scholarly journals PARAMETER NERACA HAYATI DAN PERTUMBUHAN POPULASI KUTU PUTIH Phenacoccus manihoti Matile-Ferrero (HEMIPTERA: PSEUDOCOCCIDAE) PADA DUA VARIETAS UBI KAYU

2014 ◽  
Vol 14 (1) ◽  
pp. 64-70
Author(s):  
Nila Wardani ◽  
Aunu Rauf ◽  
Wayan Winasa ◽  
Sugeng Santoso

ABSTRACTThe life history and population growth parameters of mealybug Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae) on two cassava varieties. The development, reproduction, and population growth parameters of the cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae) on two cassava varieties were studied in laboratory. The varieties tested were UJ-5 with high cyanide content (>100 mg per kg) dan Adira-1 with low cyanide content (27.5 mg per kg).  Our research revealed that P. manihoti performances were highly affected by cassava varieties.  Incubation period of eggs of P. manihoti were 7.93 ±  0.09 and 8.33 ± 0.11 days, nymphal development periode 12.32±0.13 and 15.67 ± 0.13 days, respectively on UJ-5 and Adira-1. Fecundity averaged 386.37 ± 5.83 on UJ-5 and 318.67±2.81 eggs on Adira-1. Intrinsic rate of increase (rm) were  0.258 ± 0.001 on UJ-5 and  0.220 ± 0.001 on Adira-1. Mean generation time (T) on UJ-5 and Adira-1 were 22.795 ± 0.050 and 25.532 ± 0.047 days, repectively. Our findings showed that variety UJ-5 was more suitable for development and population growth of the cassava mealybug.

2021 ◽  
Vol 26 (5) ◽  
pp. 962-972
Author(s):  
Zarir Saeidi ◽  
Alireza Nemati ◽  
Elham Riahi

The development, longevity, and reproductive potential of Schizotetranychus smirnovi concerning different almond cultivars including Sefid, Azar, Shokofeh, Shahrood6, Shahrood7, Ferragnes, Shahrood13, Shahrood21, Rabie, Nonpareil, and Mamaei were investigated in the current study. Our results indicated the longest developmental time of females on Shahrood21 (7.35 ± 0.10), while the shortest duration of this parameter was found on Rabie (6.21 ± 0.10) and Nonpareil (5.88 ± 0.17) cultivars. The total mortality ranged from 13.30 to 50.00% on Azar and Shokofeh, respectively. On the majority of cultivars, the highest proportion of mortality among all stages was allocated to larvae which indicated that it was the most sensitive stage. The fecundity of S. smirnovi on Mamaei (34.19 ± 3.60), Sefid (30.50 ± 2.67), and Ferragnes (30.31 ± 3.02) was significantly higher than other cultivars. However, the lowest fecundity (11.21 ± 1.70) was observed on Shokofeh cultivar. Moreover, different cultivars resulted in significant differences in all population growth parameters. Azar had the highest value of both intrinsic rate of increase (r) (0.2675 ± 0.0164) and finite rate of increase (λ) (1.3067 ± 0.0213), whereas the value of these parameters on Shokofeh and Shahrood21 were significantly lower than other cultivars. The mean generation time (T) ranged from 9.51 ± 0.16 on Shahrood7 to 11.69 ± 0.39 d on Shahrood21 cultivar. According to our results, Mamaei, Nonpareil, Rabie, Ferragnes and Azar cultivars were more susceptible, while Shokofeh, Shahrood21, and Shahrood13 seemed to be more tolerant to S. smirnovi.


Author(s):  
Akram Bakhshi ◽  
Ali Asghar Talebi ◽  
Yaghoub Fathipour ◽  
Ali Mirshekar

In this research, three age groups of Plodia interpunctella (Hübner) eggs (1-, 2- and 3-day-old eggs) were exposed to ultraviolet irradiation (UVC) with 254nm wavelength for 0.5, 1, 1.5, 2, 4, 8, 16, 24, 32 and 40 minutes, under controlled conditions. The effect of UVC-irradiation on reproduction and population growth parameters investigated for eggs irradiated for 0.5, 1 and 1.5 minutes. The percentage of egg hatching decreased with increase in UVC exposure time, while for each exposure time, the older eggs were more sensitive than the younger ones. The results indicated that different exposure times of UVC-irradiation could affect the reproduction and population growth parameters. The highest value of net fertility rates was observed in 1, 2 and 3-day-old eggs which were treated with 0.5 min exposure. Both the intrinsic rate of increase (rm) and the net reproductive rate (R0) decreased with increasing exposure time from 0.5 to 1.5 min while the mean generation time (Tc) and doubling time (DT) increased within this irradiation range. The lowest amount of rm was obtained in 1, 2 and 3-day-old eggs which were treated with 1.5 min exposure time. The results showed that UVC-irradiation is an appropriate technique for controlling P. interpunctella.


Acarologia ◽  
2017 ◽  
Vol 57 (3) ◽  
pp. 607-616
Author(s):  
Ali Golizadeh ◽  
Samira Ghavidel ◽  
Jabraeil Razmjou ◽  
Syed Ali Asghar Fathi ◽  
Mahdi Hassanpour

Life history parameters of plant feeders are useful tools to evaluate resistance or susceptibility of host plants including different cultivars. This study compared population growth parameters of Tetranychus urticae Koch on 10 rose cultivars, including Bella Vita, Cool Water, Dolce Vita, Maroussia, Orange Juice, Pink Promise, Roulette, Tea, Valentine, and Persian yellow in laboratory conditions at 24+/-1°C, 65+/-5% relative humidity, and a photoperiod of 16:8 (L:D) h. The results revealed that mite survival rate varied from 66.5% on Bella Vita to 85.9% on Persian yellow. The immature development time was different among the tested rose cultivars and ranged from 9.35 days on Orange Juice to 12.30 days on Bella Vita. The highest fecundity rate was recorded on Pink Promise. Consequently, population growth parameters were also significantly affected. The lowest intrinsic rate of increase (rm) was recorded on Roulette and this parameter was relatively higher on Cool Water, Orange Juice, and Persian yellow. In addition, the highest net reproductive rate (R0) was observed on Pink Promise, which was significantly higher than Roulette, Tea, and Valentine cultivars. The longest mean generation time (T) was calculated on Roulette and the shortest on Cool Water, Tea, and Orange Juice. The lowest performance of the two-spotted mite on Roulette could indicate that this is a suitable cultivar against mite infestation. Differences in mite susceptibility of tested rose cultivars here highlighted have the potential to be used for integrated pest management of T. urticae in ornamental rosa cultivations.


2017 ◽  
Vol 22 (1) ◽  
pp. 7 ◽  
Author(s):  
Fatemeh Ganjisaffar ◽  
Thomas M. Perring

The predatory mite, Galendromus flumenis (Chant) (Acari: Phytoseiidae), has shown promising traits for biological control of Banks grass mite, the major pest of date palms in California. In the present study, reproduction and population growth parameters of G. flumenis on Banks grass mite eggs were studied at 34ºC, 50±10% RH and a photoperiod of 16: 8 (L: D) hours. 100 percent of eggs hatched and 63.5 percent of the emerged larvae survived to adulthood. The total immature developmental time was 5.7 and 5.5 days for females and males, respectively. The sex ratio of G. flumenis was 0.70 (females/ females+ males). Mated females laid on average 1.6 eggs per day and 19.9 eggs during their mean ovipositional period of 12.5 days. The net reproductive rate (R0) was 11.5 females/ female/ generation, the intrinsic rate of increase (rm) was 0.200 females/ female/ day, the finite rate of increase (λ) was 1.222 population multiplication/ day, the mean generation time (T) was 12.2 days, and the doubling time (DT) was 3.5 days. The lower rm value of G. flumenis than that of its prey (0.24–0.48) explains why Banks grass mite escapes control by G. flumenis in field. These results suggest that augmentative release of this predator would offset the lower rm of the predator, thereby contributing to the control of Banks grass mite. Combined with the benefit of early releases determined in companion studies, future field studies with G. flumenis are being planned.


2017 ◽  
Vol 22 (10) ◽  
pp. 1748 ◽  
Author(s):  
Irena Međo ◽  
Bojan Stojnić ◽  
Dejan Marčić

Laboratory bioassays were conducted to evaluate the toxicity of the microbial pesticide spinosad to different life stages of the two-spotted spider mite, Tetranychus urticae Koch, as well as its sublethal effects on reproduction and population growth of this important mite pest. The biopesticide was applied to bean primary leaves or leaf discs carrying spider mites using a Potter spray tower (2.7 mg/cm2 aqueous deposit). The following LC50 and LC90 (mg/L) estimates for motile stages were obtained in acute toxicity bioassays: 27.52 and 116.72 (larvae), 36.55 and 136.20 (protonymphs), 82.76 and 721.28 (female deutonymphs), and 61.47 and 457.21 (adult females). Spinosad showed no significant ovicidal action: toxic effect observed after spraying eggs (LC50 = 105.78 mg/L, LC90 = 596.95 mg/L) was the result of its residual action on larvae that hatched from the treated eggs. The effects of spinosad on life history traits and population growth of adult female survivors from treatments with 240, 120 and 60 mg/L were evaluated in two successive 7-day bioassays on untreated leaf discs. In the first bioassay, females that survived treatments as 24 h old eggs and completed their juvenile development on treated leaves had significantly lower gross fecundity, net fecundity and instantaneous rate of increase (ri) but the reduction was merely 4–6%, 9–11%, and 2–3%, respectively. Female longevity was significantly reduced (approximately by half a day) only after treatment with 240 mg/L. In the second bioassay, in which females were treated during their pre-ovipositional period, the treatments with 240 and 120 mg/L significantly reduced their gross fecundity (16–17%), net fecundity (28–31%), ri values (8–9%) and female longevity (approximately by one day). Spinosad effects on the intrinsic rate of increase (rm) and other demographic parameters were evaluated in two successive bioassays in which life tables were constructed for females that survived treatment with 120 mg/L at the egg stage (first demographic bioassay) or pre-ovipositional period (second demographic bioassay). In the first bioassay, the intrinsic rate of increase was significantly higher in treated (rm = 0.278) than control mites (rm = 0.267) as a result of higher net fertility at the beginning of reproduction of treated females. In the second bioassay, treated females had significantly lower rm than control females (0.254 and 0.283, respectively). The results obtained in this study indicate that spinosad, applied against insect pests (at field relevant rates of 60–240 mg/L), could eliminate a part of T. urticae population as well, but survivors would retain a significant potential for population recovery. 


2018 ◽  
Vol 68 (4) ◽  
pp. 333-352 ◽  
Author(s):  
V.S. Nagrare ◽  
Bhausaheb Naikwadi ◽  
Vrushali Deshmukh ◽  
S. Kranthi

Abstract The cotton mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae), is an invasive pest of cotton, apart from several other important crops, and poses a serious threat to agricultural economy all over the world. Studies on the biology and population growth parameters of P. solenopsis on the five most preferred host plants, namely cotton (Gossypium hirsutum L.) (Malvaceae), China rose (Hibiscus rosa-sinensis L.) (Malvaceae), tomato (Lycopersicon esculentum Mill.) (Solanaceae), congress grass (Parthenium hysterophorus L.) (Asteraceae) and okra (Abelmoschus esculentus (L.) Moench) (Malvaceae) were undertaken in the laboratory under controlled temperature and relative humidity. The mean cumulative development time of females was 16.61 days on cotton, 14.16 days on China rose, 14.13 days on okra, 14.00 days on tomato and 13.57 days on congress grass. The longest oviposition period was recorded on cotton (15.20 ± 1.87 days), while it was in the range of 9-10 days in the remaining host plants. Females lived longer (27.40 ± 1.76 days) when reared on cotton, while their life was shortest on tomato (14.60 ± 0.96 days). The highest fecundity was observed on cotton (328.30 ± 23.42), whereas it was found to be in the range 178-212 on the other hosts. The survival frequency from crawler to adult in females was highest on cotton (27.53%), while it was the lowest on tomato (15.87%). The highest net reproductive rate (284.3 females/female/generation), mean length of a generation (31.24 days), and intrinsic rate of increase (0.19 day−1) were recorded on cotton. The finite rate of increase was in the range of 1.18-1.20 (females/female/day) for all the selected host plants. The weekly multiplication rate was highest on China rose and congress grass (3.78), while it was the least on tomato (3.28). The corrected generation time was dissimilar in all the selected host plants, being highest on cotton (31.39 days) and the least on congress grass (27.71 days). The doubling time was shortest on congress grass (3.61 days), while it was longest on tomato (4.11 days). Hence, the host plant species significantly affects population growth of P. solenopsis.


2020 ◽  
Vol 25 (11) ◽  
pp. 2063-2076
Author(s):  
Nuwan Weerawansha ◽  
Qiao Wang ◽  
Xiong Zhao He

Tetranychus ludeni Zacher (Acari: Tetranychidae) is an invasive polyphagous haplodiploid pest mite of many vegetable crops in many parts of the world. This study investigated the effects of simultaneous variations in the local foundress population density and size on the reproduction and population growth of T. ludeni. We show that negative population-density and -size dependency limited the reproduction of foundresses, where the effects of population size on population growth overweighed that of population density. We further demonstrate that ovipositing females could accelerate population growth rate (intrinsic rate of increase, rm) at higher population sizes by producing more daughters early during their lifespan, which can be an adaptive strategy to allow more daughters to complete development and disperse to reduce future food competition intensity. This study provided knowledge on population dynamics in response to foundress population density and size in general and T. ludeni population forecast and precise timing of pest management in particular.


1977 ◽  
Vol 109 (2) ◽  
pp. 277-284 ◽  
Author(s):  
A. Campbell ◽  
M. Mackauer

AbstractThe effect of temperature on the age-specific fecundity and the survival of apterous and alate virginoparous pea aphid, Acyrthosiphon pisum (Harris), from Kamloops, B.C., was measured. Demographic statistics were estimated for 10.3°, 14.8°, 19.7°, 26.1°, and 27.8°C constant and for fluctuating field temperatures. On a 24-h-day time-scale, temperature and longevity were inversely related in both morphs; total fecundity was highest at average and low constant temperatures. On a physiological time-scale, the intrinsic rate of increase (rm) was insensitive to changes in constant temperature in the range between 10° and 20°C; temperatures above 25°C were detrimental to aphid population growth and survival. Alate virginoparae generally had a longer pre-reproductive period and achieved a lower mean total fecundity than apterae maintained under identical conditions. The usefulness of laboratory measurements for the prediction of population growth under variable field temperatures is discussed. Differences in the reproductive patterns of alate and apterous pea aphids are considered in the context of the r- and K-hypothesis of selection.


2021 ◽  
Vol 57 (No. 4) ◽  
pp. 310-317
Author(s):  
Evin Polat Akkopru ◽  
Serdal Bozkurt

 In this study, population growth parameters of Aphis gossypii Glover (Hemiptera: Aphididae) on five different melons [Cucumis melo Linnaeus (Cucurbitaceae) cultivars (Balin, Çıtırex, 221 F1, Gediz, Yusufbey)], which are commonly grown in Turkey, were investigated in laboratory experiments. Life table parameters were estimated according to age-stage and two-sex life table theory. The results showed that A. gossypii developed more successfully on the Gediz cultivar due to the higher intrinsic rate of increase (0.5042 1/day), the finite rate of increase (1.6557 1/day) and the shorter mean generation time (8.161 days) than the other cultivars. Ecological pest control against aphids' use of resistance or less favourable host plant cultivars is considered one of the significant components of pest management. The findings obtained in this study can be used in the pest management program designed for the aphid.


1974 ◽  
Vol 25 (3) ◽  
pp. 351 ◽  
Author(s):  
RJ Rippingale ◽  
EP Hodgkin

The intrinsic rate of increase of an animal population can be calculated from data on longevity, sex ratio, maturation rate and fecundity and can be expressed as r in the population growth equation Nt = N0ert. Laboratory and field data are used to calculate the value of r per day for the copepod Gladioferens imparipes Thomson. The r values obtained, 0.146 per day at 15� C and 0.293 per day at 25� C, are both high. This high population growth potential is interpreted as an adaptation to the estuarine habitat.


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