Effect of plant nitrogen and silica on the bionomics ofSesamia calamistis(Lepidoptera: Noctuidae)

1993 ◽  
Vol 83 (3) ◽  
pp. 405-411 ◽  
Author(s):  
M. Sétamou ◽  
F. Schulthess ◽  
N. A. Bosque-Pérez ◽  
A. Thomas-Odjo

AbstractThe effects of nitrogen and silica application to maize plants on various aspects of the bionomics of the maize stem borer,Sesamia calamistisHampson, were studied in the laboratory. Increasing nitrogen doses significantly increased larval survival (from 18.7% (control) to 37.3% at 2.25 g N/plant), larval weight (from 49.0 mg (control) to 99.5 mg at 2.25 g N/plant), and female fecundity (from 77 eggs per female (control) to 365 eggs per female at 1.69 g N/plant). A significant, positive relationship was found between moth fecundity and female pupal weight. Nitrogen had no effect on larval and pupal developmental time but increased adult longevity. Intrinsic rate of increase, rm, and the net reproductive rate, Ro, were positively related to leaf and stem nitrogen, while generation time, G, was negatively related. Silica had the opposite effect from nitrogen on larval survival. Increasing silica supply reduced ultimate larval survival from 26.0% (control) to 4.0% at 0.56 g Si/plant. Immature developmental time, larval and pupal weight, pupal survival, female fecundity, egg viability and adult longevity ofS. calamistiswere not affected by silica application.

Insects ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 99 ◽  
Author(s):  
Anna Skourti ◽  
Nickolas G. Kavallieratos ◽  
Nikos E. Papanikolaou

In the current study it was investigated the suitability of semolina, cracked wheat and cracked maize as feeding commodities for the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae). The pest completed its development on all tested commodities. The developmental time of larvae was lower on cracked wheat (59.6 days) and cracked maize (54.6 days) compared to semolina (72.8 days). The developmental time of pupae did not differ significantly among tested commodities, ranging from 6.2 to 6.6 days. Female and male longevities were 70.9 and 77.1 days, 92.2 and 77.9 days and 177.0 and 183.7 days, when T. castaneum was fed on semolina, cracked wheat and cracked maize, respectively. The highest fecundity (28.7 eggs/female) was recorded when T. castaneum was fed on semolina, followed by cracked wheat (2.7 eggs/female) and cracked maize (1.2 eggs/female). The prolonged adult longevity, which was observed on cracked maize, may be attributed to the absence of the cost of reproduction, due to low fecundity on this commodity. The values of the intrinsic rate of increase were 0.014 and −0.021 females/female/day when it was fed on semolina and cracked wheat, respectively, while no demographic analysis was carried out for cracked maize due to high early larval mortality and low fecundity on this commodity. The net reproductive rate and mean generation time were 6.19 females/female and 127.5 days and 0.16 females/female and 91.9 days, when it was fed on semolina and cracked wheat, respectively. Based on demographic analysis, T. castaneum population growth is favored only on semolina. We expect semolina to act as a suitable commodity for T. castaneum, while cracked wheat and cracked maize allow only its survival by acting as alternative commodities. The estimated demographic parameters of T. castaneum on the tested commodities could be used as a useful tool to predict its population outcome in storage facilities.


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.


Author(s):  
Jie Su ◽  
Fang Dong ◽  
Si-min Liu ◽  
Yan-hui Lu ◽  
Jian-ping Zhang

Abstract The predatory mite, Neoseiulus bicaudus (Wainstein), is a potential biological control agent against spider mites and thrips. The objective of this experiment was to compare the effects of three diets on the life table of N. bicaudus. The three diets were 1) Tetranychus turkestani (Ugarov & Nikolskii) (Acari: Tetranychidae), the natural prey of N. bicaudus; 2) Tyrophagus putrescentiae (Schrank) (Acari: Acaridae), an alternative prey; and 3) artificial diet primarily consisting of decapsulated shrimp cysts, egg yolk, and honey. The computer simulation was used to project the population growth of N. bicaudus fed on different diets. The preadult developmental time (3.83 d) of N. bicaudus was shortest, and the intrinsic rate of increase (r = 0.2782 d−1) and the net reproductive rate (R0 = 18.98 offspring) were highest when reared on the alternative prey Ty. putrescentiae. The total development time (7.37 d) was longest, and the population parameters were the lowest (r = −0.0081 d−1, R0 = 0.85 offspring) when N. bicaudus was reared on artificial diet. The population projection showed that the population of N. bicaudus reared on Ty. putrescentiae could increase fast. Our results showed that the Ty. putrescentiae was the most suitable prey for mass rearing of N. bicaudus. The artificial diet could not support the N. bicaudus population and needs to be improved.


Author(s):  
Fatemeh Pirayeshfar ◽  
Seyed Ali Safavi ◽  
Hamid Reza Sarraf-moayeri ◽  
Gerben J Messelink

Blattisocius mali (Oudemans) is a candidate predatory mite on some astigmatid mite pests like Tyrophagus putrescentiae (Schrank). In current study, life table parameters of B. mali were comparatively evaluated when fed on mixed life stages, frozen (one day at -20°C) and cold stored (90 days at -20°C and 4°C) eggs of T. putrescentiae. The highest and lowest values of fecundity, total longevity, oviposition period, life span and adult longevity of B. mali were observed when the predator provided with one-day and 90-days frozen eggs (stored at 4°C) of T. putrescentiae, respectively. Moreover, the highest values of net reproductive rate (R0), intrinsic rate of increase (r) and finite rate of increase (λ) of B. mali were obtained by feeding on one-day frozen eggs (23.94 offspring/individual, 0.332 day-1, 1.39 day-1, respectively), without significant differences from the predators reared on alive mixed stages of T. putrescentiae. However, the lowest values of R0 (1.54 offspring/individual), r (0.058 day-1) and λ (1.06 day-1) were recorded when B. mali was reared on 90-days frozen eggs (stored at 4°C). The results, as first evidence of life-history of B. mali, represent not only the potential of the predator as suitable biological control agent against T. putrescentiae, but also the possibility of its mass production by frozen host stages. Provision of one-day frozen eggs of T. putrescentiae were the best choice for B. mali survival and reproduction with no harmful effects of living stages (direct damage, frass and exuviae) on crop.


2017 ◽  
Vol 57 (3) ◽  
pp. 256-267
Author(s):  
Idin Zibaee ◽  
Mojtaba Esmaeily

Abstract The tomato leafminer, Tuta absoluta is a serious pest of tomato crops worldwide. In this study the effect of sublethal concentrations of abamectin (at 10 and 30% lethal concentrations, LC10 and LC30) was investigated on developmental and reproduction parameters of the tomato leafminer Tuta absoluta. Lethal concentrations were estimated by leaf dip bioassay on the fourth instar larvae of the T. absoluta that, LC50, LC30 and LC10 were 0.23, 0.15 and 0.12 mg · l−1, respectively. The sublethal concentrations led to significant decreases in adult emergence, the percentage of pupation of the parent generation, fecundity and adult longevity compared to the control. Sublethal concentrations significantly decreased the net reproductive rate (R0), intrinsic rate of increase (r), finite rate of increase (λ), and gross reproduction rate (GRR). There was a significant decrease in the time to egg developmental and doubling time (DT) of T. absoluta. However, sublethal concentrations of abamectin had no significant effects on the percentage of pupation, larva, prepupa and pupa developmental periods, hatchability and sex ratio of offspring. The results of this study indicated that sublethal concentrations of abamectin could influence some biological parameters of T. absoluta. The results could also be helpful for making better management decisions for controlling the tomato leafminer.


2014 ◽  
Vol 54 (3) ◽  
pp. 272-278 ◽  
Author(s):  
Solmaz Azimi ◽  
Shima Rahmani ◽  
Masoud Tohidfar ◽  
Ahmad Ashouri ◽  
Alireza Bandani ◽  
...  

Abstract Transgenic Bt cotton developed against lepidopteran pests may not be compatible with parasitoid of secondary pests such as Bemisia tabaci which attack many plants such as cotton. In this study, the effects of Bt cotton on the demographic parameters of Encarsia formosa, parasitoid of B. tabaci were assessed. The data were analysed using the age specific, two-sex life table parameters. The results indicated that pre-adult developmental time, the total preoviposition period (TPOP) and the adult preoviposition period (APOP) in the Bt cotton were significantly longer than in the non-Bt cotton. Also, fecundity and body size in both lines were significantly different. The fecundity was 23.64±0.73 and 43.75±0.89 eggs/females in the Bt and non-Bt cotton, respectively. All the population parameters were affected by the Bt cotton. The intrinsic rate of increase (r) was 0.15 day-1 in the non-Bt cotton but it was 0.10 day-1 in the Bt cotton. The finite rate of increase (λ) was 1.11 day-1 in the non-Bt cotton whilst it was 1.08 in the Bt cotton. The net reproductive rate (R0) in the non-Bt cotton was 36.75 but in the Bt cotton these parameters showed 19.62 offspring/individual. Also, the mean generation time (T ) in the non-Bt and Bt cotton was 22.69 and 27.79 days, respectively. The results illustrated, that although transgenic crops are effective tools for management of the target pests, they can adversely affect, either directly or indirectly, the natural enemies dependent on these plants.


Insects ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 292
Author(s):  
Fatemeh Ganjisaffar ◽  
Thomas M. Perring

Ooencyrtus lucidus Triapitsyn & Ganjisaffar (Hymenoptera: Encyrtidae) was recently recovered from fresh sentinel eggs of Bagrada hilaris (Burmeister) (Hemiptera: Pentatomidae) in California. In the present study, life history traits of O. lucidus were studied at 26 ± 0 . 5 ∘ C, 40 ± 10 % RH, and a photoperiod of 14 L: 10 D hours. Results showed that 95.2% of the parasitized eggs yielded successful emergence of adults. The total immature developmental time was 14.27 and 13.95 days for females and males, respectively. The sex ratio of O. lucidus was 0.5 (females/offspring). Mated females laid on average 6.0 eggs per day and 222.7 eggs during their mean ovipositional period of 37.3 days. There was no significant difference in reproduction parameters between mated and non-mated females. The net reproductive rate ( R 0 ) was 103.8 females/female/generation, the intrinsic rate of increase ( r m ) was 0.171 females/female/day, the finite rate of increase ( λ ) was 1.187 population multiplication/day, the mean generation time (T) was 27.1 days, and the doubling time (DT) was 4.0 days. The highest longevity was observed in mated and non-mated females fed with honey, and they lived for 70.8 and 70.1 days, respectively. Providing females with host eggs in addition to honey, reduced their longevity by 24% in mated and 28% in non-mated individuals. Non-mated females and males deprived of honey only lived for 3.5 and 2.5 days after emergence, respectively. Our results indicate that O. lucidus has sufficient life history traits to make it a promising egg parasitoid for the biological control of B. hilaris.


1996 ◽  
Vol 128 (5) ◽  
pp. 859-863 ◽  
Author(s):  
P. Shishehbor ◽  
P.A. Brennan

AbstractLongevity and reproductive potential of adult males and females of Trialeurodes ricini Misra were determined under laboratory conditions at four constant temperatures (20, 25, 30, and 35 ± 1°C). The resulting data were used to calculate life tables and rates of increase at each temperature. Females of T. ricini oviposited means of 183, 224, 294, and 132 eggs at 20, 25, 30, and 35°C, respectively, and had a mean longevity of 38.52, 28.15, 15.78, and 10.11 days at the same four temperatures. The net reproductive rate was 49.92, 72.26, 111.08, and 38.44, and the daily intrinsic rate of increase was 0,05, 0.11, 0.18, and 0.15 at 20, 25, 30, and 35 °C, respectively. Generation times decreased from 69.88 to 24.92 days with increasing temperature. The results indicate that T. ricini can, in otherwise unlimited conditions, persist and increase in numbers within the range 20–35°C.


2018 ◽  
Vol 14 (3) ◽  
pp. 107
Author(s):  
Rudi Tomson Hutasoit ◽  
Hermanu Triwidodo ◽  
Ruly Anwar

<p><em>Thrips parvispinus</em> Karny (Thysanoptera: Thripidae) is one of the major pests of chili pepper in Indonesia. The pest<em> </em>can be found on all parts of the plants, especially flowers and leaves. Information of the biology and demographic statistic of <em>T. parvispinus </em>are still limited<em>.</em> The objective of this research was to study the biology and demographic statistic of <em>T</em>. <em>parvispinus </em>in Bogor. Fifty individual of 1<sup>st</sup> instar nymphs were reared on caged chili pepper leaves (d = 4 cm and h = 8 cm). Chilli pepper leaves were replaced everyday and observed daily to determine the development and number of offspring eggs. The collected data were used to obtain information about the biology of the pest such as the stadia of each instar, preoviposition period, life cycle, adult longevity, and fecundity. The data were also used to construct life tables for demographic statistic analysis using of the <em>Jackknife</em> method. There were 5 phases of immature stages of <em>T. parvispinus</em>: eggs, two instars nymph, prepupa, and pupa with their stadia were 4,79, 1,36, 3,54, 1,08, and 1,96 days respectively. The preoviposition period of the insect was 1,11 days, life cycle was 13,68 days, female longevity was 8,55 days, male longevity was 6,00 days, and fecundity was 15,33 eggs per female. The population development of <em>T. parvispinus </em>followed type III of survivorship curve with intrinsic rate of increase was 0,15 individual per days female per days, net reproductive rate was 5,71 individual per female per generation, generation time was 11,49 days and doubling time was 4,57 days.</p>


Author(s):  
Katayoon Kheradmand ◽  
Mahmoud Heidari ◽  
Amin Sedaratian-Jahromi ◽  
Reza Talaei-Hassanloui ◽  
Mohammadreza Havasi

Abstract Tetranychus urticae (Acari: Tetranychidae) is one of the most important pests of agricultural crops with worldwide distribution causing considerable damage to different products. Application of chemical acaricides is one of the most important strategies used for the control of this pest. Entomopathogenic fungi, however, have been proposed as alternative control agents. In this study, sub-lethal effects (LC10 = 6.76 × 102, LC20 = 8.74 × 103, and LC30 = 55.38 × 103 conidia ml−1) of Beauveria bassiana strain TV on the life table parameters of T. urticae were evaluated under laboratory conditions. The results demonstrated that by increasing the concentration, a significant decline was observed in adult longevity of both male and female individuals. Total fecundity of T. urticae was calculated as 45.16, 36.28, 23.98, and 18.21 eggs in control, LC10, LC20, and LC30 treatments, respectively. Sub-lethal concentrations drastically affected the population parameters of this mite pest. The intrinsic rate of increase (r) ranged from 0.1983 to 0.1688 day−1 for the mites treated with distilled water and LC20 treatments, respectively. The net reproductive rate (R0) was affected by the sub-lethal concentrations (lower value at LC30 concentration: 11.19 offspring/individual). Considering the detrimental effects of B. bassiana on some biological parameters of T. urticae, it can be concluded that this product can be used to develop targeted interventions aimed at integrated pest management of this pest.


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