近零磁场对褐飞虱翅型分化、趋光性及飞行能力的影响

【目的】地磁场(geomagnetic field,GMF)不是恒定不变的,而是随时间和空间时刻变化的。目前,动物对磁场变化的响应研究主要集中于迁徙性动物地磁定向导航中的磁感受方面,而迁徙性动物迁出地和迁入地之间地磁场强度差异对动物生理和行为潜在的磁场效应尚不明确。【方法】迁飞性昆虫褐飞虱Nilaparvata lugens试虫采自江苏省农业科学院试验田。本文采用亥姆霍兹线圈室内模拟近零磁场(near-zero magnetic field,NZMF)和GMF,调查了褐飞虱成虫在NZMF和GMF下的翅型分化、趋光性和飞行能力。【结果】结果表明,与GMF相比,NZMF显著提高了褐飞虱雄成虫短翅型比例(6. 4%)(P <0. 05),但对雌成虫长翅型比例影响不显著(P> 0. 05);对于长翅雌成虫,NZMF显著提高了其2日龄成虫的上灯比例(55%)(P <0. 05),但显著降低了其4日龄成虫的上灯比例(22%)(P <0. 05),对趋光性的影响总体呈现出随着龄期先增强后减弱的效应。NZMF对长翅雄成虫趋光性的影响也呈现出相同的效应,但对各日龄成虫的影响不显著(P> 0. 05); NZMF显著缩短了2日龄长翅雄成虫的飞行时间(46%)(P <0. 05),并显著提高了长翅雌成虫(65%)和长翅雄成虫(101%)的飞行速度(P <0. 05)。此外,GMF对照组的褐飞虱长翅雄成虫飞行速度显著低于长翅雌成虫(96%),而NZMF处理组中二者无显著差异。【结论】结果说明,近零磁场可提高褐飞虱成虫短翅比例,对长翅成虫趋光性的影响呈现出基于龄期增长先增强后减弱的效应,并在未影响长翅成虫飞行距离的情况下,改变了其飞行策略,即提高飞行速度,同时缩短飞行时间。     

Native subunit composition of two insect nicotinic receptor subtypes with differing affinities for the insecticide imidacloprid

Neonicotinoid insecticides, such as imidacloprid, are selective agonists of insect nicotinic acetylcholine receptors (nAChRs) and are used extensively to control a variety of insect pest species. The brown planthopper (Nilaparvata lugens), an insect pest of rice crops throughout Asia, is an important target species for control with neonicotinoid insecticides such as imidacloprid. Studies with nAChRs purified from N. lugens have identified two [³H]imidacloprid binding sites with different affinities (K_d = 3.5 ± 0.6 pM and 1.5 ± 0.2 nM). Co-immunoprecipitation studies with native preparations of N. lugens nAChRs, using subunit-selective antisera, have demonstrated the co-assembly of Nlα1, Nlα2 and Nlβ1 subunits into one receptor complex and of Nlα3, Nlα8 and Nlβ1 into another. Immunodepletion of Nlα1 or Nlα2 subunits resulted in the selective loss of the lower affinity imidacloprid binding site, whereas immunodepletion of Nlα3 or Nlα8 caused the selective loss of the high-affinity site. Immunodepletion of Nlβ1 resulted in a complete absence of specific imidacloprid binding. In contrast, immunodepletion with antibodies selective for other N. lugens nAChR subunits (Nlα4, Nlα6, Nlα7 and Nlβ2) had no significant effect on imidacloprid binding. Taken together, these data suggest that nAChRs containing Nlα1, Nlα2 and Nlβ1 constitute the lower affinity binding site, whereas nAChRs containing Nlα3, Nlα8 and Nlβ1 constitute the higher affinity binding site for imidacloprid in N. lugens.     

Phototactic responses of larvae from the marine sponges Neopetrosia proxima and Xestospongia bocatorensis (Haplosclerida: Petrosiidae)

Abstract. Previous studies suggest that phototaxis in sponge larvae is generated by the bending of a tuft of long posterior cilia (LPC). The photoresponsiveness of these cilia is often assayed by examining their reaction to sudden changes in light intensity. Here, we document and describe the larvae of the tropical marine sponges Neopetrosia proxima and Xestospongia bocatorensis and examine the phototactic behavior of their larvae. Both species brood ovoid, tufted parenchymella larvae, clearly countering an earlier hypothesis that all petrosid sponges are oviparous. Larvae of N. proxima were positively phototactic and settled after 2 d, while larvae of X. bocatorensis were negatively phototactic and settled in as little as 4 h. In both species, LPC quickly responded to changes in the light intensity. When the light intensity is reduced, the larvae of N. proxima fold the cilia inwards immediately without beating, then flare them outwards, beating for a few seconds, and then gradually return to the neutral position while continuing to beat. In contrast, the larvae of X. bocatorensis flare the cilia outwards when the light intensity is reduced and fold them inwards when the light intensity is increased. Comparisons with reported ciliary responses to light for other species demonstrate that these responses do not show the hypothesized one-to-one correspondence with phototactic behaviors and are, therefore, of limited use in explaining the mechanisms that coordinate larval swimming.     

Molecular characterization,spatial‐temporal expression and magnetic response patterns of iron‐sulfur cluster assembly1 (IscA1) in the rice planthopper,Nilaparvata lugens

The mechanisms of magnetoreception have been proposed as the magnetitebased, the chemical radical-pair and biocompass model, in which magnetite particles, the cryptochrome (Cry) or iron-sulfur cluster assembly 1 (IscA1) may be involved. However, little is known about the association among the molecules. Here we investigated the molecular characterization and the mRNA expression of IscA1 in different developmental stages, tissues and magnetic fields in the migratory brown planthopper (BPH), Nilaparvata lugens. NlIscA1 contains an open reading frame of 390 bp, encoding amino acids of 129, with the predicted molecular weight of 14.0 kDa and the isoelectric point of 9.10. Well-conserved Fe-S cluster binding sites were observed in the predicted protein. Phylogenetic analysis demonstrated NlIscA1 to be clustered into the insect's IscA1. NlIscA1 showed up-regulated mRNA expression during the period of migration. The mRNA expression of NlIscA1 could be detected in all the three tissues of head, thorax and abdomen, with the highest expression level in the abdomen. For the macropterous migratory Nilaparvata lugens, mRNA expression of NlIscA1 and N. lugens cryptochromel (Nlcry1) were up-regulated under the magnetic fields of 5 Gauss and 10 Gauss in strength (vs. local geomagnetic field), while N. lugens cryptochrome 2 (Nlcry2) remained stable. For the brachyterous non-migratory Nilaparvata lugens, no significant changes were found in mRNA expression of NlIscA1, Nlcry1 and Nlcry2 among different magnetic fields. These findings preliminarily reveal that the expression of NlIscA1 and Nlcry1 exhibited coordinated responses to the magnetic field. It suggests some potential associations among the putative magneto-sensitive molecules of cryptochrome and iron-sulfur cluster assembly.     

Phototaxis in the magnetotactic bacterium Magnetospirillum magneticum strain AMB-1 is independent of magnetic fields

Magnetotactic bacteria (MTB) can rapidly relocate to optimal habitats by magneto-aerotaxis. Little is known about MTB phototaxis, a response that might also aid navigation. In this study, we analyzed the relationship between phototaxis and magnetotaxis in Magnetospirillum magneticum strain AMB-1. Magnotactic AMB-1 cells migrated toward light, and migration increased with higher light intensity. This response was independent of wavelength, as AMB-1 cells migrated equally toward light from 400 to 750 nm. When AMB-1 cells were exposed to zero magnetic fields or to 0.2 mT magnetic fields that were opposite or orthogonal to the light beam, cells still migrated toward the light, indicating that phototaxis was independent of magnetotaxis. The R _mag value and coercive force (H _c) of AMB-1 increased when the bacteria were illuminated for 20 h, consistent with an increase in magnetosome synthesis or in magnetosome-containing cells. These results demonstrated that the M. magneticum AMB-1 responded to light as well as other environmental factors. To our knowledge, this is the first report of phototactic behavior in the bacteria of Magnetospirillum.     

Phototaxis in water fleas (Daphnia magna) is differently influenced by visible and UV light

The effects of vertical illumination with monochromatic lights on phototaxis of Daphnia magna in a test chamber were determined at five levels of equal quantal flux density (between 188 and 6.42 · 10⁻⁵ nEinstein). Visible adaptation light (500 nm) and subsequent spectral test light had the same quantal flux density. The animals reacted to ultraviolet light (260–380 nm) with negative phototaxis, whereas visible light (420–600 nm) caused positive phototaxis. Action spectra were determined, based on the evaluation of different parameters of phototactic behavior. The maximum spectral sensitivity in the ultraviolet was found at 340 nm. The maximum spectral efficiency in the visible varied in dependence on light intensity. Ecological consequences of the results are discussed. Accepted: 3 August 1998     

The regulation of lipid metabolism by a hypothetical P-loop NTPase and its impact on fecundity of the brown planthopper

BackgroundInsect fecundity can be regulated by multiple genes in several important signaling pathways which form an extremely complicated regulatory network. However, there are still many genes that have significant impact on insect fecundity but their action mode are still unknown.MethodsQuantitative real-time PCR (qRT-PCR), immunofluorescence and western blot were used to study the expression profile of Nl23867 in the brown planthopper, Nilaparvata lugens. RNA interference (RNAi), RNA-seq and isobaric tags for relative and absolute quantification (iTRAQ) were performed to investigate the action mode of Nl23867 in the regulation of fecundity. High performance liquid chromatography (HPLC) analysis was performed to detect the fatty acid contents.ResultsWe show that knockdown of Nl23867, a gene encoding a hypothetical P-loop NTPase, significantly decreased fecundity of N. lugens. Underdeveloped ovaries, fewer eggs laid and reduction in vitellogenin (Vg) protein expression were observed after RNAi knockdown of Nl23867, and most of the affected genes and pathways are fatty acid metabolism-related. We further determined that Nl23867 directly impacts the palmitic acid biosynthesis by regulating the expression of palmitoyl-protein thioesterase (PPT), subsequently affecting the content of total lipids in N. lugens.ConclusionsNl23867 regulates the fecundity of N. lugens by modulating the biosynthetic pathway of palmitic acid and affecting lipid metabolism during vitellogenesis and oocyte development.General significanceThe presented study pioneers the exploration into how a function-unknown gene takes part in the regulation of fecundity in an insect, and will contribute to the construction of gene regulatory network for insect fecundity.     

Phototaxis by the Dinoflagellate Gymnodinium splendens Lebour*

A microscope-television system was used to monitor quantitatively the behavior of Gymnodinium splendens Lebour in response to light. The predominant behavioral sequence upon stimulation is (a) an initial 2–5 sec cessation of movement (stop-response) followed by (b) positive phototaxis. The action spectra for each response are identical, having maxima at 450 and 280 nm. Upon measuring the percent response to a range of stimulus intensities, it is apparent that a stop-response is not a behavioral prerequisite for phototaxis. An identical circadian rhythm in photoresponsiveness is observed for phototaxis and for the stop-response with greatest light sensitivity occurring during the first 4 hr of the entrained light period. The implication of phototactic sensitivity and the phototactic circadian rhythm in diurnal vertical migration is discussed.     

The insecticidal activity and action mode of an imidacloprid analogue, 1‐(3‐pyridylmethyl)‐2‐nitroimino‐imidazolidine

Neonicotinoids, such as imidacloprid, are key insecticides extensively used for control of Nilaparvata lugens. However, imidacloprid resistance has been reported in many Asian countries in recent years. To understand the roles of the chlorine atom of pyridyl group on insecticidal activity and resistance, the atom was removed to generate an imidacloprid analogue DC‐Imi (DesChlorine Imidacloprid). DC‐Imi showed significantly higher toxicity than imidacloprid in the susceptible strain of N. lugens, but had medium level cross‐resistance in an imidacloprid‐resistant strain. In Xenopus oocyte expressed nicotinic acetylcholine receptors (nAChRs) Nlα1/rβ2, the inward currents evoked by DC‐Imi were detected and could be blocked by typical nAChRs antagonist dihydro‐β‐erythroidine (DHβE), which demonstrated that DC‐Imi acted as an agonist on insect nAChRs. The efficacy of DC‐Imi on Nlα1/rβ2 was 1.8‐fold higher than that of imidacloprid. In addition, the influence of an imidacloprid resistance associated mutation (Y151S) on agonist potencies was evaluated. Compared with the wild‐type receptor, the mutation reduced maximal inward current of DC‐Imi to 55.6% and increased half maximal effective concentration (EC₅₀) to 3.53‐fold. Compared with imidacloprid (increasing EC₅₀ to 2.38‐fold of wild‐type receptor), Y151S mutation decreased DC‐Imi potency more significantly. The results indicated that the selective and possibly high toxicities could be achieved through the modification of 6‐chloro‐3‐pyridyl group in imidacloprid and other neonicotinoids.     

光强度对大草蛉成虫感光性和趋光性行为的影响

运用视网膜电位（electroretinogram, ERG）技术和行为学方法研究了大草蛉Chrysopa pallens Ramber成虫的光强度反应。结果显示: （1）白光（Log I= 4.5~0.0）可引发2 h暗适应的大草蛉复眼的电位反应。随光强增强其ERG值呈近线性增大, 最强时未出现高端平台, 表明该光强范围内其感光性基本一致, 且可感受更强的光; （2）一定光强度（Log I= 4.0）以上的白光可引发大草蛉较明显的趋光性行为, 该行为具有光强域值特征和较明显的光强度依赖性。弱光时（Log I=4.5）无趋光性行为, 随光强增大趋光性反应率增大, 光较弱（Log I= 4.5~1.5）时增大缓慢, 较强（Log I=1.5~0.0）时迅速增大, 至最强（Log I=0.0）时最大（37.1%）, 呈一近“J”型式样。避光行为无或很低, 且无规律, 最大值仅为4.5%。这些结果表明: 光强度是大草蛉感光性与趋光性行为的重要决定因素, 强光时感光性电位反应与趋光性行为反应基本一致, 弱光时则不同, 暗示了光强度信息在感光性和趋光性间作用的有条件性和复杂性。     

Effect of light colours and weather conditions on captures of Sogatella furcifera (Horváth) and Nilaparvata lugens (Stål)

To study the phototactic responses of white‐backed planthopper, Sogatella furcifera (Horváth) and brown planthopper, Nilaparvata lugens (Stål) to different wavelengths, four colours of light traps (blue, green, yellow and red light‐emitting diodes) were placed in the same rice field along with a traditional black light trap. This study revealed that S. furcifera and N. lugens are more attracted to blue and green lights than that to yellow and red lights. During the 24 nights, compared with the black light trap, the blue LED trap could catch more rice planthoppers at 17 nights. Furthermore, catches of other species (moths and beetles) were substantially reduced in blue LED light traps. Multiple regression models were developed to assess the effect of weather factors on light trap catches of rice planthoppers. Rainfall and mean air temperature at a night mainly affected light trap catches of S. furcifera. Higher rainfall and lower temperature increased light trap catches of S. furcifera. However, wind speed was the main factor affecting the catches of N. lugens, and the lower incidence of catches was found in the night when wind speed exceeded 3.08 m/s. S. furcifera may be flying against wind at light wind nights by 0.3–1.5 m/s, whereas N. lugens may be flying down at strong wind nights by 1.5–3.08 m/s. Relative humidity did not significantly influence on trap catches. Consequently, light wavelengths, precipitation, average temperature and wind should be considered when monitoring rice planthoppers by light traps. Therefore, the blue LED light traps are worth using for monitoring planthoppers.     

Simulation of phototaxis in the flagellateEuglena gracilis

A three-dimensional model of the flagellateEuglena gracilis was developed to simulate phototaxis and movement in space. The simulation of the phototactic behavior was compared with thein vivo behavior in order to determine the mechanism of orientation with respect to light. Phototactic behavior with respect to one light source, can be explained by the shading hypothesis as well as by a dichroic orientation of the absorbing vectors of the photoreceptor pigments. In contrast, the behavior of the cells when exposed to two perpendicular light beams is not compatible with the shading hypothesis. Likewise, the phototactic orientation of stigmaless cells cannot be accounted for on the basis of the shading hypothesis. In contrast, simulations andin vivo observations of the behavior under polarized light strongly indicate the validity of the dichroic orientation of the photoreceptor pigments.     

Carotenoids in the eyespot apparatus are required for triggering phototaxis in Euglena gracilis

Carotenoids are the most universal and most widespread pigments in nature. They have played pivotal roles in the evolution of photosensing mechanisms in microbes and of vision in animals. Several groups of phytoflagellates developed a photoreceptive organelle called the eyespot apparatus (EA) consisting of two separable components: the eyespot, a cluster of carotenoid‐rich globules that acts as a reflector device, and actual photoreceptors for photobehaviors. Unlike other algal eyespots, the eyespot of Euglenophyta lacks reflective properties and is generally considered to act as a shading device for the photoreceptor (paraflagellar body, PFB) for major photomovements. However, the function of the eyespot of Euglenophyta has not yet been fully proven. Here, we report that the blocking carotenoid biosynthesis in Euglena gracilis by suppressing the phytoene synthase gene (crtB) caused a defect in eyespot function resulting in a loss of phototaxis. Raman spectroscopy and transmission electron microscopy suggested that EgcrtB‐suppressed cells formed eyespot globules but had a defect in the accumulation of carotenoids in those packets. Motion analysis revealed the loss of phototaxis in EgcrtB‐suppressed cells: a defect in the initiation of turning movements immediately after a change in light direction, rather than a defect in the termination of cell turning at the appropriate position due to a loss of the shading effect on the PFB. This study revealed that carotenoids are essential for light perception by the EA for the initiation of phototactic movement by E. gracilis, suggesting one possible photosensory role of carotenoids in the EA for the phototaxis.     

Susceptibility and tolerance in hybrid and pure‐line rice varieties to herbivore attack: biomass partitioning and resource‐based compensation in response to damage

Hybrid rice has been noted for its susceptibility to insects and diseases compared to pure‐line (conventional) rice varieties. We investigated herbivory by Nilaparvata lugens, Sogatella furcifera and Scirpophaga incertulas on replicated three‐line hybrid sets (parental and hybrid lines) in field and greenhouse experiments. In a field experiment, caterpillar densities and stemborer damage was similar among hybrid and parental lines. In field and greenhouse experiments, the cytoplasmic male sterile (CMS)‐lines and maintainer lines had higher densities of planthoppers (including N. lugens and S. furcifera) than restorer or hybrid lines likely because of their wild abortive CMS‐lineage. High nitrogen levels increased plant mortality due to N. lugens, but often reduced mortality from S. furcifera and S. incertulas: this was similar between hybrid and pure‐line varieties. The hybrids were generally more tolerant of herbivory (lower biomass reductions per unit weight of insect) than the inbred parental lines. The addition of nitrogen to both the hybrid and pure‐line varieties had contrasting effects on tolerance depending on the nature of the attacking insect: fertiliser increased tolerance to S. furcifera (lower losses of yield and shoot biomass per mg insect) and S. incertulas (lower yield, shoot and root biomass loss) but fertiliser reduced tolerance to N. lugens (higher loss of root biomass and no effects on yield and shoot biomass loss). Our results indicate that hybrid rice is not physiologically more susceptible to herbivores than are pure‐line varieties even under high nitrogen conditions, but does have higher tolerance to insect damage.     

The photobehaviour of Daphnia spp. as a model to explain diel vertical migration in zooplankton

Many pelagic animal species in the marine environment and in lakes migrate to deeper water layers before sunrise and return around sunset. The amplitude of these diel vertical migrations (DVM) varies from several hundreds of metres in the oceans to approx. 5–20 m in lakes. DVM can be studied from a proximate and an ultimate point of view. A proximate analysis is intended to reveal the underlying behavioural mechanism and the factors that cause the daily displacements. The ultimate analysis deals with the adaptive significance of DVM and the driving forces that were responsible for the selection of the traits essential to the behavioural mechanism. The freshwater cladoceran Daphnia is the best studied species and results can be used to model migration behaviour in general. Phototaxis in Daphnia spp., which is defined as a light-oriented swimming towards (positive phototaxis) or away (negative phototaxis) from a light source, is considered the most important mechanism basic to DVM. A distinction has been made between primary phototaxis which occurs when light intensity is constant, and secondary phototaxis which is caused by changes in light intensity. Both types of reaction are superimposed on normal swimming. This swimming of Daphnia spp. consists of alternating upwards and downwards displacements over small distances. An internal oscillator seems to be at the base of these alternations. Primary phototaxis is the result of a dominance of either the upwards or the downwards oscillator phase, and the direction depends on internal and external factors: for example, fish-mediated chemicals or kairomones induce a downwards drift. Adverse environmental factors may produce a persistent primary phototaxis. Rare clones of D. magna have been found that show also persistent positive or negative primary phototaxis and interbreeding of the two types produces intermediate progeny: thus a genetic component seems to be involved. Also secondary phototaxis is superimposed on normal swimming: a continuous increase in light intensity amplifies the downwards oscillator phase and decreases the upwards phase. A threshold must be succeeded which depends on the rate and the duration of the relative change in light intensity. The relation between both is given by the stimulus strength versus stimulus duration curve. An absolute threshold or rheobase exists, defined as the minimum rate of change causing a response if continued for an infinitely long time. DVM in a lake takes place during a period of 1-5-2 h when light changes are higher than the rheobase threshold. Accelerations in the rate of relative increase in light intensity strongly enhance downwards swimming in Daphnia spp. and this enhancement increases with increasing fish kairomone and food concentration. This phenomenon may represent a ‘decision-making mechanism’ to realize the adaptive goal of DVM: at high fish predator densities, thus high kairomone concentrations, and sufficiently high food concentrations, DVM is profitable but not so at low concentrations. Body axis orientation in Daphnia spp. is controlled with regard to light-dark boundaries or contrasts. Under water, contrasts are present at the boundaries of the illuminated circular window which results from the maximum angle of refraction at 48–9° with the normal (Snell's window). Contrasts are fixed by the compound eye and appropriate turning of the body axis orients the daphnid in an upwards or an obliquely downwards direction. A predisposition for a positively or negatively phototactic orientation seems to be the result of a disturbed balance of the two oscillators governing normal swimming. Some investigators have tried to study DVM at a laboratory scale during a 24 h cycle. To imitate nature, properties of a natural water column, such as a large temperature gradient, were compressed into a few cm. With appropriate light intensity changes, vertical distributions looking like DVM were obtained. The results can be explained by phototactic reactions and the artificial nature of the compressed environmental factors but do not compare with DVM in the field. A mechanistic model of DVM based on phototaxis is presented. Both, primary and secondary phototaxis is considered an extension of normal swimming. Using the light intensity changes of dawn and the differential enhancement of kairomones and food concentrations, amplitudes of DVM could be simulated comparable to those in a lake. The most important adaptive significance of DVM is avoidance of visual predators such as juvenile fish. However, in the absence of fish kairomones, small-scale DVMs are often present, which were probably evolved for UV-protection, and are realized by not enhanced phototaxis. In addition, the ‘decision-making mechanism’ was probably evolved as based on the enhanced phototactic reaction to accelerations in the rate of relative changes in light intensity and the presence of fish kairomones.     

Phototactic behaviour of Eucryptorrhynchus scrobiculatus and E. brandti (Coleoptera: Curculionidae) adults*

Eucryptorrhynchus scrobiculatus and E. brandti (Coleoptera: Curculionidae) are destructive weevils on Ailanthus altissima in China. This study examined phototactic behaviour of E. scrobiculatus and E. brandti in response to eight light-emitting diodes (LEDs) in the laboratory and field. Effects of gender, starvation, and light and dark experience on the phototactic behaviour of the insects were evaluated. The results demonstrated that, the two species of weevil were phototactic insects and most sensitive to violet light (400–405?nm), followed by blue–violet light (420–430?nm). They were less sensitive to red (655–660?nm), white (6000–6500?k), blue–green (470–480?nm), yellow (590–595?nm), blue (450–455?nm), and green (515–530?nm) light. In the light intensity range of 200–1000?lux, the light intensity had no significant effect on the phototatic behaviour of E. scrobiculatus and E. brandti. Phototactic behaviour of the insects was affected by gender. The phototaxis indices of the two species of weevil increased with starvation, reaching a plateau after 2 or 3?d of starvation. The phototaxis indices of E. scrobiculatus and E. brandti were significantly affected by various wavelengths of light following exposure to the light for 3?h or in different dark experience time. In the mark-release-recapture test, the number of E. scrobiculatus and E. brandti adults trapped by violet (400–405?nm) light traps is the largest. The information provided here provides a basis for survey and control of E. scrobiculatus and E. brandti.     

光谱和光强度对西花蓟马雌虫趋光行为的影响

利用行为学方法研究了光谱、光强对西花蓟马Frankliniella occidentalis (Pergande)雌成虫的趋、避光行为的影响。结果显示：（1）在340~605nm波谱内14个波长其光谱趋光行为反应为多峰型,峰间主次较明显。趋光行为反应中,蓝绿区498~524nm有一较宽峰,趋光率20.31%;其它各峰依大小次序分别位于紫光380nm、蓝光440nm;（２）避光行为反应中,蓝光440nm处略高,避光率17.19%;紫外340nm处亦有一峰,避光率15.63%;（３）随光强增强其趋光反应率增大,白光、380nm和524nm刺激时其光强趋光行为反应呈一倒“L”型式样,498nm为峰型,440nm时为一较缓的平直线型;光强最弱时仍均有一定趋光率 ,最强时均未出现高端平台;（４）随光强增强其避光反应率增大,440nm为较平缓直线;340nm刺激时为较缓波动线。结果表明：光谱对其趋光行为有很大影响,光强度的影响较大且影响大小与波长因素有关。