When a Tritrophic Interaction Goes Wrong to the Third Level: Xanthoxylin From Trees Causes the Honeybee Larval Mortality in Colonies Affected by the River Disease

AbstractDietary delivery of bacterially expressed double-stranded RNA (dsRNA) has a great potential for management of Leptinotarsa decemlineata. An important first step is to discover possible RNA-interference (RNAi)-target genes effective against larvae, especially the old larvae. In the present paper, five putative Broad-Complex (BrC) cDNAs (Z1-Z4, and Z6) were identified in L. decemlineata. The expression of the five LdBrC isoforms was suppressed by juvenile hormone signaling, whereas the transcription was upregulated by 20-hydroxyecdysone signaling at the fourth (final) instar larval stage. Feeding of bacterially expressed dsBrC (derived from a common fragment of the five LdBrC variants) in the third- and fourth-instar larvae successfully knocked down the target mRNAs. For the fourth-instar LdBrC RNAi hypomorphs, they had a higher larval mortality compared with the controls. Moreover, most dsBrC-fed beetles did not pupate normally. After removal of the apolysed larval cuticle, a miniature adult was found. The adult head, compound eyes, prothorax, mesothorax, metathorax were found on the dorsal view. Distinct adult cuticle pigmentation was seen on the prothorax. The mouthparts, forelegs, midlegs, and hindlegs could be observed on the ventral view of the miniature adults. For the third-instar LdBrC RNAi specimens, around 20% moribund beetles remained as prepupae and finally died. Therefore, LdBrC is among the most attractive candidate genes for RNAi to control the fourth-instar larvae in L. decemlineata.

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INDUCTION AND TERMINATION OF DIAPAUSE IN WYEOMYIA SMITHII (DIPTERA: CULICIDAE), AND LARVAL SURVIVAL STUDIES AT LOW AND SUBZERO TEMPERATURES

The Canadian Entomologist ◽

10.4039/ent1041937-12 ◽

1972 ◽

Vol 104 (12) ◽

pp. 1937-1950 ◽

Cited By ~ 24

Author(s):

K. W. Evans ◽

R. A. Brust

Keyword(s):

Larval Mortality ◽

Larval Survival ◽

Wyeomyia Smithii ◽

Ground Temperatures ◽

The Third ◽

Laboratory Conditions ◽

Subzero Temperatures ◽

Critical Daylength ◽

Survival Studies

AbstractDiapause in Wyeomyia smithii (Coquillett) was shown to be a function of photoperiod, and independent of temperature. The critical daylength for a population from Pinawa, Man., was 15 hr light per diem. The photoperiodic cues are monitored by the early instars, with diapause being expressed in the third instar. Development is also limited by temperatures below 15 °C even when the critical daylength is exceeded.Survival at low and subzero temperatures is aided by the diapause state. However, larvae are unable to withstand extended periods of subzero temperatures, even in the diapause condition. At −5 °C, 60% mortality occurred after 8 weeks under laboratory conditions. In the field, where ground temperatures averaged −3.7 °C during the five coldest months, larval mortality averaged 45% after four winter months.Once diapause is established, larvae consume very little food. Diapause larvae appear to be as active as non-diapause larvae, and also appear to be feeding constantly. However, the amount of food ingested is negligible compared to non-diapause larvae.

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AERIAL SPRAYING OF A BACILLUS THURINGIENSIS — CHITINASE FORMULATION FOR CONTROL OF THE SPRUCE BUDWORM (LEPIDOPTERA: TORTRICIDAE)

The Canadian Entomologist ◽

10.4039/ent1051535-12 ◽

1973 ◽

Vol 105 (12) ◽

pp. 1535-1544 ◽

Cited By ~ 5

Author(s):

W. A. Smirnoff ◽

J. J. Fettes ◽

R. Desaulniers

Keyword(s):

Bacillus Thuringiensis ◽

Larval Mortality ◽

Spruce Budworm ◽

Balsam Fir ◽

Insect Development ◽

Check Plot ◽

The Third ◽

Spray Deposit ◽

Aerial Spraying

AbstractA 10,000 acre stand of mature balsam fir, in Temiscouata County, Quebec, which had a spruce budworm population of about 21 larvae/18 in. branch-tip was sprayed with a Bacillus thuringiensis + chitinase formulation. Aerial spraying was carried out by three TBM aircraft between 4 and 7 June 1972, when insect development was at the peak of the third instar. Where the quantity of B. thuringiensis colonies per square centimeter was higher than 77 and spray deposit higher than 0.4 gal/acre (U.S.), larval mortality was between 84% and 93% compared with between 39% and 53% in the check plot. Foliage protection was 47%. The results indicate the possibilities of using B. thuringiensis + chitinase to control spruce budworm infestations.

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Larvicidal Activity of Ethyl Acetate Extract of Derris elliptica Root against the Third-instar Larvae of Cypermethrin-Resistant Aedes aegypti Offspring

Journal of Arthropod-Borne Diseases ◽

10.18502/jad.v14i4.5276 ◽

2021 ◽

Author(s):

Sayono Sayono ◽

Risyandi Anwar ◽

Didik Sumanto

Keyword(s):

Aedes Aegypti ◽

Ethyl Acetate ◽

Larvicidal Activity ◽

Ethyl Acetate Extract ◽

Larval Mortality ◽

Laboratory Strain ◽

The Third ◽

Resistant Strains ◽

Four Levels ◽

Third Instar Larvae

Background: Derris elliptica extracts have a high larvicidal potential against the laboratory strain of Aedes aegypti larvae, but the effect on offspring larvae of pyrethroid-resistant strains of the species is lack understood. This study aimed to determine the larvicidal activity of the ethyl acetate extract of tuba root against the third-instar larvae of the Cypermethrin-resistant Ae. aegypti offspring. Methods: The experimental study occupied four levels of ethyl acetate extract of D. elliptica namely 10, 25, 50, and 100 ppm, and each level was four times replicated. As many as twenty of healthy third-instar larvae, offspring of Cypermethrin-resistant Ae. aegypti were subjected to each experiment group. Larval mortality rate and lethal concentration 50% subject (LC50) were calculated after 24 and 48 hours of exposure time. Results: Mortality of larvae increased directly proportional to the increase of extract concentration. Larval mortality rates after 24 and 48 hours of exposure were 40–67.5% and 62.5–97.5%, and LC50 were 34.945 and 6.461ppm, respectively. Conclusion: The ethyl acetate extract of D. elliptica has the high effectiveness larvicidal potential against the thirdinstar larvae, offspring of the Cypermethrin-resistant Ae. aegypti. Isolation of the specific compound is necessarily done to obtain the active ingredient for larvicide formulation.

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Momordica charantia L. extracts against Aedes aegypti larvae

Brazilian Journal of Biology ◽

10.1590/1519-6984.236498 ◽

2022 ◽

Vol 82 ◽

Author(s):

L. M. P. Mituiassu ◽

M. T. Serdeiro ◽

R. R. B. T. Vieira ◽

L. S. Oliveira ◽

M. Maleck

Keyword(s):

Aedes Aegypti ◽

Ethyl Acetate ◽

Larvicidal Activity ◽

Methanol Extract ◽

Larval Mortality ◽

High Toxicity ◽

The Third ◽

Low Toxicity ◽

Aegypti Population ◽

Ethyl Acetate Extracts

Abstract Mormodica charantia (Curcubitaceae) is a plant with great medicinal potential, also used as an alternative of mosquitoes control as demonstrated by previous studies. We evaluated the larvicidal activity of crude extracts of ethyl acetate, methanol and hexane from flowers and fruits of M. charantia against Aedes aegypti (Culicidae). Flowers and fruits were macerated in methanol, ethyl acetate and hexane. Bioassays were performed with application of the extracts at final concentrations of 1 - 200 µg/mL in the middle of the third instar larvae of A. aegypti (L3). The results showed high toxicity to ethyl acetate extracts from flowers and fruits at concentrations of 200 µg/mL and 100 µg/mL, with 97% and 87% of larvae mortality (L3), respectively. Hexane extract demonstrated low toxicity, while methanol extract exhibited 78% larval mortality. The data suggested that the ethyl acetate extracts of flowers and fruits of M. charantia can effectively contribute to larvicidal activity. In addition, purification of M. charantia extracts may lead to a promising larvicidal activity to control the A. aegypti population.

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Mosquito larvicidal efficacy of phenolic acids of seaweed Chaetomorpha antennina (Bory) Kuetz. against Aedes aegypti

Biologia ◽

10.2478/s11756-011-0152-9 ◽

2012 ◽

Vol 67 (1) ◽

Cited By ~ 2

Author(s):

Subramanium Vimaladevi ◽

Ayyavu Mahesh ◽

Balaji Dhayanithi ◽

Nattarayan Karthikeyan

Keyword(s):

Aedes Aegypti ◽

Phenolic Acids ◽

Phenolic Acid ◽

Wide Spectrum ◽

Larval Mortality ◽

Inhibitory Effect ◽

The Third ◽

Third Instar Larvae

AbstractMosquito larvicidal and repellent activities of phenolic acids of Chaetomorpha antennina (Bory) Kuetz. against the third instar larvae of Aedes aegypti were investigated. The larval mortality was observed after 24 h exposure. Results of mosquito larvicidal tests revealed that insoluble bound phenolic acids and soluble conjugated phenolic acid fractions of C. antennina had an excellent inhibitory effect against A. aegypti and its LC50 values were 23.4 and 44.6 μg ml−1, respectively. The repellency assay of insoluble bound phenolic acids and soluble conjugated phenolic acid fractions of C. antennina, at 10 μg cm−2 concentration gave 100% protection up to 120 min. The results indicate that phenolic acids of C. antennina have a wide spectrum of larvicidal and repellent activities against Aedes aegypti.

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Efficacy of Entomopathogenic Nematodes Against the Tobacco Cutworm, Spodoptera litura (Lepidoptera: Noctuidae)

Journal of Economic Entomology ◽

10.1093/jee/toz262 ◽

2019 ◽

Cited By ~ 2

Author(s):

Xun Yan ◽

Muhammad Shahid Arain ◽

Yinying Lin ◽

Xinghui Gu ◽

Limeng Zhang ◽

...

Keyword(s):

Spodoptera Litura ◽

Entomopathogenic Nematodes ◽

Larval Mortality ◽

Mortality Rates ◽

The Other ◽

Exposure Rate ◽

The Third ◽

Tobacco Cutworm ◽

Different Temperatures ◽

Lepidoptera Noctuidae

Abstract Spodoptera litura (F.) is an obnoxious cosmopolitan pest that causes serious damage to different economic crops. Entomopathogenic nematodes (EPN) have the potential to control the S. litura larvae. Fifteen EPN isolates were screened, and Steinernema sp. 64-2, four isolates of S. carpocapsae (Weiser), S. longicaudum (Shen & Wang) X-7, and two isolates of H. indica (Poinar, Karunaka & David) were found to cause higher mortality of the second, third, and fourth instars of S. litura than the other tested isolates, with larval mortality rates > 90% after 48 h of exposure. An exposure rate of 12.5 infective juveniles per larva was enough for S. carpocapsae A24, All, and G-R3a-2 and S. longicaudum X-7 to cause 100% mortality of the second instar, and for S. longicaudum X-7 and H. indica 212-2 to cause 100% mortality of the third instar. Five EPN isolates were tested on their virulence at different temperatures and found that all the five EPN isolates performed well against the S. litura larvae at 25 and 30°C, but were not active at 10 and 15°C. Two S. carpocapsae isolates (All and Mex) were virulent against the S. litura larvae at lower temperatures. The five tested EPN isolates were also found to have the ability to infect and kill the pupae of S. litura in the laboratory. The present study further proves that EPN are effective at controlling S. litura, which may partially substitute the use of chemical insecticides, thus reduce the overuse of chemical insecticides.

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Larval mannitol diets increase mortality, prolong development, and decrease adult body sizes in fruit flies (Drosophila melanogaster)

10.1101/674192 ◽

2019 ◽

Author(s):

Meghan Barrett ◽

Katherine Fiocca ◽

Edward A. Waddell ◽

Cheyenne McNair ◽

Sean O’Donnell ◽

...

Keyword(s):

Drosophila Melanogaster ◽

Larval Mortality ◽

Larval Survival ◽

Offspring Performance ◽

The Third ◽

High Sugar ◽

Developmental Effects ◽

Adult Body ◽

Body Sizes ◽

Lower Magnitude

AbstractIngestion of the polyol mannitol caused sex-biased mortality in adultDrosophila melanogaster, but larval mortality was not sex-biased. High-sugar diets prolong development and generate smaller adult body sizes inD. melanogaster. We hypothesized that mannitol ingestion would generate similar developmental phenotypes as other high-carbohydrate diets. We predicted concentration-dependent effects on development similar to high-sugar diets whenD. melanogasterlarvae are fed mannitol, as well as a concentration-dependent amelioration of developmental effects if introduction to mannitol media is delayed past the third instar. Both male and female larvae had prolonged development and smaller adult body sizes when fed increasing concentrations of mannitol. Mannitol-induced increases in mortality were concentration dependent in 0 M to 0.8 M treatments beginning as early as 48 hours post-hatching. Larval survival, and pupation and eclosion times, were normal in 0.4 M mannitol treatments when larvae were first introduced to mannitol 72 hours post-hatching (the beginning of the third-instar); the adverse mannitol effects occurred in 0.8 M mannitol treatments, but at a lower magnitude. FemaleD. melanogasteradults prefer laying eggs on diets with high sugar concentrations, despite the negative effects on offspring performance. However, when given a choice, femaleD. melanogasteravoided laying eggs on mannitol-containing media that was otherwise identical to the control media, suggesting females perceived and avoided mannitol. In conclusion, the developmental effects of a larval mannitol diet closely resemble those of high-sugar diets, but adult female oviposition responses to mannitol in laying substrates are distinct from responses to other carbohydrates.

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Progress report on 21-cm observations at low latitude between longitudes (l 11) 0° and 66°

Symposium - International Astronomical Union ◽

10.1017/s0074180900100907 ◽

1967 ◽

Vol 31 ◽

pp. 177-179

Author(s):

W. W. Shane

Keyword(s):

Preliminary Report ◽

Progress Report ◽

Galactic Centre ◽

Low Latitude ◽

The Third ◽

Introductory Lecture ◽

Centre Region

In the course of several 21-cm observing programmes being carried out by the Leiden Observatory with the 25-meter telescope at Dwingeloo, a fairly complete, though inhomogeneous, survey of the regionl11= 0° to 66° at low galactic latitudes is becoming available. The essential data on this survey are presented in Table 1. Oort (1967) has given a preliminary report on the first and third investigations. The third is discussed briefly by Kerr in his introductory lecture on the galactic centre region (Paper 42). Burton (1966) has published provisional results of the fifth investigation, and I have discussed the sixth in Paper 19. All of the observations listed in the table have been completed, but we plan to extend investigation 3 to a much finer grid of positions.

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The orbit of Pluto over a long interval of time

Symposium - International Astronomical Union ◽

10.1017/s0074180900105509 ◽

1966 ◽

Vol 25 ◽

pp. 227-229 ◽

Cited By ~ 1

Author(s):

D. Brouwer

Keyword(s):

Periodic Orbit ◽

Numerical Integration ◽

Restricted Problem ◽

Three Dimensional ◽

The Third ◽

Circular Restricted Problem ◽

Resonance Relation

The paper presents a summary of the results obtained by C. J. Cohen and E. C. Hubbard, who established by numerical integration that a resonance relation exists between the orbits of Neptune and Pluto. The problem may be explored further by approximating the motion of Pluto by that of a particle with negligible mass in the three-dimensional (circular) restricted problem. The mass of Pluto and the eccentricity of Neptune's orbit are ignored in this approximation. Significant features of the problem appear to be the presence of two critical arguments and the possibility that the orbit may be related to a periodic orbit of the third kind.

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