卷蛾分索赤眼蜂雌蜂的颜色偏好性

为了确定卷蛾分索赤眼蜂Trichogrammatoidea bactrae Nagaraja 雌蜂的颜色偏好性, 在室内通过在培养皿底部黏贴彩纸的方法测定卷蛾分索赤眼蜂雌蜂对红、 黄、 黑、 紫、 绿、 白、 蓝7种颜色的行为趋性反应。结果表明, 卷蛾分索赤眼蜂雌蜂在红、 黄、 紫、 绿和蓝5种颜色上的滞留时间都极显著地高于对照（P<0.01）, 在黑和白2种颜色上的滞留时间与对照没有显著差异（P>0.05）; 对黄色的首次选择率极显著高于对照(P< 0.01), 对红、 紫、 绿和蓝色的首次选择率均显著高于对照(P＜0.05), 对黑色和白色的首次选择率与对照没有显著差异。当雌蜂分别在黄与红、 紫、 绿和蓝两两颜色之间选择时, 雌蜂在黄色彩纸上的滞留时间显著长于其他4种颜色。当雌蜂对红、 紫、 绿、 蓝和黄色5种颜色一起选择时, 在首次选择率、 滞留次数上5种颜色间都没有明显差异(P＞0.05); 但在红色和蓝色上的滞留时间显著长于紫色(P＜0.05), 在这3种颜色上的滞留时间与在黄色和绿色上的滞留时间均无显著差异(P＞0.05)。卷蛾分索赤眼蜂雌蜂在7种颜色卵卡上分别与透明纸（对照）上的米蛾卵的选择寄生时, 在黄色卵卡上的寄生卵量极显著多于对照(P＜0.01), 黑色卵卡上的寄生卵量极显著少于对照(P＜0.01), 其他5种颜色的卵卡上的寄生卵量与对照没有显著差异(P＞0.05)。结果说明, 卷蛾分索赤眼蜂雌蜂对黄色最为偏好, 其次偏好红、 紫、 绿和蓝色, 较不喜好白色和黑色。     

Spectral preference and temporal modulation of photic orientation by Colorado potato beetle on a servosphere

The Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), is a diurnal insect that strongly relies on visual cues to guide its walk. In the present study, we investigated the orientation behavior of non‐diapausing walking CPB in response to emissive colors produced by light emitting diodes (LEDs) in a dual choice arena adapted to a servosphere, where the only illumination available came from the photo‐stimuli. Our results demonstrate that CPB show positive phototactic behavior when stimulated with different wavelengths of light; they preferred to orient towards white (420–775 nm), ultraviolet (UV) (351 nm), blue (472 nm), green (570 nm), yellow (585 nm), orange (590 nm), and red (660 nm) over darkness when both alternatives were offered, but no orientation responses were elicited by infrared (940 nm). Both males and females preferred yellow and green over other colors, but did not show any particular preference between them, thus correlating with their preference for wavelengths reflected by vegetation. Sexual differences were noted in that male CPB preferred white over either red or UV, whereas female CPB did not show any preferences when offered these colors. Female CPB preferred UV and blue over red, whereas males showed no preferences when these colors were offered. Colorado potato beetles turned at higher angles and performed more tortuous walks in complete darkness and when infrared vs. darkness were offered compared with the rest of the colored lights. Both sexes preferred continuous over pulsed yellow light. Colorado potato beetles subjected to pulsed yellow light showed a temporal alteration of their walking performance by walking less, slower, and turning at a higher rate. The results are discussed with regard to the role of color in the CPB attraction to host plants and conspecifics as well as the role of intermittent photic stimuli in their orientation behavior. The information provided here provides a basis for the improvement of trapping devices for detection and survey of incipient or invasive CPB, and development of alternate control strategies for this important pest of potatoes and other solanaceous crops.     

粉蝶盘绒茧蜂中国和荷兰种群学习行为及EAG反应的比较

昆虫的取食危害可导致植物释放的挥发物发生质和量的变化,天敌利用植物在受到植食性昆虫的危害后释放的挥发性物质来寻找寄主,这种植物挥发物在寄生蜂寻找寄主过程中扮演者重要的角色。粉蝶盘绒茧蜂(Cotesia glomerata)是菜粉蝶(pieris rapae)主要的内寄生蜂,是优良的蜂种,在生物防治上具有广阔的应用前景。分别以中国种群和荷兰种群的粉蝶盘绒茧蜂为研究对象,利用Y型嗅觉仪和触角电位(Electroantennogram,EAG)技术,比较了不同地理种群粉蝶盘绒茧蜂雌蜂的学习行为和触角电生理反应差异。旨在明确虫害植株释放的挥发物在两个地理种群中的作用。Y型嗅觉仪试验结果表明,雌蜂不同的学习经历会影响其对寄主植株的趋性行为。没有学习经历的中国种群雌蜂对虫害甘蓝挥发物较虫害紫甘蓝和虫害羽衣甘蓝挥发物表现出更强地趋性行为,无学习经历荷兰种群对虫害甘蓝挥发物同样表现出更强地趋性行为,中国种群3次间隔产卵和3次间隔气味学习使其对经历过的寄主植物挥发物趋性明显提高。荷兰种群3次间隔气味学习也会提高该蜂对经历寄主挥发物的趋性。EAG试验结果显示,两个地理种群雌蜂对所测定三类挥发物(体积比10-1)的反应强弱依次为:C6化合物>脂肪族化合物>萜类化合物;且在所测定的6种化合物剂量范围内,两个地理种群雌蜂均与trans-2--己醛和乙酸己酯(体积比10-4—10-1),壬醛、月桂烯和里那醇(体积比10-4—10-2)化合物的活性成正相关。结果表明,中国和荷兰种群雌蜂均表现出较为一致的学习能力和电生理反应。研究显示粉蝶盘绒茧蜂雌蜂可能利用甘蓝挥发物作为利它素而寻觅适宜的寄主,学习经历会明显提高该蜂对经历的寄主挥发物的趋性的行为。实验结果为菜粉蝶的生物防治提供理论基础。     

Response of Trichogramma egg parasitoids to colored sticky traps

The response of Trichogramma spp. egg parasitoids to colored sticky traps was evaluated in the field during two seasons (1995/1996, 1996/1997). Traps consisted of a glass tube coated with Bird-Tanglefoot® into which colored paper was inserted or clear traps without paper. Colors tested were white, green, blue, yellow and red in the first season and white, green, yellow and black in the second season. The proportion of both female and male parasitoids caught on the sticky traps was significantly different among colors, indicating that the parasitoids actively move between plants and are not solely carried along passively by wind. White was the color most preferred by female parasitoids, followed by clear and green traps. Yellow was preferred over black but was less attractive than green. Visual cues may be used by Trichogramma spp. during the habitat location process. The color preference of male Trichogramma spp. differed significantly from females with yellow and green being more attractive than white. For all colors, more female Trichogramma spp. were caught on the sticky traps (>85% of all wasps caught), indicating a lower activity level and/or shorter lifespan for males. The use of white cylindrical sticky traps for monitoring Trichogramma spp. populations in the field is recommended.     

Olfactory Cues Are Subordinate to Visual Stimuli in a Neotropical Generalist Weevil

The tropical root weevil Diaprepes abbreviatus is a major pest of multiple crops in the Caribbean Islands and has become a serious constraint to citrus production in the United States. Recent work has identified host and conspecific volatiles that mediate host- and mate-finding by D. abbreviatus. The interaction of light, color, and odors has not been studied in this species. The responses of male and female D. abbreviatus to narrow bandwidths of visible light emitted by LEDs offered alone and in combination with olfactory stimuli were studied in a specially-designed multiple choice arena combined with a locomotion compensator. Weevils were more attracted to wavelengths close to green and yellow compared with blue or ultraviolet, but preferred red and darkness over green. Additionally, dim green light was preferred over brighter green. Adult weevils were also attracted to the odor of its citrus host + conspecifics. However, the attractiveness of citrus + conspecific odors disappeared in the presence of a green light. Photic stimulation induced males but not females to increase their speed. In the presence of light emitted by LEDs, turning speed decreased and path straightness increased, indicating that weevils tended to walk less tortuously. Diaprepes abbreviatus showed a hierarchy between chemo- and photo-taxis in the series of experiments presented herein, where the presence of the green light abolished upwind anemotaxis elicited by the pheromone + host plant odor. Insight into the strong responses to visual stimuli of chemically stimulated insects may be provided when the amount of information supplied by vision and olfaction is compared, as the information transmission capacity of compound eyes is estimated to be several orders of magnitude higher compared with the olfactory system. Subordination of olfactory responses by photic stimuli should be considered in the design of strategies aimed at management of such insects.     

Deterrent effects of intact plants on host-searching behavior of parasitoid wasps

Female parasitoids distinguish between host-infested and intact plants using chemical cues; however, the contribution of intact plants to host searching of parasitoids has not been investigated so far. Here, we tested how host-searching behavior of the parasitoid wasp, Cotesia kariyai (Watanabe) (Hymenoptera: Braconidae), was affected by intact maize plants in a wind tunnel. To determine the best color for material to create a plant model, we observed flight responses of female wasps to paper plant models of four different colors. Wasps tended to land more frequently on green models than other models. Therefore, a green paper model was used for subsequent experiments. In a no-choice test, female wasps showed higher landing rates on a paper plant model treated with herbivore-induced plant volatiles (HIPVs) than on an intact plant. Moreover, in two-choice tests, wasps preferred the plant model with HIPVs over an intact plant with HIPVs. Intact plants seem to deter C. kariyai females. Our findings suggest that information from intact plants also contributes to the host-searching behavior of females in the natural environment.

     

Olfactory response of Anagrus,nigriventrls (HYM.: Mymaridae): Effects of host plant chemical cues mediated by rearing and oviposition experience

The egg parasitoid Anagrus nigriventris Girault is an important natural enemy of the beet leafhopper, Circulifer tenellus (Baker) which has a broad host range that includes cultivated sugar beets and the weed, Russian thistle. When parasitoids were reared on leafhopper eggs deposited in sugar beets, females were attracted to sugar beet volatiles and preferred them over a blank control and over Russian thistle volatiles in Y- tube olfactometer tests. No preference was detected for either plant by female wasps that were reared on Russian thistle. Wasps reared on Russian thistle and allowed an oviposition experience on sugar beet showed a strong attraction to sugar beet volatiles; however, wasps reared on sugar beets and allowed oviposition experience on Russian thistle demonstrated no preference between the two plants. The implications of parasitoid response towards plant volatiles and their importance in biological control are discussed.     

寄主挥发物、叶色在B型烟粉虱寄主选择中的作用

在室温条件下,研究B型烟粉虱Bemisia tabaci(Gennadius)对不同寄主植物和颜色的行为趋性。笼罩实验的结果显示,烟粉虱雌虫对共存的5种寄主植物偏好存在显著差异,总体上表现为对番茄的趋性最强(35·0%),甘蓝次之(27·7%),烟草和棉花再次之,辣椒最低(7·1%);且随着时间的延长,烟粉虱数量在番茄上逐渐增加,在甘蓝上呈下降趋势,在烟草、棉花和辣椒上变动幅度不大,但数量总体上仍是番茄(48·8%)>甘蓝(18·4%)>烟草、棉花>辣椒(3·4%)。但烟粉虱在不同寄主植物上的产卵量则表现为:甘蓝>番茄>棉花、烟草>辣椒;其中甘蓝和番茄上卵量分别占总卵量的56·8%和28·2%;而烟草、棉花和辣椒上的卵量均不到总卵量的6·0%。"Y"型嗅觉仪进一步测定表明:寄主植物番茄和甘蓝气味对烟粉虱具有显著引诱作用,且表现为番茄>甘蓝,辣椒不具引诱作用;烟粉虱对3种植物(番茄、甘蓝、辣椒)的叶片颜色均有显著趋性,选择率在75%左右,但在三者之间的趋性差异不明显;烟粉虱雌虫对黄色和绿色均具有显著趋性,且对黄色的趋性显著大于对绿色的趋性,但对红色无趋性。综合分析表明,在对寄主定向和定位过程中,B型烟粉虱的视觉和嗅觉均起作用,但在对同种颜色(绿色)的寄主进行选择和定位的过程中,嗅觉起主要作用,而对不同种颜色(红、黄、绿)的选择和定位时,其视觉起决定作用。     

青斑蝶Tirumala limniace成虫颜色偏好性研究

【目的】明确青斑蝶Tirumala limniace雌、雄成虫对颜色的偏好性,可以为此蝴蝶人工饲养时的合理环境条件设定提供必要的理论支持。【方法】本研究通过在室内和野外对青斑蝶成虫对6种颜色(白色、红色、绿色、黄色、蓝色和紫色)光源的选择行为进行观察,明确青斑蝶成虫对不同颜色的偏好性。【结果】(1)在室内和在野外雌、雄成虫均优先选择黄色。(2)雌雄成虫在野外无其它光源干扰下对黄色的选择性强于室内。(3)单色光源照明和多种不同颜色光源同时存在下,成虫对颜色的偏好程度存在差异:当只有单色光源照明时,成虫对颜色的偏好程度为黄色>绿色=红色≥蓝色≥紫色;当不同颜色光源同时存在时,成虫对颜色的偏好程度则为黄色>蓝色≥绿色=红色≥紫色。(4)在不同颜色光源同时存在时,配对后的雌成虫表现出了比雄成虫更强的颜色选择性:雌成虫对黄色光源的选择性强于雄成虫,且其未产生颜色选择的成虫数量也少于雄成虫。【结论】青斑蝶成虫存在对黄色选择的颜色恒常性,野外成虫对颜色的选择性强于室内,雌、雄成虫对偏好颜色选择性存在性别差异。     

Behavioral responses of <Emphasis Type="Italic">Frankliniella occidentalis</Emphasis> to floral volatiles combined with different background visual cues

The Western flower thrips, Frankliniella occidentalis (Thysanoptera: Thripidae), is one of the most destructive sucking pests of flowering plants. We examined behavioral responses of F. occidentalis adults to the floral volatiles of Rosa chinensis, Gardenia jasminoides, and Tagetes erecta in a Y-tube olfactometer with background visual cues (green, red, white, yellow, and blue backgrounds). The results show that F. occidentalis adults had similar responses under all the different background colors, but the responses by sex varied significantly when offered floral volatile or clean air. In pairings of floral volatiles, female F. occidentalis adults presented significant preferences (R. chinensis > G. jasminoides > T. erecta) in each treatment, while male F. occidentalis adults had no significant preference. Furthermore, the responses of female F. occidentalis adults to the three different floral volatiles compared with each other were greater under green and blue backgrounds than red, white, or yellow backgrounds. However, the responses of male F. occidentalis adults to floral volatiles were similar to all five backgrounds. These results indicate that female thrips could discriminate different floral volatiles, while male thrips could not. Both male and female thrips performed steady preferences of floral volatiles under all the five visual backgrounds, and the behavioral responses of female thrips to the floral volatiles could be enhanced under the green and blue backgrounds. These findings could hopefully aid in the development of effective trapping and monitoring strategies for this pest.     

Host color preferences and short-range searching behavior of the egg parasitoid Trichogramma ostriniae

The color of lepidopteran eggs often varies by species or egg condition, and parasitoids that attack lepidopteran eggs could therefore potentially use color to obtain information about host identity or quality. The objective of our study was to determine whether females of the egg parasitoid Trichogramma ostriniae Pang & Chen (Hymenoptera: Trichogrammatidae) showed differential responses to egg color when searching for hosts over short distances and when evaluating the suitability of encountered eggs. We examined the wasps’ host‐selection behavior in a Petri dish arena using white, yellow, green, and black clay beads as egg models presented against a green background (to mimic leaf color). In no‐choice tests, bead color had a significant effect on the proportion of tested wasps that accepted a bead for further examination, on the time it took wasps to find and begin examining a bead, and on the time that wasps spent examining the beads. However, bead color had only a marginally significant effect on the proportion of wasps attempting to drill into a bead with their ovipositors, and no significant effect on the amount of time they spent drilling. The wasps also showed significant color preferences when given a choice between two adjacent beads of different colors. The results of the no‐choice and choice trials taken together indicated a color preference ranking of yellow > white > green > black. The wasps’ higher preference for the yellow and white egg models generally corresponds to the white or yellowish‐white egg color of T. ostriniae's target host, the European corn borer moth, Ostrinia nubilalis Hübner (Lepidoptera: Crambidae). The wasps’ strong rejection of black egg models is likely to be an adaptive response that reflects the fact that eggs that are wholly or partially black are often unsuitable for parasitization due to advanced caterpillar development, damage to the egg, or previous parasitization.     

Food Color Preferences of Molting House Finches (Carpodacus mexicanus) in Relation to Sex and Plumage Coloration

Food color can be indicative of specific nutrients, and thus discrimination based on color can be a valuable foraging behavior. Several bird and fish species with carotenoid-based body ornamentation show color preferences for presumably carotenoid-rich red and orange foods. However, little is known within species about whether or not individuals with (or growing) more colorful ornaments show stronger food-color preferences than those with drabber coloration. Here, we examine food color preferences in house finches ( Carpodacus mexicanus ) – a species with sexually dichromatic and selected carotenoid coloration – as a function of sex and plumage coloration during molt. We captured wild, molting juvenile house finches over 4 wk in late summer/early fall, quantified the color and size of plumage ornaments being developed in males, and determined food color preference in captivity by presenting individuals with dyed sunflower chips (red, orange, yellow, and green). On average, finches showed an aversion to yellow-dyed chips and a preference for red- and green-colored chips. We found no significant difference between male and female preferences for specific food colors, and food color preference was not significantly related to male plumage ornamentation. However, we did find that redder birds demonstrated a higher degree of food selectivity, measured as the proportion of their preferred food color consumed. These results suggest that food color is not a major factor determining food choice in molting house finches, but that there still may be aspects of foraging behavior that are linked to the development of colorful plumage.     

Can Infants Tell the Difference between Gold and Yellow?

There is a large literature focused on the color perception of matte surface. However, recent research showed that the component of surface specular reflection, such as glossiness, also affects categorical color perception. For instance, the color term “gold” was used to name high specular stimuli within a specific range of chromaticity, which overlaps with those of yellow and orange for low specular stimuli. In the present study, we investigated whether the component of surface specular reflectance affects the color perception of 5- to 8-month-old infants by using the preferential looking technique. In the first experiment, we conducted a simple test to determine whether infants perceive yellow and gold as the same color by comparing their preference for these colors over green. If the infants perceive yellow and gold as the same color, they would show similar preference scores over green. On the other hand, if infants show different preference scores over green, it indicates that infants do not perceive yellow and gold as the same color. Only the 7–8 month-old infants showed different preference scores for gold and yellow over green. This result indicates that the 7–8 month-old infants perceive gold and yellow as different colors. In Experiment 2, we eliminated the component of specular reflectance on the gold surface and presented it against green to infants. A similar preference score of yellow over green was obtained. This result suggests that the difference between the preference scores for gold and yellow over green in Experiment 1 was based on representations of glossiness.     

Hummingbird color preference within a natural hybrid population of Mimulus aurantiacus (Phrymaceae)

Hummingbird flowers are typically red in color but the reasons for this are not well understood. Relatively few studies have examined hummingbird flower color preferences under natural conditions in which flower color varies within a species. We recorded hummingbird visitation rates to flowers that vary in color from yellow to red in a natural hybrid population between red‐ and yellow‐flowered Mimulus aurantiacus subspecies. We also examined whether there were any correlations between color and flower size or nectar content. Finally, we reviewed the literature on hummingbird color choice tests using feeders and flowers. There were no correlations in this population between flower color and flower size, nectar volume, or sugar concentration. Nevertheless, hummingbirds undervisited the two most yellow color classes, overvisited orange flowers, and visited the two most red color classes in proportion to their frequency in the population. While Hummingbirds preferred flowers expressing red pigments to those that did not, the flowers with the most red hue were not the most attractive, as has been observed in similar studies with other species of Mimulus. While feeder studies generally fail to show hummingbird preference for red, all studies using flowers, including those that control all floral traits other than color, find consistent preference for red. Experiments are suggested that might help disentangle hypotheses for why hummingbirds exhibit this preference.     

Influence of cabbage resistance and colour upon the diamondback moth and its parasitoid Oomyzus sokolowskii

Host plant resistance and biological control are vital integrated pest management tools against the diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae), but to date no study has investigated this system including the DBM parasitoid Oomyzus sokolowskii (Kurdjumov) (Hymenoptera: Eulophidae). We examined oviposition and development of P. xylostella exposed to two commercial cabbage cultivars (green ‘Chato de quintal’ and red ‘Roxo’) and possible effects upon O. sokolowskii. Under free‐choice tests, DBM females laid significantly more eggs on plants of the green cabbage, even though several population growth parameters showed that DBM developed better on the red cabbage. Furthermore, a laboratory free‐choice test with artificially green‐ and red‐painted kale leaf discs demonstrated a similar oviposition preference pattern, with green colour being preferred over red colour. The preference was apparently visually mediated; olfactometer tests showed similar attraction of moths to both green and red cultivars in choice and non‐choice tests. Host plant cultivar had no statistically significant effect on female parasitoid behaviour towards DBM larvae, nor on parasitoid numbers or longevity. Moreover, wasps parasitizing DBM larvae reared on the green cultivar developed more quickly and in larger numbers per parasitized larva. Thus, feeding on green cabbage rather than red does not hinder, and potentially even enhances, control of DBM by O. sokolowskii. On a practical level, these results suggest that intercalating green cabbage cultivars as a trap crop might help protect more profitable red cultivars in growing fields.     

Visual response of the tomato fruit fly, Neoceratitis cyanescens, to colored fruit models

To determine how mature females of the tomato fruit fly, Neoceratitis cyanescens (Bezzi) (Diptera: Tephritidae), detect host fruit after arriving in their host plant habitat, behavioral responses to colored models were observed in a laboratory flight chamber. Host‐seeking females oriented themselves preferentially towards bright orange spheres (3.7 cm in diameter), irrespective of their natal host fruit: tomato, bug weed, or black nightshade. Females oriented themselves preferentially towards the orange sphere when placed against a fluorescent yellow background as opposed to a black background, but the distribution of responses to the set of colored spheres did not vary significantly with background color. In a choice situation between bright orange spheres of various sizes (1.9, 3.7, and 7.5 cm in diameter), females landed preferentially on the bigger sphere. However, they preferred a yellow color when the latter was associated with two‐dimensional models, probably mimicking leaves. The attractiveness of orange spheres depended more on the proportion of reflected light in the spectral region around 610 nm than brightness of color in itself. Low light intensity significantly influenced the activity of the flies but not their visual preference. The strong response of females to bright orange spheres confirmed the importance of visual characteristics in short‐range mechanisms of host‐plant location in specialist insects. Responses to fruit visual stimuli are discussed relative to other Tephritidae, host‐finding strategy, and pest management.     

Visual and olfactory preference of Harmonia axyridis (Coleoptera: Coccinellidae) adults to various companion plants

Natural enemies can be attracted to companion plants that can provide them with suitable habitat including food and shelter. This study was conducted to determine if the multicolored Asian lady beetle, Harmonia axyridis Pallas (Coleoptera: Coccinellidae), could be attracted to olfactory and visual cues of various companion plant species. Ten potential plants that can attract and provide H. axyridis with alternate food sources (i.e. nectar and pollen) were selected for olfactory preference tests. These plants included dill (Anethum graveolens), yarrow (Achillea spp.), butterfly weed (Asclepias tuberosa), dandelion (Taraxacum officinale), bugleweed (Ajuga reptans), marigold (Tagetes tenuifolia), tansy (Tanacetum vulgare), goldenrod (Solidago spp.), morning glory (Ipomoea spp.), and sunflower (Helianthus annuus). Visual preference tests were conducted with six different colors: white, yellow, blue, red, green, and orange. The result of the olfactory preference test showed that H. axyridis adults significantly preferred sunflower and dill among the ten potential companion plants tested in this study. In a visual preference test, H. axyridis significantly preferred yellow to any other colors. The result of this study suggested that odor and color of some companion plants (olfactory and visual cues) could assist in the use of biological control by attracting H. axyridis adults to the cropping area.     

Male mate choice in a sexually cannibalistic species: male escapes from hungry females in the praying mantid <Emphasis Type="Italic">Tenodera angustipennis</Emphasis>

While competing males and choosy females may be common in animal mating systems, male choice can evolve under certain conditions. Sexual cannibalism is such a condition because of the high mortality risk for males. In mantids, female body condition is associated with male mate preference, with fat females preferred, due to at least two reasons: females in poor nutritional condition are likely to attack and predate males, and fat females can potentially increase the number of offspring. Thus, the risk of cannibalism and female fecundity can influence male mating behavior. In this study, we attempted to separate these factors by using the praying mantid Tenodera angustipennis to examine whether male preference for fat female mantids was based on avoiding sexual cannibalism (cannibalism avoidance hypothesis) or preference for female fecundity (fecundity preference hypothesis). The feeding regimes were experimentally manipulated to discriminate between the effects of female fecundity and female hunger status on male and female mating behaviors. We found that recently starved females more frequently locomoted toward the male, and that male abdominal bending was less intensive and escape was sooner from recently starved females. These female and male behavioral responses to female hunger condition may reveal male avoidance of dangerous females in this mantid.     

白蜡虫寄生蜂对颜色的选择性及活动规律

在云南省昆明市白汉场白蜡园中采用不同颜色对白蜡虫寄生蜂进行了颜色趋性实验,利用寄生蜂对颜色的趋性进行了红色、黄色、蓝色、蓝绿色、绿色、灰褐色、白色和黑色8种颜色、6:00-9:00am,9:00-12:00am,12:00am-15:00pm和15:00pm-18:00pm4个时段、寄主林树冠上部、中部、下部3个位置高度和东、南、西、北4个方位以及在阴天、雨天和晴天3种天气下的白蜡虫寄生蜂活动规律观察。结果表明,白蜡虫花翅跳小蜂(Microterys ericeri Ishii)、白蜡虫阔柄跳小蜂(Metaphycus ericeri Xu et Jiang)和中华花翅跳小蜂(Microterys sinicus Jiang)3种寄生蜂优势种对黄色有明显的趋向性,对颜色的选择性依次为黄色>蓝色>蓝绿色>绿色>白色>灰褐色>红色>黑色。在白蜡园寄主林,寄主植物中部诱集的白蜡虫寄生蜂数量最多,占52.21%;其次是下部,占39.80%;顶部最少,仅占7.99%。白蜡虫寄生蜂的活动与白蜡虫在寄主植物上的分布密切相关。白蜡虫寄生蜂在不同方向上的活动差异不显著。在一天中的不同时段里,白蜡虫寄生蜂在6:00-9:00am有一个活动高峰期,在15:00-18:00pm出现一个次高峰期。白蜡虫寄生蜂在晴天活动较活跃,在阴天和雨天活动较少。     

Role of Vision and Mechanoreception in Bed Bug,Cimex lectularius L. Behavior

The role of olfactory cues such as carbon dioxide, pheromones, and kairomones in bed bug, Cimex lectularius L. behavior has been demonstrated. However, the role of vision and mechanoreception in bed bug behavior is poorly understood. We investigated bed bug vision by determining their responses to different colors, vertical objects, and their ability to detect colors and vertical objects under low and complete dark conditions. Results show black and red paper harborages are preferred compared to yellow, green, blue, and white harborages. A bed bug trapping device with a black or red exterior surface was significantly more attractive to bed bugs than that with a white exterior surface. Bed bugs exhibited strong orientation behavior toward vertical objects. The height (15 vs. 30 cm tall) and color (brown vs. black) of the vertical object had no significant effect on orientation behavior of bed bugs. Bed bugs could differentiate color and detect vertical objects at very low background light conditions, but not in complete darkness. Bed bug preference to different substrate textures (mechanoreception) was also explored. Bed bugs preferred dyed tape compared to painted tape, textured painted plastic, and felt. These results revealed that substrate color, presence of vertical objects, and substrate texture affect host-seeking and harborage-searching behavior of bed bugs. Bed bugs may use a combination of vision, mechanoreception, and chemoreception to locate hosts and seek harborages.