Effects of the juvenile hormone analog pyriproxyfen on German cockroach, Blattella germanica (L.), tergal gland development and production of tergal gland secretion proteins

Male German cockroaches possess secretory glands that secrete fluid into a pair of transverse depressions on the seventh and eighth abdominal tergites. We investigated the effects of altered juvenoid titer during the first part of the last instar on tergal gland secretory tissue development and the production of tergal gland secretion proteins. Male fifth (last) instar nymphs (1-3 days post-emergent) were topically treated with the JH analog pyriproxyfen. Light and transmission electron microscopy demonstrated that treatment with pyriproxyfen produced a visible decrease in the amount of tergal gland tissue present, a deformation of the overall shape of the gland located on tergite seven, and a less orderly arrangement of the secretory cells in the tissue. The protein fraction of tergal gland secretion was examined in pyriproxyfen-treated and control insects 1, 5, and 15 days after the insects molted to the adult stage. Amounts of all tergal secretion proteins were reduced in treated insects.     

Phenotypic plasticity of abdomen pigmentation in two geographic populations of Drosophila melanogaster: male–female comparison and sexual dimorphism

In Drosophila melanogaster male, the last abdominal tergites (A5–A6) are completely dark due to a strong internal constraint while, in female, all abdominal tergites (A2–A7) are phenotypically variable and highly plastic. Male A2–A4 are quite similar to those of female, but their plasticity was never investigated. In this paper, we compared the phenotypic plasticity of A2–A4 in both sexes in order to know if the major dimorphism (SD) expressed in male A5–A6 also extended toward the more anterior segments. We also compared two geographic populations living under very different climates in order to know if adaptive differences, previously observed in females also existed in males. With an isofemale line design, pigmentation variation according to growth temperature was investigated in the two populations from France and India. Male and female data were compared and sexual dimorphism (SD) analyzed in various ways. Reaction norms were quite similar in both sexes for A2 and A3, but clearly different for A4. Considering the total pigmentation (A2 + A3 + A4) males were darker than females at low temperatures and either identical to them (France) or lighter (India) above 25°C. SD (male–female difference) was genetically variable among lines and significantly different among segments. Reaction norms of SD exhibited an overall decrease with temperature and also a significant difference among populations, suggesting a local adaptation of SD to thermal conditions. The three plastic segments in male (A2–A4) seem to react adaptively to the thermal environment more efficiently than the same segments in female, in agreement with the thermal budget hypothesis. To our knowledge, it is the first time that a SD trait exhibits an adaptive difference between geographic populations.     

A new genus and species of Dictyopharidae (Homoptera) from Rovno and Baltic amber based on nymphs

Alicodoxa rasnitsynigen. et sp. n. (Dictyopharinae: Orthopagini) is described based on a nymph from Rovno amber; it also occurs in Baltic amber. A small additional wax plate dorsal to the large wax plate of abdominal tergites VI-VIII is first reported in this and other genera of Dictyopharidae. A lectotype is designated for Pseudophana reticulata Germar & Berendt, 1856 transferred to Protepiptera (Achilidae): Protepiptera reticulata (Germar & Berendt, 1856), comb. n.     

Poorly known stonefly species, <Emphasis Type="Italic">Isoperla pseudornata</Emphasis> and <Emphasis Type="Italic">Kaszabia nigricauda</Emphasis> (Plecoptera,Perlodidae), from the Eastern Palaearctic

The previously unknown male of Isoperla pseudornata Zhiltzova and nymph of Kaszabia nigricauda (Navás) of the family Perlodidae are described. Sternite VIII of the male of I. pseudornata has no vesicle, the posterior margin is covered medially with strong short brownish setae. Sternite IX forms a subgenital plate. The everted aedeagus is upcurved, turned towards the dorsum, with two rounded lobes and one finger-shaped apical lobe terminating with a membranous funnel depressed medially. The aedeagus membrane is covered with small fine pointed sclerotized spinules; spinules absent on the tip of the funnel. The funnel basally and the finger-shaped apical lobe ventrally are covered with fine pointed sclerotized spinules and rounded sclerotized formations. I. pseudornata differs from the other Eastern Palaearctic congeners in the shape of spots on the head, pronotum, and abdominal tergites. The head of K. nigricauda nymph bears a large brown M-shaped spot forming along the anterior margin two fine stripes widened on the frontoclypeus; the interocular area bears a small pale spot merged with the large transverse W-shaped spot on the occiput. The lacinia is narrowed to the apex, bidentate; the tip of the galea reaches the base of the subapical tooth. The pronotum bears a pale cruciform medial spot, the lateral fields are dark, the lateral margins are pale. The meso-and metanotum exhibit a pale complicated pattern widened to the base of the wing pads. The legs are pale. The abdominal tergites are brown, with a pale transverse stripe widened laterally on the last tergites. Tergite X bears a large pale heart-shaped spot medially. The cerci bear a silky hair fringe dorsally; in the apical part, the apical whorl of cerci has short setae; one ventral and one dorsal seta are longer than the others; the dorsal setae are longer than ventral ones.     

Scanning electron microscoscopy of the second-instar larva of Gasterophilus nasalis

The second-instar larva of the bot fly Gasterophilus nasalis (L.) (Diptera: Gasterophilidae) is described for the first time, based on scanning electron microscope (SEM) studies. On the pseudocephalum the larva bears an antenomaxillary sensory complex formed by the antenna (coeloconic sensilla) and the maxillary palp with a set of six coeloconic sensilla and four basiconica sensilla. The oral opening is latero-posteriorly limited by small spines, and exhibits strongly ornamented maxillae and mandibles. The thoracic and abdominal segments are circled by two bands, each with two rows (except the last segment that has one row) of backwardly pointed spines, and have cuticular depressions. Trichoid and campaniform sensilla surround the larval segments. The anterior spiracular opening is a small aperture. The terminal end of the eighth abdominal segment shows a spiracular cavity, lateral tubercles, eight basiconic and two trichoid sensilla. Each spiracular plate has two slightly curved slits, each with a serrated rima. There is a probable ecdysial scar. The findings of this ultrastructural study are compared with those other of larval flies.     

The type and location of homeotic transformations in the tumorous-head mutant of Drosophila melanogaster

Summary Transformations of tumorous-head Drosophila melanogaster were examined in order to investigate whether head structures were replaced by specific abdominal structures. Heads selected for the presence of genital structures were analyzed in detail. Female abnormalities included any combination of vaginal teeth, vulvar papillae, sensilla trichodea, abdominal tergites 6 (T6), 7 (T7), 8 (T8) and anal plate. Anal plate was observed in the prefrons and rostral membrane, while all other genital structures were intimately associated with modified shingle cuticle. Male abnormalities included transformation of antennal structures to penis, clasper teeth, lateral plate, anal plate and eye to T6. The distribution of each type of homeotic structure was confined to general regions of the eye-antenna, with no precise dividing lines between them. However, the spatial sequence of homeotic structures in the eye-antenna was generally the same as the sequence of the same structures in the posterior abdomen.     

Phylogenetic analysis of Myxophaga (Coleoptera) using larval characters

A phylogenetic parsimony analysis of fifty-four larval characters of Myxophaga (excluding Lepiceridae) resulted in two minimal length cladograms. The monophyly of Torridincolidae, Hydroscaphidae and Microsporidae is supported by several autapomorphies: miniaturization, flattened body with laterally extended tergites, broadened head, scale-like surface structures, broad tentorial bridge, disc-shaped labral sensilla, spiracular gills and pupation in the last larval exuviae. Hydroscaphidae are the sister group of Microsporidae. Larvae of both families are characterized by semi-entognathous mouthparts, tergites with posterior rows of lancet-shaped setae, claws with flattened basal spines and balloon-shaped spiracular gills. The monophyly of all families is supported by autapomorphies. Torridincolidae excluding Delevea is defined as a monophylum by four derived character states: body ovoid, thorax semicircular and as long as abdomen, labral sensilla fused and abdominal sternite IX distinctly reduced and triangular. The monophyly of Torridincolinae (sensu Endrödy-Younga 1997b) is supported by two autapomorphies. The proposed branching pattern suggests that the early representatives of Myxophaga (excluding Lepiceridae) were living in aquatic conditions with a preference for hygropetric habitats. The tendency to live on rocks in running water and miniaturization have played an important role in myxophagan evolution.     

Significance of shelter traps for spring monitoring of Anthonomus pomorum in apple orchards

The significance of the apple blossom weevil, Anthonomus pomorum L. (Coleoptera: Curculionidae), as a potential threat to apple, Malus domestica Borkh., has increased over the past two decades in many regions of Europe. The apple blossom weevil immigrates into orchards and colonises apple trees in early spring. Females deposit single eggs into closed blossom buds, which leads to capped blossoms. This study was designed to test the suitability of transparent shelter traps for the surveillance of colonisation under different population pressures, and to assess the quantitative relationship between number of weevils caught and: (1) absolute injury, expressed as number of infested buds, as well as (2) relative injury, expressed as a percentage of infested buds relative to all buds on the tree. The findings with the new shelter traps were contrasted to results from limb jarring. Numbers of weevils caught with the transparent shelter trap were positively correlated with absolute injury, as well as with relative injury across the five study sites, whereas weevil counts with limb jarring were not correlated with absolute injury, but only with relative injury. Our data validate the transparent shelter trap as a method for accurately monitoring the course of spring colonisation of A. pomorum and demonstrate its potential for predicting injury by the weevils to blossom buds. In contrast, the significance of limb jarring for monitoring both the time course of colonisation and subsequent injury is limited. The significant linear relationship between the number of weevils caught in shelter traps and the relative injury allows for predictions of potential damage before oviposition takes place, i.e., early enough for an insecticide application where necessary.     

Novel use of hair sensilla in acoustic stridulation by New Zealand giant wetas (Orthoptera: Anostostomatidae)

Sound production in New Zealand giant wetas (Orthoptera: Anostostomatidae) includes a femoro-abdominal mechanism, a ticking sound when alarmed (mechanism unknown) and, in two species (Deinacrida rugosa and Deinacrida parva), a tergo-tergal mechanism on the dorsal overlapping surfaces of abdominal tergites. The tergo-tergal mechanism consists of bilaterally paired patches of short curved spines on the dorsal anterior margins of tergites II–V, rubbed by opposing patches of articulated hair sensilla on the underside of each overlapping tergite. The latter are extremely robust, modified mechanoreceptors inserted at an acute angle onto raised bases which greatly restrict movement. They rub sideways against the underlying spines and produce sound during telescopic abdominal contraction which accompanies defence leg kicking stridulation. Movement analysis showed that the abdominal tergites contract asynchronously during stridulation. Sound is produced during both phases of telescoping. Femoro-abdominal sound comprises loud clicks of broadband sound principally below 10 kHz; tergo-tergal sound is a softer hiss spreading broadly from 10 kHz to the ultrasonic above 20 kHz. We propose that the tergo-tergal mechanism may have evolved under predation pressure by the ground gleaning short tailed bat endemic to New Zealand. The use of mechanosensory hair sensilla for sound production is rare in arthropods.     

二元覆盖对苹果树低耗水生育期土壤水分的影响

为探明间作油菜和果树覆膜组合措施对黄土高原旱作苹果园低耗水生育期土壤水分的影响,通过田间定位观测试验,对比分析了各处理土壤含水量、土壤储水量等参数.结果表明: 在果树萌芽期,苹果树覆膜+行间种植50%宽度油菜(PR₁)和苹果树覆膜+行间种植100%宽度油菜(PR₂)处理0～200 cm土层平均土壤含水量分别较对照(苹果树不覆膜+行间清耕)提高了7.9%、6.9%,在果树开花期分别较对照提高了3.5%、6.9%.两种处理在苹果树萌芽期均产生了土壤水分竞争,油菜边缘处是竞争最激烈的区域,这一时期PR₁处理竞争程度小于PR₂处理;在苹果树开花期PR₁处理竞争现象不明显,PR₂处理竞争现象明显;在这两个时期内PR₂处理均发现土壤水分低值区.与对照相比,两种处理均能提高果园0～80 cm土层土壤储水量,同时在0～200 cm土层不产生土壤水分亏缺现象.在黄土高原旱作苹果园,推行PR₁模式有利于改善低耗水生育期苹果园的土壤水分环境.     

Morphology of the second- and third-instar larvae of Dermatobia hominis by scanning electron microscopy

Larvae of Dermatobia hominis 10–27 days old were collected from experimentally infected rats and their morphology was studied by scanning electron microscopy. The moult from the second to third instar occurs at 18 days, with emergence from the host at 30 days post-infection. The second-instar larvae bear on the pseudocephalon, antennae (coeloconic sensilla), and coeloconic and basicoconic sensilla on the maxillary sensory complex. The thoracic segments bear small backwardly-directed spines anteriorly and ventral trichoid and campaniform sensilla. The first four abdominal segments have small and large backwardly-directed spines that are absent on segments five and six. The seventh and eighth abdominal segments have medium-sized forwardly-directed spines. Abdominal segments are encircled by campaniform sensilla. The terminal end of the eighth abdominal segment bears the anus, prominent anal lobes and two spiracular openings on each spiracular plate. Spiracular plates show a radial sun ray pattern. The rear abdomen also bears an ecdysal aperture, several pores and eight coeloconic sensilla. Although there are slight morphological differences, the spines (predominantly flat and thorn-like) and sensilla (campaniform and coeloconic) of the third-instar larvae show a similar arrangement to that of second-instar larvae. Thoracic trichoid sensilla are not seen in third-instar larvae. A perispiracular gland aperture is situated above each posterior spiracular opening. These morphological features are compared with those of other cuterebrid larvae.     

Sexual dimorphism of guava weevil Conotrachelus psidii Marshall (Coleoptera: Curculionidae)

We investigate structural and behavioral differences between male and female adults of guava weevil, Conotrachelus psidii Marshall, 1922 to help in sex determination. Weevils collected from a commercial guava orchard were individually caged and maintained under laboratory conditions. Every day ten individuals were grouped and their behavior was observed. During mating the males and females were identified. Fifty weevils of each sex were killed and they were observed with stereoscopic microscope. The antenna insertion on the rostrum and hair on the thorax and abdomen surfaces were examined. Length and width of body, pronotum, last abdominal sternite and rostrum were also taken. Behaviorally, the male weevils produce audible sound by stridulation of abdomen while females do not. In the females, the body and pronotum width and body a rostrum length were higher than in the males, but the last abdominal sternite was smaller. Three other structural differences were visible with the naked eye: 1) the anterior region of pronotum have scarce hair or have not in the females and hair is dense in the males; 2) the last tergite of females is hidden by the penultimate tergite whereas in the males is visible; 3) the first abdominal sternite of females is more prominent, very convex and without or with little bristle. In the males it is slightly concave and with abundant hair. The male-female differences found in this work allow, without hurt or change insect behavior, an efficient sex determination of guava weevil.     

Induction of somatic and male crossing-over by bleomycin in Drosophila melanogaster

Bleomycin (BLM) is well known as an antibiotic as well as for its antineoplastic activity. A clinical preparation of BLM was tested for its recombinogenicity in a higher eukaryotic organism, Drosophila melanogaster. Feeding of the F1 larvae on a medium with BLM increased somatic crossing-over spots on female tergites and induced recombination in male germ cells. However, nonlinear dose-response curves were obtained. Malformed tergites were also observed in females treated with BLM.     

Thermal orientation of Anthonomus pomorum (Coleoptera: Curculionidae) in early spring

Abstract. The selection of habitats with favourable temperature by the apple blossom weevil Anthonomus pomorum (L.) is investigated in a temperature gradient arena with a range of approximately 0–15 °C. Single female and male weevils are tested in the arena 2, 4 and 6 days after termination of diapause, during photophase and during scotophase. During photophase, weevils of both sexes choose the warmest part of the temperature gradient arena, irrespective of the time elapsed after diapause. During scotophase, high temperature is favoured by male weevils, as well as by females 2 and 4 days after diapause. However, 6 days after termination of diapause, females show no thermal preference in the temperature gradient arena during scotophase, indicating that thermal choice of female A. pomorum in the scotophase changes with time after the termination of diapause. The results suggest that both sexes benefit from thermoregulation by habitat choice during photophase when the weevils are flight active and colonize apple trees.     

The insect faunas of pear and apple orchards and the effect of windbreaks on their distribution

Two coir netting windbreaks, each 7 m tall and 46 m long, were erected in a pear and an apple orchard, to try to increase the number of insect pollinators present at blossom time. The flying insects were sampled with suction traps and insects visiting trees were sampled by examining marked clusters of blossom. The mean aerial density was calculated for each of the forty-two taxa, mainly families, identified from the aerial population. There were about 50% more insects flying in the pear than in the apple orchard. The distribution of flying insects was greatly affected by the windbreaks, and the sheltered zone contained three times as many of most species, and more than three times as many Chironomidae, Psychodidae and Bibionidae as elsewhere. Small flies were the most abundant insects in the air, in both orchards. In the pear orchard large insects comprised only about 7 % of the total aerial population, of which honeybees constituted 0–7% and wild bees 0–3%. By contrast, large insects accounted for a greater proportion of the population on blossom. The reasons for this are discussed. On apple blossom Syrphidae and honeybees were the insects most often seen, and on pear blossom Bibionidae and Mycetophilidae.     

Evidence for reproductive isolation between two colour morphs of cavity nesting honey bees (Apis) in south India

In south India there are two distinct colour morphs of cavity nesting honey bees: the yellow ‘Plain’ morph and the black ‘Hill’ morph which are collectively known as Apis cerana. We show that the Hill morph is associated with a widely distributed mitochondrial haplotype that is present throughout mainland populations of south east Asian A. cerana. In contrast, the Plain morph, which is apparently confined to low to moderate elevations in India and Sri Lanka, is associated with a unique mitochondrial haplotype that is not present in other cavity nesting honey bees. We further show that in a region of sympatry (Bangalore, Karnataka State) the drone mating flight times of the two colour morphs barely overlap. Combined, drone flight data and the complete separation of mitochondrial haplotypes suggest that the two morphs are reproductively isolated. The Plain morph is distinguished from the Hill morph by the first three abdominal tergites of the worker, which are completely yellow in the Plain morph, whereas in the Hill morph they are black or black with yellow patches. Although the two morphs are generally distinguishable in the field by overall colouration, microscopic examination of the first 3 abdominal tergites is preferred. Received 16 February 2006; revised 11 May 2006; accepted 23 May 2006.     

Assessment of the environmental fate of the biological control agent of fire blight, Pseudomonas fluorescens EPS62e, on apple by culture and real-time PCR methods

The colonization of apple blossoms and leaves by Pseudomonas fluorescens EPS62e was monitored in greenhouse and field trials using cultivable cell counting and real-time PCR. The real-time PCR provided a specific quantitative method for the detection of strain EPS62e. The detection level was around 10(2) cells g (fresh weight)(-1) and the standard curve was linear within a 5-log range. EPS62e actively colonized flowers reaching values from 10(7) to 10(8) cells per blossom. In apple flowers, no significant differences were observed between population levels obtained by real-time PCR and plating, suggesting that viable but nonculturable (VBNC) cells and residual nondegraded DNA were not present. In contrast, on apple leaves, where cultivable populations of EPS62e decreased with time, significant differences were observed between real-time PCR and plating. These differences indicate the presence of VBNC cells or nondegraded DNA after cell death. Therefore, the EPS62e population was under optimal conditions during the colonization of flowers but it was stressed and poorly survived on leaves. It was concluded that for monitoring this biological control agent, the combined use of cultivable cell count and real-time PCR is necessary.     

Methode zum Nachweis der Dauersporen des Kohlhernieerregers Plasmodiophora brassicae in gärtnerischen Kultursubstraten

Populations of pathogenic Pseudomonas syringae pv. syringae were monitored on apparently healthy leaves, blossoms, and fruit from two apple orchards with known histories of blister bark and a pear orchard with a known history of blossom blast. Populations on blossoms and fruits were higher on pears than on apples. Yellow-pigmented, non-pathogenic bacteria might have suppressed or masked the presence of P. syringae pv. syringae on apple trees. Populations of P. syringae pv. syringae on apple and pear leaves fluctuated sharply but higher levels generally occurred during the 1984/85 growing season than during the drier 1983/84 season. This investigation indicates that the resident phase of P. syringae pv. syringae is probably a major source of inoculum for apple blister bark and pear blossom blast in South Africa.     

Development of setal patterns in embryonic and adult aphids of the Hormaphidinae （Hemiptera： Aphididae）

The elementary traits and diversity of embryonic setal patterns of 31 species of 22 genera, in three tribes of Hormaphidinae are studied. The embryonic setal patterns to every species are provided. Based on the parsimony principle and the developmental principle, these patterns are analyzed in each tribe following the terminology of Richards （1965）. It is suggested that the setal patterns of abdominal tergites are the most important characters in embryonic and adult setal patterns. In conclusion, neoteny is a phylogenetic trend in the Hormaphidinae. Nipponaphidini and Hormaphidini have more typical neoteny in each genus and more diversity in different types of adult viviparous females than Cerataphidini, by showing more frequent and various protopatterns or mesopatterns.     

Ultrastructure of male sex pheromone glands in abdominal tergites of five Lutzomyia sandfly species (Diptera: Psychodidae)

The fine structure of male sex pheromone disseminating structures on abdominal segments of five species of Lutzomyia sandflies (Diptera: Psychodidae) was analyzed. Scanning electron microscopy showed that in Lutzomyia cruzi [Mem. Inst. Oswaldo Cruz 33 (1938) 349] and Lutzomyia longipalpis [Mem. Inst. Oswaldo Cruz 4 (1912) 84], the disseminating structures are located in pale spots on abdominal tergites IV or III and IV and are morphologically similar, appearing as small round cuticular elevations with a central pore. Observation of abdominal tergites of L. longipalpis pupae showed that the spots, but not the structures, are already present in this stage. In Lutzomyia lenti [Mem. Inst. Oswaldo Cruz 33 (1938) 349] and Lutzomyia carmelinoi [Mem. Inst. Oswaldo Cruz 81 (1986) 323] adult males, the disseminating structures are present on tergal segments V and VI, where pale spots could not be observed, and appear as apple-like elevations with a central pore. In Lutzomyia renei, a single disseminating structure is found at the anterior region of tergal segment VI. Transmission electron microscopy was used to analyze the gland cell fine structure in L. cruzi. Several class III gland cells are located side by side in the fourth abdominal segment. Each epidermal secretory cell contains a small reservoir and a short outlet channel through the cuticle.