INFLUENCE OF HUMIDITY ON THE PREDACEOUS MITE MELICHARES DENTRITICUS (BERLESE) (ACARINA : ACEOSEJIDAE)

1962 ◽  
Vol 40 (5) ◽  
pp. 761-766 ◽  
Author(s):  
I. Rivard
Keyword(s):  
Food Product ◽  
Prey Population ◽  
Oviposition Period ◽  
Predator Population ◽  
Immature Stages ◽  
Tyrophagus Putrescentiae ◽  
Adult Females ◽  
Rate Of Increase ◽  
Predaceous Mite

The predaceous mite Melichares dentriticus (Berlese) was reared individually on larvae and protonymphs of the stored food product mite Tyrophagus putrescentiae (Schrank) at 68.0° F and 70, 80, 90, and 100% R.H. Survival and speed of development of the immature stages increased slightly with the humidity. Longevity of adult females was similar at different humidities, though the oviposition period was much shorter at 70% R.H. More eggs were laid at 100% R.H., but then the peak of laying occurred later in the oviposition period. The rate of increase of the predator population was altered very little by different humidities in comparison with that of the prey population and thus, assuming that these rates are an accurate guide to the outcome of the interaction, the population of the prey should be better controlled at lower humidities.

INFLUENCE OF TEMPERATURE AND HUMIDITY ON LONGEVITY, FECUNDITY, AND RATE OF INCREASE OF THE MITE TYROPHAGUS PUTRESCENTIAE (SCHRANK) (ACARINA: ACARIDAE) REARED ON MOLD CULTURES

1961 ◽  
Vol 39 (6) ◽  
pp. 869-876 ◽  
Author(s):  
I. Rivard
Keyword(s):  
Egg Production ◽  
Food Products ◽  
Egg Laying ◽  
Oviposition Period ◽  
Tyrophagus Putrescentiae ◽  
Influence Of Temperature ◽  
Adult Females ◽  
Rate Of Increase ◽  
Temperature And Humidity

Adult females of Tyrophagus putrescentiae (Schrank), a mite that infests stored food products, were reared individually on mold cultures at all combinations of five temperatures and four humidities. A definite diminution in life usually occurred with increase in either temperature or humidity, and the oviposition period was the most affected. Total egg-production and rate of laying were highest at 72.5° F and 90% R.H., and both generally decreased with an increase in temperature or decrease in humidity from these values. Peak of egg-laying, however, was reached sooner at higher temperatures but egg-production was maintained at relatively high levels for shorter periods. Rate of increase was greatest and approximately the same at 90% R.H. within the range 72.5° to 81.5° F.

Effects of short-term heat stress on the development and reproduction of predatory mite Neoseiulus barkeri (Acari, Phytoseiidae)

2021 ◽  
Vol 26 (4) ◽  
pp. 713-723
Author(s):  
Wei Zhen Li ◽  
Hao Long Li ◽  
Zi Kun Guo ◽  
Su Qin Shang
Keyword(s):  
Heat Stress ◽  
Life Span ◽  
Treatment Time ◽  
Predatory Mite ◽  
Immature Stage ◽  
Oviposition Period ◽  
Hatching Rate ◽  
Short Term ◽  
Developmental Duration ◽  
Adult Females

The predatory mite Neoseiulus barkeri (Acari: Phytoseiidae), which is one of the best natural enemies, has been used as a biological control agent against multiple insect pests, such as spider mite, Tetranychus urticae and thrips. Its growth and development were affected by the environmental temperature changes. This study was conducted to evaluate the hatching rate of the eggs and the immature developmental times of N. barkeri after incubation of the eggs under heat stress at 38, 40 and 42℃, 85% ± 5% RH and a 16h:8h light: dark (L:D) photoperiod for 2, 4 and 6h. After adult females emerged, they were treated under the same conditions again, and the parameters such as oviposition period, fecundity and female longevity were observed. The results showed that with the increase of the temperature and the extension of the duration of the heat stress, the hatching rate was lower. The eggs treated at 42℃ for 2h or more could not hatch, and the developmental duration of each immature stage showed a trend of decreasing at first and then increasing. The fastest development was observed after incubation of eggs at 40℃ for 2h, and the shortest developmental duration was 4.60d. Under the condition of 38℃, the oviposition period and life span of adult females were shortened with the extension of treatment time, and the fecundity decreased at first and then increased. At 40℃, the fecundity, oviposition period and longevity of adult females showed a trend of gradual increase with the extension of treatment time. The shortest oviposition period, the lowest fecundity and the shortest life span of adult females were 12.14d, 18.92 eggs and 16.65d, respectively after incubation of eggs at 40℃, for 2h. Therefore, the short-term heat stress had a significant effect on the hatching rate and the duration of the immature stage, and also had a negative effect on the fecundity, oviposition period and longevity of adult females. In rearing and field release, heat stress should be avoided as much as possible to achieve the best predation and control effect of N. barkeri.

scholarly journals Reproductive diapause in Nysius huttoni White (Heteroptera Lygaeidae)

2002 ◽  
Vol 55 ◽  
pp. 308-311
Author(s):  
X.Z. He ◽  
Q. Wang ◽  
A. Carpenter
Keyword(s):  
Life Cycle ◽  
Immature Stages ◽  
Life Stages ◽  
Reproductive Diapause ◽  
Entire Life ◽  
Entire Life Cycle ◽  
Adult Females ◽  
Critical Photoperiod

The induction of reproductive diapause of Nysius huttoni was studied in the laboratory at 20 1C and 60 10 RH under a series of photoperiod regimes 168 h 1410 h 1212 h and 1014 h lightdark Reproductive diapause was considered to have occurred if females failed to lay eggs for 50 days after emergence The sensitivity of different life stages to diapauseinducing photoperiods varied When newly emerged females whose immature stages had been reared at 168 h were transferred to 1014 h and 1212 h 467 and 793 of them entered reproductive diapause respectively However when fifth instar nymphs were transferred from 168 h to 1014 h and 1212 h 100 of adult females entered reproductive diapause If the entire life cycle was maintained at 1014 h and 1212 h 667 and 400 of females entered reproductive diapause respectively The critical photoperiod for reproductive diapause was estimated to lie between 1311 h and 135105 h

Acute toxicity and sublethal effects of metal oxide nanoparticles against the bulb mite

2021 ◽  
Vol 26 (4) ◽  
pp. 788-800
Author(s):  
Gholamreza Tavakkoli Korghond ◽  
Najmeh Sahebzadeh ◽  
Hossein Allahyari ◽  
Sara Ramroodi
Keyword(s):  
Metal Oxide ◽  
Sublethal Effects ◽  
Metal Oxide Nanoparticles ◽  
Intrinsic Rate Of Increase ◽  
Oxide Nanoparticles ◽  
Nano Tio2 ◽  
Rhizoglyphus Robini ◽  
Adult Females ◽  
Rate Of Increase ◽  
Bulb Mite

Crocus sativus L. (Iridaceae) known as saffron is the most commercially important medicinal food product in Iran and worldwide because of its significance for exporting commercial. However, the health of this plant is adversely threatened by abiotic and biotic stress. Bulb mite Rhizoglyphus robini Claparede (Acari: Acaridae) as abiotic stress is oligophagous and the main pest of tuber plants, commonly found in all the cultivated saffron producing areas could decrease saffron economic value. The mites tunnel through corms allowing the entry of fungal and bacterial pathogens. The widespread use of commercial pesticides in modern agriculture to protect crops from pests has caused significant public concern because of their side impacts on the environment and non-target species. Nanotechnology has been used in the production, processing, storage, packaging, and transport of agricultural products. Newly, oxide nanoparticles have been introduced as novel pesticides against pests and fertilizer. This study was conducted as an effective and environmentally-friendly method to control the growth of Rhizoglyphus robini. The lethal and sublethal effects of metal oxide nanoparticles (MNPs) including nano copper oxides (nano-CuO), nano magnesium oxide (nano-MgO), nano zinc oxide (nano-ZnO), nano titanium dioxide (nano-TiO2), and nano iron oxide (nano-Fe2O3) which their lethal concentrations ranged between 159.2 and 1036.4 mg L-1 were studied on Rhizoglyphus robini adult females. The contact effect of the tested MNPs was evaluated using the corm dip bioassay method. Assays showed that the contact toxicity of the nano-CuO treatment (229.1 mg L-1) was higher than other MNPs. To assess the sublethal effects of the MNPs, adult females were exposed to the LC25 concentration of MNPs, and life history and life-table parameters of the surviving Rhizoglyphus robini were investigated. The exposure to sublethal concentrations of the tested MNPs prolonged the egg incubation, larval period, and nymphal period significantly when compared to the control mites. Compared to other MNPs or control mite, nano-MgO and nano-TiO2 led to the longest duration of the total immature stages (11.32 and 11.32, respectively). The net reproductive rate (R0), the intrinsic rate of increase (rm), the finite rate of increase (λ), and the generation time (T) were significantly different between control and MNP treatments. The population exposed to ZnO-, MgO-, and TiO2-nanoformulations had a much lower rm value (0.164, 0.164, and 0.171 d-1, respectively) compared to the control population (0.231 d-1) and those exposed to Fe3O4- and CuO-nanoformulations (1.19 and 1.19 d-1, respectively). According to our findings, all tested MNPs, especially CuO-, ZnO-, and MgO-nano formulations, have a potential application for use in the management of Rhizoglyphus robini.

Modeling the Effect of Fear in a Prey–Predator System with Prey Refuge and Gestation Delay

2019 ◽  
Vol 29 (14) ◽  
pp. 1950195 ◽  
Author(s):  
Ankit Kumar ◽  
Balram Dubey
Keyword(s):  
Hopf Bifurcation ◽  
Prey Population ◽  
Reproduction Rate ◽  
Predator Population ◽  
Maximum Lyapunov Exponent ◽  
Stable Limit ◽  
Prey Refuge ◽  
Gestation Delay ◽  
Fear Effect ◽  
Predator System

Recently, some field experiments and studies show that predators affect prey not only by direct killing, they induce fear in prey which reduces the reproduction rate of prey species. Considering this fact, we propose a mathematical model to study the fear effect and prey refuge in prey–predator system with gestation time delay. It is assumed that prey population grows logistically in the absence of predators and the interaction between prey and predator is followed by Crowley–Martin type functional response. We obtained the equilibrium points and studied the local and global asymptotic behaviors of nondelayed system around them. It is observed from our analysis that the fear effect in the prey induces Hopf-bifurcation in the system. It is concluded that the refuge of prey population under a threshold level is lucrative for both the species. Further, we incorporate gestation delay of the predator population in the model. Local and global asymptotic stabilities for delayed model are carried out. The existence of stable limit cycle via Hopf-bifurcation with respect to delay parameter is established. Chaotic oscillations are also observed and confirmed by drawing the bifurcation diagram and evaluating maximum Lyapunov exponent for large values of delay parameter.

A linear birth-and-death predator–prey process

1995 ◽  
Vol 32 (01) ◽  
pp. 274-277
Author(s):  
John Coffey
Keyword(s):  
Death Rate ◽  
Birth Rate ◽  
Prey Population ◽  
Death Process ◽  
Predator Population ◽  
Birth And Death Process ◽  
Predator Prey ◽  
Predator Prey Model ◽  
Prey Model

A new stochastic predator-prey model is introduced. The predator population X(t) is described by a linear birth-and-death process with birth rate λ 1 X and death rate μ 1 X. The prey population Y(t) is described by a linear birth-and-death process in which the birth rate is λ 2 Y and the death rate is . It is proven that and iff

DEVELOPMENT AND BIONOMICS OF CHRYSOMELOBIA LABIDOMERAE (ACARI: TARSONEMINA; PODAPOLIPIDAE), A PARASITE OF THE MILKWEED LEAF BEETLE (COLEOPTERA: CHRYSOMELIDAE)

1975 ◽  
Vol 107 (6) ◽  
pp. 627-638 ◽  
Author(s):  
Thomas C. Baker ◽  
George C. Eickwort
Keyword(s):  
Leaf Beetle ◽  
High Population ◽  
Immature Stages ◽  
Adult Males ◽  
Nymphal Instar ◽  
Male And Female ◽  
Adult Females ◽  
Original Length ◽  
Chrysomelobia Labidomerae ◽  
Pharate Adult

AbstractAdult females of Chrysomelobia labidomerae Eickwort lay eggs on the upper surfaces of the hind wings of Labidomera clivicollis (Kirby). The eggs hatch in approximately 7 days and male and female larvae feed at the base of the wings and in the meso–metathoracic crevice and swell to about twice their original length. For about the second half of the approximately 7-day larval stadium, the larvae are inactive (pharate adults) and are usually cemented to the undersurfaces of the elytra. Inactive female larvae are accompanied by adult males that apparently copulate with the newly emerged adult females. The pharate adult is enclosed in a cuticular sac that may represent a calyptostatic nymphal instar. Adult females feed on the beetle’s abdominal terga and sometimes also occur on its venter where they do not feed. Females disperse from host to host when the beetles copulate. The species is arrhenotokous. Mites overwinter on the diapausing adult beetles and do not infest the immature stages of their host. Even at high population levels, the mites do not noticeably affect the longevity or fecundity of their hosts.

The effect of temperature and moisture on the Immature Stages of Aphodius tasmaniae Hope (Scarabaeidae) in the lower South-east of South Australia.

1961 ◽  
Vol 9 (2) ◽  
pp. 173 ◽  
Author(s):  
DA Maelzer
Keyword(s):  
Mortality Rate ◽  
Water Content ◽  
South Australia ◽  
Effect Of Temperature ◽  
Annual Rainfall ◽  
Field Observations ◽  
Immature Stages ◽  
Rate Of Increase ◽  
Lower South ◽  
Third Instar Larvae

The distribution and abundance of the univoltine species A. tasmaniae in the lower south-east of South Australia appears to be related to annual rainfall. The effects of moisture on the mortality rates of the immature stages were consequently studied and observations were made of the effects of variations in moisture in the field. Laboratory experiments and field observations suggested that variations in soil moisture have little effect on the eggs and the diapausing prepupae in the field. Eggs absorbed water and hatched normally within a pF range of 2.50-3.75 in a sand and in a clay loam. At pF 4.0 in both soils, eggs lost weight and did not hatch. The adults, however, tend to lay the eggs well within the pF range in which the eggs can develop, and soil samples suggested that eggs would develop with little mortality in the kinds of places in which they are usually laid. When prepupae enter diapause they have a water content of c. 77%. When desiccated in the laboratory, few prepupae died until their water content fell below 62%. The mortality rate then increased sharply, and it was estimated that 50% of the prepupae died when their water content dropped to 57%. Droughts of sufficient duration and intensity to kill 50% of the prepupae have never been recorded from the study area, and field observations suggested that few prepupae died of desiccation in summer. Unlike the two stages above, the first and third instar larvae may be markedly affected by variations in moisture in the field. The first instar larvae, after hatching, do not move to the surface of the soil and do not feed much until the soil is saturated with rain. As rainfall is variable at this time of the year, the larvae may be in dry soil for many weeks before they are stimulated to extend their burrows to the surface and search for food. Many larvae may die of starvation during this time, and the mortality rate of the larvae was related empirically to the length of the autumn "drought". Third instar larvae may be affected, on the other hand, by excessive water. In wet winters, vast numbers of larvae are drowned when extensive flooding occurs on the poorly-drained soils, and on well-drained soils a large proportion of larvae are killed by the entomophagous fungus Cordyceps aphodii. The above data have suggested that moisture is one of the major factors affecting the distribution and abundance of the species. Temperature has little effect on the rate of increase of the species.

A new species of Centrouropoda (Acari: Uropodidae: Uropodina), with a key to the world species of the genus

Zootaxa ◽  
2019 ◽  
Vol 4706 (4) ◽  
pp. 501-516
Author(s):  
REHAM I.A. ABO-SHNAF ◽  
SALLY F.M. ALLAM
Keyword(s):  
New Species ◽  
Immature Stages ◽  
Rhynchophorus Ferrugineus ◽  
Adult Males ◽  
Red Palm Weevil ◽  
World Species ◽  
Adult Females ◽  
The World ◽  
Bahariya Oasis ◽  
A New Species

The present work provides descriptions of a new species of mite, Centrouropoda bahariyaensis n. sp. (Uropodidae), based on the adult female and male collected from the red palm weevil, Rhynchophorus ferrugineus (Oliver) (Coleoptera: Curculionidae) and its habitat at El-Bawiti, Bahariya Oasis, Egypt. Complete descriptions of the immature stages are included. Keys to the known species of genus Centrouropoda Berlese based on adult females, adult males and deutonymphs are provided.

EFFECT OF VIRAL INFECTION ON THE GENERALIZED GAUSE MODEL OF PREDATOR-PREY SYSTEM

2003 ◽  
Vol 11 (01) ◽  
pp. 19-26 ◽  
Author(s):  
J. CHATTOPADHYAY ◽  
A. MUKHOPADHYAY ◽  
P. K. ROY
Keyword(s):  
Viral Infection ◽  
Specific Growth ◽  
Dynamical Behavior ◽  
Prey Population ◽  
Predator Population ◽  
Predator Prey ◽  
Stability Behavior ◽  
Force Of Infection ◽  
Prey System ◽  
Infected Prey

The generalized Gause model of predator-prey system is revisited with an introduction of viral infection on prey population. Stability behavior of such modified system is carried out to observe the change of dynamical behavior of the system. To substantiate the analytical results of this generalized susceptible prey, infected prey and predator population, numerical simulations of the model with specific growth and response functions are performed. Our observations suggest that the disease on prey population has a destabilizing or stabilizing effect depending on the level of force of infection and may act as a biological control for the persistence of the species.

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