Activity and mating competitiveness of γHCH/dieldrin resistant and susceptible male and virgin female Anopheles gambiae and An.stephensi mosquitoes, with assessment of an insecticide-rotation strategy

Abstract Background Marking mosquitoes is vital for mark-release-recapture and many laboratory studies, but their small size precludes the use of methods that are available for larger animals such as unique identifier tags and radio devices. Fluorescent dust is the most commonly used method to distinguish released individuals from the wild population. Numerous colours and combinations can be used, however, dust sometimes affects longevity and behaviour so alternatives that do not have these effects would contribute substantially. Rhodamine B has previously been demonstrated to be useful for marking adult Aedes aegypti males when added to the sugar meal. Unlike dust, this also marked the seminal fluid making it possible to detect matings by marked males in the spermatheca of females. Here, marking of Anopheles gambiae sensu stricto with rhodamine B and uranine was performed to estimate their potential contribution. Methods Two fluorescent markers, rhodamine B and uranine, were dissolved in sugar water and fed to adult An. gambiae. Concentrations that are useful for marking individuals and seminal fluid were determined. The effects on adult longevity, the durability of the marking and detection of the marker in mated females was determined. Male mating competitiveness was also evaluated.Results Rhodamine B marking in adults is detectable for at least three weeks, however uranine marking declines with time and at low doses can be confused with auto-fluorescence. Both can be used for marking seminal fluid which can be detected in females mated by marked males, but, again, at low concentrations uranine-marking is more easily confused with the natural fluorescence of seminal fluid. Neither dye affected mating competitiveness.Conclusions Both markers tested could be useful for field and laboratory studies. Their use has substantial potential to contribute to a greater understanding of the bio-ecology of this important malaria vector. Rhodamine B has the advantage that it appears to be permanent and is less easily confused with auto-fluorescence. The primary limitation of both methods is that sugar feeding is necessary for marking and adults must be held for at least 2 nights to ensure all individuals are marked whereas dusts provide immediate and thorough marking.

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Fluorescent markers rhodamine B and uranine for Anopheles gambiae adults and matings

10.21203/rs.2.19818/v2 ◽

2020 ◽

Author(s):

Erica i Aviles ◽

Rachel D Rotenberry ◽

C Matilda Collins ◽

Ellen M Dotson ◽

Mark Q Benedict

Keyword(s):

Anopheles Gambiae ◽

Rhodamine B ◽

Seminal Fluid ◽

Adult Longevity ◽

Potential Contribution ◽

Laboratory Studies ◽

Unique Identifier ◽

Mating Competitiveness ◽

Fluorescent Markers ◽

Auto Fluorescence

Abstract Background Marking mosquitoes is vital for mark-release-recapture and many laboratory studies, but their small size precludes the use of methods that are available for larger animals such as unique identifier tags and radio devices. Fluorescent dust is the most commonly used method to distinguish released individuals from the wild population. Numerous colors and combinations can be used, however, dust sometimes affects longevity and behavior so alternatives that do not have these effects would contribute substantially. Rhodamine B has previously been demonstrated to be useful for marking adult Aedes aegypti males when added to the sugar meal. Unlike dust, this also marked the seminal fluid making it possible to detect matings by marked males in the spermatheca of females. Here we evaluate marking in Anopheles gambiae s. s. with rhodamine B and uranine to estimate their potential contribution. Methods Two fluorescent markers, rhodamine B and uranine, were dissolved in sugar water and fed to adult Anopheles gambiae. Concentrations that are useful for marking individuals and seminal fluid were determined. The effects on adult longevity, the durability of the marking and detection of the marker in mated females was determined. We also evaluated effects on mating competitiveness. Results Rhodamine B marking in adults is detectable for at least three weeks, however uranine marking declines with time and at low doses can be confused with auto-fluorescence. Both can be used for marking seminal fluid which can be detected in females mated by marked males, but, again, at low concentrations uranine-marking is more easily confused with the natural fluorescence of seminal fluid. Neither dye affected mating competitiveness. Conclusions Both markers tested could be useful for field and laboratory studies. Their use has substantial potential to contribute to a greater understanding of the bio-ecology of this important malaria vector. Rhodamine B has the advantage that it appears to be permanent and is less easily confused with auto-fluorescence. The primary limitation of both methods is that sugar feeding is necessary for marking and adults must be held for at least 2 nights to ensure all individuals are marked whereas dusts provide immediate and thorough marking.

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Anopheles gambiae (s.l.) exhibit high intensity pyrethroid resistance throughout Southern and Central Mali (2016–2018): PBO or next generation LLINs may provide greater control

10.21203/rs.2.24378/v4 ◽

2020 ◽

Author(s):

Arthur Sovi ◽

Chitan Keita ◽

Youssouf Sinaba ◽

Abdourhamane Dicko ◽

Ibrahim Traore ◽

...

Keyword(s):

Anopheles Gambiae ◽

High Intensity ◽

Pyrethroid Resistance ◽

Fold Increase ◽

Malaria Vectors ◽

Effective Control ◽

Pirimiphos Methyl ◽

Anopheles Gambiae S.L ◽

Agricultural Use ◽

Rotation Strategy

Abstract Background: Millions of pyrethroid LLINs have been distributed in Mali during the past 20 years which, along with agricultural use, has increased the selection pressure on malaria vector populations. This study investigated pyrethroid resistance intensity and susceptible status of malaria vectors to alternative insecticides to guide choice of insecticides for LLINs and IRS for effective control of malaria vectors. Methods: For 3 years between 2016 and 2018, susceptibility testing was conducted annually in 14–16 sites covering southern and central Mali. Anopheles gambiae (s.l.) were collected from larval sites and adult mosquitoes exposed in WHO tube tests to diagnostic doses of bendiocarb (0.1%) and pirimiphos-methyl (0.25%). Resistance intensity tests were conducted using CDC bottle bioassays (2016–2017) and WHO tube tests (2018) at 1×, 2×, 5×, and 10× the diagnostic concentration of permethrin, deltamethrin and alpha-cypermethrin. WHO tube tests were conducted with pre-exposure to the synergist PBO followed by permethrin or deltamethrin. Chlorfenapyr was tested in CDC bottle bioassays at 100 µg active ingredient per bottle and clothianidin at 2% in WHO tube tests. PCR was performed to identify species within the An. gambiae complex. Results: In all sites An. gambiae (s.l.) showed high intensity resistance to permethrin and deltamethrin in CDC bottle bioassay tests in 2016 and 2017. In 2018, the WHO intensity tests resulted in survivors at all sites for permethrin, deltamethrin and alpha-cypermethrin when tested at 10× the diagnostic dose. Across all sites mean mortality was 33.7% with permethrin (0.75%) compared with 71.8% when pre-exposed to PBO (4%), representing a 2.13-fold increase in mortality. A similar trend was recorded for deltamethrin. There was susceptibility to pirimiphos-methyl, chlorfenapyr and clothianidin in all surveyed sites, including current IRS sites in Mopti Region. An. coluzzii was the primary species in 4 of 6 regions. Conclusions: Widespread high intensity pyrethroid resistance was recorded during 2016–2018 and is likely to compromise the effectiveness of pyrethroid LLINs in Mali. PBO or chlrofenapyr LLINs should provide improved control of An. gambiae (s.l.). Clothianidin and pirimiphos-methyl insecticides are currently being used for IRS as part of a rotation strategy based on susceptibility being confirmed in this study.

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Basal Lamina Formation in DMBA Induced Mammary Carcinoma

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100080109 ◽

1977 ◽

Vol 35 ◽

pp. 534-535

Author(s):

I. Russo ◽

J. Saby ◽

J. Russo

Keyword(s):

Mammary Carcinoma ◽

Virgin Female ◽

Mammary Glands ◽

Sesame Oil ◽

Female Rats ◽

Ultrastructural Changes ◽

Post Inoculation ◽

Intermediate Type ◽

Sprague Dawley ◽

Intercellular Spaces

It has been previously demonstrated that DMBA-induced rat mammary carcinoma originates in the terminal end bud (TEB) of the mammary gland by proliferation of intermediate type cells (1). The earliest lesion identified is the intraductal proliferation (IDP), which gives rise to intraductal carcinomas. These evolve to cribriform, papillary and comedo types (2). In the present work, we report the ultrastructural changes that take place in the IDP for the formation of a cribriform pattern.Fifty-five-day-old Sprague Dawley virgin female rats were inoculated intra- gastrically with 20 mg 7,12-dimethylbenz(a)anthracene (DMBA) in 1 ml sesame oil. Non-inoculated, age-matched females were used as controls. Mammary glands from both control and experimental rats were removed weekly from the time of inoculation until 86 days post-inoculation. The glands were fixed and processed for electron microscopy (2).The first change observed in IDP's was the widening of intercellular spaces and the secretion of an electron dense material into these spaces (Fig. 1).

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Ultrastructural Changes in the Mammary Epithelial Cell Population During Neoplastic Development Induced by A Chemical Carcinogen.

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100091238 ◽

1976 ◽

Vol 34 ◽

pp. 250-251 ◽

Cited By ~ 2

Author(s):

J. Russo ◽

W. Isenberg ◽

M. Ireland ◽

I.H. Russo

Keyword(s):

Mammary Gland ◽

Cell Population ◽

Virgin Female ◽

Histological Change ◽

Mammary Epithelial ◽

Female Rats ◽

Ultrastructural Changes ◽

Post Inoculation ◽

Chemical Carcinogen ◽

Sprague Dawley

The induction of rat mammary carcinoma by the chemical carcinogen DMBA is used as a model for the study of the human disease (1). We previously described the histochemical changes that occur in the mammary gland of DMBA treated animals before the earliest manifested histological change, the intraductal proliferation (IDP), was observed (2). In the present work, we demonstrate that a change in the stable cell population found in the resting mammary gland occurs after carcinogen administration.Fifty-five day old Sprague-Dawley virgin female rats were inoculated intragastrically with 20mg of 7,12-dimethylbenz(a)anthracene (DMBA) in 1ml sesame oil. Non-inoculated, age-matched females were used as controls. Mammary glands from control and inoculated rats were removed weekly from the time of inoculation until 60 days post-inoculation. For electron microscopy, the glands were immersed in Karnovsky's fixative, post-fixed in 1% OsO4, dehydrated, and embedded in an Epon-Araldite mixture. Thick (lμ) sections were stained with 1% toluidine blue and were used for selecting areas for ultrastructural study.

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The brain structure and neurosecretory cells of noctuid moth Anadevidia peponis: Noctuidae

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100159722 ◽

1990 ◽

Vol 48 (3) ◽

pp. 436-437

Author(s):

M. Sato ◽

Y. Ogawa ◽

M. Sasaki ◽

T. Matsuo

Keyword(s):

Biological Clock ◽

Virgin Female ◽

Basic Structure ◽

Fixed Time ◽

Neurosecretory Cells ◽

Nerve Cells ◽

Noctuid Moth ◽

The Right ◽

20 Nm ◽

The Brain

A virgin female of the noctuid moth, a kind of noctuidae that eats cucumis, etc. performs calling at a fixed time of each day, depending on the length of a day. The photoreceptors that induce this calling are located around the neurosecretory cells (NSC) in the central portion of the protocerebrum. Besides, it is considered that the female’s biological clock is located also in the cerebral lobe. In order to elucidate the calling and the function of the biological clock, it is necessary to clarify the basic structure of the brain. The observation results of 12 or 30 day-old noctuid moths showed that their brains are basically composed of an outer and an inner portion-neural lamella (about 2.5 μm) of collagen fibril and perineurium cells. Furthermore, nerve cells surround the cerebral lobes, in which NSCs, mushroom bodies, and central nerve cells, etc. are observed. The NSCs are large-sized (20 to 30 μm dia.) cells, which are located in the pons intercerebralis of the head section and at the rear of the mushroom body (two each on the right and left). Furthermore, the cells were classified into two types: one having many free ribosoms 15 to 20 nm in dia. and the other having granules 150 to 350 nm in dia. (Fig. 1).

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EFFECT OF NICOTINE ON SEXUAL BEHAVIOUR OF MUTANT STRAIN (CURLED) OF DROSOPHILLA MELANOGASTER

FLORA AND FAUNA ◽

10.33451/florafauna.v24i1pp113-118 ◽

2018 ◽

Vol 24 (1) ◽

Author(s):

SHAMIM AKHTER CHOUDHARY

Keyword(s):

Mutant Strain ◽

Sexual Behaviour ◽

Virgin Female ◽

P Value ◽

Pooled Data ◽

Mating Latency ◽

Males And Females ◽

Food Medium ◽

Food Media ◽

Dose Dependent

In the present study, an attempt was made to study the effect of plant extract on Sexual behaviour of Mutant Strain (Curled) of Drosophila melanogaster. The LC50 has been estimated with 1% of the food media. The virgin females and males were isolated and fed with normal food media for three days. Then sub-lethal concentrations of 0.625 μl / 100 ml food, 1.2 μl /100 ml food, 2.5μl /100 / food of nicotine were mixed in food medium and allowed in flies to feed for two days. Then appropriate combination of untreated / treated males and females were introduced into the mating chamber. Courtship latency, mating latency and copulation duration were studied. After observation of the behaviour, mated flies were allowed to produce progeny. The sexual behaviour of bachelor male and virgin female obtained in the progeny was also studied. The pooled data were analyzed by student t-test and the result indicates p-value significant at 0.05 levels. The courtship latency was affected by in treatment but it is neither dose dependent nor sex dependent.

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