华山松木蠹象聚集信息素分离鉴定和引诱效果

为了研制华山松木蠹象Pissodes punctatus Langor et Zhang的引诱剂,对华山松木蠹象的虫粪和雄虫后肠挥发性物质进行了分析鉴定和室内外生物活性测试。经GC-MS测定,发现在华山松木蠹象的新鲜虫粪和雄虫后肠挥发性物质中,除了松树挥发性的单萜烯如α-蒎烯、β-蒎烯和3-蒈烯以外,还存在1-甲基-2-异丙烯基-环丁烷乙醇（grandisol）。室内Y-型嗅觉仪趋向实验表明,较低浓度的3-（+）-蒈烯、1-甲基-2-异丙烯基-环丁烷乙醇及其相应的醛1-甲基-2-异丙烯基-环丁烷2醛（grandisal）,引起华山松木蠹象的正趋向反应。林间引诱试验表明,1-甲基-2-异丙烯基-环丁烷乙醇和1-甲基2-异丙烯基-环丁烷2醛对华山松木蠹象具有一定的引诱作用。由此推断,1-甲基-2-异丙烯基-环丁烷乙醇可能是华山松木蠹象的集结信息素成分之一。     

Aggregation pheromone in Sternechus subsignatus (Coleoptera: Curculionidae): olfactory behaviour and temporal pattern of emission

The Brazilian soybean stalk weevil, Sternechus subsignatus Boehman (Coleoptera: Curculionidae), is a pest of economic importance in many regions of Brazil. Volatiles from both sexes of S. subsignatus were collected by aeration and the behavioural response of males and females was evaluated using a Y‐olfactometer. The results obtained demonstrate that the communication in S. subsignatus is mediated by aggregation pheromone as both sexes were attracted to host plant (HP) volatiles, and this attraction was increased by the addition of male volatiles. At least five male‐specific compounds (1–5) were detected in the chromatographic analysis, providing chemical support to the behavioural data. Release of these volatiles is dependent on the presence of the HP as the amount of compounds differs significantly when volatiles are collected from weevils with or without access to food. The release takes place mainly during photophase, showing a peak between 4 and 6 h after its beginning, which is also a peak of the insect activity in the field. Studies are underway to elucidate the structures of these putative aggregation pheromone components, in order to evaluate their biological activity under laboratory and field conditions.     

Impact of azadirachtin on vine weevil (Coleoptera: Curculionidae) reproduction

Abstract 1 The dose–response of azadirachtin on vine weevil, Otiorhynchus sulcatus (Fabricius), reproduction is investigated by confining adults to feed on treated Taxus × media leaves, and by counting and evaluating development in the resulting eggs. 2 A dosage‐dependent reduction in oviposition is discovered for foliar surface residues of azadirachtin, with an EC₅₀ of 25–50 parts per million (p.p.m) and 99.2% inhibition of viable egg production with 100 p.p.m. 3 Switching weevils from treated to untreated foliage allows reproductive capability to be restored for weevils that cease egg laying after azadirachtin exposure of 50 p.p.m. Weevils that had already started laying eggs in untreated groups soon cease oviposition once switched to azadirachtin‐treated foliage. 4 A transovarial effect results in a decrease in the percentage of viable eggs as the azadirachtin concentration increases. 5 The amount of feeding on foliage does not appreciably decrease at these hormonally effective concentrations, and adult weevil mortality is only slightly greater in the azadirachtin‐treated groups. Therefore, the overall effect of azadirachtin on weevil populations in the field is difficult to assess, except by collecting weevils to determine whether they are able to lay viable eggs.     

Pheromone trapping of the sugarcane weevil borer, Rhabdoscelus obscurus (Boisduval) (Coleoptera: Curculionidae): an evaluation of trap design and placement in the field

Abstract  The sugarcane weevil borer ( Rhabdoscelus obscurus ) is a pest of sugarcane and palm plantations in high rainfall areas of far north Queensland. Pheromone mass trapping of adult borers is an effective method of monitoring and may also impact on their population densities. Trials to evaluate different designs of pheromone trap showed the 'water trap' to be the most effective in capturing the highest number of adult borers. The water trap is a 20 cm-diameter pot with a plastic bag inserted to hold water with pheromone lures and cane pieces held together in a plastic container suspended over the water from a square of wire mesh. Results also showed that adult borers in adjacent fields are able to sense the lures and migrate into treated fields. The sex ratio of captured borers in split-cane traps (which is a standard population monitoring tool) was male biased from February to April but was more balanced later in the year. However, the pheromone traps mainly attracted female borers all year round, except during May. Thus, we recommend pheromone traps to be deployed early in the season (November to early December) to attract the maximum number of adult females at a critical time for the population as it starts to build up. In addition, placing pheromone traps inside cane paddocks did not improve the total catch in most cases. Therefore, placing pheromone traps under the shade of trees outside the paddock or at the edge of the paddock under sugarcane can be a feasible mass trapping method that can easily be implemented by cane growers.     

Temperature-dependent development and reproduction of the boll weevil (Coleoptera: Curculionidae)

Abstract Effects of temperature on development, survival, and fecundity of boll weevil, Anthonomus grandis grandis Boheman, were assessed at 10, 11, 12, 15,20,25,30,35,45, and 46 °C; 65% relative humidity; and a photoperiod of 13:11 (L: D) h. The mortality of boll weevil immature stages was 100% at 12°C and decreased to 36.4% as the temperature increased to 25°C. When the temperature increased from 30 °C to 45 °C, the mortality of weevils also increased from 50.1% to 100%. From 15°C to 35°C, the bollweevilpreimaginal development rate was linearly related to temperature. The average development time of total boll weevil immature lifestages decreased 3.6-fold and the preovipositional period decreased 3.3-fold when the temperature was increased from 15°C to 30°C. The lower threshold for development was estimated at 10.9, 6.6, 7.0, and 9.0 °C for eggs, larval, pupal, and total immature stages, respectively, with total thermal time requirement to complete immature stages of 281.8 DD (degree day) (15°C) and 247.8 DD (35 °C). At 1LC and 46°C, weevil females did not oviposit. Longevity of adult females decreased 4.6-fold with increasing temperatures from 15°C to 35°C. Fecundity increased with increasing temperatures up to 30°C and significantly decreased thereafter. These findings will be useful in creating a temperature-based degree-day model for predicting the occurrence of key life stages in the field. An accurate predictor of a pest's development can be very important in determining sampling protocols, timing insecticide applications, or implementing an integrated pest management control strategy targeting susceptible life stages.     

Compensatory response of cranberry to simulated damage by cranberry weevil (Anthonomus musculus Say) (Coleoptera: Curculionidae)

Cranberry weevil (Anthonomus musculus Say), a key pest of cranberry (Vaccinium macrocarpon Aiton) in Massachusetts, deposits eggs in unopened flowers and often severs the flower pedicel from the peduncle. The compensatory response of cranberry to simulated cranberry weevil damage was investigated by severing the pedicel of unopened flowers with scissors. When intensity of damage was varied on the cultivar Early Black, complete compensation was observed at three of four sites after removal of 33% of a peduncle's unopened flowers, but a approximately 37% decline in number of fruit and weight of berries per peduncle was observed when 67% of unopened flowers were removed. When timing of damage was varied at sites planted to the cultivar Howes, no differences were observed when 50% of unopened flowers were clipped from a peduncle early versus late in preblossom peduncle growth. However, both the early and late clipping treatments resulted in a 30% decrease in the number and weight of berries per peduncle when compared with the no clipping treatment. These results suggest that cranberry has the ability to tolerate low to moderate levels of weevil damage, but a substantial data base will be required to determine any appropriate changes in threshold recommendations.     

Microstructure of mandibulate mouthparts in the greater rice weevil,Sitophilus zeamais (Coleoptera: Curculionidae)

The greater rice weevil, Sitophilus zeamais, is a serious pest of stored grain. It chews a hole in the grain and deposits an egg inside. For the purpose of excavating a tunnel, these weevils are equipped with effective mandibulate mouthparts for penetrating and boring holes. The mouthparts of the weevil are a long slender snout, which consist of a labrum, a pair of mandibles, a pair of maxillae and a labium. Mothparts exhibit typical morphology of phytophagous coleopteran beetles and have characteristics of chewing mouthparts. Mandibles are connected to the head capsule through dicondyous articulation, which allows movement along one single rotating axis. Both labrum and labium are fused to the snout and form the upper and lower lips, respectively. Along the depressed surface of the snout, a number of short sensory hairs are sparsely arranged. The distal apexes of the maxillary and labial palpi are deeply depressed into a sensillar field, and only one type of the basiconic sensilla, which function as chemo‐ or gustatory receptors, occurs in both sexes.     

Proteolytic gut activities in the rice water weevil,Lissorhoptrus brevirostris Suffrian (Coleoptera: Curculionidae)

Digestive endoprotease activities of the rice water weevil, Lissorhoptrus brevirostris Suffrian (Coleoptera: Curculionidae), were characterized based on the ability of gut extracts to hydrolyze specific synthetic substrates, optimal pH, and hydrolysis sensitivity to protease inhibitors. Larvae of this species were found to use a complex proteolytic system that includes cathepsin D-, cathepsin B-, trypsin-, and chymotrypsin-like activities. Trypsin-like activity was evenly distributed among the anterior, middle, and posterior portions of the gut, whereas cathepsin B- and cathepsin D-like activities were mainly located in the anterior and middle sections, and the chymotrypsin-like activity was highest in the middle and posterior sections. Gelatin-containing native-PAGE gels indicated the presence of several aspartyl, cysteine, and serine protease forms and confirmed the spatial organization of the proteolytic digestive process.     

多种植物挥发物及马铃薯甲虫聚集素对马铃薯甲虫的引诱作用

马铃薯甲虫Leptinotarsa decemlineata (Say)是马铃薯上一种最主要的毁灭性害虫。由于其严重的抗药性, 急需寻找一种替代杀虫剂的防治方法。本实验从开发马铃薯甲虫引诱剂的目的出发,用“Y”型嗅觉仪测定了马铃薯甲虫对来自植物的7种挥发物单体、8个挥发物混合物配方以及马铃薯甲虫聚集素的行为反应,并进一步进行了田间诱集试验。室内生测结果表明,2-苯乙醇对马铃薯甲虫雌雄虫都有明显的引诱作用。芳樟醇+水杨酸甲酯+顺乙酸-3-己烯酯的混合物对马铃薯甲虫雄虫有很强的引诱作用(81.67%), 但是对雌虫引诱作用不明显(63.33%)。在其中加入马铃薯甲虫聚集素不但提高了对雄虫的引诱率（88.33%）,还消除了之前的雌雄性别间反应差异现象,使对雌虫的引诱率达到了83.33%。田间诱集结果显示,芳樟醇+水杨酸甲酯+顺乙酸-3-己烯酯+马铃薯甲虫聚集素在所研究的引诱剂配方中引诱效果最好。从而为马铃薯甲虫发生的预测预报和诱杀技术提供了研究基础。     

Comparisons of standard and extended-life boll weevil (Coleoptera: Curculionidae) pheromone lures

The Southeastern Boll Weevil Eradication Program has proposed reducing maintenance program costs in eradicated zones by using an extended-life "superlure" in traps to detect populations of the boll weevil, Anthonomus grandis grandis Boheman. However, superlure effectiveness has not been extensively evaluated. We compared the superlure (30 mg of eugenol plus 25 mg of grandlure) to a standard lure (10 mg of grandlure) based on captures of weevils and changes in lure pheromone content. Lure treatments (standard and superlure, replaced biweekly or not replaced) were compared in 4-mo-long trapping periods. Captures of weevils did not generally reflect differences among lure treatments indicated by assays of lure contents. During the first 2 wk of exposure, amounts of pheromone released by the superlure were generally comparable with those of the standard lure, but pheromone composition was more stable. During the second 2 wk of exposure, the superlure usually released more pheromone than similarly aged standard lures, but less than half as much as the standard lure replaced biweekly. Based on numbers of captured weevils during the last 2 wk of an extended trapping period, the superlure performed similarly to the standard lure replaced biweekly. However, corresponding pheromone releases by the superlure were less than those by the standard lure replaced biweekly. This inconsistency suggests that numbers of captured weevils alone may be inadequate for evaluation of pheromone formulations. Our results suggest that better understanding of the consequences of reduced pheromone release during an extended trapping period is needed before adoption of the superlure can be recommended.     

Characterization of microsatellite loci in Brachyderes rugatus,the Canary Islands pine weevil (Coleoptera: Curculionidae)

The Canary Island pine weevil Brachyderes rugatus (Wollaston) consists of four allopatric subspecies that are thought to have arisen from several historic colonization events within the archipelago. We have isolated and optimized seven microsatellite loci from Brachyderes rugatus calvus from Gran Canaria. Six of these loci are polymorphic within B. rugatus (11–22 alleles per locus; heterozygosity between 0.43 and 0.84). There is no evidence for heterozygote deficit within populations or for linkage disequilibrium between pairs of loci. These molecular markers are likely to prove useful tools for quantifying the genetic variability of bottlenecked island populations.     

Oviposition aggregation pheromone in the Simulium damnosum complex

Abstract. Communal oviposition by the Simulium damnosum complex of Afrotropical blackflies (Diptera: Simuliidae) was investigated under controlled laboratory conditions, using wild-caught flies in Sierra Leone. Volatile compounds emitted by Simulium eggs were trapped using a closed collection system, and their attractiveness to gravid flies was tested in a two-choice behavioural bioassay. Significantly more female blackflies oviposited on substrates baited with freshly laid eggs (100% chose the baited substrate), or with the volatiles collected from freshly laid eggs (85% chose the baited substrate), in preference to the relevant control substrates. Substrates baited with volatiles from 12-h-old eggs were not significantly more attractive than controls (only 31% chose the baited substrates; P = 0.33). Gas chromatographic analysis of the egg volatiles consistently showed two peaks emanating from fresh eggs, but significantly lower amounts from 12-h-old eggs ( P <0.05). A novel system for collecting the volatiles from this and other blackfly species, as they laid eggs on a substrate in flowing water, is described. Volatiles collected using this method showed identical gas chromatographic profiles to those of fresh eggs alone, indicating that the flies themselves produced no other volatile chemical signals during oviposition. Evidently communal oviposition by S. damnosum s.l . was mediated by a pheromone emanating from fresh eggs. The role of pheromone-mediated egg aggregation in blackfly ecology is discussed, and its possible manipulation is considered.     

Survival of boll weevil （Coleoptera： Curculionidae） adults after feeding on pollens from various sources

The survival of overwintering boll weevil, Anthonomus grandis grandis （Boheman）, adults on non-cotton hosts in the Lower Rio Grande Valley （LRGV） of Texas was examined from 2001 to 2006. The success of the Boll Weevil Eradication Program, which was reintroduced into the LRGV in 2005, depends on controlling overwintering boll weevil populations. Laboratory studies were conducted using boll weevil adults that were captured in pheromone traps from September through March. The number of adults captured per trap declined significantly in the field from fall to the beginning of spring （3.5-7.0-fold）. The proportion of trapped males and females did not differ significantly. The mean weight of boll weevil adults captured in September was 13.3 mg, while those of captured adults from November to February were significantly lower and ranged from 6.7 to 7.8 mg. Our results show that boll weevil adults can feed on different plant pollens. The highest longevity occurred when adults were fed almond pollen or mixed pollens （72.6 days and 69.2 days, respectively） and the lowest when they fed on citrus pollen or a non-food source （9.7 days or 7.4 days, respectively）. The highest adult survival occurred on almond and mixed pollens [88.0%-97. 6% after 1st feeding period （10 days）, 78.0%-90.8% after 3rd feeding period （10 days）, 55. 0%-83.6% after 5th feeding period （10 days）, and 15.2%-32.4% after lOth feeding period （10 days）]. The lowest adult survival occurred on citrus pollen [52.0%-56.0% after 1st feeding period （10 days）, 13.3% after 3rd and 5th feeding periods （10 days）, and 0 after 6th feeding period （10 days）]. Pollen feeding is not a behavior restricted to adult boll weevils of a specific sex or physiological state. Understanding how boll weevil adults survive in the absence of cotton is important to ensure ultimate success of eradicating this pest in the subtropics.     

Laboratory biology and impact of a stem-boring weevil Apocnemidophorus pipitzi (Coleoptera: Curculionidae) on Schinus terebinthifolia

Brazilian peppertree, Schinus terebinthifolia Raddi (Anacardiaceae), was introduced into Florida, USA, from South America as an ornamental plant in the late 19th and early 20th centuries. It eventually escaped cultivation and is a serious threat to the state’s biodiversity. In the 1980s, this invasive weed was targeted for classical biocontrol. Surveys for natural enemies of Brazilian peppertree conducted in the native range resulted in the discovery of several candidate biocontrol agents. A stem-boring weevil identified as Apocnemidophorus pipitzi (Faust) was collected in Paraguay and transported under permit to Florida, USA. A laboratory colony of A. pipitzi was established in April 2007 by caging adults on cut branches of Brazilian peppertree supplemented with leaf bouquets. Adults are defoliators that feed mainly on the upper surface of subterminal leaflets. Females deposit eggs singly inside the stems and larvae feed under the bark where they damage the vascular cambium. There are five instars, pupation occurs inside the stem and a new generation is produced in 3–4 months. Growth of potted plants with and without exposure to weevil herbivory was compared over an 11-month period. Feeding damage by adults and larvae significantly increased leaf abscission and reduced leaf and root biomass accumulation.     

A host monoterpene influences Ips typographus (Coleoptera: Curculionidae,Scolytinae) responses to its aggregation pheromone

1 Host tree terpenes can influence attraction of conifer‐infesting bark beetles to their aggregation pheromones, and both synergistic and inhibitory effects have been reported. 2 We tested a gradient of ratios of (–)‐α‐pinene, the predominant monoterpene in Norway spruce, to the pheromone of Ips typographus, a major pest of Norway spruce. 3 Attraction of I. typographus increased as the release rate of (–)‐α‐pinene increased. The two highest (–)‐α‐pinene : pheromone ratios (526 : 1 and 2595 : 1) attracted twice as many I. typographus as pheromone alone, whereas low to intermediate ratios (56 : 1, 274 : 1) did not differ from pheromone alone. 4 Our results are in agreement with a proposed model, which suggests that bark beetles display unique response profiles to host terpenes depending on the physiological condition of the host trees that they typically colonize. Ips typographus, which is an aggressive species capable of colonizing and killing healthy trees, showed an increased attraction to monoterpene : pheromone ratios, and this may be high enough to inhibit attraction of less aggressive beetle species typically colonizing dead, dying or stressed trees. 5 Attraction of associates of I. typographus was also modified by (–)‐α‐pinene. Ips duplicatus, a competitor of I. typographus, showed increased attraction to the pheromone of I. typographus across all concentrations of (–)‐α‐pinene.     

上海地区红棕象甲的耐寒性研究

红棕象甲Rhynchophorus ferrugineus (Olivier)是我国危害棕榈科植物的重要入侵害虫, 为探明其越冬抗寒性, 利用过冷却点测定仪测定了红棕象甲上海种群不同虫态的过冷却点, 在低温箱内测定了该虫不同虫态的耐寒性, 然后结合田间越冬模拟试验、气象资料和寄主分布情况, 初步确定了红棕象甲在我国的越冬北界。结果表明： 红棕象甲过冷却点随虫态的发育程度的升高而下降, 卵、1龄幼虫、5龄幼虫、9龄幼虫和成虫的平均过冷却点分别为-5.92, -6.42, -7.19, -7.43和-11.84℃, 过冷却点由高到低的顺序依次为: 卵>幼虫>成虫。在6, 24, 48和72 h 4个时间处理下, 各虫态在低温与存活率之间呈显著或极显著的logistic回归, 半致死温度（Ltemp₅₀）均随处理时间的延长而上升, 不同虫态在处理72 h 后, 卵、1龄幼虫、5龄幼虫、9龄幼虫和成虫之间的Ltemp₅₀分别为1.61, -1.67, -2.39, -2.40和-0.40℃, 各虫态耐寒性由弱到强的顺序依次为: 卵<成虫<幼虫。红棕象甲不同发育阶段的过冷却点与其耐寒性并不完全相关, 幼虫和成虫均可能是该虫的越冬虫态。连续两年的田间模拟越冬试验表明, 在上海地区, 红棕象甲的幼虫和成虫的越冬存活率均在60％以上, 说明红棕象甲在上海地区是可以越冬的。根据这些结果, 结合寄主分布情况, 初步将红棕象甲在我国的越冬北界定于北纬35°附近, 即1月份0℃等温线左右。     

A review of the biology and control of the vine weevil, Otiorhynchus sulcatus (Coleoptera: Curculionidae)

At the turn of the century, damage by Otiorhynchus sulcatus was sporadic and limited to small areas. Increasing horticultural intensification and the adoption of husbandry techniques favourable to the weevil, such as the use of polythene mulches, increased its pest status. The development of the early inorganic pesticides reduced the number of serious outbreaks of this pest and weevil control was further improved by the development of the persistent organochlorine insecticides in the 1940's. The banning of a number of the more persistent insecticides over recent years has now left the horticultural industry in a very vulnerable position. O. sulcatus is now a pest on a range of horticultural crops throughout the temperate regions of the world. Infestations are most common in Europe (where it originated) and the USA, and nearly 150 plants species have been identified as potential hosts to O. sulcatus. Damage is most frequently caused by the root feeding larval stage. Populations as low as one larva plant can kill sensitive species such as Cyclamen. Severe damage by the leaf feeding adults is less common, although low levels of damage or contamination by adults may be unacceptable in certain situations. There is one generation a year. Oviposition by the flightless parthenogenetic females occurs over the summer months with oviposition rates of c. 500 and 1200 eggs adult^-1for outdoor and laboratory populations, respectively. O. sulcatus mainly overwinters as larvae, although significant numbers of adults may survive in areas where winter temperatures are not too severe. A number of natural enemies, such as hedgehogs, frogs and predatory beetles, help to maintain O. sulcatus populations at a low level in natural environments, but they are less successful in intensive horticultural systems where persistent chemicals have been heavily relied on to maintain the population below the economic threshold level. Increasing environmental concern is now forcing growers to consider new pest control strategies. Controlled release formulations of non-persistent products, such as fonofos and chlorpyrifos, have shown potential as control agents for O. sulcatus larvae. Biological control agents, such as insect parasitic nematodes, have been developed commercially and new microbial control agents are in the process of development. Most of the new control products are directed towards control of O. sulcatus larvae. Adult vine weevils are nocturnal and a much more difficult target for the new control agents. It is likely that an integrated approach to pest control will be required to maintain O. sulcatus populations below their economic threshold level.     

The effect of the CpTi gene in strawberry against attack by vine weevil (Otiorhynchus sulcatus F. Coleoptera: Curculionidae)

The degree of protection against insect feeding conferred upon transgenic strawberry lines expressing the Cowpea trypsin inhibitor was evaluated under glasshouse conditions. Insect bioassays were carried out using vine weevil (Otiorhynchus sulcatus) in two experiments and in both experiments there was a highly significant reduction in damage by weevil larvae on the transgenic lines.     

Isolation and characterization of polymorphic microsatellite loci in the boll weevil,Anthonomus grandis Boheman (Coleoptera: Curculionidae)

The boll weevil (Anthonomus grandis Boheman) is a major insect pest of cotton in North America. Dispersal activity poses a threat to ongoing eradication efforts in the US, but little is known about the frequency of long‐distance migration. Nuclear molecular markers are needed to assess gene flow in relation to geographical distance. A biotin‐enrichment strategy was employed to develop microsatellite markers for the boll weevil. Of 23 loci isolated, 14 were polymorphic with three to 10 alleles per locus. Twelve of the polymorphic loci showed Mendelian inheritance and are likely to be useful in population genetics studies.     

Antennal sensilla of male and female of the nut weevil,Curculio nucum Linnaeus, 1758 (Coleoptera: Curculionidae)

The nut weevil, Curculio nucum (Linnaeus, 1758), is the main pest in hazelnut orchards (Corylus avellana L.). Semiochemicals are interesting bio control tools that could be used to manipulate the pest behaviour and to control pest populations. The study of the sensorial equipment of the insect antennae provides information on the importance of olfaction in the adult life for host plants and mate findings as well as on the putative other senses. Before electrophysiological investigation, the knowledge of antennae equipment is also necessary. The aim of this study is to determine the types, number and location of sensilla on the antennae of male and female adult C. nucum in order to determine their implication in seeking a sexual partner and a host plant. The 12-segmented antenna comprises a scape, a 7-segmented funicle and a 4-segmented club. Out of the nine sensillum types listed, three are present on the scape and the funicle and seven types on the club which gathers 71–73% of the total of sensilla. Tactile aporous sensilla chaetica C1, gustatory uniporous sensilla chaetica C2, olfactory multiporous sensilla basiconica B1 and B2 are found on both the dorsal and ventral surfaces of the club in both sexes. Thermo-hygroreceptive dome-shaped sensilla D, olfactory multiporous sensilla basiconica B3 and olfactory multiporous fluted sensilla basiconica F are found exclusively on the ventral surface of the club, suggesting that these sensilla are utilized in host plant acceptance during antennal tapping. The sexual dimorphism concerns only the numbers of sensilla chaetica C1 and sensilla basiconica B2.