Mean Preoviposition Research Articles

チャバラアブラコバチの活動停止特性の個体群間差異

The dormancy characteristics of five Japanese populations of Aphelinus asychis were examined to find strains useful as biological control agents against pest aphids under winter greenhouse conditions in Japan. The weak diapause, strictly oligopause sensu Mansingh (1971), response in the adult stage differed among populations under 10L : 14D at 15°C. The percentage of newly emerging females with immature ovaries was significantly lower in one of the Kagoshima populations, KGS1 (12%) than in the other four populations (51–66%). The mean preoviposition period was significantly shorter in the Kochi population, KCH (1.8 d) than in the Kyoto population (7.8 d), and oviposition was more incessant in the former than in the latter. KGS1 and KCH, which showed a weaker diapause response, are considered to be better candidates for the biological control of pest aphids in winter greenhouses because they are more likely to be active during the winter.

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The rice leaf bug, Trigonotylus caelestialium (Kirkaldy), is a plant feeder which feeds on gramineous grasses. It has been confirmed that the conspecific eggs are sucked dry by female and male adults. This egg predation indicates the bug is omnivorous. Fecundity and longevity of adults served wheat seedlings, as both a food source and oviposition site, were examined at 30°C, 25°C and 20°C with a 16-h photophase. The mean preoviposition period at 20°C was significantly longer than at 30°C and 25°C. The averages of the total number of eggs laid per female were 127.3, 107.7 and 107.6 at 30°C, 25°C and 20°C, respectively. Both females and males lived longer at lower temperatures. Males tended to live longer than females under all temperature conditions.

Influence of sublethal exposure to abamectin on the biological performance of Neoseiulus longispinosus (Acari: Phytoseiidae).

Effects of sublethal exposure to abamectin on the biological performance of Neoseiulus longispinosus (Evans) were studied under ambient laboratory conditions of 28 +/- 2 degrees C and 80 +/- 15% RH with 24 h light. The red form of the twospotted spider mite, Tetranychus urticae Koch, complex (Acari: Tetranychidae), was offered as prey. The LC50 obtained from the contact bioassay at 48 h after treatment was 0.015 ppm (AI). A big change in kill for a given variation in dosage for the regression slope probably indicated that abamectin was unlikely selective. Sublethal exposure to abamectin caused a reduction in survival with the female reaching 50% mortality by the sixth day and the male 4 d later. The mean preoviposition period was extended by almost 1 d, whereas the mean oviposition period was shortened by almost 5 d causing a reduction in the mean fecundity female-1 to almost half that of the untreated females. The net reproductive rate (Ro), the intrinsic rate of increase (rm), and the finite rate of increase (lambda) of the treated females were markedly inferior. Treated males were seriously affected; the mean life span was almost half that of the untreated.

The mechanism of oviposition in Argas (Persicargas) walkerae (Acari: Argasidae).

The process of oviposition in A. walkerae was observed and found to be a sequence of exactly coordinated, interlocking events independent of the age of ticks. Egg-laying always commenced with numerous dorso-ventral movements of the capitulum. The pedipalps were spread during the last dorso-ventral movement and lowered to the ventral body wall embracing the genital aperture on both sides. Simultaneously, the cuticular sac of Gene's organ emerged and immediately everted maximally. Immediately afterwards the vestibulum vaginae prolapsed from the genital aperture touching the cuticular sac. The vestibulum vaginae handed over an egg to the cuticular sac after a brief contact. Then the vestibulum vaginae invaginated, the pedipalps closed and the cuticular sac was retracted. Finally, the capitulum very frequently moved up and down and the free egg was pushed in front of the ticks. The total time of laying an egg averaged 27 min in both 4-week-old and 12-month-old ticks. In 4-week and 12-month-old ticks, egg-laying was preceded by a mean preoviposition period of 6.1 days and 7.5 days, respectively, while the mean oviposition was completed in 14 and 10 days and the average egg totals were 119 and 103.

Thermal effects on reproductive diapause induction in Orius sauteri (Heteroptera : Anthocoridae)

All females of Orius sauteri exhibited reproductive diapause at 22°C but 37% of them initiated oviposition at 26°C under 10L-14D. Although less females initiated oviposition under 10L-14D than under 14L-10D at 26°C, the mean preoviposition period under 10L-14D was shorter than that under 14L-10D at 26°C. The short photoperiod did not appear to prolong the preoviposition period under 26°C. If O. sauteri is used as a biological control agent against non-diapausing thrips like Thrips palmi in greenhouses under short photoperiod, maintaining a high temperature should be considered to prevent reproductive diapause induction in O. sauteri.

Longevity and Fecundity of Brachymeria lasus (WALKER) (Hymenoptera: Chalcididae), a Pupal Parasitoid of the Oriental Tea Tortrix, Homona magnanima DIAKONOFF (Lepidoptera: Tortricidae) under Laboratory Conditions

The life span of Brachymeria lasus (WALKER) adults fed on 10% sugar solution was longer than those fed on 1% sugar solution and distilled water. Although no mature eggs were found in the ovaries of newly-emerged females, the mean number of mature eggs per female increased with age until 7 days after emergence with a maximum of 8 mature eggs. The mean preoviposition period was 4.7 days. The mean number of progeny per day produced decreased by a single female fed on 10% sugar solution was about 6 or 5 weeks after emergence and decreased subsequently. The sex ratio of progeny was male biased and changed with age. No female progeny were observed at 13 weeks after emergence. The net reproductive rate and intrinsic rate of natural increase were 118.1 and 0.102, respectively, when females were fed on 10% sugar solution.

Globemallow, Sphaeralcea spp., as Reproductive Hosts for the Boll Weevil (Coleoptera: Curculionidae) in Arizona

Use of Sphaeralcea spp. as reproductive hosts of overwintering boll weevils, Anthonomus grandis grandis Boheman. in Arizona was investigated. Female weevils that had attained reproductive status on cotton squares, Gossypium hirsutum L., consistently failed to oviposit into flower buds of two species of Sphaeralcea. Flower buds of Sphaeralcea treated with an aqueous cotton extract contained significantly more boll weevil feeding punctures than untreated buds. A small proportion of females deposited eggs into the extracttreated Sphaeralcea buds. Significantly lessfeeding and oviposition occurred in cotton squares treated with an aqueous Sphaeralcea extract, suggesting that Sphaeralcea buds may contain chemical deterrents. Female boll weevils attained reproductive maturity after feeding exclusively on buds of S. emoryi. Mean preoviposition periods for weevils on cotton squares were significantly shorter when females fed on S. emoryi before being placed on cotton; however, the total preoviposition period on Sphaeralcea and cotton combined was considerably longer than when females fed exclusively on cotton. Boll weevils provided S. emoryi buds in simulated Arizona winter and spring environments were capable of attaining sexual maturity during a 60-d test. The role of Sphaeralcea as a potential reproductive host of boll weevils during cotton-free periods is discussed.

CIRCULIFER TENELLUS (BAKER), THE BEET LEAFHOPPER (HOMOPTERA: CICADELLIDAE): LABORATORY STUDIES ON FECUNDITY AND LONGEVITY

AbstractCirculifer tenellus (Baker) has a mean preoviposition period of 13.1, 8.2, 6.4, and 5.0 days when held at 20, 25, 28, and 32°C, respectively. The fecundity of C. tenellus averaged 105.0, 98.9, 115.7, and 196.9 eggs per female when held under the same temperatures, respectively. The longevity of the adult C. tenellus females when held under constant conditions of 20, 25, 28, and 32°C averaged 58.1, 52.7, 41.9, and 44.8 days, respectively. Fluctuating temperatures of 19–36°C under greenhouse conditions resulted in a mean preoviposition of 10.7 days and a fecundity rate of 163.4 eggs per female with females living an average of 96.3 days with a longevity range of 142 days.

Biology of Leptothrips mali,1 a Common Predator in Virginia Apple Orchards

Leptothrips mali (Fitch) (Thysanoptera: Phlaeothripidae) was studied in the laboratory with the European red mite, Panonychus ulmi (Koch), as prey. Aspects of its development and biology were determined. Mean number of days required for development of each stage at 23.9°C were: egg, 7.5; first larva, 5.7; second larva, 5.4; prepupa, 1.0; pupa I, 1.5; pupa II, 4.0; total (egg to adult), 25.6. An inverse relationship was found with temperature and development times for the egg, first- and second-stage larvae, pupa II, and total (egg to adult) at 18.3, 23.9, and 29.4°C. The mean preoviposition period (range = 5–7 days) of mated and unmated or field-collected (FC) and laboratory-reared (LR) females did not differ. Mean numbers of eggs per female were: mated LR, 13.0; mated FC, 28.0; unmated LR, 11.7; and unmated FC, 45.1. Mean longevity of unmated females (LR and FC = 50.1 and 54.2 days, respectively) did not differ from that for mated females. L. mali completed development on Golden Delicious apple pollen in 23 days (first larva to adult), which was slower than on diets containing various stages of P. ulmi.

BIOLOGY OF THE CRUCIFER FLEA BEETLE, PHYLLOTRETA CRUCIFERAE (COLEOPTERA: CHRYSOMELIDAE), IN SOUTHWESTERN ONTARIO

AbstractThe biology of the crucifer flea beetle, Phyllotreta cruciferae (Goeze), was studied in the laboratory, and under field conditions in southwestern Ontario. Field-collected adults, held in a state of induced hibernation were used for some laboratory studies. A rearing procedure was developed and a culture maintained for eight generations provided additional adults for laboratory work. Development and behaviour of the various crucifer flea beetle stages at different temperatures were studied. The mean preoviposition period ranged from 3.8 (32°C) to 22 (20°C) days. Time required for development from egg to adult varied from 24 (30°C) to 54 (20°C) days. For oviposition capability and egg to adult development, developmental thresholds were ca. 17° and 11°C, respectively, and 61 and 456 degree days were required. Crucifer flea beetle adults overwintered in leaf litter and the top 2.5 cm of soil, in windbreaks, fencerows, and cultivated areas. Adults appeared in early spring. Peak adult movement occurred at this time, primarily within 2 m of the ground, and oriented toward crucifer plots. Using heat unit summations calculated from soil temperatures, adult emergence in the field from eggs set out at various times was predicted with an accuracy of ± 3.7 days. Population studies and heat unit accumulations indicated that there was a single generation of crucifer flea beetle in 1974, and two generations in 1975. Adults were restricted primarily to cruciferous crops, with rutabaga and Chinese cabbage being the preferred hosts, among those varieties tested.

Comparative Development and Fecundity of Corn Earworm1 Reared on Selected Wild and Cultivated Early-Season Hosts Common to the Southeastern U.S.2,3

The corn earworm, Heliothis zea (Boddie), was reared on corn soy blend (CSB) artificial diet, flowers and fruit of toadflax, Linaria canadensis L.; frosty blue lupine, Lupimis augttstifolins L., cranesbill, Geranium carolinianum L; crimson clover, Trifolium incarnatum L; narrow leaf vetch, Vicia angustifolia Reichard; cudweed, Gnaphalium spathulatum Lam.; or on the leaf roll of whorl-stage Ioana sweet corn. There were significant differences in time to pupation and adult emergence, weights of pupae and adults, preoviposition periods, numbers of spermatophores transferred, and numbers of eggs oviposited. Mean time to pupation ranged from 21.8 days on CSB diet to 30.6 days on corn leaf roll. Mean preoviposition period ranged from 2.0-2.9 days on CSB diet and crimson clover, respectively, and total number of eggs oviposited ranged from 2069 to 417, respectively.

Mating, Oviposition Patterns, Fecundity and Longevity of the Western Corn Rootworm12

Field-collected mating pairs of Diabrotica virgifera LeConte were maintained under controlled laboratory conditions. Females lived an average of 78.2 days, had a mean preoviposition period of 12.2 days, and a mean fecundity of 1087 eggs laid in 13.5 clutches over a reproductive period of 76.4 days. Intervals between clutches averaged 5.0 days through the 8th clutch or to 75% oviposition. Females reared from field-collected soil and mated in the laboratory laid fewer eggs. Males lived an average of 102.4 days. Females copulated only once; males will mate with several females. Egg-laying started at a high level with the 3rd clutch averaging largest and, for each female observed, one of her 1st 4 clutches was the largest. On a seasonal basis, 24% of the potential egg population were laid by Aug. 25, and 57% by Sept. 10, 83% by Sept. 30, and 90% by Oct. 10. Mating apparently speeds ovarian development. Ovaries of active gravid females fluctuate between ratings 4 to 3 to 4 etc., and this fact should be considered in interpretations of field populations examined for ovarian development.

The subgenus Persicargas (Ixodoidea: Argasidae: Argas). 19. Preliminary studies on diapause in A. (P.) arboreus Kaiser, Hoogstraal & Kohls.

In the population of Argas (Persicargas) arboreus in the Cairo area, incidence of diapause, as expressed by oviposition delay, increases from September to October in the laboratory environment. Diapause terminates from November to May in the laboratory and from April to June outdoors. The laboratory environment does not alter incidence of diapause but lowers its intensity (mean preoviposition period) after females feed in October. Diapause intensity and the difference between diapausing and nondiapausing preoviposition periods is greater in laboratory-reared F1 females than in field-collected females. The nondiapausing preoviposition period in fieldcollected females is 6–40 days and in laboratory-reared females 4–50 and 4–17 days after the 1st and 2nd blood meals, respectively.

Adult Western Corn Rootworms: Oviposition, Fecundity, and Longevity in the Laboratory123

In the laboratory, adults of Diabrotica virgifera LeConte had a mean preoviposition period of 14.3 days, a mean longevity of 94.8 days, and a mean fecundity of 1023 eggs per female (or 10.4 eggs per female per day). The pattern of egg laying indicated that oviposition began at a high level, peaked after about 10–15 days, and then slowly declined. Female beetles apparently were able to lay viable eggs for at least 60 days after mating.

Development, Fecundity, and Longevity of Leschenaultia adusta, a Tachinid Parasite of the Salt-Marsh Caterpillar123

The tachinid parasite Leschenaultia adusta (Loew) developed from egg to adult in the salt-marsh caterpillar, Estigmene acrea (Drury) in a maximum of 89.5±2.8 days at 15°C and a minimum of 17.6±0.8 days at 30°C. Parasitized larvae did not survive at 35°C. One female produced 4572 eggs, whereas the mean was 1939±1365 for al females tested. At 26.7±1.1°C, the mean preoviposition period was 7.6±1.0 days, the mean days of oviposition 9.1±6.5, and the mean longevity 17.0±6.8 days.

Biology of Euxoa tristicula in the Field and Laboratory1

A moderate to severe infestation of larvae of E. tristicula Morrison on sugarbeets at Taber, Alberta, in 1967 provided an opportunity for studies on the biology of this cutworm. A diapause permits the larvae to survive the winter and to resume feeding in the spring. In the laboratory the mean durations of egg and pupal stages were 6 and 20 days, respectively, and each varied inversely with temperature. The mean preoviposition period was 9 days, mean oviposition per female was 402 (range 260–762), and mean longevity of moths was approximately 20 days. Temperatures below 10°C inhibited hatching and if hatching temperatures were not suitable, embryos died.