scholarly journals Hiding among traps? Mortality of early instar odonate larvae in the presence of bladderwort plants

2020 ◽  
Vol 23 (2) ◽  
pp. 103-111
Author(s):  
Sandra Manasov ◽  
Frank Suhling
Keyword(s):  
Odonate Larvae ◽  
Early Instar

Bagworm Survival and Feeding Preferences as Indicators of Resistance among Maples

2002 ◽  
Vol 20 (3) ◽  
pp. 138-142
Author(s):  
William E. Klingeman
Keyword(s):  
Host Plant ◽  
Ornamental Plants ◽  
Larval Feeding ◽  
Eastern United States ◽  
Feeding Preferences ◽  
Survival And Development ◽  
Early Instar ◽  
Moderate Resistance ◽  
Hybrid Cross ◽  
Plant Susceptibility

Abstract The bagworm (Thyridopteryx ephemeraeformis (Haworth)) is a polyphagous, native pest of numerous deciduous and evergreen ornamental plants. Bagworm larvae were used to investigate host plant susceptibility among ten species and cultivars of maples that are economically important and commonly encountered in landscapes in the eastern United States. Data analyses from 48-hour choice assays, conducted in the laboratory during 2000 and 2001, indicated that differences existed among maples for bagworm feeding preferences and host plant susceptibility. Results from the 48-hour trials were not as accurate as seasonal no-choice assays, however. No-choice assays during both seasons quantified resistance among maples that limited larval bagworm survival and development. Measurements of larval feeding injury demonstrated resistance in paperbark maple (Acer griseum (Franch.) Pax) and trident maple (A. buergerianum Miq.) when compared with other maples. Laboratory results were corroborated during 2001 by a no-choice field assay, in which early instar bagworm larvae performed well on the majority of maples. In contrast, paperbark maple and trident maple were resistant to bagworm feeding, while ‘Autumn Blaze’ Freeman maple (A. x freemanii E. Murray), a hybrid cross obtained by breeding A. rubrum with A. saccharinum, showed moderate resistance.

Influence of Stand Factors on Survival of Early Instar Spruce Budworm 1

1979 ◽  
Vol 8 (6) ◽  
pp. 993-996 ◽  
Author(s):  
W. P. Kemp ◽  
G. A. Simmons
Keyword(s):  
Spruce Budworm ◽  
Early Instar

Abundance of leafminers and leaf area loss by chewing herbivores in hybrids between Quercus crispula and Quercus dentata

2004 ◽  
Vol 34 (12) ◽  
pp. 2501-2507 ◽  
Author(s):  
Takahide A Ishida ◽  
Kouhei Hattori ◽  
Masahito T Kimura
Keyword(s):  
Leaf Area ◽  
Parental Species ◽  
Quercus Crispula ◽  
Species Dominance ◽  
Area Loss ◽  
Early Instar ◽  
Sap Feeding ◽  
Leaf Area Loss ◽  
Quercus Dentata ◽  
Northern Japan

We examined responses of phytophagous insects to hybrids between Quercus crispula Blume and Quercus dentata Thunberg in a natural population in northern Japan. The abundance of leafminers and leaf area loss by chewing insects in hybrids were intermediate between those in the parental species (additive mode), close to those of either of the parental species (dominance mode), or similar to those of both parental species (no difference). Hybrids were neither more susceptible nor resistant to the insect herbivores we monitored. In Phyllonorycter (Gracillariidae) species, which are specialized to either of the parental oak species, the mortality of sap-feeding early instar larvae did not differ between hybrids and the parental species. The abundance of four leafminer taxa was correlated with environmental conditions (i.e., distance from the coastal edge of the forest or the timing of budbreak) as well as genetic factors.

THE POPLAR-AND-WILLOW BORER, STERNOCHETUS (= CRYPTORHYNCHUS) LAPATHI (COLEOPTERA: CURCULIONIDAE), IN BRITISH COLUMBIA

1967 ◽  
Vol 99 (4) ◽  
pp. 411-418 ◽  
Author(s):  
John W. E. Harris ◽  
Harry C. Coppel
Keyword(s):  
British Columbia ◽  
Life Cycle ◽  
Larval Mortality ◽  
Vancouver Island ◽  
Water Emulsion ◽  
Early Instar ◽  
Preferred Hosts ◽  
North Latitude

AbstractA study was made of the poplar-and-willow borer, Sternochetus (= Cryptorhynchus) lapathi (L.) (Coleoptera: Curculionidae), in British Columbia between 1959 and 1964. The borer occurred principally south of 52 degrees north latitude. Willows were the preferred hosts. Ornamentals, hybrids in commercial plantings, and natural growing trees were attacked. The life cycle of the insect on southern Vancouver Island lasted up to 3 years; overwintering took place in early instar and adult stages. Eggs were laid in the bark; larvae mined first in the bark and then in the wood, where pupation took place. Few parasites and predators were found. DDT, dieldrin, and BHC killed adults; lindane (0.5% water emulsion), applied in the spring, caused larval mortality up to 96%.

scholarly journals Extraordinary morphological changes in valve morphology during the ontogeny of several species of the Australian ostracod genus Bennelongia (Crustacea, Ostracoda)

2013 ◽  
Author(s):  
Patrick De Deckker ◽  
Koen Martens
Keyword(s):  
Adult Stage ◽  
Morphological Changes ◽  
The Other ◽  
Left Valve ◽  
Ventral Region ◽  
Valve Morphology ◽  
Other Hand ◽  
Early Instar ◽  
Juvenile Stages

Ostracods belonging to the genus Bennelongia differ much in valve morphology between adults and juveniles. Adult valves are asymmetrical, characterised by a beak-like feature in the antero-ventral region of the left valve, and, with some notable exceptions, mostly have smooth or weakly-ornamented valves. Juvenile specimens, on the other hand, have valves that are almost symmetrical, with no beak-like feature and are often heavily ornamented.We have examined the last 3 - 4 juvenile stages of 6 Bennelongia species from 5 different lineages, in order to decipher the types of external valve ornamentation and their recurrences during ontogeny and across lineages. It is clear that ornamentation is more prevalent at the early instar stages compared to the last 2 pre-adult stages, and especially when compared to the adult stage itself.We also examined the surprising presence of a calcified inner lamella with a prominent inner list in the pre-adult stages of Bennelongia species, that is usually absent in juveniles of other ostracods, thus questioning if heterochronic processes have provided an intermediate valve morphology between the simple (normal) cypridinid juvenile state and the heavily derived and modified state of adult Bennelongia.We discuss the possible (speculative) functionality of the ornamentation in juveniles.

FACTORS AFFECTING MORTALITY OF THE EUROPEAN CORN BORER, OSTRINIA NUBILALIS (HÜBNER), IN ALBERTA

1988 ◽  
Vol 120 (10) ◽  
pp. 841-853 ◽  
Author(s):  
Dennis A. Lee
Keyword(s):  
Ostrinia Nubilalis ◽  
European Corn Borer ◽  
Larval Mortality ◽  
Reproductive Potential ◽  
Moisture Stress ◽  
Mortality Factors ◽  
Corn Borer ◽  
Factors Affecting ◽  
Rainy Weather ◽  
Early Instar

AbstractA combination of laboratory and field trials, from 1983 to 1985, were used to determine mortality factors affecting all life stages of Alberta populations of the European corn borer, Ostrinia nubilalis (Hübner), feeding on corn. The resulting life table demonstrated that greatest mortality occurred during the first and second larval instars (62.2%), when mature larvae are in diapause (69.5%), and from moth migration and loss in reproductive potential (70.3%). Stages where mortality was slight included the egg stage (11.7%), non-diapausing third- to fifth-instar larvae (2%), and pupae (10.4%).Laboratory trials showed that greater egg mortality occurred at relative humidities (RH) of 35 and 55% than at a RH of 75%. In the field, egg parasitism was nil, predation of early-instar larvae (5.2%) and diapausing larvae (6%) was low, and parasitoids were scarce (emerging from ca. 2% of pupae). Sustained periods of hot, dry weather with high moisture stress were related to mortality of both eggs and early-instar larvae. Death of early-instar larvae also was related to periods of rainy weather with low evaporation. The 64% non-diapause larval mortality was much lower than that reported elsewhere. The dramatic increase in the corn borer since its recent introduction to Alberta may be due to a lack of natural enemies, and because only non-resistant corn hybrids are grown.

CHEMICAL CONTROL OF THE RASPBERRY ROOT BORER, BEMBECIA MARGINATA (HARR.), ON LOGANBERRY IN BRITISH COLUMBIA

1960 ◽  
Vol 40 (1) ◽  
pp. 160-164
Author(s):  
J. Raine ◽  
H. Andison
Keyword(s):  
British Columbia ◽  
Chemical Control ◽  
Early Instar

A single spray of 25 per cent Diazinon emulsible concentrate applied as a drench to loganberry crowns in March, April or October against early instar larvae of the raspberry root borer, Bembecia marginata (Harr.) reduced a severe infestation (77 per cent or more) to 4 per cent or less of the crowns. This outstanding control was obtained at rates as low as 2 pints per 100 gallons and 1/2 pint of drench per plant (43 gallons per acre). Applications in May at 2 pints of drench per crown reduced the infestation to 10 per cent. The following emulsible concentrates reduced the infestation to between 0 and 10 per cent: at 1 pint of drench per crown applied in October, lindane at 5 pints, Thimet at 1 pint, or 12008 at 1 pint per 100 gallons; at 2 pints of drench per crown applied in April, Sevin at 8 pints, NC262 at 1/2 pint, or Phosdrin at 1 pint per 100 gallons. The drenches apparently killed the early instar larvae which overwinter in hibernacula at the base of the canes until early April, and feed just beneath the bark in May. Thus damage to canes that would bear fruit the following year was prevented.

scholarly journals Effect of plant protection products on Rhynchophorus palmarum L. (Coleoptera: Curculionidae) larvae in laboratory

2018 ◽  
Vol 85 (0) ◽  
Author(s):  
Samara dos Santos ◽  
Valdemir Albuquerque da Silva Júnior ◽  
Sonia Maria Forti Broglio ◽  
Aldomario Santo Negrisoli Junior ◽  
Elio Cesar Guzzo
Keyword(s):  
Analysis Of Variance ◽  
Artificial Diet ◽  
Plant Protection ◽  
Larval Mortality ◽  
Plant Protection Products ◽  
Fungal Diseases ◽  
Laboratory Conditions ◽  
Rhynchophorus Palmarum ◽  
Early Instar

ABSTRACT: With the aim of developing tools for simultaneously managing Rhynchophorus palmarum and the coconut stem bleeding disease, we evaluated the effects of the insecticide thiamethoxam and the fungicide cyproconazole on R. palmarum larvae under laboratory conditions. Early-instar and intermediate-instar larvae were fed on an artificial diet containing 0.1% concentration of insecticide, fungicide or a mixture of both. Larval mortality was assessed daily during the 48 hours after the application of the treatments. Mean mortality values were subjected to analysis of variance and compared by Tukey’s test (p ≤ 0.05). Thiamethoxam caused mortality of 100% of early-instar and 90% of intermediate-instar larvae. In contrast, mortality was significantly lower in the cyproconazole treatment (60% for early-instar and 0% for intermediate-instar larvae) and the control (0% mortality for both treatments). The insecticide/fungicide mixture was equally effective (100% for early-instar and 86.67% for intermediate-instar larvae) to the insecticide only treatment. Differences in mortality between early-instar and intermediate-instar larvae were significant only for the thiamethoxam and cyproconazole treatments. These results indicate that, for the doses used here, thiamethoxam is toxic to both early-instar and intermediate-instar larvae, while cyproconazole is toxic just to early-instar larvae. Moreover, cyproconazole does not increase the toxicity of thiamethoxam. Early-instar larvae are more sensitive to thiamethoxam and cyproconazole than intermediate-instar larvae. We conclude that thiamethoxam + cyproconazole mixture may be effective for managing R. palmarum and associated fungal diseases on coconut palms.

scholarly journals Asian citrus psyllid adults inoculate huanglongbing bacterium more efficiently than nymphs when this bacterium is acquired by early instar nymphs

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
El-Desouky Ammar ◽  
Justin George ◽  
Kasie Sturgeon ◽  
Lukasz L. Stelinski ◽  
Robert G. Shatters
Keyword(s):  
Latent Period ◽  
Salivary Glands ◽  
Emerging Adults ◽  
Citrus Greening ◽  
Asian Citrus Psyllid ◽  
Diaphorina Citri ◽  
Citrus Greening Disease ◽  
Early Instar ◽  
Liberibacter Asiaticus ◽  
Greening Disease

Abstract The Asian citrus psyllid (Diaphorina citri) transmits the bacterium ‘Candidatus Liberibacter asiaticus’ (CLas), which causes huanglongbing (citrus greening) disease, in a circulative-propagative manner. We compared CLas inoculation efficiency of D. citri nymphs and adults into healthy (uninfected) citron leaves when both vector stages were reared from eggs on infected plants. The proportion of CLas-positive leaves was 2.5% for nymphs and 36.3% for adults. CLas acquisition by early instar nymphs followed by dissections of adults and 4th instar nymphs revealed that CLas bacterium had moved into the head-thorax section (containing the salivary glands) in 26.7–30.0% of nymphs and 37–45% of adults. Mean Ct values in these sections were 31.6–32.9 and 26.8–27.0 for nymphs and adults, respectively. Therefore, CLas incidence and titer were higher in the head-thorax of adults than in nymphs. Our results suggest that following acquisition of CLas by early instar D. citri nymphs, emerging adults inoculate the bacteria into citrus more efficiently than nymphs because adults are afforded a longer latent period necessary for multiplication and/or translocation of CLas into the salivary glands of the vector. We propose that CLas uses D. citri nymphs mainly for pathogen acquisition and multiplication, and their adults mainly for pathogen inoculation and spread.

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