Identification of First-Instar Aedine Mosquito Larvae of Minnesota (Diptera: Culicidae)

1960 ◽  
Vol 92 (7) ◽  
pp. 544-560 ◽  
Author(s):  
Roger D. Price
Keyword(s):  
Larval Stage ◽  
Fourth Instar ◽  
Mosquito Larvae ◽  
Vast Amount ◽  
First Instar ◽  
Mosquito Ecology ◽  
Egg Morphology ◽  
Early Instar

The emphasis in mosquito identification has been centered for the most part on the fourth-instar, or mature, larval stage and on both sexes of the adult forms. Some stress in recent years has been placed on pupal and egg morphology; however, as pointed out by Bohart (1954) and others, in comparison with the vast amount of literature on these stages, the amount of work published on the identification of early-instar mosquito larvae has been relatively slight. Regardless of the reasons for this, it would be, for instance, of immeasurable value to a person studying mosquito ecology to be able to identify directly to species any larval stage of the mosquito that he might collect. It is hoped that this paper, even though limited to Minnesota Aedes, will contribute further to the ability to recognize first-instar Aedes larvae and that it will serve as an added stimulus to workers in other geographical areas to collect and assimilate materials in a similar manner.

EFFECT OF TEMPERATURE AND STAGE OF DEVELOPMENT ON SUSCEPTIBILITY OF AEDES EUEDES AND AEDES STIMULANS (DIPTERA: CULICIDAE) LARVAE TO TEMEPHOS

1983 ◽  
Vol 115 (6) ◽  
pp. 623-628 ◽  
Author(s):  
B. V. Helson ◽  
G. A. Surgeoner
Keyword(s):  
Maximum Concentration ◽  
Fourth Instar ◽  
Effect Of Temperature ◽  
Recommended Dosage ◽  
Stage Of Development ◽  
First Instar ◽  
Early Instar ◽  
Increasing Temperature

AbstractIn laboratory trials, the susceptibility of Aedes euedes Howard, Dyar and Knab and Aedes stimulans (Walker) larvae to temephos (Abate®), was positively correlated with increasing temperature. Early instar larvae were more susceptible than late instars. Susceptibility differed 36 times from the fourth instars at 4 °C (24 h LC50 = 16.92 ppb) to the first instars at 19 °C (24 h LC50 = 0.47 ppb) the extremes of instar and temperature tested. The minimum recommended dosage of temephos (6 ppb) was ca. 9 times the LC90 of first instar A. stimulans and A. euedes at 19 °C. By contrast, the 24 h LC90 of 67.4 ppb for the fourth instar of A. stimulans at 4 °C was ca. 4 times the maximum concentration of temephos (18 ppb) currently recommended for Aedes spp. control. However, in simulated pool studies, satisfactory control of A. stimulans was achieved by 72 h posttreatment at the highest recommended dosage.

scholarly journals Inheritance of Antibiosis Resistance to the Dectes Stem Borer, Dectes texanus, in Soybean PI165673

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 738
Author(s):  
Lina M. Aguirre-Rojas ◽  
Lawrent L. Buschman ◽  
Brian McCornack ◽  
William T. Schapaugh ◽  
Erin D. Scully ◽  
...  
Keyword(s):  
North America ◽  
Larval Stage ◽  
Stem Borer ◽  
Plant Introduction ◽  
Lower Number ◽  
Soybean Plant ◽  
Yield Losses ◽  
First Instar ◽  
Significant Yield ◽  
Antibiosis Resistance

Dectes texanus larvae girdles the stems of soybean and cultivated sunflowers causing significant yield losses in North America. The soybean Plant Introduction (PI) 165673 exhibits antibiosis resistance to the larval stage. The objectives of this study were: (1) to determine the inheritance of D. texanus resistance in PI165673; (2) evaluate PI165673 antibiosis resistance before 21 d post infestation; (3) evaluate girdling damage in PI16563 at the end of the season. K07-1544/PI165673 F2 and F2:3 populations were tested for resistance to D. texanus in 2011 and 2012, and PI165673 antibiosis resistance and girdling damage were evaluated in 2014. Segregation for resistance to D. texanus and heritability estimates in the F2 and F2:3 populations indicated that resistance was controlled by two genes with dominant and recessive epistasis. Antibiosis evaluations indicated: (1) PI165673 contained lower number of larvae and eggs relative to the number of oviposition punctures at 15 d post infestation; (2) the proportion of first-instar larvae was higher in PI165673 at 15 d post infestation; (3) larvae reach the sixth-instar stage in PI165673. None of the PI165673 plants were girdled at the end of the season. Identification of additional sources of D. texanus resistance is required to impair larval development in the stem.

scholarly journals Efficacy of Bacillus thuringiensis (Berliner) isolates on fig moth, Ephestia cautella (Walker) Larvae

2014 ◽  
Vol 11 (2) ◽  
pp. 943-951
Author(s):  
Baghdad Science Journal
Keyword(s):  
Bacillus Thuringiensis ◽  
Larval Stage ◽  
Filter Paper ◽  
Larval Instar ◽  
Ephestia Cautella ◽  
Larval Stages ◽  
The Third ◽  
Total Percentage ◽  
First Instar ◽  
Paper Method

The following dilution 5×10-1, 10-1, 10?2 , 10-3 gm/L for the indigenous isolate of Bacillus thuringiensis bacteria and the commercially isalate were used for experiments against the different stages of fig moth of E.cautella which exposed by filter paper method. The results showed that mortality of larval stages was increased with the increasing concentration of the biocide, in addition to increase in the mortality of the larval stages reached to the highest percentage in the third days of treatment of the larval stage in comparison with the first and second days of exposure. The results also showed that the sensitivity of larval stages was increased in first and second instars while reduced in the last instars .The high percentage of first instar mortality for the indigenous isolate in the concentration of 5×10-1 was 72.8% , while the low percentage of mortality showed in the concentration of 5×10-1 for the fifth instar larvae which was 13.3% in third days of treatment while a high percentage of mortality was showed for the first instar larvae for the commercially isulate in the concentration of 5×10-1 was 59.4% Furthermore, low percentage of mortality was shown in the concentration of 5×10-1 in fifth instar larval which was 8.3% in the third days of treatment. The results also showed that the indigenous isolated was more effective than the commercially produced bacteria for killing larval instars of fig moth E.cautella .The total percentage of larval instar mortality reached to 44.5 % after the third days of treatment in concentration 5×10-1 in the indigenous isolate , and it was 33.8 % in the commercially produced bacteria .

scholarly journals Biologi Stenocranus pacificus Kirkaldy (Hemiptera: Delphacidae) pada tanaman jagung (Zea mays L.) di rumah kasa

2020 ◽  
Vol 17 (2) ◽  
pp. 104
Author(s):  
Dosma Ulina Simbolon ◽  
Maryani Cyccu Tobing ◽  
Darma Bakti
Keyword(s):  
Zea Mays ◽  
Life Cycle ◽  
Sex Ratio ◽  
Zea Mays L ◽  
Instar Nymph ◽  
Fourth Instar ◽  
The Third ◽  
First Instar ◽  
Corn Plants ◽  
North Sumatra

<p><em>Stenocranus pacificus </em>Kirkaldy (Hemiptera: Delphacidae) is destructive pest on corn plants in South Lampung and it has been reported to cause corn damages in North Sumatra. The  objective of this research was to study some aspects biology of <em>S. pacificus</em> on corn plants in screenhouse. The research was conducted by observing the biology of <em>S. pacificus</em> that was reared on corn plants in screenhouse.<em> </em>The results showed that life cycle of <em>S. pacificus </em>was 38–47 (41,60 ± 3,19) days: egg was 9–11 (10,20 ± 0,79) days, the first instar nymph was 3–4 (3,70 ± 0,48) days, the second instar nymph was 3–4 (3,90 ± 0,32) days, the third instar nymph was 3–4 (3,70 ± 0,48) days, the fourth instar nymph was 3–4 (3,80 ± 0,42) days, and the fifth instar nymph was 3–4 (3,60 ± 0,52) days. Age of female was 13–17 (15,30 ± 1,34) days. It was longer than age of male which was 8–12 (10,10 ± 1,20) days. Female could produce 181–214 (197,60 ± 11,64) eggs during its life. The sex ratio was 1:1,98.</p>

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 Ceratothripoides claratris, a New Vector of a Capsicum chlorosis virus Isolate Infecting Tomato in Thailand

2005 ◽  
Vol 95 (6) ◽  
pp. 659-663 ◽  
Author(s):  
W. T. S. D. Premachandra ◽  
C. Borgemeister ◽  
E. Maiss ◽  
D. Knierim ◽  
H.-M. Poehling
Keyword(s):  
Larval Stage ◽  
Vector Competence ◽  
Close Association ◽  
Transmission Efficiency ◽  
Adult Males ◽  
Tomato Plants ◽  
First Instar ◽  
Thrips Species ◽  
Infected Tomato ◽  
Capsicum Chlorosis Virus

Ceratothripoides claratris, the predominant thrips species on tomato in Thailand, was tested for vector competence and efficiency to transmit Capsicum chlorosis virus (CaCV) (isolate AIT) to tomato. The efficiency of adult-stage transmission was influenced by the larval stage at which virus was acquired. Adult C. claratris showed 69% transmission efficiency after acquiring the virus as freshly emerged (<1 h) first-instar larvae. However, when just molted (<1 h) second-instar larvae acquired the virus, the percentage of adult transmitters significantly decreased (48%). Transmission efficiency of up to 47% was detected with second-instar larvae of C. claratris which had acquired the virus as freshly emerged first-instar larvae. Transmission efficiency did not significantly differ between adult males and females, irrespective of the larval stage at which the virus was acquired. Highest transmission efficiency for CaCV was recorded in adult C. claratris derived from second-instar larvae collected from infected tomato plants in a greenhouse. Lowest transmission efficiency was observed in adults directly collected from infected tomato plants in the greenhouse. The spread of CaCV on tomato plants in greenhouses showed a close association with thrips infestations.

scholarly journals Biology and Predation of Stethorus punctillum Weise (Coleoptera: Coccinellidae) feeding on Tetranychus urticae Koch

1970 ◽  
Vol 15 ◽  
pp. 1-5 ◽  
Author(s):  
GC Biswas ◽  
W Islam ◽  
MM Haque
Keyword(s):  
Tetranychus Urticae ◽  
Developmental Stages ◽  
Instar Larva ◽  
Predation Rate ◽  
Fourth Instar ◽  
Fourth Instar Larva ◽  
First Instar ◽  
Different Seasons ◽  
Two Spotted Spider Mite ◽  
Stethorus Punctillum

The duration of hatching, larval instars and pupal stages of Stethorus punctillum feeding on two-spotted spider mite, Tetranychus urticae were investigated in different seasons under laboratory conditions. The highest values of different developmental stages were obtained during winter. Higher temperature significantly reduced the duration of different developmental stages. No significant effect of relative humidity was exerted on the development stages of S. punctillum. The predation rate of fourth instar larva of S. punctillum was the highest whereas the first instar larva consumed the lowest number of prey. The fourth instar larva of the predator consumed 135.8 eggs, 126.4 larvae, 96.6 nymphs and 72.8 adults per day separately. But the first instar consumed 41.6 eggs, 36.2 larvae, 26.8 nymphs and 16.8 adults during the same period. Keywords: Developmental durations, predation, Tetranychus urticae, Stethorus punctillum   doi: 10.3329/jbs.v15i0.2196 J. bio-sci. 15: 1-5, 2007

Studies on the biology of the palm aphid, Cerataphis variabilis (Homoptera: Pemphigidae), on Raphia hookeri–1: Developmental period of the immatures, fecundity and longevity of the apterous adults

1985 ◽  
Vol 6 (2) ◽  
pp. 177-181 ◽  
Author(s):  
D. A. Enobakhare
Keyword(s):  
Relative Humidity ◽  
Developmental Period ◽  
Fourth Instar ◽  
First Instar ◽  
Raphia Hookeri

AbstractThe biology of the aphid, Cerataphis variabilis H.R.L., on Raphia hookeri Mann & Wendl., was studied in the laboratory and the field using a ‘clip-on’ cage and a sleeve cage. The first instar lasted 5.1 days. The second and third instars each lasted 2.45 days, while the fourth instar lasted 2.4 days. The total developmental period of the nymphs was 11.3 days at 26.4 ± 1.43°C and r.h. 83 ± 1.46%; 11.6 days at 26.4 ± 1.63°C and r.h. 85 ± 1.19%; 12.9 days at 27.9 ± 1.04°C and r.h. 75.5 ± 1.64%; 12.95 days at 27.8 ± 0.33°C and r.h. 69 ± 1.23%; 15 days at 21.4 ± 0.58°C and r.h. 45 ± 1.77%. These periods were significantly different at 5% level (LSD = 0.59 days). The higher the temperature and relative humidity the shorter the developmental period (with temperature: r = −0.69, 20.8–28.9°C; r.h.: r = −0.97, 43.2–86.2%). The number of progeny per adult ranged from 54 to 60 in a period of 28–31 days. The longevity ranged from 31 to 34 days.

Ecology and coexistence of two species of Brachycentrus (Trichoptera) in a Rocky Mountain river

1986 ◽  
Vol 64 (7) ◽  
pp. 1469-1474 ◽  
Author(s):  
F. Richard Hauer ◽  
Jack A. Stanford
Keyword(s):  
Rocky Mountain ◽  
Late Summer ◽  
Growth Patterns ◽  
Mountain River ◽  
Spring Runoff ◽  
Winter Conditions ◽  
First Instar ◽  
Spring Freshet ◽  
Early Instar ◽  
Peak Runoff

Life-cycle dynamics, growth rates, and relative abundance of Brachycentrus occidentalis and Brachycentrus americanus were studied over a 3-year period in the Flathead River, Montana. Brachycentrus occidentalis appeared as early instar larvae in mid to late summer, grew rapidly during autumn, and reached fourth and fifth instars prior to winter conditions. Most larvae remained active until mid-spring and the onset of spring runoff. Individuals pupated during late April through May and adults emerged after peak runoff in mid-June. Brachycentrus americanus larvae appeared as first instar larvae in autumn and overwintered as early instars. Larvae grew rapidly during spring as temperatures began to rise, but growth was discontinued during spring runoff. Larvae completed growth during summer after the runoff period and emerged in late August and early September. Growth patterns and emergence of both species occurred primarily during fall or spring and late summer, with little growth during winter or spring freshet. Thus growth was associated with quantitatively similar but temporally different periods of organic seston, temperature, and moderate flow.

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