Ultrastructure of the aporous sensilla on the galea of larval Mamestra configurata (Walker) (Lepidoptera: Noctuidae)

1994 ◽  
Vol 72 (11) ◽  
pp. 2032-2054 ◽  
Author(s):  
Vonnie D. C. Shields
Keyword(s):  
Distal Portion ◽  
Sheath Cell ◽  
Mamestra Configurata ◽  
Bipolar Neuron ◽  
Campaniform Sensillum ◽  
Tubular Body ◽  
Lepidoptera Noctuidae ◽  
Sheath Cells

The galea of fifth-instar Bertha armyworms, Mamestra configurata, has three types of aporous sensilla: one spire-shaped basiconic peg, two short basiconic pegs, and one campaniform sensillum. The spire-shaped peg is set in an inflexible socket, innervated by three bipolar neurons, and enveloped by three sheath cells. One microtubule-laden dendrite completely fills the distal portion of the dendritic sheath and ends within the peg. It is joined by a lamellate and a scolopidium-like dendrite that end near and below the base of the peg, respectively. The ciliary sinus is large and the membrane of the enveloping inner sheath cell is highly elaborate. This sensillum exhibits features characteristic of thermo-hygrosensilla. The short basiconic pegs and campaniform sensillum are each innervated by a single bipolar neuron and each is associated with three sheath cells. In both sensilla, the dendrite ends in a tubular body, typical of mechanosensilla.

Ultrastructure of the uniporous sensilla on the galea of larval Mamestra configurata (Walker) (Lepidoptera: Noctuidae)

1994 ◽  
Vol 72 (11) ◽  
pp. 2016-2031 ◽  
Author(s):  
Vonnie D. C. Shields
Keyword(s):  
Sheath Cell ◽  
Bright Field ◽  
Mamestra Configurata ◽  
Outer Sheath ◽  
Transmission Electron ◽  
Campaniform Sensillum ◽  
Tubular Body ◽  
Styloconic Sensillum ◽  
Lepidoptera Noctuidae ◽  
Sheath Cells

The structure and innervation of sensilla on the galea of fifth-instar Bertha armyworms, Mamestra configurata, were examined using bright-field light, scanning electron, and transmission electron microscopy. Four sensillar types were identified. The galea bears two uniporous styloconic sensilla, one aporous spire-shaped basiconic sensillum, two aporous basiconic sensilla, and one campaniform sensillum. The uniporous styloconic sensillum consists of a small socketed peg inserted into a large cone or style. Each styloconic sensillum is innervated by five bipolar neurons and associated with three sheath cells. Four distal dendrites end in the peg at various levels beneath the pore and the fifth ends in a tubular body at the base of the peg. The intermediate and outer sheath cells enclose a very large liquor-filled sensillar sinus. The inner sheath cell forms a nonlapped cylindrical sleeve around the neurons. These sensilla exhibit features of contact chemosensilla.

Fine structure of sensilla on the ovipositor of the tephritid fly Urophora affinis

1986 ◽  
Vol 64 (4) ◽  
pp. 973-984 ◽  
Author(s):  
R. Y. Zacharuk ◽  
R. M. K. W. Lee ◽  
D. E. Berube
Keyword(s):  
Fine Structure ◽  
Epidermal Cell ◽  
Fruit Flies ◽  
Sheath Cell ◽  
Outer Sheath ◽  
Dendritic Segment ◽  
Tubular Body ◽  
Tubular Bodies ◽  
Sheath Cells

There are four types of sensilla on the ovipositor blade of Urophora affinis Frauenfeld, one more than was observed on three other species of fruit flies studied by other authors. Three of the types, uniporous gustatory pegs, campaniform organs, and tactile short hairs are common to the four species and generally are in similar positions on the blade. The fourth, uniporous gustatory plates, were noted in U. affinis only. The chemosensilla are innervated by three chemosensory dendrites that terminate below the pore and a mechanosensory dendrite with a tubular body that is attached to a basal cuticular apodeme of the covering cuticle. The dendritic tubular bodies of the campaniform organs and tactile hairs terminate parallel to the surface in a right-angular bend, where they are attached to basal apodemes of the covering cuticle. The chemosensilla and tactile hairs have individual outer and inner sheath cells, but the campaniform organs have individual inner sheath cells only. The part of the ciliary dendritic segment that is encased by the dendritic sheath passes through an epidermal cell, often with several sensilla sharing the same epidermal cell in place of an outer sheath cell. The role of these sensilla during oviposition is discussed.

Ultrastructure of the larval antenna of Tenebrio molitor L. (Coleoptera: Tenebrionidae): structure of the trichoid and uniporous peg sensilla

1982 ◽  
Vol 60 (7) ◽  
pp. 1528-1544 ◽  
Author(s):  
J. W. Bloom ◽  
R. Y. Zacharuk ◽  
A. E. Holodniuk
Keyword(s):  
Tenebrio Molitor ◽  
Instar Larva ◽  
Terminal Segment ◽  
Sheath Cell ◽  
Dendrite Bundles ◽  
Tubular Body ◽  
Coleoptera Tenebrionidae ◽  
Sheath Cells

The antenna of the final instar larva of Tenebrio molitor has three segments. The reduced third (terminal) segment bears a large trichoid sensillum, four uniporous peg sensilla, one blunt tipped peg sensillum, and one papillate sensillum. The second segment bears a very large multiporous placoid sensillum, three uniporous peg sensilla, one blunt-tipped peg sensillum, and one papillate sensillum. The numbers and arrangement of these sensilla are usually stereotyped, but variations occur.The trichoid sensillum is a long, thin, unsocketed, aporous hair. It is innervated by two (sometimes one) bipolar neurones and has five sheath cells. The three sheath cells which distally delimit the large sensillar sinus have extremely elaborate microvillate inner borders. The uniporous peg sensillum is a short, stout, socketed peg with a single terminal pore. It is innervated by two to six (usually six) bipolar neurones. The dendrite from one of these always ends as a tubular body in the base, while the dendrites from the others extend to the tip of the peg. This sensillum has a small sensillar sinus and only four sheath cells. The inner sheath cell of both types of sensilla forms a cylindrical, nonlapped sleeve around the dendrite bundles.

SURVIVAL OF PUPAE OF MAMESTRA CONFIGURATA (LEPIDOPTERA: NOCTUIDAE) AND TWO OF ITS PARASITES IN UNTILLED AND TILLED SOIL

1984 ◽  
Vol 116 (2) ◽  
pp. 257-267 ◽  
Author(s):  
W. J. Turnock ◽  
R.J. Bilodeau
Keyword(s):  
Soil Type ◽  
Brassica Campestris ◽  
Total Mortality ◽  
Pupal Stage ◽  
Mamestra Configurata ◽  
Overwintering Mortality ◽  
Lepidoptera Noctuidae ◽  
Athrycia Cinerea

AbstractThe survival of Mamestra configurata Wlk. was determined from autumn and spring samples in 1973/74, 1980/81, and 1981/82 taken from unfilled and tilled portions of 12 fields of canola (Brassica campestris L. and B. napus L.). Survival from the pre-pupal stage in the autumn to post-diapause pupae in the spring varied from 2.9 to 56.5% in unfilled soil and from 0 to 25.4% in tilled soil. In untilled soil, the variations among fields in total mortality of M. configurata were related to parasitism by Banchus flavescens and to overwintering mortality. In tilled soil, overwintering mortality accounted for most of the variability in total mortality among fields. The percentage of mortality from injury to pupae, and their disappearance following tillage, greatly increased but this type of mortality did not account for much of the variability in total mortality. The disappearance of pupae following tillage was attributed to predation. In both untilled and tilled soils, the amount of overwintering mortality was related to the depth of accumulated snow, and mortality was lower in untilled soil because the stubble trapped more snow. The survival of M. configurata was not related to soil type, the type of tillage equipment, or the frequency of tillage. The number of adults emerging from untilled and tilled soil in one field were 2.58 and 0.27/m2 for M. configurata, 5.22 and 2.85/m2 for the parasite B. flavescens, and 4.46 and 3.60/m2 for the parasite Athrycia cinerea, indicating that the survival of the parasites was less affected by tillage than that of their host.Tillage may reduce the frequency and severity of outbreaks of M. configurata not only by increasing mortality but also by differentially affecting the survival of its main parasites.

DENSITY, PARASITISM, AND DISEASE INCIDENCE OF LARVAE OF THE BERTHA ARMYWORM, MAMESTRA CONFIGURATA WALKER (LEPIDOPTERA: NOCTUIDAE), IN MANITOBA, 1973–1986’

1988 ◽  
Vol 120 (5) ◽  
pp. 401-413 ◽  
Author(s):  
W. J. Turnock
Keyword(s):  
Disease Incidence ◽  
Population Declines ◽  
Mamestra Configurata ◽  
Trends Over Time ◽  
Nuclear Polyhedrosis ◽  
Physiographic Regions ◽  
River Plain ◽  
Swan River ◽  
Lepidoptera Noctuidae ◽  
Bertha Armyworm

AbstractPopulations of larvae of the bertha armyworm, Mamestra configurata Wlk., in four physiographic regions of Manitoba showed similar trends over time: a decline from the outbreak of 1971–1972 to very low densities in 1975–1977, an increase to a peak during the years 1979–1981, and a subsequent decline. During the period of peak larval populations, brief (1 or 2 years) outbreaks [at least some fields with > 20 larvae per square metre) occurred at five locations in two regions, the Swan River Plain and the Valley River Plain, but not in the Western Uplands or the Manitoba Lowlands. In the first two regions, larval densities rose rapidly (from < 1.6 to > 13.8/m2) in 1 year. Although the general trend of population density was similar, there were differences in density among and within regions, and in the timing, severity, and duration of peak populations. Two parasitoids (Banchus flavescens Cress., Athrycia cinerea (Coq.)) and two pathogens (a nuclear polyhedrosis virus (NPV) and fungi of the Entomophthorales) occurred regularly in larval populations. Of these, B. flavescens had the highest constancy among collections and may help to keep bertha armyworm populations at low densities. NPV was rarely found among larvae from low-density populations but appeared in all populations that reached outbreak levels. No single biotic agent could be associated with the population declines because of multiple parasitism and the difficulty in partitioning mortality when only a single sample could be taken. The rapid increase of bertha armyworm larvae from very low to outbreak levels in 1 year will prevent predictions of outbreaks from being based on larval densities in the preceding year.

EFFECT OF LATITUDE ON THE CRITICAL PHOTOPERIOD FOR DIAPAUSE INDUCTION IN THE BERTHA ARMYWORM, MAMESTRA CONFIGURATA (LEPIDOPTERA: NOCTUIDAE)

1983 ◽  
Vol 115 (8) ◽  
pp. 1039-1042 ◽  
Author(s):  
B. M. Hegdekar
Keyword(s):  
Temperature Regime ◽  
Diapause Induction ◽  
The Other ◽  
Fluctuating Temperature ◽  
Mamestra Configurata ◽  
Ambient Temperatures ◽  
Critical Photoperiod ◽  
Lepidoptera Noctuidae ◽  
H 20 ◽  
Bertha Armyworm

AbstractThe critical photoperiod for diapause induction in pupae of Mamestra configurata Walker in Manitoba was 16 h 06 min at Glenlea (49°38′ N), 16 h 20 min at Grandview (51°10′ N), and 16 h 42 min at Birch River (52°24′ N). The differences in cirtical photoperiods observed at Glenlea and Grandview were not significant. At least two different photoperiods exist, one in the Glenlea and Grandview areas and the other in the Birch River area. In the laboratory, the critical photoperiod was 13.5 h when larvae were exposed to a daily fluctuating temperature regime of 12 h at 25 °C and 12 h at 10 °C. Longer critical photoperiods found for the field populations may be related to the relatively low ambient temperatures to which the larvae were exposed in field cages.

EFFECTS OF AGE, EGG DEVELOPMENT, AND MATING ON CALLING BEHAVIOR OF THE BERTHA ARMYWORM, MAMESTRA CONFIGURATA WALKER (LEPIDOPTERA: NOCTUIDAE),

1986 ◽  
Vol 118 (12) ◽  
pp. 1221-1230 ◽  
Author(s):  
M.A. Howlader ◽  
G.H. Gerber
Keyword(s):  
Refractory Period ◽  
Egg Laying ◽  
Calling Behavior ◽  
Diel Periodicity ◽  
Egg Development ◽  
Mamestra Configurata ◽  
First Time ◽  
Lepidoptera Noctuidae ◽  
Bertha Armyworm

AbstractThe effects of age, egg development, and mating on calling behavior of the bertha armyworm, Mamestra configurata Walker, were studied at 20°C, 60% RH, and a 16-h L: 8-h D photoperiod. Most virgin females called and copulated for the first time during the second or third scotophase after emergence. The first copulation was 17.0 ± 0.2 h (mean±SE) long and was terminated within 1 h after lights off in the scotophase following the initiation of copulation. The ovaries contained the first chorionated eggs before the beginning of the second scotophase after emergence. The first egg laying occurred during the same scotophase in which the first copulation was terminated, i.e. scotophase three or four. Almost 75% of the eggs were laid by the end of the seventh scotophase after emergence. Mated females resumed calling after a refractory period of about 2 days. Once calling was resumed after copulation, most females laid eggs and called nightly, with egg laying occurring during the first 5–6 h and calling during the last 2–3 h of the scotophase. Mated females called for a shorter period during each scotophase than virgin females of the same age (1–3 h vs. 4–6 h). In virgin females, the diel periodicity of calling was advanced and the length of the daily calling period was increased with age until the seventh scotophase after emergence; thereafter, both remained relatively unchanged.

Fine structure of aesthetasc chemoreceptors in the crayfish Orconectes propinquus

1986 ◽  
Vol 64 (2) ◽  
pp. 392-399 ◽  
Author(s):  
Ann Jane Tierney ◽  
C. S. Thompson ◽  
D. W. Dunham
Keyword(s):  
Distal Portion ◽  
Main Body ◽  
Decapod Crustaceans ◽  
Orconectes Propinquus ◽  
Outer Sheath ◽  
Apical Pore ◽  
Cell Layers ◽  
Chemical Stimuli ◽  
Sensory Endings ◽  
Sheath Cells

The outer antennular flagella of decapod crustaceans bear chemoreceptive hairs called aesthetascs. In the crayfish Orconectes propinquus these sensilla are located ventrally on the 11–13 most distal segments of the outer flagella. Two clumps of 3–6 aesthetascs occur on each segment, giving a total of approximately 80 aesthetascs per outer flagellum. Aesthetascs are100–150 μm long and about 12 μm in diameter. Each has a single annulation 30 μm from the hair base. The sensilla arise from immovable sockets and are directed distally at a 45° angle to the main body of the antennule. Aesthetascs lack an apical pore. However, the distal portion of each sensillum has thin cuticular walls which are readily penetrated by dye; this is probably the site where chemical stimuli enter. In O. propinquus each aesthetasc is innervated by 40–110 sensory neurons. Each neuron gives rise to a dendrite that branches into two cilia (9 × 2 + 2 structure; 0.15–0.20 μm in diameter). No further branching of outer dendritic segments occurs and thus each aesthetasc contains 80–220 sensory endings. Within the antennule lumen the dendrites are surrounded by two sheath cell layers, an inner layer and an outer layer. The inner sheath cells ascend 50 μm into the aesthetasc lumen; the outer sheath cells terminate at the sensilla bases. The outer dendritic segments gradually taper in diameter and terminate 25 μm from the sensilla tips.

RESIDUES OF METHOMYL IN RAPE PLANT AND SEED FOLLOWING ITS APPLICATION FOR THE CONTROL OF BERTHA ARMYWORM, MAMESTRA CONFIGURATA (LEPIDOPTERA: NOCTUIDAE)

1972 ◽  
Vol 104 (11) ◽  
pp. 1745-1750 ◽  
Author(s):  
Y. W. Lee ◽  
R. J. Ford ◽  
H. McDonald ◽  
K. S. McKinlay ◽  
L. G. Putnam ◽  
...  
Keyword(s):  
Rape Seed ◽  
Mamestra Configurata ◽  
Rape Plant ◽  
Plant Samples ◽  
Three Samples ◽  
Lepidoptera Noctuidae ◽  
Bertha Armyworm

AbstractResidues of methomyl in rape plants and seed were determined after its application for bertha armyworm control. In one experiment application of 3 oz of methomyl per acre left 17 p.p.m. residue on the rape plants immediately after application. This level rapidly declined to 1.5, 1.0, 0.4, and 0.2 p.p.m. 1, 2, 5, and 9 days later, respectively, and no residue was detected (less than 0.02 p.p.m.) in seed harvested 22 days after application of the toxicant. Rape plant samples collected from several farms immediately after the application of 3 to 4 oz of methomyl per acre had 2.5 to 16 p.p.m. residues, indicating inefficient application of the insecticide in some cases. Analysis of rape seed samples collected from 36 farms showed little residue in three samples (0.02 to 0.03 p.p.m.) and none in 33, indicating that the use of methomyl for bertha armyworm control is not likely to contaminate rape seed with undesirable levels of residues.

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