Hatching Of Larvae Research Articles

Experimental life cycle of Lagochilascaris minor Leiper, 1909.

The life cycle of Lagochilascaris minor was studied using material collected from human lesion and applying the experimental model: rodents (mice, hamsters), and carnivores (cats, dogs). In mice given infective eggs, orally, hatch of the third stage larvae was noted in the gut wall, with migration to liver, lungs, skeletal musculature and subcutaneous tissue becoming, soon after, encysted. In cats infected with skinned carcasses of mice (60 to 235 days of infection) it was observed: hatch of third stage larvae from the nodules (cysts) in the stomach, migration through the oesophagus, pharynx, trachea, related tissues (rhino-oropharynx), and cervical lymph nodes developing to the mature stage in any of these sites on days 9-20 post inoculation (P.I.). There was no parasite development up to the mature stage in cats inoculated orally with infective eggs, which indicates that the life cycle of this parasite includes an obligatory intermediate host. In one of the cats (fed carcass of infected mice) necropsied on day 43 P.I., it was observed the occurrence of the self-infective cycle of L. minor in the lung tissues and in the cervical region which was characterized by the finding of eggs in different stages of development, third stage larvae and mature worms. It's believed that some component of the carnivore gastrointestinal tracts may preclude the development of third stage larvae from L. minor eggs what explains the interruption of the life cycle in animals fed infective eggs. It's also pointed out the role of the intermediate host in the first stages of the life cycle of this helminth.

Effects of egg composition and prey density on the larval growth and survival of lake whitefish (Coregonus clupeaformis Mitchill)

Eggs were collected from two stocks of lake whitefish, Coregonus clupeaformis, in Lakes Michigan and Huron to assess the effect of egg composition and prey density on larval growth and survival. Egg composition parameters including wet weight (mg egg−1), dry weight (mg egg−1), percent water, total caloric content (cal egg−1), caloric density (cal egg−1), percent lipid content, and total lipidcontent (mg egg−1) were measured. Fish hatched from six parental females in each stock were fed one of four rations (0, 18, 24, 50 brine shrimp larva−1 day−1) after yolk sac absorption. Length at hatch, endogenous growth, exogenous growth, and survival were measured during a 42‐day laboratory experiment. Length at hatch of larvae was positively related to egg caloric content (r2=0.780). Endogenous growth for lake whitefish larvae was positively related to percent lipid content (r2=0.896) and total egg lipid content (r2=0.876) of parental females. Exogenous growth and survival of larval lake whitefish was positively related to prey availability. Larval fish growth was accurately modelled (r2=0.973) as a function of prey abundance using a threshold‐corrected hyperbolic equation. These results indicate that both egg composition and prey availability have the potential to influence the growth and survival dynamics of larval lake whitefish significantly.

Effect of temperature on egg hatching and survival of larvae of Anisakis simplex B (Nematoda: Ascaridoidea)

Eggs of the parasitic nematode Anisakis simplex B, obtained from a white-beaked dolphin (Lagenorhynchus albirostris Gray), were incubated in seawater at constant temperatures from −0.7 to 24.3 °C and hatching times determined. Eggs hatched at all temperatures except −0.7 °C. The number of days until hatching ranged from 3 at 24.3 °C to 74–81 at 1.9 °C. There was a declining curvilinear relationship between temperature and both hatching time and duration of the hatching period. The hatching period increased and became more variable with decreasing temperature and ranged from 5 days at 24.3 °C to 55–72 days at 3.8 °C. The percentage of eggs that hatched at each temperature was variable but generally fell in the range 30–60% and was not correlated with temperature. Survival times of hatched larvae peaked at 75–105 days at 8.6 °C, with a minimum of 3–8 days at 24.3 °C. Dimensions of eggs (length, width, volume) differed significantly among individual worms but were not correlated with worm size (wet weight). Egg hatching and larval survival characteristics indicate a species adapted to cold-temperate waters and are consistent with the known distribution of A. simplex B. Preliminary experiments indicated that harpacticoid copepods will ingest newly hatched larvae of A. simplex B and become infected, suggesting that these microcrustaceans may be involved in the life cycle of the nematode.

Hatching of second-stage larvae of Toxocara canis: a rapid method for processing large numbers of worms

A method for hatching second-stage larvae of Toxocara canis is described. Whole adult worms are processed by centrifugation in the presence of hypochlorite which allows the grinding step to be eliminated. The technique is more rapid and a high yield is obtained.

Comparative Reproductive Success of Winter Flounder in Long Island Sound: A Three-Year Study (Biology, Biochemistry, and Chemistry)

In a 3-yr study, late prespawning winter flounder were collected from various stations in Long Island Sound (three of them heavily urbanized) and spawned in the laboratory. For comparative purposes, flounder from two sites in the Boston Harbor area were similarly treated in 1987 and 1988. Of the stations in Long Island Sound, New Haven Harbor alone consistently produced low percent viable hatch and small larvae. Boston Harbor produced the smallest larvae of all sites. There were no significant station-to-station differences in lipid utilization during larval development; yolk reserves at stations showing a low percent viable hatch, small larvae, and low embryonic development rate were probably used in part for stress metabolism. No significant differences in concentrations of polychlorinated biphenyls for collections from Long Island Sound were found either in livers of spawned fish, in sediments, or in eggs of winter flounder. The very low metal concentrations in winter flounder eggs showed no relation to the degree of metal contamination found at stations in Long Island Sound and Boston Harbor.

Offspring fitness and fecundity of an Indian major carp, Labeo rohita (Ham.), in relation to egg size

Effects of egg size on offspring fitness and fecundity of an Indian major carp, Labeo rohita (Ham.), have been studied over a period of 2 years. Offspring from larger eggs tended to be larger at hatching than those from smaller eggs. The size at hatching of larvae hatched from eggs of 3.04 to 4.49 mm diameter varied from 3.12 to 4.64 mm. There was no effect of egg size on hatching and start-feeding (yolk-sac absorption) times. Survival rates of offspring (up to start-feeding) hatched from larger eggs were significantly higher than those from smaller eggs. Growth rates of fed larvae were also found to be a function of egg size. These growth rates varied from a minimum of 0.21 mm day −1 to a maximum of 0.44 mm day −1 in offspring from eggs of 3.04 to 4.49 mm diameter, respectively. Under starvation conditions, offspring from larger eggs took comparatively longer to starve. Running fecundity ranged from 90 415 to 323 209 in fish of 517 to 1474 g, respectively. A curvilinear relationship existed between egg size and weight-specific egg number (number of eggs g −1 fish body weight). With an increase in egg diameter from 3.04 to 3.7 mm, there was an increase in weight-specific egg number (175–261). But larger eggs corresponded to fewer eggs per unit body weight.

Winter aspects of the ichthyoplankton community in Antarctic Peninsula waters

Ichthyoplankton was sampled from the Antarctic Peninsula area of the South Polar Ocean in early winter (May and June 1986). A total of 153 eggs from two species and 1368 larvae or juvenile stages from 12 species were obtained. These included pelagic species, and demersal species with a long pelagic larval or juvenile phase. Most abundant were larvae of Pleuragramma antarcticum and Notothenia kempi, and eggs of Notothenia neglecta. The distribution of notothenioid and paralepidid larvae was apparently unaffected by ice cover, whereas myctophid larvae were confined to ice-free waters. Areas where newly hatched Chionodraco hamatus occurred coincided with dense aggregations of Euphausia superba (Krill) furcilia larvae which is a potential food resource during winter. The hatching of icefish larvae during winter is apparently independent of the seasonal production cycle. Epipelagic eggs of Notothenia neglecta were found during the spawning season, which suggests that eggs ascend to the surface after demersal spawning and that development takes place near the sea surface during winter. Larvae of Notothenia kempi were chiefly confined to shelf and slope waters to the west of the Antarctic Peninsula, with larger larvae found in coastal shelf areas. Pleuragramma antarcticum occurred in the coastal waters off the Biscoe Islands, in the Gerlache Strait, and in the northern Bransfield Strait. The smallest larvae were found in the northern Bransfield Strait, whereas those at the Biscoe Islands and in Gerlache Strait waters were larger and of a similar size. A cyclonic gyre to the west of the Antarctic Peninsula observed in the austral summer was likely to have affected the larval drift of Pleuragramma antarcticum and Notothenia kempi. Differences in the timing of spawning and hatching and the vertical distribution of these larvae will lead to different transport and spatial distribution patterns. It is hypothesized that early winter conditions do not imply severe limitations on the year-class success of larval fish. Dispersal and increased mortality may occur during the second half of the winter.

Structure and differentiation of the sensilla of the ventral sensory field on the maxillary palps ofPeriplaneta americana (Insecta, Blattodea), paying special attention to the ciliogenesis of the sensory cells

The embryonic development of palpal contact chemosensitive sensilla was studied from 42% of development up to the hatching of the larvae. Ciliogenesis of the sensory cells can be observed at the earliest stages investigated. A complex consisting of two basal bodies and a cap-like ciliary vesicle is localized in the dendritic inner segment. It migrates apically and fuses with the cytoplasmic membrane. At the same time, microtubule doublets of the distal basal body elongate, thus generating the dendritic outer segment. Furthermore, the typical accessory structures of a motile cilium are formed. Although the central pair of microtubules is lacking, the dendritic outer segment can be considered as a modified motile cilium. At about 84% of development the hair structure starts to be formed. Whereas the socket is generated by the tormogen cell, the trichogen cell produces the hair shaft and terminal porus. The dendrite sheath, which rises above the newly formed hair, is attached apically to the embryonic cuticle forming an irregular pore. In larvae and imagines, the inner surface of the dendrite sheath is highly differentiated. A range of circular ledges and filamentous structures wrapping around the dendritic outer segments can be distinguished. These may have a stabilizing function. Furthermore, in cryofixed specimens, the dendritic outer segments possess regularly spaced swellings which are about 1 μm in length and about 0.5 μm in diameter. Their functional significance is still unclear.

The use of irradiated embryos of Chrysomya bezziana for the detection of the Old World screw‐worm fly

Irradiation of Chrysomya bezziana embryos 1 h before hatching with doses less than or equal to 7 kilorad (kr) had a significant effect on percentage egg hatch, weights and survival of larvae. Doses greater than or equal to 1 kr allowed larval development to the end of the 3rd instar stage in vitro, but prevented normal pupal development. Cattle with wounds infested with 1st instar larvae derived from irradiated embryos had 3rd instar larvae present after 3 d but these failed to pupate. Thus it would be feasible to use such larvae for wound infestation for the enhanced detection of screw-worm fly in areas where the release of fertile flies is undesirable.

Effects of urea analogs on egg hatching and movement of unhatched larvae of monogenean parasiteAcanthocotyle lobianchi from skin ofRaja montagui

Rapid hatching in the monogenean parasiteAcanthocotyle lobianchi from the skin ofRaja montagui is stimulated by urea. Structurally similar to the urea molecule, the following analogs of urea provide amino groups, carboxyl groups, or combinations of these, but fail to stimulate hatching at concentrations of 1 mM in seawater: methylurea (MU); 1, 3-dimethylurea (DU); 1, 1, 3, 3-tetramethylurea (TMU); thiourea (TU); 1, 1, 3, 3-tetramethyl-2-thiourea (TMTU); and 1-phenyl-2-thiourea (PTU). All of these analogs except PTU elicit movements of unhatched larvae, and posttreatment of the eggs with urea showed that the ability to hatch is not impaired by initial treatment with any of the urea analogs. Thus the larval chemoreceptor that initiates hatching appears to be highly specific for the urea molecule.

Impact of Planktivorous Fishes on Dispersal, Hatching, and Morphology of Estuarine Crab Larvae

The effect of planktivory on life history patterns of estuarine crabs was studied by determining preferences of common estuarine fishes for crab larvae in the laboratory and the upper Newport River estuary, North Carolina. Plankton samples (68) and fishes were collected from an upstream and downstream site, on spring and neap low tides, and during the day and night. Over 99.6% of the plankters collected were decapod larvae, copepods, barnacle nauplii, and cyprids. Predominant fishes in the upper estuary were silversides, Menidia menidia, anchovies, Anchoa mitchelli, and killifish, Fundulus heteroclitus, as is typical for other estuaries on the east coast of the United States. Gut contents of 1861 fishes 15—100 mm long were analyzed. Silversides and anchovies preyed upon crab larvae more often than did killifish, and are most likely to influence the life history patterns of crabs inhabiting upper estuaries. Fishes that eat crab larvae are more abundant in estuaries than coastal waters during summer. Fishes in the estuary and the laboratory showed strikingly similar preferences for prey. In order to descending preference, natural populations of fishes preferred copepods, crab larvae that are exported from estuaries (Uca, Sesarma cinereum), and decapod larvae that develop in estuaries (Sesarma reticulatum, Palaemonetes, Rhithropanopeus harrisii). In the laboratory, juvenile and adult silversides and killifish preferred Artemia nauplii to crab larvae, they fed randomly on Uca larvae, and they avoided R. harrissii larvae. These planktivores preferred zoeae that are exported to coastal waters over those that are retained because exported larvae are smaller and have shorter spines. While the large size and spines of retained larvae protect them from their predators in estuaries, vulnerable zoeae may emigrate from estuaries to coastal waters because the rate of encounter with predators offshore is less than in estuaries. The risk of predation also appears to vary spatially and temporally within the estuary. Predation generally was greatest upstream in shallow, narrow areas of the upper estuary on diurnal neap tides. The spatial gradient in predation apparently was due largely to the great abundance of fishes, and particularly small zooplanktivorous fishes, occurring upstream. In contrast, temporal patterns of planktivory were not due to differences in fish size and abundance, but to diurnal foraging of fishes and changes in the availability of prey. Resident zooplankters generally were preyed upon more during neap tides, perhaps because they remained nearer to the substrate on spring tides to prevent being swept downstream. Uca and S. cinereum zoeae were eaten in similar numbers during diurnal neap and spring tides because most zoeae had been transported downstream before dawn when fishes resumed feeding. Estuarine crabs may have responded to predictable trends in planktivory by dispersing newly hatched zoeae downstream on nocturnal ebb tides, regardless of where larvae develop. Small vulnerable zoeae eventually disperse offshore, whereas large well—defended zoeae apparently remain in estuaries. Peak hatching on spring high tides may not have evolved to expedite transport to coastal waters, but instead may facilitate dispersal of larvae of semiterrestrial crabs from the shore where mortality may be high. This study suggests that predation pressure exerted by planktivorous fishes is predictable in time and space, and the timing of larval release, dispersal patterns, and larval morphologies of estuarine crabs have evolved together to reduce the risk of planktivory regardless of whether zoeae develop offshore or in estuaries.

Influence of Cocoons on Egg Laying of Colony-Founding Carpenter Ant Queens (Hymenoptera: Formicidae)

Patterns of brood production by colony-founding queens of Camponotus pennsylvanicus (De Geer), C. novaeboracensis (Fitch), and C. modoc Wheeler were examined. The presence of workers or larvae had either no effect or a negative one on oviposition by the queens, but the presence of cocoons stimulated oviposition. This regulation may control the worker/brood ratio or may synchronize the hatching of larvae, with the eclosion of new workers to care for them.

Differentiation of membrane excitability in isolated cleavage‐arrested blastomeres from early ascidian embryos.

1. Differentiation of excitable cells was studied electrophysiologically and histochemically in cleavage-arrested blastomeres isolated from early ascidian embryos. Blastomeres were isolated at the 4- or 8-cell stage, and cultured in sea water containing cytochalasin B until the time of hatching of control larvae. Electrical responses, immunoreactivity to epidermis-specific monoclonal antibody (2C5) and activity of muscle-specific acetylcholinesterase were examined. 2. All cleavage-arrested blastomeres isolated from an 8-cell embryo differentiated to elicit either muscular- or epidermal-type action potentials, but no neural-type action potentials were observed in these blastomeres. The anterior-animal and the posterior-animal blastomeres developed only epidermal-type action potentials, which involved expression of Ca2+ channels and immunoreactivity to 2C5. One-third of anterior-vegetal blastomeres developed epidermal-type action potentials which are mediated by Ca2+ channels though the immunoreactivity to 2C5 was absent. A majority of remaining blastomeres showed action potentials composed of Ca2+ currents and TEA-sensitive delayed K+ currents (type I response), and a few of them had fast transient K+ currents (A-currents) in addition (type II response). One-third of posterior-vegetal blastomeres developed epidermal-type action potentials without expression of the immunoreactivity to 2C5. The remainder differentiated into muscular-type cells, which expressed Ca2+ currents, TEA-sensitive and TEA-insensitive delayed K+ currents, and showed acetylcholinesterase activity. 3. Cleavage-arrested blastomeres isolated from a 4-cell embryo also differentiated into epidermal- or muscular-type cells, but not neural-type cells. The anterior blastomere, which is the parent cell of anterior-animal and anterior-vegetal blastomeres of an 8-cell embryo, developed epidermal-type, type I or type II responses, as was the case in the anterior-vegetal blastomere isolated from an 8-cell embryo. The posterior blastomere, which was the parent cell of posterior-animal and posterior-vegetal blastomeres of an 8-cell embryo, differentiated into either epidermal-type or muscular-type cells in terms of both membrane excitability and immunochemical reactivity. 4. Cleavage-arrested 1-cell embryos differentiated exclusively into epidermal-type cells in terms of membrane excitability and 2C5 immunoreactivity, even when the cytochalasin B concentration was decreased below 0.1 microgram/ml.(ABSTRACT TRUNCATED AT 400 WORDS)

Regulation of brood size in a burying beetle,Nicrophorus tomentosus (Silphidae)

Regulation of brood size in a biparental burying beetle, Nicrophorus tomentosusWeber, was studied by providing pairs with one of two sizes of mouse carcasses in the laboratory. For a given carcass size, there was an inverse relationship between number and mass offspring in a brood. The requirement for regulation was that brood size was adjusted such that mean mass of individual larvae was constant for carcasses of different size. Brood size was regulated if parents were present but regulation did not occur if parents were removed prior to hatching of larvae. Pairs bred in quick succession on two carcasses raised fewer than the regulated number of young in the second reproductive attempt. Reasons for regulation of brood size in this genus are discussed.

Comportement et écologie de la Fourmi énigmatiqueLeptanilla japonica Baroni Urbani (Hymenoptera: Formicidae: Leptanillinae)

The present study ofLeptanilla japonica has clarified for the first time the biology of the Leptanillinae. Males were obtained, which are the first specimens of the subfamily to be collected in association with workers.L. japonica is a totally subterranean ant. Colonies are monogynous with a dichthadiiform queen. Worker population per colony is small, usually 100–200. Development of immature individuals is strictly seasonally synchronized. Colonies often emigrate to the site of paralyzed prey (geophilomorph centipedes). For carrying larvae workers grasp peculiar structures projecting from the larval prothorax with the lower mouthparts. The final-instar larvae have a pair of specialized lateral duct organs on the 4th abdominal segment. Through these organs larval hemolymph is provided for consumption by adults, especially by the queen. Nutrition of the queen depends exclusively on this process. The frequency of larval hemolymph feeding by queens is abruptly elevated when the larvae mature. Owing to this the queen is able quickly to achieve full physogastry, and to lay a batch of 100–200 eggs within a few days. Emergence of new workers from pupae is synchronized with hatching of the 1st-instar larvae from the eggs. In a concluding section the lifemode ofLeptanilla is compared with that of doryline and ecitonine army ants

Serosal cells of Biosteres longicaudatus (Hymenoptera: Braconidae): Ultrastructure and release of polypeptides

AbstractAs a prelude to a study in vitro of the function of the embryonic serosa of the parasitic wasp Biosteres longicaudatus (Braconidae), the ultrastructure of serosas of different ages reared in vivo and in vitro were compared. The evidence suggests that the serosal capsule consists of one to three cell layers. The innermost (internal cells) which line the serosal capsule and the outermost (external) cells which are bathed by the host's hemolymph are secretory. Large, coated vesicles in the internal cells increase in number and size with age and, likely, take up and transport molecules into the serosa. Multivesicular bodies, Known for their enzyme‐degradative function, occur in external cells and are eventually extruded into the surrounding environment. Distinctive electrondense, rod‐shaped particles appear in external cells within 8 h after larvae hatch, increase in number with larval age, and occur at the bases of microvilli. The latter appear electron dense with age and eventually they and the lobulated microvilli in internal cells fragment into the surrounding environment. To determine whether parasites and/or their serosas release substances into the host Anastrepha suspensa (Diptera: Tephritidae), hemolymph from unparasitized and superparasitized (> 1 parasite/host) pharate pupae was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE). Serosas and/or parasite larvae were incubated in artificial media and each of these was subjected to SDS‐PAGE. A polypeptide, approximately 24 kilodaltons (Kd) occurred in the hemolymph of 24‐h‐old superparasitized pharate pupal hosts but not in the control. A similar polypeptide was observed in medium cultured with parasite larva and serosa as well as serosa alone, but was not in their respective control media. This approximately 24‐Kd band in SDS‐PAGE gels corresponds to a band in the serosa homogenate and may be identical to it. Serosas and parasite larvae in vivo and in vitro have similar protein profiles. Based upon these ultrastructural and electrophoretic studies, it appears that the serosa of B. longicaudatus has a synthetic function, as has been reported for the extra‐embryonic membrane of other parasitic Hymenoptera. It may sequester and degrade molecules from the host hemolymph and likely release newly synthesized as well as degraded products into the host.

Increase of macromolecule synthesis after hatching of Concholepas concholepas veliger larvae: Effect of sulfate in the synthesis of proteoglycans

1. 1. The synthesis of proteins, glycoproteins and sulfated macromolecules increase after hatching of the gastropod Concholepas concholepas larvae. 2. 2. Sulfate present in the sea-water, stimulates over 30-fold the sulfation of sulfated macromolecules but not the proteins. 3. 3. Analysis of the sulfated macromolecules indicates that almost 90% are localized in the larval insoluble material, corresponding to a high molecular weight macromolecule, probably a proteoglycan.

Ecdysteroids during ovarian development and embryogenesis in the cricket,Gryllus bimaculatusde Geer

Summary Ecdysteroid levels in Gryllus bimaculatus eggs have been determined at each of the developmental stages by a radioimmunoassay. Freshly laid eggs contained low amounts of free and conjugated ecdysteroids (c. 120 ng ecdysone equivalents per g wet wt.). A slight increase around day 8/9 (time of cuticle secretion) was followed by a conspicuous rise of free ecdysone, free 20-hydroxyecdysone and polar conjugated 20-hydroxyecdysone at the tenth day, that means one day before hatching of larvae. To examine possible metabolic transformations contributing to this increase in immunoreactive ecdysteroids during late embryogenesis, metabolism of [3H]ecdysone administered to vitellogenic females was investigated. Freshly laid eggs showed low amounts of labelled ecdysteroids, mainly in an apolar conjugated form. This pattern of labelled hormones did not change significantly during embryonic development. Comparable studies with [4–14C] cholesterol administered per os to ovipositing females revealed a similar patt...

Parasitic flies (Conopidae, Diptera) may be important stress factors for the ergonomics of their bumblebee hosts

Bumblebees harbour a wide range of parasitic organisms that attack all stages of their life cycles (reviews in Postner, 1951; Pouvreau, 1973, 1974; Alford, 1975; Kistner, 1982). Among them, conopid flies (Conopidae, Diptera) are particularly interesting because they attack foraging bumblebees which are handling flowers, or even on the wing (Frison, 1926; Cumber, 1949; Postner, 1951; Howell, 1967; Askew, 1971). A single egg is attached to (Frison, 1926; Plath, 1934; Cumber, 1949) or inserted into (DeMeijre, 1904; Howell, 1967) the host's abdomen, where the larva hatches and feeds on haemolymph and internal organs. Within 6–10 days the larva passes through three recognizable stages (Pouvreau, 1974) before the fly pupates in situ within the abdomen. The host bee dies shortly before the parasite pupates (Postner, 1951; Smith, 1966) and the parasite overwinters in its puparium; the adult fly then emerges in early summer (Frison, 1926; Townsend, 1935; Cumber, 1949; Postner, 1951). Conopid flies as parasites of bumblebees are known from all major habitats where the hosts occur (e.g. Kröber, 1939; Smith, 1966). However, the effect of parasitism on distribution and abundance of bumblebees is not known. In this preliminary note we have estimated degrees of infestation and concomitant reduction of life span in affected workers. The results are compared with literature reports on infestation levels in Europe.

Influence of Delayed Mating on Egg Production, Egg Viability, Mating, and Longevity of Female Pink Bollworm (Lepidoptera: Gelechiidae)

Virgin female pink bollworm, Pectinophora gossypiella (Saunders), were paired individually with a 2- to 3-d-old virgin male for one night at ages <1, 1, 5, 10, and 15 d from eclosion in lots of 25. Virgin females served as controls. Records were kept on numbers of eggs deposited daily, percentage hatch, and day of adult death. All dead females were dissected to determine mating status. When total females of each age group were considered, mating at the age of 5, 10, and 15 d resulted in significantly less mating, fewer eggs, less hatch, and fewer first-instar larvae than when mating occurred at the age of <1 and 1 d. Virgins lived significantly longer than females mated at <1, 1, and 5 d of age. Mating delays of 10 and 15 d resulted in longevities similar to that of virgins. Differences in mating and oviposition between treatments for mated and total females were statistically similar, and there were no significant differences in percentage hatch of eggs produced by mated females regardless of the female's age. These results suggest that one mating provided adequate sperm to fertilize available eggs. Mated females showed a marked oviposition response on the second night after mating. Generation increases established from previously reported field populations and compared with reproduction in the current study show that mating delays of 5 d or more could result in a 5-fold decrease in population density over four generations.