Total Immature Stages Research Articles

보리두갈래진딧물 [Schizaphis graminum (Rondani)]의 온도발육과 발육모형

The development of Schizaphis graminum (Rondani) was studied at various constant temperatures ranging from 15 to , with RH, and a photoperiod of 16L:8D. Mortality of the stage nymphs were similar at most temperature ranges while at high temperature of , more stage individuals died. The total developmental time ranged from 13.8 days at to 4.9 days at suggesting that the higher the temperature, the faster the development. However, at higher end temperature of the development took 6.4 days. The lower developmental threshold temperature and effective accumulative temperatures for the total immature stage were and 105.9 day-degrees, respectively and the nonlinear shape of temperature related development was well described by the modified Sharpe and DeMichele model. The normalized cumulative frequency distributions of developmental period for each life stage were fitted to the three-parameter Weibull function. The attendance of shortened developmental times was apparent with nymph, and total nymph stages in descending order. The coefficient of determination ranged between 0.80 and 0.87.

Effect of temperature on the development, fecundity, progeny sex ratio and life-table of Campoletis chlorideae, an endolarval parasitoid of the pod borer, Helicoverpa armigera

Development, survival, fecundity, progeny sex ratio (PSR) and age-specific life-table parameters of the parasitoid Campoletis chlorideae Uchida (Hymenoptera: Ichneumonidae) were examined at six different constant temperatures (12, 17, 22, 27, 32 and 37°C) in the laboratory [70 ± 10% RH and 10:14 h (light:dark) photoperiod]. Second instar larvae of Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) were reared on chickpea (Cicer arietinum L.) and used as the host. Development times shortened as the temperature increased from 12 to 37°C. The estimated lower developmental threshold (tL) was 3.4°C. The thermal summation for total immature stages was 379.97 degree-days. A reciprocal relationship between temperature and longevity was observed in the range of 12–17°C. The maximum mortality of pupae (71.8%) occurred at 37°C. At 22°C, the yield of a female parasitoid averaged 137.3 ± 14.7 (mean ± SD) progeny, of which 89.6 ± 7.6 were daughters. The number of daughters produced decreased when the females were kept either above or below 22°C, although the PSR was female biased in the range of 17–27°C. The analyses of life-table parameters, developmental rates, reproduction, mortality and PSR suggest that maximum population growth (rm) is near 27°C. There was little variation observed in most of the desired qualities of C. chlorideae in the range of 17–27°C, and it appears that the parasitoid is adapted to a wide range of temperatures. We suggest that for maximum production the parasitoid should be reared at 22 ± 4°C and be released in areas where the temperature ranges between 17° and 27°C, as in the plains of northern India.

Immature Morphology and Development of <I>Opius caricivorae</I> (Hymenoptera: Braconidae), an Endoparasitoid of the Leafminer <I>Liriomyza sativae</I> (Diptera: Agromyzidae)

The immature development and morphological characteristics of Opius caricivorae Fischer (Hymenoptera: Braconidae), an endoparasitoid of dipteran leafminers, were studied under laboratory conditions at 25°C constant temperature on the host Liriomyza sativae Blanchard (Diptera: Agromyzidae). Most of the parasitoid females prefer to oviposit into the third instars of the host. They always laid a single egg per ovipositor insertion and superparasitized the same host in a few occasions when hosts were limited. Parasitoid eggs are of the hymenopteriform type. During the embryonic development (49 h) the eggs increased in size more than two-fold. Five instars occurred in this species. The first instar is of the caudate-mandibulate type bearing falcate appendages, whereas the second to fifth instars are hymenopteriform with simple mandibles, and they are similar to each other. The first instar remains inside its chorion after hatching until it molts into a second instar. A new structure, namely, transverse sclerite, in the cephalic structure of the fifth instar was found located between the maxillary palpi. Under laboratory conditions, the duration of the total immature stages lasted ≈327 h. The immature stages are described and illustrated using light microscopy, and they are compared with those of other apocritan parasitoids.

Effects of Temperature on the Immature Development of the Stone Leek Leafminer <I>Liriomyza chinensis</I> (Diptera: Agromyzidae)

The effect of nine constant temperatures (15, 17.5, 20, 22.5, 25, 27.5 30, 32.5, and 35 degrees C) on the development of the stone leek leafminer, Liriomyza chinensis (Kato), on Japanese bunching onion, Allium fistulosum L., was studied in the laboratory. Developmental times for immature stages were inversely proportional to temperature between 15 and 30 degrees C but increased at 32.5 degrees C. Total developmental times from egg to adult emergence decreased from 69.6 to 17.1 d for temperatures from 15 to 30 degrees C, with pupae requiring more time for development than the combined egg and larva stages. Both linear and nonlinear (Logan equation VI) models provided a reliable fit of development rates versus temperature for all immature stages. The lower developmental thresholds that were estimated from linear regression equations for the egg, first, second, and third instars, total larva, egg-larval, pupa, and total combined immature stages were 12.1, 10.6, 13.6, 8, 9.6, 11.3, 11.2, and 11.4 degrees C, respectively. The degree-day accumulation was calculated as 312.5 DD for development from egg to adult emergence. By fitting the nonlinear models to the data, the upper and optimal temperatures for egg, larva, pupa, and total immature stages were calculated as 37.8 and 31.7, 34.9 and 30.1, 35.8 and 30.6, and 35.0 and 30.9 degrees C, respectively. These data are useful for predicting population dynamics of L. chinensis under field conditions and determining the maximum proportion of susceptible individuals for facilitating improved timing of application of control measures.

Temperature effects on life history traits of the corn leaf aphid, Rhopalosiphum maidis (Homoptera: Aphididae) on corn in Taiwan

The effects of temperature on the life history traits of Rhopalosiphum maidis (Fitch) were determined at 6, 10, 15, 20, 25, 30, and 35±1°C on corn leaves, Zea mays (L.). At 35°C, only a few nymphs survived and completed development, but all failed to reproduce. Total immature stages from birth to adult decreased as temperature increased from 51.7 d at 6°C to 5.2 d at 30°C, but became 8.0 d at 35°C. Overall immature development required 119.05 degree-days above 4.44°C. Adult longevity was as high as 26.7 d at 15°C, but significantly declined at 30 and 35°C. The average adult fecundity was as high as 45 offspring at 15 and 20°C, but dropped to 1.8 at 6°C and 8.6 at 30°C. In general, as temperatures increased, age-specific survivorship (lx) declined more quickly, but age-specific fecundity (mx) peaked earlier. At 25°C, the age-specific net maternity (vx=lxmx) was the highest in the early reproductive period, resulting in the highest intrinsic rates of increase (rm=0.329). At 20–30°C, the values of rm were significantly higher than those at lower temperatures. The results indicate that corn leaf aphids probably are better adapted in population growth to a wider range of high temperatures in warm regions.

Temperature-dependent development and reproduction of the boll weevil (Coleoptera: Curculionidae)

Abstract Effects of temperature on development, survival, and fecundity of boll weevil, Anthonomus grandis grandis Boheman, were assessed at 10, 11, 12, 15,20,25,30,35,45, and 46 °C; 65% relative humidity; and a photoperiod of 13:11 (L: D) h. The mortality of boll weevil immature stages was 100% at 12°C and decreased to 36.4% as the temperature increased to 25°C. When the temperature increased from 30 °C to 45 °C, the mortality of weevils also increased from 50.1% to 100%. From 15°C to 35°C, the bollweevilpreimaginal development rate was linearly related to temperature. The average development time of total boll weevil immature lifestages decreased 3.6-fold and the preovipositional period decreased 3.3-fold when the temperature was increased from 15°C to 30°C. The lower threshold for development was estimated at 10.9, 6.6, 7.0, and 9.0 °C for eggs, larval, pupal, and total immature stages, respectively, with total thermal time requirement to complete immature stages of 281.8 DD (degree day) (15°C) and 247.8 DD (35 °C). At 1LC and 46°C, weevil females did not oviposit. Longevity of adult females decreased 4.6-fold with increasing temperatures from 15°C to 35°C. Fecundity increased with increasing temperatures up to 30°C and significantly decreased thereafter. These findings will be useful in creating a temperature-based degree-day model for predicting the occurrence of key life stages in the field. An accurate predictor of a pest's development can be very important in determining sampling protocols, timing insecticide applications, or implementing an integrated pest management control strategy targeting susceptible life stages.

The Morphology and Temperature-dependent Development of Mylabris phalerata Pallas (Coleoptera: Meloidae)

The morphology and life history of Mylabris phalerata Pallas (Coleoptera: Meloidae) were observed. The effect of temperature on the duration of immature stages of M. phalerata reared at 18, 22, 25, 28, 31, and 34°C was determined. The adaptable temperature for artificial mass rearing was ≥28°C. Lower developmental thresholds were estimated to be 6.38, 6.29, 7.72, 7.08, 5.25, 17.62, and 5.58°C for egg, larval instars L1, L2, L3, L4, L5 and pupa, respectively, and the thermal constant was 1,715.59 degree-days for total immature stages, using the linear model. Based on the developmental cycle of M. phalerata, its known geographic distribution, and temperature data, diapause is attributed to the overwintering fifth-instar larva.

Seasonal Distributions of Eggs and Larvae of Rhagoletis indifferens Curran (Diptera: Tephritidae) in Cherries

The seasonal distributions of eggs and first-, second-, and third-instar larvae of the western cherry fruit fly, Rhagoletis indifferens Curran (Diptera: Tephritidae), in sweet cherries were determined at three sites in central Washington in 2002 and 2003. The egg was the major stage during early, mid and late season. The distributions of eggs (i.e., the percentages of total immature stages that were eggs) were similar all season, but those of first, second and third instars were greatest in late season. First, second and third instars occurred in similar numbers in 2002, but third instars were the most abundant in 2003. Tree quadrant had no effect on egg and larval densities and distributions. The majority of infested fruit had only one egg or larva, but there were significant increases in percentages of fruit with two or ≥ three eggs or larvae as percentages of fruit that were infested increased during the season. When there were two larvae in a fruit, one was larger than the other in 90.8% of cases. Results indicate time of season but not location within trees (1.5 to 2 m above ground) has differential effects on egg and larval distributions in fruit and on female oviposition behaviors that may result in multiple infestations and larval interactions. Seasonal effects on immature stages are probably related to developmental times and stage-specific mortality; whereas, effects on adults may be related to reduced availability of unoccupied fruit for oviposition.

Effect of Temperature on Development, Survivorship, and Reproduction of Rice Root Aphid (Homoptera: Aphididae)

Development, survivorship, and reproduction of rice root aphid, Rhopalosiphum rufiabdominalis (Sasaki), were measured at 10, 15, 20, 25, 30, and 35°C. The developmental time from 1st instar to adult varied from 20.7 d at l0°C to 4.4 d at 30°C. The lower-temperature developmental thresholds for 1st through 4th instars and total immature stages were estimated at 7.0, 6.2, 6.3, 5.1, and 6.1°C, respectively. A modified Logan model was used to describe the relationship between developmental rate and temperature. The survival of total immature stages varied from 52.7 to 90.23% within the temperature range of 10–30°C. At 35°C, nymphs did not develop beyond the 4th instar. The average longevity of adults ranged from 29.73 d at 10°C to 9.42 d at 30°C. The mean number of nymphs produced by R. rufiabdominalis varied from 63.32 at 20°C to 31.88 at 30°C. Life table parameters also were determined at 5 constant temperatures (10–30°C). The population reared at 25°C had the highest intrinsic rate of increase ( r m) (0.432), the shortest population doubling time (1.61 d) and shorter mean generation time (8.7 d) compared with populations reared at other temperatures. The highest net reproduction rate ( Ro ) was recorded at 20°C (57.23). The optimum range of temperatures for R. rufiabdominalis population growth was 20–25°C.

Development of Microcharops anticarsiae Gupta (Hym., Ichneumonidae), an endoparasitoid of the velvetbean caterpillar, Anticarsia gemmatalis (Lep., Noctuidae) and morphology of its immature stages

Abstract: Microcharops anticarsiae Gupta, a solitary larval endoparasitoid, is an efficient enemy of its natural host, Anticarsia gemmatalis, as well as some other lepidopterous pests. Development and behaviour of this insect species, as well as morphology of immature stages were studied in the present work. As an oviposition site, most of the parasitoid females preferred the posterior region of the host body. During the embryonic development the eggs increased in size. The larval stage consisted of four instars. The morphometric measurements of the head and mandibles were determined. The first instar larva is caudate‐mandibulate type. During each successive molt it turns more and more cylindrical with reduced tail length. Among the fourth instar larvae, rudiments of legs, spiracles and of genital openings are visible. Under laboratory conditions the duration time of the total immature stages lasted an average of 18.48 ± 0.13 days. While male adult longevity was on average 18.7 ± 1.5 days, that of the female extended for 21.9 ± 1.6 days. The total life cycle of males and females lasted 41.6 ± 1.7 and 45.9 ± 0.26 days, respectively.