Neurosecretory cells and their axon pathways in Culiseta inornata (Williston) (Diptera: Culicidae)

1971 ◽  
Vol 49 (6) ◽  
pp. 889-901 ◽  
Author(s):  
L. Burgess
Keyword(s):  
Adult Emergence ◽  
Neurosecretory Cells ◽  
Fourth Instar ◽  
Corpora Allata ◽  
Neurosecretory Material ◽  
Similar Form ◽  
Posterior Portion ◽  
Neurohaemal Organ ◽  
Culiseta Inornata ◽  
Intermediate Cells

Paired medial, intermediate, and anterior groups of neurosecretory cells are present in the protocerebrum of Culiseta inornata (Williston). The medial and intermediate cells seem to persist through larval, pupal, and adult stages; the anterior cells become inconspicuous about the time of adult emergence. Axons of the intermediate neurosecretory cells could not be traced for an appreciable distance, but axons of the medial cells could be traced to a neurohaemal organ on the aorta, and they appear to constitute the NCC I. Branches of the anterior-cell axons seem to constitute the NCC II, and other branches of these axons in fourth-instar larvae and young pupae can be traced into the ventral nerve chain. From the neurohaemal organ some neurosecretory axons pass into the oesophageal nerves, and the expanded posterior portion of each oesophageal nerve in adults may be a storage and release organ of neurosecretory material. A neurosecretory pathway can be traced from the neurohaemal organ to the corpora allata in adults; it is probably present also in larvae. Conspicuous neurosecretory axons of uncertain origin, which are distinct from the anterior-cell axons, can be traced from the protocerebrum through the circumoesophageal connectives and along the whole length of the ventral nerve chain in fourth-instar larvae; these axons are present, probably in a similar form, also in younger larvae, in pupae, and in newly emerged adults.

The Stomodaeal Nervous System, Neurosecretion, and Related Endocrine and Nervous Structures in Aedes aegypti (L.) (Diptera: Culicidae)

1964 ◽  
Vol 96 (1-2) ◽  
pp. 105-106 ◽  
Author(s):  
L. Burgess ◽  
J. G. Rempel
Keyword(s):  
Nervous System ◽  
Aedes Aegypti ◽  
Common Property ◽  
Neurosecretory Cells ◽  
Corpora Allata ◽  
Prothoracic Gland ◽  
Neurosecretory Material ◽  
Purple Colour ◽  
Aldehyde Fuchsin ◽  
The Common

This exhibit represents some portions of a study of the stomodaeal nervous system, neurosecretory cells, corpora allata, corpora cardiaca, and prothoracic gland cells in post-embryonic stages of Aedes aegypti (L.), the yellow fever mosquito. Some of these structures share the common property of being involved in the production of hormones.Mosquitoes were reared under standard conditions. Larvae, pupae and adults were fixed at timed intervals in histological fixatives. Sectioned specimens were stained in Gomori's aldehyde-fuchsin, Gomori's chrome-haematoxyh-phloxin and other stains. The aldehyde-fuchsin technique, which imparted a bright purple colour to neurosecretory material, was particularly useful. Vita1 staining with methylene blue was used to trace the stomodaeal nervous system

A Comparative Study of the Endocrine System of the Honey Bee Larvae under Normal and Experimental Conditions

1977 ◽  
Vol 32 (7-8) ◽  
pp. 637-642 ◽  
Author(s):  
G. S. Dogra ◽  
G. M. Ulrich ◽  
H. Rembold
Keyword(s):  
Honey Bee ◽  
Larval Instar ◽  
Endocrine System ◽  
Neurosecretory Cells ◽  
Corpora Allata ◽  
Neurosecretory Material ◽  
Experimental Conditions ◽  
Histological Techniques ◽  
Larval Stages ◽  
Queen Larvae

Abstract The endocrine system of the honey bee (Apis mellifera L.) has been studied morphologically through post-embryonic development with several histological techniques. Marked differences in the structure of the neurosecretory complex of queen and worker larvae have been observed during larval stages. In queen larvae, morphogenesis of the neurosecretory cells, their axons and the formation of the chiasma takes place during end of 2nd and beginning of 3rd, in the workers at beginning of 4th larval instar. Stainable neurosecretory material was found in queen larvae at the beginning, in worker larvae at the end of 4th instar. In early larval stages, the corpora allata are more active in the queen. During initial 3 - 5 days of larval development the gland volume is reduced in both castes. After 36 to 48 hours of endocrine retardation, the glands become active again. The same histological effects are found under experimental conditions, where worker larvae of 2nd instar were reared in the incubator on basic food, Royal Jelly and with topically applied juvenile hormone I.

EFFECTS OF ECDYSONES, JUVENILE HORMONE ANALOGS, AND 6-OXOOCTANOIC ACID ON THE DEVELOPMENT OF THE MOSQUITO, CULEX TARSALIS (DIPTERA: CULICIDAE)

1974 ◽  
Vol 106 (1) ◽  
pp. 79-85 ◽  
Author(s):  
P. I. Ittycheriah ◽  
M. S. Quraishi ◽  
E. P. Marks
Keyword(s):  
Juvenile Hormone ◽  
Topical Treatment ◽  
Adult Emergence ◽  
Fourth Instar ◽  
Culex Tarsalis ◽  
Juvenile Hormone Analog ◽  
Hormone Analog ◽  
High Doses ◽  
Hormone Analogs ◽  
Very High

AbstractEggs, larvae, and pupae of Culex tarsalis Coquillett were treated with ecdysones, juvenile hormone analogs, and 6-oxooctanoic acid. Effects of these agents on mortality, induction of supernumerary stages, and adult emergence were determined. Topical treatment of eggs with CRD9499 (a juvenile hormone analog), β-ecdysone, and 22-isoecdysone caused a reduction in adult emergence. Treatment of fourth-instar larvae with these chemicals not only induced mortality but also caused the formation of supernumerary intermediate stages. Larvae of C. tarsalis were very susceptible to CRD9499, but pupae were resistant. The ecdysones caused some mortality but only at very high doses and would thus be of little use as larvicides. 6-Oxooctanoic acid caused high rates of mortality at 0.001 M concentrations.

THE IMMATURE STAGES OF PTYCHOPTERA LENIS LENIS (DIPTERA: PTYCHOPTERIDAE) WITH NOTES ON THEIR BIOLOGY

1973 ◽  
Vol 105 (8) ◽  
pp. 1091-1099 ◽  
Author(s):  
I. D. Hodkinson
Keyword(s):  
Life Cycle ◽  
Water Depth ◽  
Adult Stage ◽  
Atmospheric Oxygen ◽  
Adult Emergence ◽  
Fourth Instar ◽  
Immature Stages ◽  
Experimental Conditions ◽  
Marginal Areas ◽  
Pharate Adult

AbstractThe four larval instars and the pupa of Ptychoptera lenis lenis Osten Sacken are described. Instars 2 to 4 are very similar morphologically but instar 1 is markedly different. Both a pharate pupal and a pharate adult stage were observed. Larvae are found in stagnant marginal areas of ponds where water depth does not exceed 4 cm and where benthic deposits of plant detritus exceed 8 cm. Fourth instar larvae, under experimental conditions, survived up to 45 days without contact with atmospheric oxygen but development was arrested. P. lenis has a 1 year life cycle with an extended adult emergence season from late May to the end of July.

Changes in cell number and activity of the corpora allata of the cockroach Diploptera punctata: a role for mating and the ovary

1984 ◽  
Vol 62 (11) ◽  
pp. 2178-2182 ◽  
Author(s):  
S. S. Tobe ◽  
N. Clarke ◽  
B. Stay ◽  
R. P. Ruegg
Keyword(s):  
Juvenile Hormone ◽  
Cell Number ◽  
Neurosecretory Cells ◽  
Corpora Allata ◽  
Surgical Removal ◽  
Gonotrophic Cycle ◽  
Biosynthetic Activity ◽  
Diploptera Punctata ◽  
Number Of Cells ◽  
Mated Female

The corpora allata (CA) of mated female Diploptera punctata showed an increase in cell number from 6000 cells/CA on the day of emergence to a maximum of about 9000 cells/CA by day 5. The number of cells per CA then declined and, by day 8, the CA was composed of about 6000 cells. In the normal mated animal, the previously established increase in biosynthetic activity of the CA correlated with the increase in number of cells in the CA. In virgin females no significant change in cell number was observed during this period and this correlates with the demonstrated low and constant rates of juvenile hormone (JH) biosynthesis. Following ovariectomy, however, an increase in cell number occurred (to 10 000 cells/CA) by day 5 and cell number remained elevated until at least day 8. Low rates of JH biosynthesis have been observed previously in ovariectomized females and thus the increase in cell number observed in these females is not accompanied by a corresponding increase in biosynthetic activity. The cell number of the CA in ovariectomized females was reduced by injection of 20-hydroxyecdysone. We propose that either mating or surgical removal of inhibitory signals from cerebral neurosecretory cells permits the proliferation of the cells of the CA. We also propose that factors from the ovary are responsible for both the initiation of the cycle of JH biosynthesis and the reduction of CA cell number at the end of the gonotrophic cycle.

The effect of feeding on the cerebral neurosecretory system of the adult male tsetse, Glossina austeni Newst

1978 ◽  
Vol 56 (9) ◽  
pp. 1988-1992 ◽  
Author(s):  
M. Grossman ◽  
K. G. Davey
Keyword(s):  
Adult Male ◽  
Neurosecretory Cells ◽  
Neurosecretory System ◽  
Neurosecretory Material ◽  
Corpus Cardiacum ◽  
Pars Intercerebralis ◽  
Corpora Cardiaca ◽  
Glossina Austeni ◽  
Effect Of Feeding

An analysis of the intensity of staining of the corpus cardiacum and of the neurosecretorty cells of the pars intercerebralis in 3-day-old fed or fasting adult male tsetse has revealed two periods of apparent release of neurosecretion. In fed males, stainable neurosecretion disappears from 14 of the 20 recognizable neurosecretory cells within 10 min of the termination of feeding. There is always less neurosecretory material in the corpora cardiaca of fed males. Secondly, there is an indication of a depletion of material from the cardiaca of both fed and fasted males at about 1700 hours EST.

Growth and development of larvae and adults of Tipula sacra Alexander (Insecta: Diptera) in a series of abandoned beaver ponds

1976 ◽  
Vol 54 (2) ◽  
pp. 266-284 ◽  
Author(s):  
G. Pritchard
Keyword(s):  
Growth Rate ◽  
Life History ◽  
Growth And Development ◽  
Adult Emergence ◽  
Head Capsule ◽  
Fourth Instar ◽  
Beaver Ponds ◽  
The Third ◽  
First Instar ◽  
Two Peaks

Collections of all stages of the crane fly, Tipula sacra have been made over a period of years from a series of abandoned beaver ponds in the Kananaskis Valley, Alberta. The growth of larvae was followed by head-capsule measurements and weights. Eggs hatch within a month; first-instar larvae grow rapidly and enter the second instar after a few weeks. The second instar may last for 3 months and the third instar usually lasts for 6 months, including the first winter. Most larvae spend almost a full year in the fourth instar and overwinter for a second time. However, there was much variation in growth rate within the population. Adult emergence curves were consistent in form in 4 years. Each spanned a period of just over 2 months, although individual adults lived for only a few days. These curves snowed two peaks, the second of which contained 15–20% of the year's emergents. These two groups may represent different cohorts that have grown at different rates, suggesting that the life history may be semivoltine or univoltine. The sex ratio changes from about 1:1 in the third instar to 2:1 in favor of males in the late fourth instar, pupa, and adult.

A comparison of the juvenilizing effect of six juvenile hormone-like activity compounds on Egyptian Culex pipiens L.

1980 ◽  
Vol 95 (1) ◽  
pp. 203-212 ◽  
Author(s):  
N. L. Kelada ◽  
I. A. Gaaboub ◽  
I. A. Rawash
Keyword(s):  
Sex Ratio ◽  
Juvenile Hormone ◽  
Culex Pipiens ◽  
Adult Stage ◽  
Adult Emergence ◽  
Time Lapse ◽  
Fourth Instar ◽  
Gonotrophic Cycle ◽  
Juvenilizing Effect

SummaryTests were made to determine the juvenilizing effects of TH6040, JH-25, Altosid, Altozar, ZR-777 and ZR-619 on Culex pipiens L. using the IC50 value (dose to inhibit the emergence of 50% of adults) as a criterion. The descending order of activity was Altosid, TH6040, Altozar, ZR-777, JH-25 and ZR·619. Insignificant prolongations were recorded in the larval or pupal durations except in the case of TH6040 (Dimilin). The time lapse from larval treatment (early fourth instar) to adult emergence was prolonged by about 18·7% following treatment with 0·0001–0·1 μg/ml.Juvenilizing effects of the tested compounds applied to the early fourth instar extended to the adult stage of Culex pipiens L. and affected the duration of the first gonotrophic cycle. The concentrations of TH6040, JH-25, Altosid, Altozar, ZR-777 and ZR-619 tested caused prolongation of the time between emergence and first oviposition by about 20–50% (at 0·0001–0·1 μg/ml), 3–26% (at 0·001–5μg/ml), 0–15% (at 0·1 × 10-8–0·001 μg/ml), 3-–23% (at 0·1 × 10-8–0·001 μg/ml), 9–27% (at 0·1 × 10-7–0·01 μg/ml), and 11–32% (at 0·1 × 10-7–0·01 μg/ml), respectively.The results obtained indicated that the sex ratio of C. pipiensL. changed progressively in all treatments but with an inconsistent trend according to the concentration of each compound. This conclusion provides further evidence on the effect of juvenile hormone-like activity compounds on adults emerging from treated larvae. The numbers of females produced were increased by about 15–30%, 9–27%, 1–35%, 1–38%, 6–44% and 31–71% after treatment with 0·0001–0·1 μg TH6040, 0·001–5μg JH-25, 0·1x 10-8–0·001 μg Altosid, 0·1 x 10-8–0·001 μg Altozar, 0·1 x lO-7–O·Ol μg ZR-777 and 0·01 × 10-7–0·01 μg ZR-619‘sol;ml, respectively.

THE STOMODAEAL NERVOUS SYSTEM, THE NEUROSECRETORY SYSTEM, AND THE GLAND COMPLEX IN AEDES AEGYPTI (L.) (DIPTERA: CULICIDAE)

1966 ◽  
Vol 44 (4) ◽  
pp. 731-765 ◽  
Author(s):  
L. Burgess ◽  
J. G. Rempel
Keyword(s):  
Nervous System ◽  
Aedes Aegypti ◽  
Neurosecretory Cells ◽  
Sensory Nerves ◽  
Corpora Allata ◽  
Prothoracic Gland ◽  
Neurosecretory System ◽  
Endocrine Gland ◽  
Adult Females ◽  
The Central Nervous System

The stomodaeal nervous system in Aedes aegypti (L.) possesses a frontal, a hypocerebral, and two ventricular ganglia. It innervates parts of the alimentary tract and some muscles of ingestion, and it has associated with it certain motor nerves from the central nervous system, and sensory nerves. In larvae these sensory nerves originate from tactile head hairs, and from sensilla on the epipharyngeal apparatus. The neurosecretory system is generally similar to that in other insects. The pars intercerebralis contains three paired groups of neurosecretory cells, with axons from one pair leading to the dorsal mass, a structure fused to the hypocerebral ganglion. Evidence suggests that the dorsal mass functionally corresponds to part of the corpus cardiacum of other insects. However, what seem to be cardiacum cells are located some distance away in two groups in the endocrine gland complex in the thorax. The corpora allata, also contained in this complex, can first be recognized as distinct organs early in the third instar. In the corpora allata of adult females, cell division and an increase in the amount of cytoplasm occur soon after emergence, rather than after a blood meal. When adult females are about 1 day old, vacuoles begin to develop in the corpora allata. Cells in the gland complex corresponding to the prothoracic gland cells begin to histolyze in the pupa, and most of them are completely broken down before adults are 1 day old.

WEIGHT AND DEVELOPMENT TIME OF DIFFERENT STADIA OF MOSQUITOES REARED AT VARIOUS CONSTANT TEMPERATURES

1967 ◽  
Vol 99 (9) ◽  
pp. 986-993 ◽  
Author(s):  
R. A. Brust
Keyword(s):  
Weight Gain ◽  
Development Time ◽  
Adult Stage ◽  
Larval Instar ◽  
Dry Weight ◽  
Specific Weight ◽  
Fourth Instar ◽  
Rearing Temperature ◽  
Males And Females ◽  
Culiseta Inornata

AbstractDevelopment time decreased with each increase in rearing temperature in Aedes vexans, A. nigromaculis, and Culiseta inornata until the optimum survival temperature was reached. The optimum survival temperature for A. vexans was 26.5 °C, for A. nigromaculis 21 °C, and for C. inornata 21 °C. Dry weight gain per hour in female larvae was greater than in male larvae in all three species, at all temperatures. There was a significant reduction in weight in each larval instar, pupal, and adult stage, with each 5.5 °C increase in rearing temperature. Times to larval–pupal ecdysis and pupal–adult ecdysis were the same for males and females of A. nigromaculis at all developmental temperatures tested. Time to larval–pupal ecdysis and pupal–adult ecdysis in A. vexans and C. inornata occurred 1 to several days later in females, depending upon the developmental temperature. In all three species the duration of the fourth instar was longest and the specific weight gain greatest.

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