Bionomics of Glycyphagus domesticus (de Geer) (Acarina: Glycyphagidae), a pest of stored grain

1968 ◽  
Vol 46 (1) ◽  
pp. 89-92 ◽  
Author(s):  
Philip S. Barker

The life history and reproductive rates of Glycyphagus domesticus (de Geer) were examined at different temperatures and two humidities. Most rapid development of the eggs occurred at 24.4 °C; the optimum temperature for the post-embryonic stages was 22.2 °C. A higher percentage of hypopi were formed at 70 to 75% than at 95 to 100% relative humidity. G. domesticus has a net reproductive rate of over 20, which was intermediate between those of Tyrophagus putrescentiae (Schrank) and Aëroglyphus robustus (Banks).

1967 ◽  
Vol 45 (1) ◽  
pp. 91-96 ◽  
Author(s):  
Philip S. Barker

The biology and reproductive rates of Tyrophagus putrescentiae have been examined for different temperatures and high humidity. The most rapid development took place at 32.2 °C, whereas 33.9 °C was slightly less favorable. A normal life cycle was accomplished at 11.2 °C. It was calculated that the major portions of populations of T putrescentiae with stable age distributions are the non-mobile stages: the eggs comprise over half of population and one-third of the immature stages are quiescent. The adults account for close to 10% of the population. These theoretical data were confirmed by the examination of a young culture. It was concluded that sampling techniques should account for the immobile stages to give a true picture of a population of this species.


Author(s):  
Jayme Magalhães Santangelo ◽  
Bruno Nascimento Soares ◽  
Thecia Paes ◽  
Paulina Maia-Barbosa ◽  
Ralph Tollrian ◽  
...  

Cladocerans serve as prey for several aquatic predators like fish and Chaoborus larvae. However, because different predators consume different sized prey, cladocerans may display differing life-history responses depending on predator type. Although most studies use the genus Daphnia to evaluate phenotypic plasticity in cladocerans, other genera might also respond to predator infochemicals. In this study, we compared life-history responses of Daphnia similis and Moina macrocopa to infochemicals released by a vertebrate (fish) and an invertebrate (Chaoborus) predator. As expected, some life-history parameters were altered depending on the type of predator. Overall, fish infochemicals increased the size at primipara, clutch size, net reproductive rate and longevity in both cladocerans. We argue that increased body lengths in the presence of fish promote bigger clutch sizes. Conversely, responses to Chaoborus were weaker, affecting only the net reproductive rates and longevity. Non-daphniid cladocerans may display similar responses to Daphnia when exposed to predators. However, as Daphnia is usually underrepresented in tropical lakes, studying other genera might offer new insights into predator-prey relationships and food webs in lake ecosystems.


1983 ◽  
Vol 115 (1) ◽  
pp. 93-105 ◽  
Author(s):  
John V. Boyne ◽  
Fred P. Hain

AbstractExperiments were conducted on Fraser fir, Abies fraseri (Pursh) Poir, seedlings or cut terminals. Results indicate that Oligonychus ununguis (Jacobi) responds most favorably to temperatures approximating 26 °C and to relative humidity levels approaching 50 to 60%. Developmental time, time to 50% mortality, net reproductive rate, mean generation time, intrinsic rate of natural increase, finite rate of increase, and days for populations to double were computed for each temperature and relative humidity regime. Simulated rainfall severely limits population density on Fraser fir seedlings.


Insects ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 181
Author(s):  
Weiwei Sun ◽  
Miao Cui ◽  
Liyuan Xia ◽  
Qing Yu ◽  
Yang Cao ◽  
...  

Cheyletus malaccensis Oudemans is a predatory mite inhabiting grain depots in China. The relationship between temperature and the population growth rate of C. malaccensis is useful for predicting its population dynamics. Age-stage, two-sex life tables of the predator, C. malaccensis, reared on Acarus siro were constructed under laboratory conditions at 22, 24, 28, 30, and 32 °C, 75% relative humidity, and a 0:24 h (L:D) photoperiod. Increasing temperature shortened the development time of the immature stages. The complete generation time of C. malaccensis ranged from 11.10 d to 27.50 d. Life table parameters showed that 28 °C was the optimum temperature for the growth and development of C. malaccensis; populations could increase rapidly at this temperature. The highest net reproductive rate (R0 = 290.25) and highest fecundity (544.52) occurred at 28 °C. Temperature significantly affected the intrinsic rate of increase (r), fecundity, and finite rate of increase (λ). The values of age-specific fecundity (high to low) were 28 °C > 24 °C > 30 °C > 32 °C > 22 °C, while the values of age-stage-specific fecundity had the same trend.


Author(s):  
Anneke van den Brink ◽  
Mandy Godschalk ◽  
Aad Smaal ◽  
Han Lindeboom ◽  
Colin McLay

The duration of brood development in the introduced crab, Hemigrapsus takanoi in the Oosterschelde, The Netherlands, was compared at three different water temperatures. At 12, 18 and 24°C the females took an average of 32, 11 and 8 days respectively to lay eggs, which took 86, 28 and 18 days respectively to complete development. Five stages of development were identified, with each brood stage comprising a similar proportion of the duration time at different temperatures. The duration of each brood stage was also somewhat proportional to the number of females found carrying each brood stage in the field at the beginning of the breeding season. There appears to be a trigger for the breeding season in H. takanoi in the field at around 15°C above which ovary development begins. The results suggest that an increase in water temperature as a result of climate change may result in an increased net reproductive rate in H. takanoi due to earlier onset of the breeding season and increased number of broods per inter-moult period resulting in population growth. Increased temperatures may therefore lead to increased invasiveness of H. takanoi where it is already present, and range extension into locations where its establishment is currently excluded by unsuitable temperature.


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.


1967 ◽  
Vol 45 (4) ◽  
pp. 479-483 ◽  
Author(s):  
Philip S. Barker

The biology and reproductive rates of Aëroglyphus robustus (Banks) were examined at two humidities and different temperatures. The life cycle was shorter at 70–75% relative humidity (r.h.) than at 85–90% r.h. At 28 °C more eggs were laid at 85–90% r.h. than at 70–75% r.h. Low net reproduction rates were found for this species.


2019 ◽  
Vol 112 (5) ◽  
pp. 2116-2120
Author(s):  
M Amin Jalali ◽  
M Reza Mehrnejad ◽  
Peter C Ellsworth

Abstract Aspects of the nutritional ecology and life histories of five predatory coccinellids (Coleoptera: Coccinellidae)—two arboreal predator species, Oenopia conglobata contaminata (Menetries) and Adalia bipunctata (Linnaeus), and three herbaceous dwelling predator species, Coccinella undecimpunctata aegyptica (Reiche), Exochomus nigripennis (Erichson), and Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae)—were compared when fed either Agonoscena pistaciae Burckhardt and Lauterer (Hemiptera: Aphalaridae), the key psylla pest of pistachio trees, or Aphis gossypii Glover (Hemiptera: Aphididae), a common aphid on herbaceous plants in pistachio orchards. The putative habitat preferences of four of the five coccinellids studied were consistent with their performance on the major herbivore present in those two habitats in terms of net reproductive rate. Oenopia conglobata contaminata and Ad. bipunctata showed higher net reproductive rates when fed on pistachio psylla prey, whereas C. undecimpunctata aegyptiaca and E. nigripennis had better reproductive output on aphid prey. Moreover, E. nigripennis was the most specialized of these generalist predators, eating more and reproducing better when fed aphids. Hippodamia variegata was relatively unaffected by the diet offered, suggesting greater ability to switch among herbivore prey and perhaps better potential as a biocontrol agent with abilities to exploit Ag. pistaciae without large life history tradeoffs.


1991 ◽  
Vol 69 (9) ◽  
pp. 2321-2325 ◽  
Author(s):  
Philip S. Barker

The duration and mortality of immature stages of the predatory mite Cheyletus eruditus (Schrank) were examined at 14, 18.5, 22, and 25 °C and 76% RH. Life tables and schedules of female eggs laid by each female per day were made from records of daily oviposition and adult mortality. The net reproductive rate (ratio of total female births in two successive generations) of C. eruditus varies from 40.7 at 18.5 °C to 74.4 at 25 °C and brackets the net reproductive rates of the prey Lepidoglyphus destructor (Schrank). Mean generation time and finite rates of increase (multiplication per female each day) varied from 52.2 days and 1.073 at 18.5 °C to 24.2 days and 1.194 at 25 °C. Maximum longevity was 107, 67, and 56 days at 18.5, 22, and 25 °C, respectively. Cheyletus eruditus also consumed first-instar larvae of the rusty grain beetle, Cryptolestes ferrugineus (Stephens), and first- and second-instar larvae of the flour mill beetle, Cryptolestes turcicus (Grouvelle).


2010 ◽  
Vol 6 (6) ◽  
pp. 850-853 ◽  
Author(s):  
Lev R. Ginzburg ◽  
Oskar Burger ◽  
John Damuth

One of Robert May's classic results was finding that population dynamics become chaotic when the average lifetime rate of reproduction exceeds a certain value. Populations whose reproductive rates exceed this May threshold probably become extinct. The May threshold in each case depends upon the shape of the density-dependence curve, which differs among models of population growth. However, species of different sizes and generation times that share a roughly similar density-dependence curve will also share a similar May threshold. Here, we argue that this fact predicts a striking allometric regularity among animal taxa: lifetime reproductive rate should be roughly independent of body size. Such independence has been observed in diverse taxa, but has usually been ascribed to a fortuitous combination of physiologically based life-history allometries. We suggest, instead, that the ecological elimination of unstable populations within groups that share a value of the May threshold is a likely cause of this allometry.


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