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At least 19 recordsLinked to original sources
PubMed1967

Time of arrival of gravid Culex pipiens fatigans at an oviposition site, the oviposition cycle and the relationship between time of feeding and time of oviposition.

One of the most important activities in a female mosquito's life is the flight to the breeding place and the subsequent deposition of eggs. During this phase, motivated by endogenous and exogenous stimuli, the female is particularly exposed and susceptible to attack. It is therefore important to investigate these episodes in the gravid female's life.The work reported in this paper shows that gravid Culex pipiens fatigans females are easily trapped over breeding-water; there are two peaks in the arrival at a breeding site, one just after sunset and the other at sunrise. The oviposition cycle is biphasic, the two peaks coinciding, in calm weather, with the two arrival peaks; wind and rain cause marked disturbances in the oviposition cycle.The mean duration of the gonotrophic cycle depends on the time of feeding; this finding is of practical importance since the length of the cycle is often used to calculate the daily survival rate of adult mosquitos. It appears that oviposition is stimulated by a change in light: from light to dark for mosquitos ovipositing in the evening and from dark to light for those ovipositing in the morning.Apart from revealing some hitherto unknown behaviour patterns, the techniques evolved could also be used in the assessment of mosquito populations and hence the effects of control measures.

Animals↗
PubMed2005

Egg size-number trade-off and a decline in oviposition site choice quality: female Pararge aegeria butterflies pay a cost of having males present at oviposition.

Once mated, the optimal strategy for females of the monandrous butterfly, Pararge aegeria, is to avoid male contact and devote as much time as possible to ovipositing, as there is little advantage for females to engage in multiple matings. In other butterfly species the presence of males during egg laying has been shown to affect aspects of oviposition behavior and it has been suggested that repeated interference from males has the potential to reduce reproductive output. The aim of this study was to assess the effects of male presence during oviposition on reproductive output and behavior of a population of P. aegeria obtained from Madeira Island, Portugal, and maintained in the laboratory. Two experiments were performed where females were housed individually in small cages. Experiment 1 examined how social factors influenced the egg laying behavior of females. To do this the presence or absence of males was manipulated and egg size and number was measured over the first 14 days of oviposition. It was observed that when males were present during oviposition females made a trade-off between egg size and number. Experiment 2 examined how social factors affected oviposition site choice. Again, male presence/absence was manipulated, but in this experiment where the female laid her egg in relation to host quality was scored, and the size of the egg laid was measured. In the absence of males females selectively positioned their larger eggs on good quality host plants. However, selective oviposition was no longer observed when females were in the presence of males. We suggest that P. aegeria females from the Madeira Island population are adapted for a flexible oviposition strategy, governed by external cues, allowing a trade-off between egg size and number when the time available for egg laying is limiting.

Animals↗
PubMed2004

Laboratory and field responses of the mosquito, Culex quinquefasciatus, to plant-derived Culex spp. oviposition pheromone and the oviposition cue skatole.

Laboratory and field studies were conducted on the oviposition behavior of the pathogen-vectoring mosquito, Culex quinquefasciatus, in response to the oviposition pheromone 6-acetoxy-5-hexadecanolide, produced from a renewable plant resource, Kochia scoparia (Chenopodiaceae) (plant-derived pheromone, PDP), and via an established synthetic route (synthetic oviposition pheromone, SOP). Responses to the oviposition cue skatole (3-methylindole), presented individually and in combination with the plant-derived and synthetic oviposition pheromone, were also studied. Both laboratory and field assays showed that PDP and SOP were equally attractive. Synergistic effects were observed with one combination of PDP and skatole combinations in laboratory assays. Synergy was also observed under field conditions. SOP and skatole combinations showed additive effects in laboratory assays, but were not tested in field bioassays. Although synergism has been previously demonstrated with combinations of SOP and polluted waters, the work presented here is the first example of synergy between a specific oviposition attractant and the oviposition pheromone. Furthermore, the efficacy of mosquito pheromone produced from a cheap, renewable botanical source has been demonstrated.

Animals↗
PubMed1989

Oviposition behavior of Aedes triseriatus (Diptera: Culicidae): prevalence, intensity, and aggregation of eggs in oviposition traps.

The oviposition behavior of the treehole mosquito Aedes triseriatus (Say) was studied by counting the eggs laid in 300 oviposition traps weekly for one season (May-October) in Illinois. Eggs were aggregated spatially among traps each week, and temporally among weekly samples and for individual traps over weekly counts. Aggregation could be associated with a nonrandom dispersion pattern of oviposition events and with the oviposition of 20-60 eggs per event. Thus, females were laying clumps of eggs in an overdispersed manner. The greatest number of eggs was found in late July when prevalence (proportion of traps with eggs) and intensity (number of eggs per positive trap) peaked simultaneously. Intensity also peaked in May and prevalence peaked in mid-June and early September. When traps from which eggs were removed each week were compared with traps in which eggs were allowed to accumulate, prevalence was naturally higher in the latter group. However, the intensity of eggs was similar in both groups, indicating that more eggs were laid in traps from which eggs were removed. Thus, the presence of eggs on oviposition surfaces was associated with a decrease in further oviposition.

Aedes↗
PubMed1990

Genetic variation for oviposition behavior in Drosophila melanogaster. II. Oviposition preferences and differential survival.

Several behavioral traits connected with oviposition were studied in Drosophila melanogaster strains which ahd been kept on regular and ethanol-supplemented food. All strains preferred food with a low agar content for oviposition, though this tendency was more pronounced in an ethanol-adapted strain. Oviposition on regular and ethanol-supplemented food was tested both under choice and no-choice conditions. Though dependent on the alcohol dehydrogenase genotype adapted strains in general preferred ethanol food, while control strains preferred regular food. There was a strong tendency for oviposition on the vertical sides, when food blocks were offered. This tendency was more pronounced in the ethanol adapted strains. For egg insertion (for which the genetic basis was analyzed in the preceding paper; Kamping and van Delden, 1990), it was shown that inserted eggs laid on ethanol food hatched more often than noninserted eggs. The adaptive significance of the genetic differences in oviposition behavioral traits is discussed.

Alcohol Dehydrogenase↗
PubMed1997

The influence of 2-propanol and acetone on oviposition rate and oviposition site preference for acetic acid and ethanol of Drosophila melanogaster.

Drosophila melanogaster strains, homozygous for the alcohol dehydrogenase alleles AdhF, AdhS, and Adhn4 respectively, were tested for oviposition site preference with a Multiple Choice Device consisting of 18 patches per choice disk. Equal numbers of patches with ethanol-, acetic acid-, and water-supplemented medium were offered simultaneously. Patches with acetic acid-supplemented medium were chosen predominantly as oviposition sites. Pretreatment of flies with increasing concentrations of 2-propanol to inhibit alcohol dehydrogenase (ADH) activity resulted not only in a decreasing choice of acetic acid patches, but also in the laying of a decreasing number of eggs. Adh-null mutant flies showed a similar change in behavior pattern after 2-propanol treatment. Therefore it was concluded that ADH activity is not involved primarily in oviposition site preference behavior. A complicating factor is acetone, the oxidation product of 2-propanol, which had an even larger impact on egg production. However, differences in ADH allozymes with respect to biochemical oxidation capacity of secondary alcohols will not necessarily lead to differences between the Adh genotypes in oviposition rates or apparent changes in preferences, due to additional biochemical differences in inhibition rates by acetone of the various allozymes and other enzyme systems.

1-Propanol↗
PubMed2003

Larval exposure to oviposition deterrents alters subsequent oviposition behavior in generalist, Trichoplusia ni and specialist, Plutella xylostella moths.

The present study was undertaken to determine the effects of larval feeding experience on subsequent oviposition behavior of the resulting moths. Larvae of the cabbage looper (Trichoplusia ni, Noctuidae) and the diamondback moth (Plutella xylostella, Plutellidae) were exposed to the phenylpropanoid allelochemical trans-anethole (at 100 ppm fw in artificial diet) or the limonoid allelochemical toosendanin (10 ppm sprayed on cabbage leaves). Both compounds had been shown to deter oviposition in naive moths in previous choice tests. Moths developing from "experienced" larvae (both sexes) showed a decrease in oviposition deterrence response when given a choice between control and treated leaves, unlike naïve moths. This phenomenon, analogous to habituation to feeding deterrents in lepidopteran larva, occurred irrespective of duration of feeding on the deterrent compound. We also observed that F1 larvae resulting from experienced moths (previously exposed to toosendanin as larvae) grew as well on toosendanin-treated foliage as on control foliage. In contrast, growth of F1 larvae from naïve moths was significantly impaired by toosendanin. These results demonstrate that host-selection behavior in cabbage looper (a generalist) and diamondback moth (a specialist) may be shaped by feeding experience according to Hopkins' Host Selection Principle in addition to chemical legacy.

Allylbenzene Derivatives↗
PubMed2005

Oviposition responses of culex pipiens to a synthetic racemic Culex quinquefasciatus oviposition aggregation pheromone.

The oviposition pheromone of Culex quinquefasciatus was synthesized in a racemic form in a simple (five steps), efficient, high yielding (45% total yield), and low cost way (use of relatively low cost reagents). Our synthetic racemic pheromone (SRP) was tested in the laboratory for its bioactivity on Culex pipiens biotype molestus, which is a member of the species complex that Culex quinquefasciatusbelongs. In the testing conditions, bioactivity at the doses of 0.01, 0.1, 1, and 10 microg per cage was found with the best bioactivity achieved at 1 mug per cage. The effectiveness of our SRP offers a capable tool for improving mosquito oviposition traps for surveillance or even control programs.

Animals↗
PubMed1982

Preliminary evaluation of 1,1-Bis (4-ethoxyphenyl)-2-nitropropane as an oviposition deterrent for the Australian sheep blowfly Lucilia cuprina, and development of methods for evaluating oviposition deterrents against sheep blowfly.

1,1-Bis(4-ethoxyphenyl)-2-nitropropane (GH74) was evaluated as an oviposition deterrent for the sheep blowfly Lucilia cuprina. In several test situations, flies laid only very few egg masses on fleece to which 0.5% GH74 had been applied, and which had been exposed in the field for up to 6 months. However, a significant number of egg masses were laid on the breech of severely scouring sheep when tested several weeks after application of GH74 at the same concentration. Procedures for evaluating oviposition deterrents against sheep blowfly are discussed.

Animals↗
PubMed2005

Oviposition preferences of Culex restuans and Culex pipiens (Diptera: Culicidae) for selected infusions in oviposition traps and gravid traps.

Field studies were conducted in southwestern Virginia to determine the ovipositional preferences of Culex restuans and Culex pipiens by using ovitraps and gravid traps baited with selected infusions. For the ovitrap collections, 4 different infusions (manure, hay, grass, and rabbit chow) were used. Significant differences among infusions were detected on most sample dates for both species. For 3 of the first 4 wk of collections, the manure infusion collected significantly more Cx. restuans than all the other infusions. The hay and grass infusions collected the majority of the egg rafts during weeks 5-9. Cx. pipiens egg rafts were absent from the first 3 wk of collections. Of the remaining 6 wk, 4 showed significant differences in attractiveness of infusions, with the hay and grass infusions preferred by Cx. pipiens. Two infusions, manure and hay, were used for the gravid trap experiment and both Cx. restuans and Cx. pipiens data were combined for analysis. Only the first 2 wk showed significance, with manure being preferred over hay in both weeks. In later collections, the relative attractiveness of the hay infusion increased. A seasonal shift in infusion preference may be related to incubation temperature during preparation of the infusions. New infusions were prepared each week and incubation was done outside. Increased attractiveness of the hay infusion coincided with higher average temperatures in July and August. Hay infusion was very effective for trapping both Cx. pipiens and Cx. restuans in southwestern Virginia and is more convenient to use than manure. However, cool outside temperatures in the early season may interfere with the fermentation process and thus incubation should be done for a longer time or brought indoors.

Animals↗
PubMed2004

Daily oviposition patterns of the African malaria mosquito Anopheles gambiae Giles (Diptera: Culicidae) on different types of aqueous substrates.

BACKGROUND: Anopheles gambiae Giles is the most important vector of human malaria in sub-Saharan Africa. Knowledge of the factors that influence its daily oviposition pattern is crucial if field interventions targeting gravid females are to be successful. This laboratory study investigated the effect of oviposition substrate and time of blood feeding on daily oviposition patterns of An. gambiae mosquitoes. METHODS: Greenhouse-reared gravid and hypergravid (delayed oviposition onset) An. gambiae sensu stricto and wild-caught An. gambiae sensu lato were exposed to three types of substrates in choice and no-choice cage bioassays: water from a predominantly anopheline colonised ground pool (anopheline habitat water), swamp water mainly colonised by culicine larvae (culicine habitat water) and distilled water. The daily oviposition pattern and the number of eggs oviposited on each substrate during the entire egg-laying period were determined. The results were subjected to analysis of variance using the General Linear Model (GLM) procedure. RESULTS: The main oviposition time for greenhouse-reared An. gambiae s.s. was between 19:00 and 20:00 hrs, approximately one hour after sunset. Wild-caught gravid An. gambiae s.l. displayed two distinct peak oviposition times between 19:00 and 20:00 hrs and between 22:00 and 23:00 hrs, respectively. During these times, both greenhouse-reared and wild-caught mosquitoes significantly (P < 0.05) preferred anopheline habitat water to the culicine one. Peak oviposition activity was not delayed when the mosquitoes were exposed to the less preferred oviposition substrate (culicine habitat water). However, culicine water influenced negatively (P < 0.05) not only the number of eggs oviposited by the mosquitoes during peak oviposition time but also the overall number of gravid mosquitoes that laid their eggs on it. The differences in mosquito feeding times did not affect the daily oviposition patterns displayed. CONCLUSION: This study shows that the peak oviposition time of An. gambiae s.l. may be regulated by the light-dark cycle rather than oviposition habitat characteristics or feeding times. However, the number of eggs laid by the female mosquito during the peak oviposition time is affected by the suitability of the habitat.

Journal Article↗
PubMed1985

The developmental viability and sizes of sequentially oviposited eggs of Boophilus decoloratus and Boophilus geigyi.

The viability and sizes of eggs sequentially laid up to the 10th day of oviposition by engorged Boophilus decoloratus and Boophilus geigyi were studied. The average length and breadth of eggs laid on the 1st and 2nd days of oviposition were statistically greater than at subsequent ovipositions. The eclosion periods of eggs laid from 7th to 10th day of oviposition were shorter than those of eggs laid earlier by both Boophilus species. The percentage mortality of eggs of 9th and 10th day of oviposition was significantly higher than that of the earlier ovipositions. The numbers of larvae which engorged on rabbits after hatching from eggs of 7th-10th day ovipositions were significantly fewer than those which hatched from eggs of earlier ovipositions. It is concluded that eggs of early ovipositions of B. decoloratus and B. geigyi are more viable and survive longer than those of later ovipositions. It is also suggested that the shorter eclosion period of the eggs of later ovipositions is due to the process of embryogenesis which is gradual in the eggs of early ovipositions and faster in those of later ovipositions.

Animals↗
PubMed1986

Prostaglandin concentrations in peripheral plasma and ovarian and uterine plasma and tissue in relation to oviposition in hens.

An increase in the plasma concentrations of prostaglandins (PGs) is associated with uterine contractile activity and with oviposition in the hen. In order to assess the contribution of potential sources of prostaglandins to the increase in prostaglandin levels observed at oviposition, prostaglandins E2, F2 alpha, and 13,14-dihydro-15-keto PGF2 alpha (PGFM, the stable but biologically less active metabolite of PGF2 alpha) were measured in plasma from the brachial vein, ovarian follicular vein and uterine vein, and in tissues from ovarian follicles and the uterus 12 h before and at midsequence oviposition or a terminal oviposition. These two ovipositions differ in that a midsequence oviposition is followed within 0.25-1.0 h by the next ovulation of the sequence, whereas the terminal oviposition is followed by an ovulation 14 h later. The concentration of PGFM in plasma from the brachial vein increased at midsequence oviposition, while the levels of PGE2 were unchanged. Prostaglandin E2, F2 alpha, and FM levels were each similar in the plasma from the brachial and uterine veins at the time of midsequence oviposition. In plasma from the largest preovulatory follicle, the concentration of PGF2 alpha and PGFM increased 19- and 7-fold, respectively, from 12 h before midsequence oviposition to midsequence oviposition, although no changes were observed in the concentrations of PGE2 during this interval. The levels of PGF2 alpha increased in the tissues of the two largest preovulatory follicles and the two most recently ruptured follicles during the 12-h period before a midsequence oviposition, while there was no change or a decrease in PGE2 levels in these tissues during the same interval. In contrast, the concentration of PGF2 alpha did not increase during the 12-h period preceding the terminal oviposition of the sequence in plasma from the brachial, uterine, or follicular veins.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗