Spine number on the pecten and comb of fourth instar larvae of Aedes aegypti L. differences between two populations

Genetica ◽  
1990 ◽  
Vol 46 (1) ◽  
pp. 33-44 ◽  
Author(s):  
R. J. Wood
Keyword(s):  
Aedes Aegypti ◽  
Fourth Instar ◽  
Two Populations ◽  
Spine Number

ENCAPSULATION OF RHABDITOID NEMATODES IN MOSQUITOES

1962 ◽  
Vol 40 (7) ◽  
pp. 1269-1275 ◽  
Author(s):  
Joan F. Bronskill
Keyword(s):  
Aedes Aegypti ◽  
Endemic Species ◽  
Body Cavity ◽  
Fourth Instar ◽  
The Body ◽  
Histological Structure ◽  
Adult Tissue ◽  
Defence Reaction ◽  
Blood Sinus

In third and fourth instar larvae of Aedes aegypti (L.), juveniles of the rhabditoid, DD136, penetrate the blood sinus and cardial epithelium of the proventriculus to enter the body cavity of the host, where they complete their development. By 5 hours, a thick capsule developed about many of the ensheathed immature adults of DD136 within the body cavity of A. aegypti larvae. This rapid defence reaction of the mosquito to DD136, which has both a melanin and a cellular manifestation, occurs both in the exotic mosquito A. aegypti and in the two endemic species tested, Aedes stimulans (Walker) and Aedes trichurus (Dyar). The resistance of A. stimulans to an endemic rhabditoid, possibly of the Diplogasteridae, is also similar. The histological structure of the capsule is not affected during metamorphosis in A. aegypti; however, during histogenesis of adult tissue displacement and (or) distortion of some tissues and organs may be caused by the presence of the capsule within the host's body cavity. The activity of the adult A. aegypti is normal when this distortion or displacement is minor. Though usually encapsulated DD136 are retained within the body cavity of A. aegypti during metamorphosis, sometimes they are partially or completely expelled from the host's body cavity at the time of molting.

Evidence for Na+/H+ and Cl-/HCO3- Exchanges During Independent Sodium and Chloride Uptake by the Larva of the Mosquito Aedes Aegypti (L.)

1971 ◽  
Vol 54 (1) ◽  
pp. 19-27 ◽  
Author(s):  
R. H. STOBBART
Keyword(s):  
Aedes Aegypti ◽  
Fourth Instar ◽  
Organic Ions ◽  
Chloride Uptake ◽  
Ionic Movements

1. Ionic movements into and out of the starved salt-depleted fourth instar larvae of Aëdes aegypti have been studied during independent uptake of Na+ and Cl-. 2. About 33% of the Na+ taken up from Na2SO4 is balanced electrically by a loss of K+, about 49% is exchanged for H+, and about 17.5% is accompanied by SO4-2. 3. About 36% of the Cl- taken up from KCl is presumably balanced electrically by a loss of unknown and possibly organic ions, about 41% is exchanged for HCO3- (and possibly OH-) and about 23% is accompanied by K+.

scholarly journals Aedes aegypti survival in the presence of Toxorhynchites violaceus (Diptera: Culicidae) fourth instar larvae

2011 ◽  
Vol 28 (4) ◽  
pp. 538-540 ◽  
Author(s):  
Daniel S Albeny ◽  
Gustavo F Martins ◽  
Mateus R Andrade ◽  
Rodrigo F Krüger ◽  
Evaldo F Vilela
Keyword(s):  
Aedes Aegypti ◽  
Fourth Instar

The Bionomics of an African Megarhinus (Dipt., Culicidae) and its possible use in Biological Control

1951 ◽  
Vol 42 (2) ◽  
pp. 355-370 ◽  
Author(s):  
J. Muspratt
Keyword(s):  
Biological Control ◽  
Life Cycle ◽  
Aedes Aegypti ◽  
Pacific Islands ◽  
Natural Habitat ◽  
Fourth Instar ◽  
Medium Size ◽  
Sugar Solution ◽  
First Instar ◽  
Annual Range

Living specimens of Megarhinus brevipalpis were transported from southern Natal to Johannesburg to establish an insectary-bred colony. The natural habitat of these predatory mosquitos consisted of small isolated patches of sub-tropical forest, in which the rainfall is 40–50 ins. (102–127 cm.) with a mean winter temperature of 64°F. (17·7°C.) and an annual range of 27°–33°F. (15°–18°C). The breeding places were leaf axils of Strelitzia nicolai (a plant resembling a wild banana), small rot holes in trees and larger ones in Strelitzia stumps. The larvae were collected from leaf axils with an apparatus consisting of a rubber bulb to which were attached lengths of glass and rubber tubing.The insectary was a room 9 ft.×8 ft. 6 ins. and 9 ft. high which was kept at tropical heat and humidity. Mating of the adults was observed, copulation being effected while at rest or in flight. Oviposition was usually accomplished in flight but also while at rest on the surface of the water. In the summer time two females, which were tested, laid about 85 eggs each during the month following emergence from the pupa, six or seven days elapsing after emergence before the first oviposition. In the middle of the winter, oviposition (with later generations) became very irregular in spite of the temperature and humidity remaining constant. The adults, which were comparable to those of the natural habitat, were fed on sugar solution, honey and fruit juice. One bred out as a gynandromorph.When given an abundant supply of larvae of laboratory bred Aëdes aegypti, the life-cycle of M. brevipalpis was normally : egg (incubation), less than two days ; larva, 11–20 days (average 14·5 days) ; pupa, five days. This does not include a small number of exceptional cases in which the life as a fully grown larva was abnormally prolonged (in one case nearly four months) for reasons which are not absolutely clear. The larvae killed from 100 to 200 or more Aëdes larvae during the normal larval life, but many of these were not eaten when the brevipalpis were in the late fourth instar. By a special technique they were also induced to eat dead tissues including minced pork brawn, minced maggots and minced flies. Except for the latter these were not satisfactory foods although there was slow development.Fourth-instar larvae were kept out of water for three to four weeks (without food), in a damp atmosphere, and afterwards when fed most of them developed normally, but pupation was sometimes suspended for a considerable time. They have been sent by post (out of water) in tubes with damp cotton wool and filter paper.The egg differed from that of other Megarhinus species in having a crown of projections at one end with a cup-like structure in the centre. The exochorion had roughly hexagonal cells but without numerous tubercles as in other species.First-instar larvae remained in the egg-shell after hatching when the eggs-were out of water but on a damp surface and in a saturated atmosphere. They survived like this for up to six days or about the same time as the larvae survived in tap water if there was no food. When liberated in water the head of the first-instar larva was comparatively small with the mouth parts folded in. Within two hours of liberation in water the head enlarged considerably and the mouth parts came into position ; the larva was then ready to catch its Culicine prey. When in water containing dead leaves, these larvae survived from a few days to over four weeks and some grew to the third instar without any Culicine food.Cannibalism was investigated. Fourth-instar larvae did not attack each other readily ; they devoured smaller larvae of their own species and small to medium size larvae resorted to cannibalism, particularly in the absence of Culicine prey. There was evidence that fourth-instar Aëdes aegypti occasionally ate first-instar Megarhinus.The discussion traces attempts which have been made in certain Pacific islands, notably Hawaii and Fiji, to use Megarhines for biological control of disease-carrying mosquitos. M. brevipalpis has a shorter life-cycle than the species introduced into these islands and the conclusion reached is that laboratory breeding, to enable large numbers to be released in certain areas, would be a suitable adjunct to a programme of general control, in this part of the world. Airmail consignments of larvae are being sent to Hawaii with the object of starting a laboratory colony there.

scholarly journals Accelerating the Morphogenetic Cycle of the Viral Vector Aedes aegypti Larvae for Faster Larvicidal Bioassays

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
José Domingos Fontana ◽  
Rafael Lopes Ferreira ◽  
Tatiana Zuccolotto ◽  
Cibelle de Borba Dallagassa ◽  
Leonardo Pellizzari Wielewski ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Room Temperature ◽  
Food Source ◽  
Viral Vector ◽  
Low Cost ◽  
Mosquito Species ◽  
Larval Growth ◽  
Fourth Instar ◽  
Coconut Water ◽  
Last Stage

Any bioassay to test new chemically synthesized larvicides or phytolarvicides against Culicidae and more harmful mosquito species, such as Aedes aegypti and Aedes albopictus, which specifically transmit dengue, yellow fever, chikungunya viral fevers as well as Zika virus, or Anopheles gambiae, a vector for malaria and philariasis, requires thousands of well-developed larvae, preferably at the fourth instar stage. The natural morphogenetic cycle of Aedes spp., in the field or in the laboratory, may extend to 19 days at room temperature (e.g., 25°C) from the first permanent contact between viable eggs and water and the last stage of larval growth or metamorphosis into flying adults. Thus, accelerated sequential molting is desirable for swifter bioassays of larvicides. We achieved this goal in Aedes aegypti with very limited strategic and low-cost additions to food, such as coconut water, milk or its casein, yeast extract, and to a lesser extent, glycerol. The naturally rich coconut water was excellent for quickly attaining the population of instar IV larvae, the most advanced one before pupation, saving about a week, for subsequent larvicidal bioassays. Diluted milk, as another food source, allowed an even faster final ecdysis and adults are useful for mosquito taxonomical purpose.

Frequency-dependent prey selection by larvae of Toxorhynchites splendens (Diptera: Culicidae)

1996 ◽  
Vol 86 (6) ◽  
pp. 633-639 ◽  
Author(s):  
D. Dominic Amalraj ◽  
P. K. Das
Keyword(s):  
Aedes Aegypti ◽  
Foraging Behaviour ◽  
Anopheles Stephensi ◽  
Prey Size ◽  
Prey Selection ◽  
Fourth Instar ◽  
Frequency Dependent ◽  
Size Selection ◽  
The Stability

AbstractThe foraging behaviour of frequency-dependent prey selection by larval instars of Toxorhynchites splendens (Wiedemann) was studied in the laboratory. Prey size selection (second vs fourth instars of Aedes aegypti Linnaeus or Anopheles stephensi Liston) by third and fourth instar predators was frequency-dependent. However, in the case of second instar predators, prey size selection was not frequency-dependent and the predator preferred second instar to fourth instar prey. When offered second instars of Aedes aegypti and Anopheles stephensi the preference for one species over the other was frequency-dependent in all the three predator instars. The role of frequency-dependent prey selection in the stability of prey—predator interaction at low equilibrium levels is discussed.

Development of the lateral palatal brush in larvae of Aedes aegypti (L.) (Diptera: Culicidae)

1990 ◽  
Vol 68 (7) ◽  
pp. 1454-1467 ◽  
Author(s):  
K. M. Fry ◽  
S. B. McIver
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Golgi Apparatus ◽  
Aedes Aegypti ◽  
Rough Endoplasmic Reticulum ◽  
Light And Electron Microscopy ◽  
Fourth Instar ◽  
Muscle Fibres ◽  
Final Length

Light and electron microscopy were used to observe development of the lateral palatal brush in Aedes aegypti (L.) larvae. Development was sampled at 4-h intervals from second- to third-instar ecdyses. Immediately after second-instar ecdysis, the epidermis apolyses from newly deposited cuticle in the lateral palatal pennicular area to form an extensive extracellular cavity into which the fourth-instar lateral palatal brush filaments grow as cytoplasmic extensions. On reaching their final length, the filaments deposit cuticulin, inner epicuticle, and procuticle sequentially on their outer surfaces. The lateral palatal crossbars, on which the lateral palatal brush filaments insert, form after filament development is complete. At the beginning of development, the organelles involved in plasma membrane and cuticle production are located at the base and middle of the cells. As the filament rudiments grow, most rough endoplasmic reticulum, mitochondria, and Golgi apparatus move to the apex of the epidermal cells and into the filament rudiments. After formation of the lateral palatal brush filaments and lateral palatal crossbars, extensive organelle breakdown occurs. Lateral palatal brush formation is unusual in that no digestion and resorption of old endocuticle occurs prior to deposition of new cuticle. No mucopolysaccharide secretion by the lateral palatal brush epidermis was observed, nor were muscle fibres observed to attach to the lateral palatal crossbars, as has been suggested by other workers.

scholarly journals Hyalodendrins A and B, New Decalin-Type Tetramic Acid Larvicides from the Endophytic Fungus Hyalodendriella sp. Ponipodef12

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 114 ◽  
Author(s):  
Ziling Mao ◽  
Weixuan Wang ◽  
Ruixue Su ◽  
Gan Gu ◽  
Zhi Long Liu ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Larvicidal Activity ◽  
Endophytic Fungus ◽  
Spectroscopic Data ◽  
Lethal Dose ◽  
Chemical Conversion ◽  
Fourth Instar ◽  
Tetramic Acid ◽  
Median Lethal Dose ◽  
New Compounds

Two new decalin/tetramic acid hybrid metabolites, hyalodendrins A (1) and B (2) were isolated from plant endophytic fungus Hyalodendriella sp. Ponipodef12. The structures of the new compounds were elucidated by analysis of the spectroscopic data, including NMR, HRMS and ECD, and by chemical conversion. Compounds 1 and 2 were phomasetin analogues, and both showed potent larvicidal activity against the fourth-instar larvae of Aedes aegypti with the median lethal dose (LC50) values of 10.31 and 5.93 μg/mL, respectively.

Behavior of Aedes aegypti (L.) larvae and pupae in direct-current electric fields

1971 ◽  
Vol 49 (5) ◽  
pp. 581-586 ◽  
Author(s):  
D. F. Riordan
Keyword(s):  
Aedes Aegypti ◽  
Electric Fields ◽  
Direct Current ◽  
Aquatic Organisms ◽  
Fourth Instar ◽  
Larval Instars ◽  
Electrical Fields ◽  
First Instar ◽  
Field Strengths

Larval instars and pupae of Aedes aegypti (L.) were subjected to direct-current electrical fields of 0.1–13.44 V per centimeter and 0.0106–1.06 mA per square centimeter. In general, when field strengths reached a certain level more larvae were attracted to the cathode than to the anode. As field strengths were increased, this reaction was reversed and then as they were further increased the cathode again exerted the greater attraction. Maximum numbers attracted to either anode in 20 min were first instar 80%, second instar 62%, third instar 86%, fourth instar 72%, and pupae 82%. No explanation can be given for the changes in polarity of attraction and it has no counterpart in other work recording the behavior of aquatic organisms (mainly fish) in electrical fields, in which attraction was always to the anode. Change of effect caused by increasing the current while holding voltage constant was found to be due to the larvae absorbing NaCl via the anal gills and thus changing their resistance. At the higher field strengths some paralysis was caused, varying from temporary to lethal.

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