Structure, mechanism and mechanical properties of pupal attachment in Greta oto (Lepidoptera: Nymphalidae: Ithomiinae)

The structure and mechanism of pupal attachment are described for the nymphalid Greta oto using electron microscopy, and high‐speed and time‐lapse photography. The cremaster is composed of a 3‐D array of hooked setae that engage with silk fibers spun into layers in a pad on the lower leaf surface. Each seta comprises a shaft terminating in a strongly curved hook, tipped with two lateral barbs. These hook into the silk pad, which is densely laid and built‐up in the central portion, flattening out peripherally. Time‐lapse photography showed that silk pad construction by fifth instar larvae is completed in four distinct spinning movements, producing a random fiber arrangement. It is proposed that such a fiber arrangement provides isotropic strength, giving greater flexibility to the attachment. The cremaster is attached to the silk pad by a series of lateral movements of the pupa's posterior abdomen. This movement, together with the shape of the setal hooks, is thought to be integral to the attachment process. Tensile loading tests showed that attachment failure is due to the breakage of the silk pad, which undergoes gradual destruction before releasing the cremaster. The attachment was found to have high tensile strength and fracture toughness, both of which suggest that it has evolved for the dual purpose of preventing the pupa being pulled from the leaf by a predator and preventing the attachment being weakened by wind, which causes the pupa to swing.     

Baculoviral infection reduces the expression of four allergen proteins of silkworm pupa

Silkworm (Bombyx mori) larvae are widely used to express exogenous proteins. Moreover, some silkworm pupal proteins can be used as drug‐loading materials for selfexpressed oral tolerance drugs. However, several proteins expressed in silkworm pupae cause severe allergic reactions in humans and animals. Interestingly, some baculovirus vectors have been shown to alter the host gene and its expression in insect cells, but this has not been confirmed in silkworm. Here, we analyzed the effects of infection with an empty B. mori baculovirus (BmNPV) vector on silkworm pupal protein expression. Using a proteomics approach, the allergens thiol peroxiredoxin (Jafrac1), 27‐kDa glycoprotein (p27k), arginine kinase, and paramyosin as well as 32 additional differentially expressed proteins were identified. Downregulation of the messenger RNA expression of the four known allergens was observed after BmNPV infection; subsequent changes in protein expression were confirmed by the western blot analysis using polyclonal antibodies prepared with recombinant proteins of the four allergens. Collectively, these data indicate that the four known allergens of silkworm pupae can be reduced by infection ith an empty BmNPV vector to increase the safety of silkworm pupa‐based exogenous protein expression and drug delivery of oral pharmaceuticals. In addition, the four recombinant allergen proteins may contribute to the diagnosis of allergic diseases of silkworm pupa.     

Pathogenicity of three entomopathogenic nematodes against the onion thrips,Thrips tabaci Lind. (Thys.; Thripidae)

Pathogenicity of a native isolate of Steinernema feltiae (H1) and two exotic strains, Heterorhabditis bacteriophora and Steinernema carpocapsae was assessed under laboratory conditions using different concentrations i.e. 4000, 6000, 8000 and 10,000 infective juveniles/ml against second instar larvae, prepupa and pupa of Thrips tabaci Lindeman. The mortality data were recorded 24 and 48?h post-inoculation. The highest mortality rate was recorded for prepupa (62%) than second instar (12.5%) by H. bacteriophora and S. carpocapsae, respectively, 24?h after treatment. No significant differences were found in mortality between prepupa and pupa with increasing the nematodes concentrations (from 4000 to 10,000 nematode/ml) but increasing nematode concentrations increased the mortality of second instar. At the end of the experiment (48?h.), S. feltiae H1 caused the highest mortality on second instar larvae (74%), whereas all other species caused 80–83% mortalities on pupa. This study suggests that native isolate of S. feltiae (H1) had high potential to infect soil-dwelling stages of T. tabaci.     

Sublethal effects of indoxacarb on the diamondback moth, <Emphasis Type="Italic">Plutella xylostella</Emphasis> (L.) (Lepidoptera: Yponomeutidae)

The effects of sublethal concentrations of indoxacarb on Plutella xylostella (L.) (Lepidoptera: Yponomeutidae) were examined. In comparison with the control, sublethal concentrations led to a significant decrease in adult emergence, the percentage of pupation and pupal weight of the parent generation, fecundity, and adult longevity. They also significantly decreased the net reproductive rate (R ₀), intrinsic rate of increase (r _m), finite rate of increase (λ), and gross reproduction rate (GRR), and had significantly increased egg developmental time and doubling time (Dt) of P. xylostella. However, sublethal concentrations of indoxacarb had no significant affect on adult emergence, percentage of pupation, larva, prepupa and pupa developmental periods, hatchability, and sex ratio of offspring. The results of this study indicated that sublethal concentrations can decrease the biological parameters of P. xylostella.     

Structure and metamorphic changes in the brain of the lemon butterfly Papilio demoleus L. (Lepidoptera: Papilionidae)

The morphology of the larval and adult brain of Papilio demoleus, and changes in the cell population and neuropile morphology during the pupal period have been described. The larval brain has more simple fibre areas than that of the adult. Dividing neuroblasts have been found which form the adult neurones. The larval brain contains the three neuromeres (proto-, deuto-, and tritocerebrum). The protocerebrum has well developed corpora pedunculata, a central body, a pons cerebralis and developing optic centres. The corpora ventralia are joined with each other by paired ventral commissures (single in adult). The deutocerebrum is simple and small, the antennal centres are small and simple (ef. adult). The glomerular tritocerebrum is posteroventral to the deutocerebrum, and fibres from the former travel to the crura cerebri. The cortex of the brain consists of four types of glial cells and of association cells, and large and medium sized motor neurones. The number of mitoses is greatest in the larval and prepupal stages; in the pupa it decreases gradually and in late stages it does not occur. Histolysis and pyknosis begin in the prepupa and decrease considerably in the late pupa. The entire neural lamella is broken down in the early pupa. Numerous haemocytes penetrate the laminae of the neural lambella and envelop the entire brain. In the adult, behind the well-developed central body is an ellipsoid body. The medulla interna is divided into two smaller lobes and the deutocerebral lobes are differentiated into cortical and medullary zones. Chiasmata between optic centres are also formed during the pupal period.     

The fossil pupa Simulimima and the evidence it provides for the Jurassic origin of the Simuliidae (Diptera)

Abstract. Examination of the Middle Jurassic dipteran pupal fossil Simulimima grandis Kalugina shows it to possess the pupal diagnostic characters of Simuliidae and to be not significantly distinguishable from the pupa of modern Prosimulium . The nominal monotypic genus Simulimima Kalugina is assigned to that family, but provisionally maintained as valid in the absence of knowledge of associated life stages. The holotype and only specimen of S. grandis is redescribed and illustrated photographically and by line drawings, with emphasis on features which pertain to its family placement. Unambiguous assignment to Simuliidae implies an earlier Mesozoic origin for the blackflies than previously evidenced by available fossils, and it is suggested that the origins of the Simuliidae go back to Lower Jurassic times.     

Caste-specific modulation of juvenile hormone III content and ecdysteroid titer in postembryonic development of the stingless bee,Scaptotrigona postica depilis

Summary Juvenile hormone III content and ecdysteroid titer were analyzed for larval and pupal development of the stingless bee,Scaptotrigona postica depilis. Castespecific differences in juvenile hormone III content were detected at three developmental phases: at the transition from the fourth to the fifth larval stadium, in the spinning phase of the fifth larval stadium, and shortly after the imaginal moult. During the fifth larval stadium, juvenile hormone content closely reflects corpora allata activity. Juvenile hormone synthesis may thus be responsible for the elevated hormone titer in spinning-phase queen larvae, a phase of known sensitivity for induction of queen characters by exogenous juvenile hormone. For ecdysteroids, two phases of caste-specific differences were found: in the pre-pupal phase, and shortly after the imaginal moult. In both periods the titer in queens is distinctly higher compared to workers.Abbreviations Im imago 1 day after eclosion - L3, L4, L5 larval instars 3, 4, and 5 - L5F1, L5F2 substages of feeding phase in fifth larval instar - L5S1, L5S2, L5S3 substages of spinning phase in fifth larval instar - PP1, PP2 substages of prepupal phase - Pw white eyed pupa - Pp pink eyed pupa - Pr red eyed pupa - Pd dark eyed pupa - Pdl, Pdm, Pdd dark eyed pupa with progressive tanning of cuticle - RIA radioimmunoassay     

Observation of Varroa destructor behavior in capped worker brood of Africanized honey bees

The behavioral activity of Varroa destructor was observed using transparent cells. Mite oviposition started at 45.0?±?25.0?h post capping, followed by the next eggs laid at regular 27.3?±?2.0?h intervals. On the prepupa, mites were found to feed often and there was no preference for a specific segment as a feeding site. During the pupal stage the mite fed less often and almost always at the same point. Varroa showed a preference for defecation in the posterior part of the cell. A significant association was observed between the position of the feeding point in the pupa and the defecation site on the cell wall. Displacement behavior was observed in 71?% of the infested bee larvae and a major change in the free space available for varroa in the cell occurred when the prepupa molted into a pupa.     

A possible role of ecdysteroids in pre-ecdysial tanning in larvae of Sarcophaga bullata (Diptera: Sarcophagidae)

The levels of ecdysteroids in Sarcophaga bullata were determined by radioimmunoassay (RIA) from the time of larviposition (0 hr) to after the 2nd ecdysis and from late larval to pupal development. Two distinct peaks of ecdysteroid activity were recorded mid-way through the first and second stadia (14 and 34 hr) and two smaller peaks occurred a few hours prior to each ecdysis. A large release of ecdysteroids occurred from 8 hr before and up to 18 hr after formation of the white prepupa. This peak initiated the formation of the prepupa, the tanning of the puparium, larval/pupal apolysis and secretion of the pupal cuticle.Assays for the cuticle tanning hormone, bursicon, in pre-ecdysial larvae were not positive and a possible role for ecdysone in pre-ecdysial tanning of larval cuticular structures is proposed.     

MICROMORPHOLOGY OF A SMALL DINOFLAGELLATE PROROCENTRUM MARIAE-LEBOURIAE (PARKE & BALLATINE) COMB. NOV.1,2,3

The surface structures of the bivalvate dinoflagellate Prorocentrum mariae-lebouriae are described in detail. It has an almost spheroidal shape in face-view, a compressed saucer-shape in side view, with a distinct striated band at the edge of the cell. Its surface is covered with small spines in a regular pattern, with 450 nm distance between pairs. The spines are 100–120 nm wide and 200–300 nm long. There are 600–700 spines on each valve. At the anterior cell end, one of the values has a V-shaped depression which contains a specialized structure accommodating the 2 flagellar pores. The flagellar pores are-enclosed by 8 small, thick plates held together and to the values by sutures. The flagellar pore area consists of 2 distinct structures: an apical collar possessing a curved forked plate and a larger structure composed of an unbranched, plate. There are 2 flagellar canals located between the flagellar pore plates. Beneath each flagellar canal lies a row of 11 microtubules. A row of microtubules forming a microtubular cylinder is situated adjacent to the oblong flagellar canal near a simple pusule. The microtubular cylinder encircles electron dense bodies. The bases of the longitudinal and transverse flagella appear to lie at an angle to each other. The above features are illustrated with transmission and scanning electron micrographs.     

意大利蜜蜂工蜂脂肪体胚后发育过程中细胞的增殖和凋亡

脂肪体是昆虫体内物质贮备和中间代谢的重要组织。本研究通过显微形态观察、 BrdU免疫组织化学和原位末端转移酶标记(TUNEL)细胞凋亡检测技术, 对意大利蜜蜂Apis mellifera ligustica工蜂脂肪体胚后发育过程中细胞的增殖和凋亡特点进行了比较研究。结果表明： 意大利蜜蜂工蜂脂肪体细胞数量的快速增加集中在幼虫发育前期（1-3龄）, 而细胞的凋亡则集中在蛹发育早期的2-3 d（预蛹-2日龄蛹）时间之内。在变态发育中, 工蜂幼虫脂肪体凋亡降解后重新组建形成成虫的脂肪体。本研究为昆虫脂肪体的功能研究以及昆虫组织细胞自噬和凋亡的机制研究提供一定的证据。     

The pupa of Calamoceras illiesi Malicky & Kumanski, 1974 (Trichoptera Calamoceratidae)

The previously unknown pupa of Calamoceras illiesi Malicky & Kumanski, 1974 is described and illustrated, based on material collected from northwestern Turkey. It is compared with Calamoceras marsupus Brauer, 1865, the second species of the genus Calamoceras found in western Europe. The pupa of C. illiesi is very different from that of C. marsupus, in particular in having a flattened abdomen, the arrangement of the transversal fringes of the abdominal segments, the shape of the sclerotised hook plate of abdominal segment I, and the shape of the anal processes.     

Effects of gamma radiation on the postembryonic stages of a dermestid beetle, Anthrenus vorax waterhouse

The postembryonic stages of Anthrenus vorax proved to be susceptible to doses of 5, 10, 15 and 20 k rad. Pupation was more or less completely inhibited, but some larvae pupated after repeated moults, reduction in size and regrowth, and emerged as normal adults. Percentage of successful moults decreased with increasing doses.At lower doses, more last-stage larvae died in the prepupal stage; at higher doses, larval mortality was higher. Radiation of the early prepupa hampered the pupal moult, that of the late prepupa did not, but produced certain malformations in the adult.In the pupal stage, the later the pupa was radiated, the less susceptible it was, radiation during the first 3 days after pupation being more harmful than later. Pre-emergent adults and pupae of 5 and 6 days old were exposed to different doses of radiation. Data on the fecundity and fertility of various mating combinations of irradiated and non-irradiated males and females are presented and discussed.

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Zusammenfassung Die postembryonalen Stadien von Anthrenus vorax erwiesen sich gegen Strahlendosen von 5, 10, 15 und 20 k rad als empfindlich. Die Verpuppung war mehr oder weniger vollständig gehemmt, jedoch verpuppten sich einige wenige Larven nach wiederholten Häutungen, Größen-rückgang und erneutem Wachstum und schliipften als normale Adulte. Der Prozentsatz erfolgreicher Häutungen verringerte sich mit ansteigenden Dosen.Bei niederen Dosen starben die älteren Larven vor allem im Präpuppenstadium; bei höheren Dosen war ihre Larvensterblichkeit höher. Bestrahlung im frühen Präpuppenstadium hemmte die Puppenhäutung, im späten Puppenstadium dagegen nicht, verursachte dann aber gewisse Mißbildungen bei der Imago.Das Puppenstadium war gegenüber der Bestrahlung um so weniger empfindlich, je später die Puppe bestrahlt wurde. Während der ersten drei Tage nach der Verpuppung wirkte die Bestrahlung schädlicher als danach. Schlüpfreife Käfer und 5–6 Tage alte Puppen wurden verschiedenen Strahlendosen ausgesetzt. Es werden Angaben über Zeugungsfähigkeit und Fruchtbarkeit verschiedener Paarungskombinationen bestrahlter und unbestrahlter Männchen und Weibchen gemacht und besprochen.

     

Descriptions of the previously unknown xylobiont larva and pupa of <Emphasis Type="Italic">Atypophthalmus inustus</Emphasis> (Diptera,Limoniidae)

The larval and pupal morphology of Atypophthalmus inustus (Meigen, 1818) are described for the first time. The main diagnostic characters are the following: head capsule massive, frons with 3 short terminal projections, hypostomium with 11 teeth and long narrow split, hypopharynx and labium with well-developed conical teeth, stigmal area with 2 long ventral pigmented spots.     

中华蜜蜂咽下神经节的结构和胚后发育

咽下神经节是昆虫腹神经索的第一个复合神经节, 主要调节口器附肢的活动。本研究通过形态解剖、 BrdU免疫组织化学等技术, 对中华蜜蜂Apis cerana cerana咽下神经节的组织结构和胚后发育过程进行了比较研究。结果表明： 中华蜜蜂的咽下神经节由上颚、 下颚和下唇3个神经节组成。在胚后发育过程中, 细胞增殖的活跃期主要集中在预蛹和蛹发育的第1天, 增殖活动一直持续到蛹发育的第4天结束。根据神经胶质细胞的位置和形态, 咽下神经节中的神经胶质可分为3种类型--表面神经胶质、 皮层神经胶质和神经纤维网神经胶质。本研究为蜜蜂神经系统的发育和功能研究提供了理论基础。     

The loss,uptake and tissue distribution of copper and zinc during the moult cycle in an ecological series of talitrid amphipods (Crustacea:Amphipoda)

The exuvial loss, subsequent uptake, and tissue and body distributions of the essential trace metals copper and zinc were investigated in an ecological series of talitrid amphipods, immediately after moult and throughout a post-moult period. Negligible quantities of copper or zinc were detected in cast exuvia of individual talitrids. Neither tissue nor whole body copper and zinc concentrations underwent significant changes during the moult cycle and all species showed extreme conservatism in their handling of body copper. There appeared to be no differential treatment of copper between species at the time of moult throughout the ecological series, with no obvious increase in copper retention by the more terrestrial species. The impact of moult cycle stage therefore is unlikely to affect the use of littoral talitrid amphipods as biomonitors for ambient copper and zinc concentrations.     

Structure of insect chitin isolated from beetle larva cuticle and silkworm (Bombyx mori) pupa exuvia

Chitin samples in a alpha-form structure were isolated from beetle larva cuticle and silkworm (Bombyx mori) pupa exuvia by treatment with 1 N HCl and 1 N NaOH. Chitosan was prepared by treating them in 40% NaOH containing NaBH(4). Chitin and chitosan were analyzed by X-ray, [13C]CP/MAS NMR, [13C]FT-NMR, and scanning electron microscopy (SEM) methods. Insect chitin degraded more readily than shrimp chitin when treated with 6 N HCl and the enzyme-chitinase. After treatment with 2 N HCl at 100 degrees C, the insect chitin crystallinity increased. N-deacetylation of insect chitin was easier than that of crustaceous chitin, and about 94% of the N-acetyl groups were removed in one treatment with 40% NaOH for 4 h at 110 degrees C. After treatment with 2 N HCl, 55% of the N-acetyl groups of silkworm chitin were removed under the same conditions. Beetle chitin showed a higher affinity for chitinase than shrimp chitin.     

Phylogenetic analysis of the tribe Macropelopiini (Chironomidae: Tanypodinae): adjusting homoplasies

Macropelopiini is a widely distributed tribe of Tanypodinae, with immature stages inhabiting cool seeps, springs, and small streams. The present study evaluated the monophyly and the supporting synapomorphies within a phylogenetic context for the first time for Macropelopiini. The monophyly and the intergeneric relationships were tested by morphological evidence in a cladistic framework, and the information gained from each homoplastic character was evaluated. The monophyly of Macropelopiini is corroborated through the objective synapomorphy ‘outer fringe decreasing from base to apex ending in small spines’ in the pupa, and the subjective synapomorphies ‘tibial spurs with main teeth and short lateral tooth’ in males and ‘dorsal setae arising from prominent tubercles’ in the pupa. Fittkauimyia Karunakaran, 1969 is excluded from Macropelopiini, Gressitius Sublette & Wirth, 1980 is established as a junior synonym of Alotanypus Roback, 1971, and the new combination A lotanypus antarcticus comb. nov. is proposed. Character combination, mainly through the use of the characters with informative taxonomical value, remains an efficient tool to diagnose the Macropelopiini genera. The new genus Paggipelopia gen. nov. for P aggipelopia spaccesii gen. et sp. nov. is erected and the emendation of the species diagnosis of Wuelkerella toncekensis Añón Suárez & Sublette, 2012 is conducted. © 2015 The Linnean Society of London