Male Nymphs Research Articles

A review of the Margarodidae sensu stricto (Hemiptera: Coccomorpha) in China, with descriptions of three new species.

The research history of the family Margarodidae Cockerell sensu stricto (Hemiptera: Coccomorpha) from China is reviewed. Four species of Porphyrophora Brandt and three species of Neomargarodes Green from China are described and illustrated, including three new species: Neomargarodes chenopodium Zheng & Wu, sp. nov. based on the morphology of the adult female, first-instar nymph and second-instar female and male nymphs (cysts); Porphyrophora ejinensis Zheng & Wu, sp. nov. based on the adult female, second-instar female nymph (cyst) and third-instar female nymph (cyst); and Porphyrophora neimonggolensis Zheng & Wu, sp. nov. based on the adult female. Porphyrophora ningxiana Yang, 1979, stat. rest. is resurrected from synonymy under Porphyrophora sophorae (Archangelskaya, 1935), and lectotypes of Neomargarodes gossypii Yang, 1979 and P. ningxiana Yang are designated. A record of Porphyrophora ussuriensis Borchsenius, 1949 from China was found to be based on a misidentification. An identification key to genera and species of Margarodidae s.s. found in China is provided, based on adult female morphology.

The structure and morphogenic changes of antennae of Spilococcus alhagi (Hall) (Hemiptera: Coccoidea: Pseudococcidae) in different instars

To better understand the antennal morphology and sensilla distribution of Spilococcus alhagi (Hall) in different instars, the antennae are examined using light microscopy and scanning electron microscopy. The results show that the antennae of S. alhagi could be differentiated in different instars based on their stucture, number of flagellomere, and sensillar distribution. Functional antennae of S. alhagi appear in first instar nymphs, adult females, and adult males as many scale insects. The antennae of first-instar nymphs comprise six segments, and each antenna has 62–71 sensilla of eight types, including sensilla basiconica (SB), one type of sensilla trichoidea (ST1), two types of sensilla companiform (SCa, sSCa), two types of sensilla coeloconica (SCo1, SCo2) and two types of sensilla chaetica (SCh1, SCh2). The antennae of adult females have eight segments, but each antenna has 164–188 sensilla of the same eight types as the first instar nymphs. The antennae of adult males are more developed, and each antenna contains ten segments and 670–725 sensilla of eleven types, including knobbed seta sensilla (Ks), intersegmental sensilla (Ins), two types of sensilla trichoidea (ST1, ST2), two types of sensilla companiform (SCa, sSCa), two types of sensilla coeloconica (SCo1, SCo2) and three types of sensilla chaetica (SCh1, SCh2, bSCh). Of these, four types of sensilla, viz., Ks, ST2, Ins, bSCh are only observed on the antennae of adult males. The prepupa-like and pupa-like male nymphs both possess simplified antennae, and exhibit four types of sensilla (ST1, SCa, SCh1, SCh2). Based on these results, the morphogenic changes and potential functions of antennae of S. alhagi in different instars are discussed.

A new genus and species of soft scale insect (Hemiptera: Coccomorpha: Coccidae) on Ficus sp. from Côte d’Ivoire

During a brief visit to the West African Rice Development Association (WARDA) in Bouaké, Côte d'Ivoire, several samples of scale insects (Hemiptera: Coccomorpha) were collected. Amongst these was an undescribed genus and species of soft scale (Coccidae: Coccinae), Bandamacoccus labiosus Hodgson (gen. nov. and sp. nov.). The adult female and second-instar male nymph are described below. A striking feature of both stages is the large size of the labium, which is wider than the clypeolabral shield, whilst the second-instar male also has a prominent inner submarginal band of ventral microducts.

Predictors of individual performance and evolutionary potential of life-history traits in a hematophagous ectoparasite.

Little is known about the intraspecific variation of parasite life‐history traits and how this variation may affect parasite fitness and evolution. We investigated how life‐history traits predict success of individual tree‐hole ticks Ixodes arboricola and estimated their evolutionary potential, as well as genetic correlations within stages and phenotypic correlations within and across stages. Ticks were followed individually over two generations while allowed to feed on great tits Parus major. After accounting for host and tick maternal effects, we found that short feeding times and high engorgement weights strongly increased molting success. Molting time was also positively correlated with feeding success in adults. In larvae and nymphs, we found negative phenotypic correlations between engorgement weight and both feeding and molting time, the latter supported by a negative genetic correlation. We found sex‐related differences in feeding time (longer in male nymphs) and molting time (longer in male larvae but shorter in male nymphs). Also, time since the last feeding event (set experimentally) reduced larval and nymphal fitness, whereas it increased adult female fitness. Furthermore, we found significant heritability and evolvability, that is, the potential to respond to selection, for engorgement weight and molting time across all stages but no significant heritability for feeding time. Our findings suggest that variation in tick fitness is shaped by consistent individual differences in tick quality, for which engorgement weight is a good proxy, rather than by life‐history trade‐offs.

Effect of insect growth regulator, chromafenozide on the food consumption and metabolic efficiencies of the desert locust

The objective of the current investigation was to assess the food deterrence property of chromafenozide and its impact on different food metabolic parameters of the 5th instar nymphs of the desert locust Schistocerca gregaria. For this purpose, three doses (10, 100 and 150 µg/nymph) were topically applied (once) onto the newly molted last (5th) instar nymphs. chromafenozide exhibited contradictory effects on the feeding since it acted as a weak antifeedant against female nymphs only at the lowest dose but acted as phagostimulant against their congeners at the higher two doses. Furthermore, the compound exerted a general phagostimulant action on the male nymphs, regardless the dose. The food intake by the last nymphal instar females was slightly reduced only at only the lowest dose but remarkably increased at the higher doses. The male nymphs had been promoted to consume more food amount. Treated nymphs of both sexes attained slightly or significantly increasing relative weight gain and discharged more frass pellets. The treated nymphs of both sexes achieved slightly increasing approximate digestibility (AD), with two exceptions for the male nymphs which had a slightly decreased AD at the medium dose and un-affected AD at the highest dose. Both the efficiency of conversion of ingested food into biomass (ECI) and efficiency of conversion of digested food into biomass (ECD) of the female nymphs slightly increased. ECI of male nymphs was enhanced but ECD was slightly inhibited. Depending on the present results, Chromafenozide cannot be recommended as a promising agent for controlling S. gregaria.

Influence of Irradiation on the Biology of the Brown Marmorated Stink Bug (Hemiptera: Pentatomidae).

Fifth-instar brown marmorated stink bug (Halyomorpha halys Stål) nymphs were treated by gamma-radiation 60Co at different doses of 8-64 Gy to investigate their irradiation biology and potential for the sterile insect technique (SIT). At adult emergence, males were mated with non-irradiated virgin females to assess the longevity of both sexes, female fecundity, and egg sterility. Biological parameters of their F1 progeny were investigated to determine whether negative effects from parental exposure to radiation were inherited. Results showed that irradiation significantly reduced the lifespan of male insects at doses above 20 Gy. Irradiated males did not affect the longevity and fecundity of their female partners, nor of their resulting adult progenies, but it did reduce the developmental duration of nymphs as well as weight gain of male F1 offspring. Egg hatch was significantly reduced at all tested doses and reached complete sterility at 64 Gy. Low hatch of eggs produced by F1 or F1 crossed adults indicated that negative effects from radiation were inherited by the subsequent generation. But F1 male offspring were not less fertile than their irradiated male parent, unlike what was observed in Lepidoptera. The results support the potential for the use of SIT for H. halys management by irradiating the fifth-instar male nymphs at doses from 16 Gy to 64 Gy.

Sex differences in survival: viability selection in nymphal tree crickets from a conopid fly parasitoid

1. Variation in mortality due to parasitoids is expected to be affected by host sex and size.2. We use selection analyses to examine the effects of Stylogaster neglecta (Diptera: Conopidae), a recently discovered parasitoid of nymphal Oecanthus nigricornis (Orthoptera: Gryllidae), on sex and size viability in the host crickets.3. O. nigricornis nymphs were sampled across Ontario and New York State and dissected to determine whether they were parasitised. Logistic regression was used to examine parasitism by host body size and sex.4. There was strong evidence for an effect of sex and body size on parasitism, with males and smaller crickets being more likely to be parasitised and containing more parasitoids in them. There was also weaker evidence of an interaction effect between sex and body size, with body size being a significant predictor of parasitism only in males. Using a selection analysis, we found evidence of positive and disruptive selection on male body size.5. Causes of these viability differences may include sex differences in larval cricket immune function, riskier behaviour of male nymphs as they acquire resources necessary for adult trait development, as well as the effects of S. neglecta flies targeting hosts that maximise fitness.

Studi Biologi Hama Kutu Putih Pepaya Paracoccus marginatus Williams & Granara de Willink (Hemiptera: Pseudococadea)

The goal of this research was to understand the biology of P. marginatus, a common pest for papaya plants. This research used 1 type of treatment which was repeated 10 times. The results of this research were intended to illustrate the average development time of each development phase of P. marginatus. These phases were: the egg phase (6 days), the female nymph phase (10 days), the male nymph phase (17 days), female adult stage (11 days), male adult stage (3 days). On average, the female life cycle was 27 days, and the male life cycle was 26 days. On average, the pre-fertile stage lasted 4 days, the fertile stage lasted 6 days and the post fertile stage lasted 1 day. On average the pre-egg-laying adult stage lasted 4 days, the egg-laying adult stage lasted 6 days and the post-egg-laying stage lasted 1 day. After the egg-laying stage, the average fecundity of P. marginatus was 370 eggs per female and from these, a total of 350 offspring were hatched per individual. The ratio of surviving Descendents to reproductive couples of P. marginatus white lice was 9:1.

Pre-adult aggression and its long-term behavioural consequences in crickets.

Social experience, particularly aggression, is considered a major determinant of consistent inter-individual behavioural differences between animals of the same species and sex. We investigated the influence of pre-adult aggressive experience on future behaviour in male, last instar nymphs of the cricket Gryllus bimaculatus. We found that aggressive interactions between male nymphs are far less fierce than for adults in terms of duration and escalation. This appears to reflect immaturity of the sensory apparatus for releasing aggression, rather than the motor system controlling it. First, a comparison of the behavioural responses of nymphs and adults to mechanical antennal stimulation using freshly excised, untreated and hexane-washed antennae taken from nymphs and adults, indicate that nymphs neither respond to nor produce sex-specific cuticular semiochemicals important for releasing aggressive behaviour in adults. Second, treatment with the octopamine agonist chlordimeform could at least partially compensate for this deficit. In further contrast to adults, which become hyper-aggressive after victory, but submissive after defeat, such winner and loser effects are not apparent in nymphs. Aggressive competition between nymphs thus appears to have no consequence for future behaviour in crickets. Male nymphs are often attacked by adult males, but not by adult females. Furthermore, observations of nymphs raised in the presence, or absence of adult males, revealed that social subjugation by adult males leads to reduced aggressiveness and depressed exploratory behaviour when the nymphs become adult. We conclude that social subjugation by adults during pre-adult development of nymphs is a major determinant of consistent inter-individual behavioural differences in adult crickets.

Bionomic notes on parthenogenetic females and a record of parasitism by Forcipomyia Meigen (Diptera: Ceratopogonidae) in the stick insect Cladoxerus cryphaleus (Westwood) (Phasmatodea: Phasmatidae)

ABSTRACT Stick insects (Phasmatodea) are among the least studied insect groups in Brazil. Although in recent years there has been an increase in the number of published studies on taxonomy and morphology of Brazilian stick insects, they remain very little-known concerning biological and bionomic aspects. From five females of Cladoxerus cryphaleus (Phasmatidae: Cladomorphinae) collected in the Iguacu National Park, Parana, Brazil, a captive colony of parthenogenetic females was started, based on which data on longevity, fertility, and viability of eggs of this species were recorded for the first time. After imaginal molting, the 21 females studied had an average longevity of 103.7 days. Each female produced on average 125.3 eggs, which had a hatching rate of 34.2%. In addition, we recorded a C. cryphaleus male nymph being parasitized by a biting midge of the subgenus Forcipomyia (Microhelea) (Diptera: Ceratopogonidae). The male, in pre-imaginal instar and already parasitized, was collected in the municipality of Petropolis, Rio de Janeiro.

Effects of the juvenile hormone mimic NC-184 on the development of the reproductive organs and mating behaviour of nymphs of the desert locust, Schistocerca gregaria (Orthoptera: Acrididae)

The insect growth regulator NC-184, a juvenile hormone mimic, prevents moulting to the adult stage in the desert locust, Schistocerca gregaria (Forskal) (Orthoptera: Acrididae). Male nymphs treated in the penultimate or final nymphal instar with NC-184 exhibit precocious mating behaviour in the final instar. We examined whether this chemical affects the development of the internal reproductive organs of crowded nymphs. In treated males, both accessory glands and seminal vesicles were underdeveloped, and no sperm was found in the seminal vesicle, whereas these organs in control individuals had greatly increased in size 10 days after treatment, when all the insects had moulted to adults. Testis size in treated males was similar to that in controls, regardless of their smaller body size due to the inhibition of moulting. Oogenesis and development of spermatheca in females treated with NC-184 continued to some degree, but no eggs matured, unlike what occurred in the control. In conclusion, treatment of S. gregaria nymphs with NC-184 resulted in changes in the reproductive organs in both sexes.

Sexual Dimorphism in Wax Secretion Offers Ecological Adaptability During Ericerus pela (Hemiptera: Coccidae) Evolution.

The scale insect, Ericerus pela Chavannes, shows a typical sexual dimorphism. Males and females are different not only in morphology, but also in their ability to secrete wax and ecological adaptability. Here we report the morphological and structural characteristics of wax glands on E. pela females and males. The differences in wax glands and wax secretion between females and males reflect their different needs for living habitats and different ecological strategies. Sciophilous male nymphs are with five types of wax glands, and the wax glands on the dorsum secrete a layer of wax filaments plausibly for protection against direct light irradiation. On the other hand, five types of wax glands were found on the abdomen of females. Heliophilous female nymphs hardly secrete any wax, but the wax glands located along the spiracle on the abdomen may help this insect to breathe. Female adults secrete wax filaments on eggs to protect them from predators and prevent themselves from sticking to each other. In summary, males appear to secreted wax for creating a shaded niche that fits their sciophilous life style, whereas females are likely to adopt an ecological strategy with thickened epidermis for heliophilous acclimatization and overwintering.

Taxonomy of coccids (Hemiptera: Coccidae: Coccus L.) associated with Crematogaster ants (Hymenoptera: Formicidae) in the stems of Macaranga plants (Euphorbiaceae) in Southeast Asia.

The Southeast Asian soft scale insects (Hemiptera: Coccomorpha: Coccidae) associated with ants of the Crematogaster borneensis-group (Hymenoptera: Formicidae) and living in the hollow stems of Macaranga plants (Euphorbiaceae) are revised taxonomically. Ten species of the genus Coccus L. are recognised: seven were described previously and three new species are described herein. The species are: Coccus caviramicolus Morrison, C. circularis Morrison, C. heckrothi Gullan Kondo sp. n., C. lambirensis Gullan Kondo sp. n., C. macarangicolus Takahashi, C. macarangae Morrison, C. penangensis Morrison, C. pseudotumuliferus Gullan Kondo sp. n., C. secretus Morrison and C. tumuliferus Morrison. All of these species are described or redescribed and newly illustrated based on the adult females, and a key to distinguish the species is provided. We designate a lectotype for C. macarangicolus. The first-instar nymphs of all species are morphologically extremely similar and therefore only the first-instar nymph of C. macarangae is described and illustrated. Seven of these species currently are known only from Macaranga, but C. macarangae, C. secretus and perhaps C. pseudotumuliferus have been recorded from the hollow stems of several other ant-plants and a few non-myrmecophytes. The Coccus species from Macaranga are closely related to C. hesperidum L., the type species of the genus, and therefore are retained in the genus Coccus even though the adult females exhibit a few morphological differences from C. hesperidum. The species of Coccus from Macaranga appear to be parthenogenetic because no male nymphs or adults have been found, despite extensive collecting.

Parasitoids and Predators of Physokermes hellenicus (Hemiptera: Coccomorpha: Coccidae) in Greece

The genus Physokermes Targioni Tozzetti includes species that are distributed in the Holarctic region and feed on conifers. The recently described scale Physokermes hellenicus (Kozár and Gounari) (Hemiptera: Coccidae) is an endemic species of Greece whose host plants are fir trees of the genus Abies (Pinales: Pinaceae). It is considered as beneficial scale insect species since its honeydew secretions are exploited by honeybees leading to the production of a special honey with important physicochemical characteristics. Since there are no previous data on the natural enemies of P. hellenicus, an investigation was carried out during 2013 in forested areas of eight mountains in south and central Greece aiming to correlate the presence of P. hellenicus with certain parasitoids and predators. Seven species of Encyrtidae, Eulophidae, Pteromalidae, and Eurytomidae (Hymenoptera); five species of Anthribidae and Coccinellidae (Coleoptera); and four species of Dictinidae, Linyphiidae, and Theridiidae (Araneae) were identified. Twelve of them were identified at the species level while four at the genus level. Among them Microterys lunatus (Dalman) (Hymenoptera: Encyrtidae), Pseudorhopus testaceus (Ratzeburg) (Hymenoptera: Encyrtidae), and Anthribus fasciatus Forster (Coleoptera: Anthribidae) were the most abundant natural enemies of P. hellenicus adult female while Metaphycus unicolor Hoffer (Hymenoptera: Encyrtidae) and Trichomasthus sp. (Hymenoptera: Encyrtidae) were found to parasitize P. hellenicus male nymph. Cinetata gradata (Simon) (Araneae: Linyphiidae) is reported for first time in the Greek arachnofauna. Our results suggest that the abundance of the fir scale P. hellenicus could be affected by a complex of parasitoid and predator species of different taxa. Future long-term research on these species in relation with abiotic factors would help to understand possible fluctuation of the scale's population.

Attraction of Male Nymphs to Adult Male Volatiles in the Bronze Bug Thaumastocoris peregrinus Carpintero & Dellape (Heteroptera: Thaumastocoridae).

The bronze bug, Thaumastocoris peregrinus Carpintero & Dellape (Heteroptera: Thaumastocoridae), is an exotic emerging pest in Eucalyptus commercial forests in South America, Africa and southern Europe. Information on the chemical communication system and reproductive ecology of this insect is scant, and it may be relevant for designing management strategies for eucalypt plantations. Adults and nymphs usually aggregate in the field, possibly by means of chemical signals. Males emit large amounts of 3-methyl-2-butenyl butyrate, which attracts conspecific adult males but not females. The ecological role of this putative male aggregation pheromone remains unknown. Here, we report olfactometer bioassays showing that late-instar male nymphs are also attracted to synthetic 3-methyl-2-butenyl butyrate and to adult male volatile extracts, which contain this compound as the major component. As previously shown for adult females, nymphs that moulted into females were not attracted to either volatile stimulus. The intra-gender attraction of nymphs and adults may be related to the exploitation of food resources, or as a reproductive strategy for newly emerged males. Further studies on the reproductive behaviour and mating system of T. peregrinus will contribute to understanding the ecological significance of male-male, adult-nymph attraction, as well as the practical applications that may result from these findings.

Effects of temperature on the growth, development and reproduction of Dysmicoccus neobrevipes Beardsley (Hemiptera: Pseudococcidae).

In recent years, Dysmicoccus neobrevipes Beardsley (Hemiptera: Pseudococcidae) is found as one of important alien species in China. For the alien pest, temperature always is a crucial factor on constructing stable population. In this study, the development and reproduction of D. neobrevipes population of pumpkin under different temperatures were investigated. The developmental duration, developmental rate, survival rate and fecundity of D. neobrevipes were compared in the laboratory under the conditions of 17, 20, 23, 26, 29 and 32 ℃, photoperiod 14L:10D, RH (75±5)%, and the life table of the laboratory population was constructed. The results showed that in 20-29 ℃, the developmental durations of every stage of D. neobrevipes all decreased with the increasing temperature; under 20 ℃, both female and male nymph D. neobrevipes had the longest duration, being 46.95 and 50.26 d, respectively. The female and male nymph D. neobrevipes grew most fast under 29 ℃ (20.28 d) and 32 ℃ (20.70 d). The relationship between the developmental rate and temperature for each stage could be simulated by the quadratic regression. In addition, we found that the temperature could impact the survival rate of D. neobrevipes. The highest survival rate of D. neobrevipes was recorded at 29 ℃ for both female (70.3%) and male (69.3%) nymphs. The developmental threshold temperature of female and male was 13.80 ℃ and 11.61 ℃, and the accumulated temperature of female and male was 491.50 and 388.85 day-degrees, respectively. Both pre-oviposition duration and adult longevity decreased with increasing temperature, and the highest fecundity per female was 442.2 eggs at 29 ℃, and the lowest 111.8 eggs at 20 ℃. The population trend indexes under 20 ℃ and 29 ℃ were 19.1 and 168.2, respectively. At 17 ℃ and 32 ℃, D. neobrevipes of the 1st instar nymphs and 3rd instar nymphs were found to stop growth, suggesting that excessively high or low temperature was unfavorable to the growth of D. neobrevipes. In conclusion, temperature could significantly affect the growth and development, survivorship, reproduction and population increasing of D. neobrevipes, and the most suitable temperature range for this pest is from 23 ℃ to 29 ℃.

Sex ratio of mirid populations shifts in response to hostplant co-infestation or altered cytokinin signaling .

Herbivore species sharing a host plant often compete. In this study, we show that host plant-mediated interaction between two insect herbivores - a generalist and a specialist - results in a sex ratio shift of the specialist's offspring. We studied demographic parameters of the specialist Tupiocoris notatus (Hemiptera: Miridae) when co-infesting the host plant Nicotiana attenuata (Solanaceae) with the generalist leafhopper Empoasca sp. (Hemiptera: Cicadellidae). We show that the usually female-biased sex ratio of T. notatus shifts toward a higher male proportion in the offspring on plants co-infested by Empoasca sp. This sex ratio change did not occur after oviposition, nor is it due differential mortality of female and male nymphs. Based on pyrosequencing and PCR of bacterial 16S rRNA amplicons, we concluded that sex ratio shifts were unlikely to be due to infection with Wolbachia or other known sex ratio-distorting endosymbionts. Finally, we used transgenic lines of N. attenuata to evaluate if the sex ratio shift could be mediated by changes in general or specialized host plant metabolites. We found that the sex ratio shift occurred on plants deficient in two cytokinin receptors (irCHK2/3). Thus, cytokinin-regulated traits can alter the offspring sex ratio of the specialist T. notatus.

The fitness of the cotton mealybug Phenacoccus solenopsis (Tinsley) is reduced after feeding on virus-infected Hibiscus rosa-sinensis

The cotton mealybug Phenacoccus solenopsis (Tinsley) and Cotton leaf curl Multan virus (CLCuMV), serious threats to economic crops and garden plants, have invaded southern China and widely infected Hibiscus rosa-sinensis. Whether an inter-species connection has facilitated the invasion process is unclear. In this study the interaction between P. solenopsis and H. rosa-sinensis infected with CLCuMV was investigated in the laboratory. We observed that 1st and 2nd instar nymphs of P. solenopsis preferred to feed on healthy H. rosa-sinensis leaves, whereas 3rd instar nymphs and female adults had no preference between healthy and virus-infected H. rosa-sinensis leaves. The developmental time of each P. solenopsis developmental stage increased significantly after feeding on infected H. rosa-sinensis leaves (p < 0.05). In particular, the development time for 2nd instar female and male nymphs and 3rd instar female nymphs increased by approximately twofold. The generation time of female mealybugs increased from 25.84 d on healthy H. rosa-sinensis to 32.12 d when feeding on CLCuMV-infected H. rosa-sinensis, and the survival rate decreased from 71.04 % on healthy H. rosa-sinensis to 5.80 % on infected plants. Nymph survival was most affected by feeding on infected plants. Additionally, the fecundity of female mealybugs feeding on infected H. rosa-sinensis decreased by 47.8 %. Thus, feeding on CLCuMV-infected H. rosa-sinensis significantly decreased the biological fitness and invading and colonizing abilities of P. solenopsis.

AN ODORANT-BINDING PROTEIN INVOLVED IN PERCEPTION OF HOST PLANT ODORANTS IN LOCUST Locusta migratoria.

Locusts, Locusta migratoria (Orthoptera: Acrididae), are extremely destructive agricultural pests, but very little is known of their molecular aspects of perception to host plant odorants including related odorant-binding proteins (OBPs), though several OBPs have been identified in locust. To elucidate the function of LmigOBP1, the first OBP identified from locust, RNA interference was employed in this study to silence LmigOBP1, which was achieved by injection of dsRNA targeting LmigOBP1 into the hemolymph of male nymphs. Compared with LmigOBP1 normal nymphs, LmigOBP1 knockdown nymphs significantly decreased food (maize leaf, Zea mays) consumption and electro-antennography responses to five maize leaf volatiles, ((Z)-3-hexenol, linalool, nonanal, decanal, and (Z)-3-hexenyl acetate). These suggest that LmigOBP1 is involved in perception of host plant odorants.

The structure and morphogenic changes of antennae of Matsucoccus matsumurae (Hemiptera: Coccoidea: Matsucoccidae) in different instars

To better understand the functioning and morphogenic changes of the antennae of Matsucoccus matsumurae (Kuwana) in different instars, the antennae are examined using light microscopy, scanning and transmission electron microscopy. The results show that the antennae of M. matsumurae display three different styles in morphology and sensillar distribution in different instars. The antennae of first instar nymphs are relatively simple, including one campaniform sensillum (Ca), four smooth aporous trichoid sensilla (SAt), two intersegmental sensilla (Ins), two coeloconic sensilla (Co), three multiporous pegs (Mp) and four uniporous pegs (Up). The antennae of adult females and third instar male nymphs both possess similar antennae, and exhibit seven types of sensilla. Adult female antennae have in total 82–108 sensilla, including 9–16 Böhm's bristle (Bb), 3–7 Ca, 50–75 SAt, 0–3 Ins, 3–10 Co, 8 Mp and 5 Up, whereas third instar male nymph antennae possess approximately 62–79 sensilla. Adult male antennae are the most developed, possessing 259–312 sensilla, including 7–15 Bb, 2–5 Ca, 7–11 grooved aporous trichoid sensilla, 4–9 SAt, 0–3 Ins, 2–7 Co, 23–29 knobbed seta sensilla, 179–230 multiporous trichoid sensilla and 8 Mp. Based on these results, the main functions and morphogenic changes of antennae M. matsumurae in different instars are discussed.