,20,25,30,35℃,越南斧瓢虫成虫的寻找效率(a)分别为0.3226,0.4496,0.5868,0.5788和0.6235,处置时间(Th)分别为0.2348,0.1451,0.1039,0.0904和0.0976,均与温度(T)则呈二次曲线关系。越南斧瓢虫对烟粉虱4龄若虫的捕食作用率(E)在捕食者密度较低(在1~5头)时,捕食作用率下降较快,而在捕食者>6时,其对捕食作用率的影响效果减小。寻找系数为0.0607,干扰系数为0.5569。【结论】随着猎物龄期的增加,越南斧瓢虫成虫的寻找效率降低,处置时间延长;越南斧瓢虫成虫对烟粉虱4龄若虫的寻找效率随着温度的升高而提高,而在更高的温度条件下,其寻找效率略有下降。瓢虫对烟粉虱的处置时间则随着温度的升高而不断缩短;越南斧瓢虫成虫自身密度对其捕食作用产生干扰反应,捕食作用率随着捕食者密度的增加而降低。     

温度和氮肥对褐飞虱存活、生长发育和繁殖的交互作用

在实验室条件下,研究了不同温度（20 ℃、23 ℃、26 ℃、29 ℃和32 ℃）和氮肥水平（不施氮：0 kg·hm^-2;高氮：250 kg·hm^-2）对褐飞虱存活、发育和繁殖的影响和交互作用.结果表明：在20 ℃~29 ℃范围内,随着温度的升高,褐飞虱的卵孵化率和若虫存活率提高,卵和若虫历期缩短,成虫寿命缩短,同时产卵量增加;32 ℃时, 褐飞虱卵孵化率和若虫存活率降低、卵和若虫历期延长、成虫生殖力降低;在不同温度下,高氮植株上的褐飞虱卵孵化率和若虫存活率、成虫生殖力均明显高于低氮稻株上的褐飞虱,同时高氮植株上褐飞虱的卵和若虫历期明显短于低氮稻株上的褐飞虱,说明施用高水平氮肥提高了褐飞虱对逆境条件的生态适应性;温度和氮肥对褐飞虱卵存活率、若虫历期和产卵量的交互作用显著,表明全球气候变暖和长期施用高水平氮肥很可能是近年来褐飞虱猖獗暴发的重要原因.     

褐飞虱致害性变异过程及其体内酶的变化

在室内连续用具不同抗虫基因的水稻品种TNl、IR26、Mudg。和ASD7、单管饲养褐飞虱(Nilaparvata lugens)种群,研究它对抗虫水稻品种的适应过程及其体内酶的变化规律。 结果表明：褐飞虱在抗虫品种上取食2代的若虫存活率、若虫历期和短翅成虫体重均明显比取食感虫品种TNl的低,第3代以后与取食TNl者基本相同。第2代是褐飞虱适应抗虫品种的关键期。天冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)和丁-谷氨酰基转移 酶(GGT)的活性在关键的第2代最低,而超氧物歧化酶(SOD)和过氧化氢酶(CAT)的含量增加。褐飞虱在适应抗虫品种以后体内天冬氨酸氨基转移酶活性明显提高。     

取食施硅水稻对褐飞虱成虫体内保护酶和解毒酶活性的影响

【目的】本研究旨在明确褐飞虱Nilaparvata lugens成虫取食施硅水稻对其体内保护酶及解毒酶活性的影响,为硅介导的水稻抗虫性的应用提供证据。【方法】以TN1(感虫品种)为供试水稻品种,采用营养液添加Na₂SiO₃·9H₂O的方法设置112 mg Si/L(Si+)和0 mg Si/L(Si-)2种施硅水平,通过酶活性分析测定取食Si+或Si-水稻植株24, 48, 72和96 h后褐飞虱成虫体内保护酶［过氧化氢酶(catalase, CAT)、过氧化物酶(peroxidase, POD)和超氧化物歧化酶(superoxide, SOD)］以及解毒酶［谷胱甘肽S-转移酶(glutathione-S-transferase, GST)、羧酸酯酶(carboxylesterase, CarE)和多功能氧化酶(mixed-functional oxidase, MFO)］活性的动态变化。【结果】与取食Si-水稻植株的褐飞虱成虫相比,取食Si+水稻植株24和48 h时,褐飞虱成虫POD活性分别显著增加101.2%和55.2%,SOD活性分别显著增加78.2%和19.6%;取食72 h时,CAT和SOD活性分别显著增加16.5%和29.7%;取食96 h时,CAT和POD活性稍有降低,SOD活性显著降低12.6%。添加硅总体上增加GST和MFO活性,降低CarE活性。取食Si+水稻植株24, 48, 72和96 h时,GST活性分别显著升高57.2%, 200.7%, 84.7%和45.9%;MFO活性在取食72和96 h时分别显著升高70.2%和28.3%;而CarE活性在取食72和96 h时分别显著降低38.1%和32.0%。【结论】取食施硅水稻引起褐飞虱成虫体内保护酶和解毒酶活性发生了变化,进而对褐飞虱生理代谢产生了影响。     

Effects of elevated CO2 and transgenic Bt rice on yeast‐like endosymbiote and its host brown planthopper

The effects of elevated CO₂ (750 vs. 375μl/l) on population abundances and metabolism enzyme of AChE and protective enzymes of SOD, POD and CAT in brown planthoppers (BPH) Nilaparvata lugens, and on size and abundances of yeast‐like endosymbiotes (YLES) were studied as BPH fed Bacillus thuringiensis (Bt) rice expressing pure Cry1Ab after successively two generations in open‐top chambers. The results indicated that: (1) Brachypterous and macropterous subpopulations and total population increased with elevated CO₂. Significant increases were found as BPH fed non‐transgenic rice while only significant increase as macropterous‐BPH fed Bt rice. (2) The responses of brachypterous and macropterous‐BPH to Bt rice were different. Brachypterous‐subpopulation significantly decreased (13.6%) while macropterous ones significantly increased (43.8%) as fed Bt rice relative to non‐transgenic rice at elevated CO₂. (3) Elevated CO₂ only significantly inhibited AChE activity as brachypterous‐BPH fed non‐transgenic rice. Significant increases in POD and SOD, and significant decrease in CAT were found as brachypterous‐BPH fed Bt rice, while significant increases in CAT and significant decrease in POD were also observed as fed non‐transgenic rice in elevated CO₂ relative to ambient CO₂. (4) Bt rice significantly inhibited POD and SOD activity at ambient CO₂, while only significantly enhanced SOD activity at elevated CO₂. (5) Elevated CO₂ significantly decreased YLES per mg/head of brachypterous‐BPH females while only significantly decreased YLES per mg/head as brachypterous‐BPH males fed Bt rice. And there were significant differences in YLES width or length between females and males. Elevated CO₂ can markedly affect the symbiosis relationship between YLES and BPH through the bottom‐up forcing on BPH physiological metabolism. And the damage inflicted by BPH on rice, irrespective of the presence of insecticidal genes, is predicted to be higher at elevated CO₂. Furthermore, transgenic Bt rice can also exacerbate emigrating‐macropterous‐BPH occurring especially at elevated CO₂.     

褐飞虱长翅型和短翅型雌雄成虫体内磁性物质定位和定量检测

【目的】地磁定向是昆虫远距离迁飞定向的重要机制之一。本研究以迁飞性害虫褐飞虱Nilaparvata lugens长翅型和短翅型雌雄成虫为研究对象,系统开展虫体内磁性物质定量研究。【方法】本研究利用MPMS-7型超导量子磁强计检测褐飞虱长翅型和短翅型雌雄成虫体内的磁性物质,并将经普鲁士蓝染色后的虫体超薄石蜡切片于JEM-2100型透射电子显微镜下观察磁性物质的分布状况,最后利用原子发射光谱法对虫体内的磁性物质进行定量分析与比较。【结果】超导量子磁强计检测发现,仅在褐飞虱长翅型和短翅型雌雄成虫腹部的磁滞曲线有明显闭合现象,证明该部位存在磁性物质;经透射电镜观察发现,普鲁士蓝沉淀主要呈点簇状存在于虫体腹部,证明该部位存在铁磁性物质;通过等离子发射光谱检测发现,同一性别长翅型成虫体内铁离子含量显著高于短翅型成虫,且相同翅型雄成虫体内铁离子含量显著高于雌成虫。【结论】褐飞虱长翅型和短翅型雌雄成虫腹部普遍存在铁磁性物质,且不同翅型和性别间磁性物质含量差异显著。     

稻飞虱翅型纯系后代个体的翅型分化对光周期变化不敏感

【目的】为了明确光周期和遗传因子在稻飞虱翅型分化中的作用, 研究了3种稻飞虱（褐飞虱Nilaparvata lugens、白背飞虱Sogatella furcifera和灰飞虱Laodelphax striatellus）翅型纯系或近纯系在不同光照时数下的翅型分化比率。【方法】以经过5~45代连续翅型筛选后的褐飞虱、白背飞虱和灰飞虱的长翅型和短翅型纯系或近纯系为材料, 在室内分别测定了其在长光照（16和20 h）、短光照(4~12 h)和正常光照(14 h) 3类光周期条件下饲养后, 雌、雄成虫中长翅和短翅个体出现的比率及存活率。【结果】白背飞虱和灰飞虱的长翅型纯系M♂×M♀或短翅型纯系B♂×B♀在不同光周期下的翅型比率均无显著差异（P>0.05）。褐飞虱短翅型近纯系B♂×B♀的雌虫短翅率和成虫总短翅率在不同光周期下也无显著差异（P>0.05）, 但雄虫短翅率在正常光照14 h和短光照4 h下显著高于长光照20 h下的（P<0.05）。当褐飞虱短翅型达到纯系后, 其后代翅型在6~16 h光照条件下无显著差异。褐飞虱长翅型近纯系M♂×M♀的后代虽有短翅个体出现, 但是雌虫和雄虫的各自短翅率在不同光周期下无显著差异（P>0.05), 仅总体短翅率在12 h光照条件下的显著高于16 h下的（P<0.05）。褐飞虱长、短翅型杂交筛选品系M♂×B♀的雌虫短翅率随光照时数的延长而升高; 灰飞虱杂交筛选品系M♂×B♀的短翅雄虫随光照时数的缩短而增多（P<0.05）, 但当筛选代次达到45代时, 这种趋势不再显著。3种稻飞虱长翅型和短翅型纯系或近纯系若虫的存活率会稍低于长、短翅型杂交后代的存活率, 但长、短翅型品系的存活率在6~16 h光照条件下差异不显著(P>0.05)。【结论】稻飞虱翅型分化对光周期的反应受飞虱本身遗传背景的影响, 翅型纯系后代个体的翅型分化对光周期变化不敏感。     

Biological Studies on Agamermis unka (Nematoda: Mermithidae), a Parasite of the Brown Planthopper Nilaparvata lugens

The mermithid parasite, Agamermis unka, is the most important natural enemy of the brown planthopper (BPH), Nilaparvata lugens, in Korean rice fields. Very little is known about many aspects of the mermithid's life cycle and behavior, and a study was undertaken to close the data gap. The sex ratio of A. unka isolated from field-collected BPH showed a strong female bias. Even when several A. unka occurred within a BPH, the majority were females. Similarly, the sex ratio of field-collected A. unka adults that were in the soil was strongly biased towards females and, in many instances, the females were found in the absence of males. Females collected from the field from January to May and maintained in water at 25 C had a mean pre-oviposition period of 17-28 days and a mean oviposition period of 17-37 days, and averaged 543-1851 eggs/female. The eggs averaged 20, 17 and 36 days to hatch at 30, 25 and 20 C respectively, but none hatched at 15 C. Most of the eggs (96%) hatched at 25 and 20 C, but only 64% hatched at 30 C. Agamermis pre-parasites could be found on rice stems in the field and laboratory. In the field, BPH-susceptible and BPH-resistant rice cultivars showed no significant difference in the numbers of pre-parasites on the stem. In the laboratory, the number of pre-parasites recovered/rice stem was significantly higher in two out of three trials when BPH nymphs and adults were present. When BPH nymphs were exposed to the pre-parasites in the laboratory, 39% of the brachypterous females and 4.5% of the brachypterous males were parasitized, whereas 0.3% of the macropterous females and 0% of the macropterous males were parasitized. The parasitism data obtained under field conditions showed similar trends. The reason(s) for these differences in parasitism between the BPH sex and wing types that have been observed both in the laboratory and field is unknown. Because brachypterous males and macropterous females and males occur in lesser numbers than the brachypterous females, this may, in part, account for the differences in parasitism observed. However, BPH behavior cannot be discounted as a factor in the differential parasitism.     

褐飞虱的交配行为及与保幼激素滴度的关系

受5龄末期和羽化初期较高保幼激素滴度的影响,褐飞虱Nilaparvata lugens(Stal)短翅型成虫性成熟比长翅型成虫早40～50h。5日龄前短翅型雌成虫的交配成功率较高,雄成虫的交配竞争能力较强;1、2日龄的长翅型雌成虫不交配,5日龄后长翅型成虫的交配能力渐渐超过短翅型成虫。实验种群的交配持续时间为(70.38±41.77)s;交配成功率为51.63%;雌、雄虫均可重复交配。一日中0～4h和10～14h交配成功率较高。     

Molecular characterization of the flightin gene in the wing-dimorphic planthopper,Nilaparvata lugens,and its evolution in Pancrustacea

Flightin was initially identified in Drosophila melanogaster. Previous work has shown that Drosophila flightin plays a key role in indirect flight muscle (IFM) function and has limited expression in the IFM. In this study, we demonstrated that flightin is conserved across the Pancrustacea species, including winged insects, non-winged insects, non-insect hexapods and several crustaceans. The brown planthopper (BPH), Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), a long-distance migration insect with wing dimorphism, is the most destructive rice pest in Asia. We showed that flightin was one of the most differentially expressed genes in macropterous and brachypterous BPH adults. In female BPHs, flightin was expressed in the IFM of macropterous adults, no expression was detected in brachypterous ones; while in male BPHs, flightin was not only expressed in the IFM of macropterous adults, but also in the dorsal longitudinal muscle (DLM) in the basal two abdominal segments of both macropterous and brachypterous ones. RNAi and transmission electron microscopy results showed that flightin played key roles in maintaining IFM and male DLM structure, which drive wing movements in macropterous adults and the vibration of the male-specific tymbal, respectively. Using Daphnia magna as an example of a crustacean species, we observed that flightin was expressed in juvenile instars and adults, and was localized in the antenna muscles. These results illustrate the functional variations of flightin in insects and other arthropod species and provide clues as to how insects with flight apparatuses evolved from ancient pancrustaceans.     

Temporal pattern of feeding activity in the firebug Pyrrhocoris apterus and its relation to sex, wing dimorphism and physiological state of adults

Abstract.  The present study tested whether the pattern of feeding activity in the firebug Pyrrhocoris apterus (L.) is sex- and wing morph-related, diurnal or nocturnal, as well as whether the feeding rhythm persists in constant darkness. Temporal patterns of feeding activity are analysed in macropterous and brachypterous adults reared under long-day (LD 18 : 6 h) and short-day (LD 12 : 12 h) photoperiods, and in adults transferred to constant darkness. In females, the total feeding activity is highest in long-day reproductively active brachypters, intermediate in short-day diapausing brachypters, and lowest in macropters; the differences among males are substantially smaller. Although the total feeding activity of macropterous males is higher than in macropterous females, no sex-related differences are found in feeding activity of diapausing and reproductively active brachypters. The frequency of feeding exhibits sex-related differences, with obviously higher values in males. Mean feeding periods of macropterous and reproductively active brachypterous males are shorter than in females of the same wing morph. Mean interfeeding periods are longest in macropters, intermediate in diapausing brachypters, and shortest in reproductively active brachypters, and always lower in males than in females. The study shows that the feeding activity of P. apterus adults is age-, sex- and wing morph-related, and exhibits a diurnal pattern, except in reproductively active brachypterous females. The latter do not express a clear diurnal rhythm of feeding, presumably because of interactions with cycles of egg development and oviposition. The persistence of diurnal rhythm of feeding activity in short-day brachypterous females transferred to constant darkness indicates an endogeneity of this rhythm in P. apterus .