Stadium Larvae Research Articles

Descriptions of the larvae of Huosoma Guan, Dumont, Yu, Han amp; Vierstraete, 2013 from China (Odonata: Coenagrionidae).

The final stadium larvae of Huosoma latiloba (Yu, Yang Bu, 2008) and Huosoma tinctipenne (McLachlan, 1894) from Yunnan Province, China are described and illustrated for the first time, with diagnostic differences between the two species identified. While no morphological characters separating the adults of this genus, and the closely related western Palaearctic Pyrrhosoma Charpentier, 1840 have been found, the larvae of these two genera do show differences which are discussed here.

Dragonflies (Insecta: Odonata) from Mananciais da Serra, a Tropical-Araucaria Forest ecotonal remnant in the southern Atlantic Forest, state of Paraná, Brazil

This study provides a comprehensive checklist of Odonata species from the protected area of Mananciais da Serra. The survey was conducted in the endangered Atlantic Forest domain at the southern Serra do Mar mountain chain within a well-preserved area in the municipality of Piraquara, state of Paraná, Brazil. Adults and larvae were sampled between June 2017 and March 2020 using different techniques in numerous mesohabitats, including phytotelmata, pools, small streams, and large reservoirs. A total of 1,708 specimens from 9 families, 43 genera and 84 species were sampled resulting in 53 new records for the state of Paraná, almost doubling the known occurrence records for dragonflies and damselflies in that state. Furthermore, two hitherto undescribed females from the generaPlaniplaxandHeteragrion, four ultimate stadium larvae fromPlaniplax,Neocordulia,Heteragrion, andAcanthagrion, and five undescribed species were detected, one each from the generaHeteragrion,Progomphus,Brechmorhoga,Erythrodiplax, andDasythemis. The estimated richness of odonates in this area is greater than 100 species, while the observed richness corresponding to almost 10% of all Odonata species in Brazil, the species-richest country in the world. These results reiterate the need to investigate undersampled areas to improve knowledge on diversity, taxonomy, and distribution of neotropical species. Finally, taxonomic notes for some species, including the rare corduliidNeocordulia mambucabensisCosta & T.C. Santos, 2000, are provided.

Descriptions of the last instar larvae of two species of Megalestes Selys from Yunnan, China (Odonata: Zygoptera: Synlestidae)

The final stadium larvae of Megalestes micans Needham, 1930 and M. kurahashii Asahina, 1985 are described and illustrated from Yunnan Province, China, and a key to the known larvae of seven species...

The subfamily Platycnemidinae (Zygoptera: Platycnemididae) in Thailand, with description of the final stadium larva of Copera chantaburii Asahina, 1984

Within the damselfly subfamily Platycnemidinae, eight species are currently recognized in South-East Asia. The final stadium larvae of only three of them have been so far described. The final stadi...

Urinary capillariosis in dogs

Background. Urinary capillariosis in dogs is caused by Capillaria plica (syn. Pearsonema plica), a ubiquitous parasitic nematode resembling a string which belongs to the family Capillariidae. It parasitizes the feline, canine and musteline urinary bladder, and has been found in ureters and renal pelvises as well. C. plica has an indirect life cycle, with earthworms (Lumbricina) as intermediate hosts and domestic and wild animals (dog, cat, fox and wolf) as primary hosts. Infection of primary hosts occurs via ingestion of earthworms that contain infective first stadium (L1) larvae. An alternative path of infection for primary hosts is assumed to be ingestion of soil contaminated by infectious larvae derived from decomposed earthworms. Infection is mostly asymptomatic, but the clinical picture presents with pollakiuria, dysuria, haematuria, polydipsia, incontinence and/or fever. Scope and Approach. The aim of this review is to highlight the importance of urinary capillariosis in dogs. Since the health care of wild and domestic carnivores is extremely important, this review provides information about the morphology, biology and epizootiology of the C. plica nematode. Due to the importance of this disease for clinicians and increased disease prevalence during the last decade in many countries, this review presents the latest information on the pathogenesis, clinical signs, diagnosis, treatment and prevention of this infection. Key Findings and Conclusions. Capillariosis is usually accidentally diagnosed due to the nonspecific clinical signs and there is no treatment of choice. Practitioners should consider latent urinary capillariosis infection as a possible cause while examining for urinary tract diseases.

Larvicidal Activity in vivo of Ethanolic and Aqueous Extracts From Moringa (Moringa oleifera Lam.) on Aedes aegypti L. (Diptera: Culicidae)

The insecticides properties of Moringa oleifera (moringa) were evaluated in Aedes aegypti larvae, throughout an entirely randomized trial, represented by ethanolic and aqueous extracts obtained from leaves, flowers, barks, seeds and moringa roots, besides the control group. Five batches of 10 in 3rd stadium larvae were distributed in distilled water, added an extract concentration of 50 mL L-1, and the control treatment (distilled water). The test reading was measured after 24, 48 and 72 hours after larvae exposure, were considered dead those who did not respond to a mechanical stimulation of a clamp. The seed ethanolic extract produced the best performance after 24 hours (34% mortality), but after 48 hours, the flower extract was the more potent (38% mortality). The largest larvicidal activity was observed with the extract concentration of 90 mL L-1. The results indicate that moringa has larvacides properties against Aedes, but its chemical constituents need to be isolated and tested separately to enhance your larvicidal activity.

The larval ontogeny of Coryphaeschna perrensi (McLachlan, 1887): Supporting monophyletic groups in Aeshnidae dragonflies (Insecta: Odonata: Anisoptera).

The development of the larval external morphology of Coryphaeschna perrensi is reported based primarily on a comparison of successive exuviae of reared specimens, with the second stadium larvae first described separately. Accentuated changes observable throughout successive moltings occur in some structures, such as the head capsule, labium, and anal appendages, allowing for the definition of characters with naturally ordered, polarized, and linear states (transformation series) by ontogenetic evidence. The terminal (less general) and nonterminal (more general) states of the described transformation series correspond by primary homology to the conditions found in larvae of other dragonfly species. Consequently, as the result of a parsimony analysis and subsequently ontogenetic rooting, the disposition of the states of 17 characters in a sample of final-stadium larvae of 23 species, representatives of the six Aeshnidae tribes (21) and Austropetaliidae (2), results in a hierarchical network comprising six distinct taxonomic levels of inclusion of C. perrensi. The levels correspond to Aeshnidae, Aeshninae, Aeshnini (part) + Gynacanthini, Coryphaeschna + Remartinia, Coryphaeschna, and Coryphaeschna except C. adnexa, which are groups previously recognized as monophyletic resulting from analyses considering adult morphology. Immature insect morphology coupled with ontogenetic observation presenting great potential to hypothesize phylogenetic relationships and investigate heterochronic events.

Effect of SSP – 11 on Weight and Tissue Composition of 4th Instar Larvae of Silkworm, Bombyx mori

The anti-juvenoid, SSP-11 ((E) 4-chloro-a, a, a-trifluro-N [ 1 (1 H-imidazole- 1 –y1)- 2-propoxy ethylyledene] O, toludine) was used to induce trimoulters from tetramoulter larvae of the silkworm, Bombyx mori (race NB7). The compound was fed for two days through an artificial diet at the concentration of 200 ppm to newly ecdysed 4th stadium larvae. Body and silkgland fresh weight were recorded daily in the 4th larval stadium and protein profiles of haemolymph, fat body and silkgland were determined at the end of the stadium. In larvae treated with SSP-11, feeding period in stadium 4 was prolonged by 3-4 days and 80-85% of the larvae started to spin as trimoulters. Eight and thirty fold increases in the larval body and silkgland weights respectively were the result of SSP-11. Further, total proteins, total carbohydrates, glycogen and nucleic acid (DNA & RNA) also increased. The activity levels of alanine aminotransferase and aspartate aminotransferasc increased significantly than in the control indicating increased mobilization of aminoacids into transamination activities.

First record of extra-abdominal processes in adult Odonata

Paired extra-abdominal processes (ap) were found in the pleural region of abdominal segments 6–9 in adult Odonata for the first time. They are unsegmented bulge-like or rod-like structures of different size, degree of sclerotization and movability. A short search across odonatan families has shown that ap are inherent for all studied Aeshnidae and for some other Anisoptera. A comparative study of final stadium larvae has shown that ap appear as remnants of larval lateral spines originally situated on larval tergites. This fact provides evidence about the complex nature of the pleural region in the Aeshnidae imago which includes part of the area of the larval tergite.

Description of two final stadium Onychogomphus larvae from Thailand(Odonata: Gomphidae).

The final stadium larvae of Onychogomphus castor Lieftinck and O. duaricus Fraser are described and illustrated for the first time based on reared specimens from Thailand. The taxonomic characteristics of the larvae of the genus Onychogomphus are discussed and summarized. The larva of O. castor differs from other Southeast Asian species in having distinct mid-dorsal spines on S2-9, divergent wing pads reaching S5, and lateral spines on S6-9. The larva of O. duaricus has a weakly swollen third antennal segment, with short blunt mid-dorsal spines on S2-9, divergent wing sheaths reaching the middle of S4, and lateral spines present on S7-9.

PHYTOCHEMISTRY AND ANTIFEEDANT ACTIVITY OF ROOT EXTRACTS FROM SOME VINCETOXICUM TAXA AGAINST LEPTINOTARSA DECEMLINEATA AND SPODOPTERA LITTORALIS

ABSTRACT Antifeedant activities of dichloromethane, dichloromethane: methanol (1:1), methanol and total ethanol extracts of five Vincetoxicum N.M. Wolf taxa were investigated using leaf disc no-choice method against third stadium larvae of Spodoptera littoralis Bois. and Leptinotarsa decemlineata Say.. Further, phytochemical constituents were also screened qualitatively. Among the 20 tested extracts, 7 extracts against L. decemlineata larvae and 3 extracts against S. littoralis larvae showed 100 % antifeedant activity after exposure maximal dose. The activity results indicated that roots of studied Vincetoxicum taxa were effective against both tested pests. The dichloromethaneand dichloromethane: methanol (1:1) extracts of V. fuscatum subsp. boissieri (Kusn) Browicz indicated the highest effectiveness against L. decemlineata larvae (16 μg /cm2 ED50 value) and CH2Cl2 extract of V. canescens subsp. canescens (Willd.) Decne. showed the highest effectiveness against S. littoralis larvae (ED50 48 μg /cm2 value). Furthermore the growth inhibition and chronic toxicity on S. littoralis larvae were determined. The CH2Cl2 extract of V. fuscatum subsp. boissieri and MeOH: CH2Cl2(1:1) extract of V. canescens subsp. canescens displayed the highest effectiveness causing growth inhibition with ED50 0.04 mg/g and 0.09 mg/g respectively. Also the same extract of V. fuscatum sub-species boissieri produced chronic toxicity with the highest effectiveness letal dose (LD50 1.11 mg/g value). Phytochemical studies showed the presence of steroidal glycosides, sugars and starch. The root of V. fuscatum subsp. boissieri also contained saponins. MS History: 27.10.2015 (Received)-28.10.2015 (Revised)-31.10.2015 (Accepted)

Olfactory response of the omnivorous mirid bug Nesidiocoris tenuis to eggplants infested by prey: Specificity in prey developmental stages and prey species

We studied olfactory responses of Nesidiocoris tenuis Reuter (Heteroptera: Miridae), an omnivorous mirid bug, to volatiles from eggplants infested by different developmental stages of tobacco cutworms, Spodoptera litura Fabricius (Lepidoptera: Noctuidae) and of female two-spotted spider mites, Tetranychus urticae Koch (Acari: Tetranychidae). We first conducted predation experiments and found that N. tenuis preyed on first and second stadium larvae, but not on third and fourth stadium S. litura larvae. N. tenuis also preyed upon T. urticae females that had been reported to be less suitable prey species. When offered first stadium S. litura larvae and T. urticae females simultaneously, N. tenuis, preferred to prey upon S. litura larvae. We then tested the olfactory responses of N. tenuis to volatiles from eggplants using a Y-tube olfactometer. A significant preference for volatiles from uninfested eggplants over clean air was found. Volatiles of eggplants infested by either first, second or fourth stadium S. litura larvae were preferred over volatiles from uninfested eggplants. The olfactory preferences of N. tenuis to S. litura-infested eggplants were: eggplants infested by 10 first stadium larvae=eggplants infested by 10second stadium larvae>eggplants infested by 1 fourth stadium larva. Volatiles from eggplants infested by 200 T. urticae females also attracted N. tenuis, but the volatiles were not as attractive as those from eggplants infested by 10 first stadium larvae. Chemical analyses showed that volatiles from eggplants infested by different developmental stages of S. litura larvae had qualitative differences. First stadium larvae induced higher amounts of volatiles than second and fourth stadium larvae, despite the first stadium S. litura larvae doing the least damage. T. urticae female-induced volatiles were both qualitatively and quantitatively different from those induced by first stadium S. litura larvae. The specific olfactory responses of N. tenuis to different prey species/developmental stages were discussed in terms of prey availability and biological control.

Dorsolateral cuticular outgrowths in second stadium larvae ofGomphus flavipes(Odonata: Gomphidae)

Second and third stadium larvae of Gomphus flavipes have dorsolateral cuticular outgrowths in the form of small basal tubercles bearing fan-shaped setae. These sensilla are aligned in two rows on each side of the thorax and abdomen. European species of Gomphus, Onychogomphus and Ophiogomphus that we examined lack these structures, having instead, at most, short hairlike setae in double rows. The fan-shaped setae of G. flavipes are present only in second and third stadia, apparently being lost later in larval development. We speculate that this loss might be due to changes in microhabitat or might be some kind of phylogenetic constraint.

Description of the final stadium larvae of Polycanthagyna ornithocephala (McLachlan, 1896) from Taiwan, with a key to the known larvae of the genus (Odonata: Anisoptera: Aeshnidae)

Description of the final stadium larvae of Polycanthagyna ornithocephala (McLachlan, 1896) from Taiwan, with a key to the known larvae of the genus (Odonata: Anisoptera: Aeshnidae)

Fusion to Snowdrop Lectin Magnifies the Oral Activity of Insecticidal ω-Hexatoxin-Hv1a Peptide by Enabling Its Delivery to the Central Nervous System

BackgroundThe spider-venom peptide ω-hexatoxin-Hv1a (Hv1a) targets insect voltage-gated calcium channels, acting directly at sites within the central nervous system. It is potently insecticidal when injected into a wide variety of insect pests, but it has limited oral toxicity. We examined the ability of snowdrop lectin (GNA), which is capable of traversing the insect gut epithelium, to act as a “carrier” in order to enhance the oral activity of Hv1a.Methodology/Principal FindingsA synthetic Hv1a/GNA fusion protein was produced by recombinant expression in the yeast Pichia pastoris. When injected into Mamestra brassicae larvae, the insecticidal activity of the Hv1a/GNA fusion protein was similar to that of recombinant Hv1a. However, when proteins were delivered orally via droplet feeding assays, Hv1a/GNA, but not Hv1a alone, caused a significant reduction in growth and survival of fifth stadium Mamestra brassicae (cabbage moth) larvae. Feeding second stadium larvae on leaf discs coated with Hv1a/GNA (0.1–0.2% w/v) caused ≥80% larval mortality within 10 days, whereas leaf discs coated with GNA (0.2% w/v) showed no acute effects. Intact Hv1a/GNA fusion protein was delivered to insect haemolymph following ingestion, as shown by Western blotting. Immunoblotting of nerve chords dissected from larvae following injection of GNA or Hv1a/GNA showed high levels of bound proteins. When insects were injected with, or fed on, fluorescently labelled GNA or HV1a/GNA, fluorescence was detected specifically associated with the central nerve chord.Conclusions/SignificanceIn addition to mediating transport of Hv1a across the gut epithelium in lepidopteran larvae, GNA is also capable of delivering Hv1a to sites of action within the insect central nervous system. We propose that fusion to GNA provides a general mechanism for dramatically enhancing the oral activity of insecticidal peptides and proteins.

Effects of prohydrojasmon‐treated corn plants on attractiveness to parasitoids and the performance of their hosts

AbstractWe investigated the effect of prohydrojasmon [propyl (1RS,2RS)‐(3‐oxo‐ 2‐pentylcyclopentyl) acetate] (PDJ) treatment of intact corn plants, on their attractiveness to the specialist endoparasitoid, Cotesia kariyai Watanabe (Hymenoptera: Braconidae), and on the performance of the common armyworm, Mythimna separata (Walker) (Lepidoptera: Noctuidae) under laboratory conditions. Attractiveness of C. kariyai to PDJ‐treated plants was studied in a wind tunnel, whereas performance of M. separata larvae was tested in plastic cages. The attractiveness of the treated plants increased with concentrations of PDJ increasing to 2 mm, which was equivalent to the attractiveness of host‐infested plants. PDJ‐treated corn plants emitted 16 volatile compounds (α‐pinene, β‐myrcene, (Z)‐3‐hexenyl acetate, limonene, (E)‐β‐ocimene, linalool, (E)‐4,8‐dimethyl‐1,3,7‐nonatriene, (+)‐cyclosativene, ylangene, (E)‐β‐farnesene, (E, E)‐4,8,12‐trimethyl‐1,3,7,11‐tridecatetraene, α‐bergamotene, γ‐cadinene, δ‐cadinene, α‐muulolene and nerolidol), most of which were observed in the headspace of host‐infested corn plants with some quantitative and qualitative differences. We also tested the effects of PDJ treatment on the performance of M. separata larvae. The survival rates of the larval and pupal stages were significantly lower at 2 mm level of PDJ. A significant decrease in weight at 6th stadium larvae was observed only at 2 mm level of PDJ. In contrast, PDJ treatment at all PDJ concentration levels caused significant reduction in weight of pupal stage as compared to control. These data suggested that PDJ, originally developed as a plant growth regulator, especially to induce coloring of fruits, has the potential to induce direct and indirect defenses in corn plants against common armyworm, M. separata.

Description of the final stadium larvae of Polycanthagyna ornithocephala (McLachlan, 1896) from Taiwan, with a key to the known larvae of the genus (Odonata: Anisoptera: Aeshnidae)

The final stadium larvae of Polycanthagyna ornithocephala is described and compared to those of its congeners occurringin Taiwan. A key is provided to identify the known larvae of three Polycanthagyna species. General habitus of adult and larva are also discussed.

Description of the final stadium larva of Telebasis obsoleta (Selys, 1876) (Odonata: Coenagrionidae)

The final stadium larvae of Telebasis obsoleta is described and illustrated based on one reared specimen from Argentina.Notes on habitat and new provincial records of Odonata are also provided. The larva of Telebasis obsoleta has five palpalsetae, a feature shared only with the larva of T. demerara. All other known Telebasis species have six or seven palpal setae.Telebasis obsoleta and T. demarara can be distinguished by the presence of two small denticles near the tip of the prementum in T. obsoleta, and by the color pattern of the distal half of the caudal lamellae.

SOIL SUPPRESSIVENESS TOWARDS MELOIDOGYNE, VERTICILLIUM OR PYTHIUM IN GREENHOUSE HORTICULTURE

Soils originating from fourteen greenhouse horticultural companies were assessed for the level of suppressiveness of three major pathogens of vegetables and flowers, namely the root knot nematode Meloidogyne incognita, Pythium aphanidermatum and Verticillium dahlia. As controls, three well-documented soils in terms of disease suppressiveness and coarse sand were included for each pathogen. Soils were distributed over three treatments with forty replicates each in a random block design under standardized conditions. Each soil was treated with ?-radiation in order to assess the contribution of abiotic properties to disease suppressiveness. Non-sterilized soils served as a measure of abiotic- and biotic factors, and soil without the addition of pathogens served as a control to determine background contamination of indigenous pathogens. Soils were acclimatized for one week. Afterwards, irrigation was started and pathogens were inoculated. Survival stages of V. dahlia or P. aphanidermatum were added as pure suspensions, i.e., microsclerotia or oospores, respectively. For Meloidogyne, second stadium larvae (J2) were used. Seedlings were planted for M. incognita, while for P. aphanidermatum and V. dahlia, seeds were used. A large variation in the level of suppressiveness was observed. Soil suppressiveness towards Meloidogyne, Verticillium or Pythium was not correlated. This means that suppressiveness is pathogen dependent. However, soil structure contributes to a large extent to the level of suppressiveness as exemplified by the survival rate of Meloidogyne and Pythium in sandy soils. With this dataset we aim to unravel the underlying mechanisms and investigate whether suppressiveness levels can be increased and used in an integrated soil management system.

Zootoxic effects of reduviid Rhynocoris marginatus (Fab.) (Hemiptera: Reduviidae) venomous saliva on Spodoptera litura (Fab.)

Rhynocoris marginatus is a predominant and potential reduviid predator of many economically important pests in India. The venomous saliva (VS) was collected by milking method and diluted with HPLC grade water to prepare different concentrations (200, 400, 600, 800 and 1000ppm). The VS from R. marginatus was found to be toxic and the LD50 of the VS in Spodoptera litura third instar were 768 and 929ppm at 48 and 96h for microinjection and oral toxicity studies, respectively. Level of hydrolase and detoxification enzymes significantly decreased in a dose-dependent manner after treating the host with VS for 96h. A decrease in carbohydrate (21%) and lipid (46%) contents and an increase in the protein content (50%) were prominent in the experimental category. The VS reduced the relative growth rate, approximate digestibility, efficiency of conversion of ingested and digested food of S. litura in the oral toxicity study. Salivary venom inhibits the haemocytes from aggregation and affects spreading behavior of haemocytes separated from the fifth stadium larvae of S. litura. The result showed that VS toxins caused mortality, changed the nutritional indices, and altered the levels of macromolecule quantity and digestive enzymes of S. litura. We concluded that the VS of R. marginatus is venomous to a prey species, S. litura.