Zamani 2006 J. Pest Science.pdf

Journal of Thermal Biology, 2001

The effects of parasitisation by Aphidius ervi on the thermoregulatory behaviour of the pea aphid Acyrtosiphon pisum were studied in alfalfa fields and in an experimental thermal gradient. In the field, mummies were found exclusively on the adaxial surface of the upper leaves, and aphids in the mid canopy. The adaxial surface of the upper leaves was ca. 2°C hotter that the mid-canopy. In the thermal gradient, the thermal effect (selected minus exposure temperature) was higher in magnitude in non-parasitised than in parasitised aphids; the thermal effects of both types of aphids were linearly and negatively correlated with exposure temperature (i.e. aphids showed negative thermal sensitivity). The thermal sensitivity of parasitised aphids was lower than that of non-parasitised aphids. The results are discussed in relation to hypotheses on factors governing the host-parasite relationship.

2017

The cotton aphid, Aphis gossypii Glover is a major pest of greenhouse cucumber in the world. In this study, age specific functional response of Aphidius matricariae Haliday and Praon volucre (Haliday) were investigated on A. gossypii at 25±1°C, 60±5% RH and a photoperiod of 14 L: 10 D h. The results showed that the functional response of A. matricariae was type III during 1st, 2nd, 3rd, 4th and 5th days and type II in 6th day of adult parasitoid lifetime. The type of functional response of P. volucre was type II in whole parasitoid lifetime. The highest b value (0.02±0.003 h-1) and the lowest handling time (Th) (0.70±0.013 h) of A. matricariae were observed in the 1st day of parasitoid lifetime. The maximum attack rate (T/Th) of A. matricariae occurred in the first day of parasitoid lifetime (34.28 nymphs). The maximum searching efficiency of P. volucre was determined in the 2nd and 3rd days (0.03±0.003 and 0.03±0.005 h-1) and the minimum handling time was recorded in the 2nd day (0...

Insects, 2021

Testing fluctuating rather than constant temperatures is likely to produce more realistic datasets, as they are ecologically more similar to what arthropods experience in nature. In this study, we evaluated the impact of three constant thermal regimes (7, 12, and 17 °C) and one fluctuating thermal regime (7–17 °C with a mean of 12 °C) on fitness indicators in the rosy apple aphid Dysaphis plantaginea, a major pest of apple orchards, and the parasitoid Aphidius matricariae, one of its natural enemies used in mass release biological control strategies. For some—but not all—traits, the fluctuating 7–17 °C regime was beneficial to insects compared to the constant 12 °C regime. Both aphid and parasitoid development times were shortened under the fluctuating regime, and there was a clear trend towards an increased longevity under the fluctuating regime. The fecundity, mass, and size were affected by the mean temperature, but only the mass of aphids was higher at 7–17 °C than at a constant...

Journal of Insect Behavior, 2015

The cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae) is one of the major pests of many greenhouse crops. The aphid parasitoids, Aphidius colemani Viereck and Aphidius matricariae (Haliday) (Hymenoptera: Braconidae: Aphidiinae) have been considered good agents for the biological control of A. gossypii. In Mediterranean area, these parasitoids can currently be released under elevated temperature conditions. However, few findings on their behavior changes with temperature are available. In this study, we analyze the consequence of constant temperatures ranging from 20 to 32°C on the flight, walking and oviposition capacities of Aphidius colemani and Aphidius matricariae. Our results revealed that flight capacity is clearly influenced by temperature. The optimal temperatures for flying are 20 and 25°C for A. colemani and A. matricariae, respectively. For both species, we observed an increase in the walking capacity but a decrease in the reproductive potential at higher temperatures. Furthermore, regardless of the tested temperature, the mummy production rate was always higher in A. colemani than in A. matricariae. These results indicate that A. colemani is more suitable than A. matricariae for the biological control of A. gossypii in Mediterranean environments.

Journal of Environmental Science and Natural Resources, 2016

An experiment was carried out to study the extinction and permanence of host-parasitoid systems with Allee effects, for both parasitism attacking before and after the growth phase of host. Allele effects and parasitism are common biological phenomena observed in nature. Allee effects and parasitism can lead to extinction of both species due to Allee effects at their low population density, multiple attractors, strange interior attractors and even crisis of strange attractor due to high parasitism. This study concentrated on Aphidius colemani an important and efficient endoparasitoid of several economically important aphid species under in-vitro conditions. The investigation studied its behavior and population change in relation to host and other environmental factors. Aphidius colemani discriminated between parasitized and unparasitized hosts. It is also suggested that this parasitoid performs best between 20 and 25°C and its population declines above or below this temperature.

Aphelinus asychis Walker (Hymenoptera: Aphelinidae) is a solitary endoparasitoid that parasitizes and host-feeds more than 40 aphid species, and has been considered a potential biological control agent of aphids. In many species of hymenopterous parasitoid, female wasps cause important additional mortality by non-reproductive killing (e.g., host-feeding and stinging behaviour). Host mortality caused by non-reproductive host killing of A. asychis was studied on cotton aphid, Aphis gossypii Glover (Homoptera: Aphididae) when infesting cucumber (Cucumis sativus L.), in the laboratory at 25°C and photoperiod of 16L: 8D. The females killed 3.3 aphids per day and 73.9 aphids until they died by host-feeding and stinging during an average of 21.3 days. Peak age-specific aphid mortality (5.2 aphids per day) was observed on the fifth day after parasitoid emergence. A. asychis females continued non-reproductive host killing until died.

Journal of Insect Physiology, 2006

Parasitoid virulence and host resistance are complex interactions depending on metabolic rate and cellular activity, which in aphids additionally implicate heritable secondary symbionts among the Enterobacteriaceae. As performance of the parasitoid, the aphid host and its symbionts may differentially respond to temperature, the success or failure of aphid parasitism is difficult to predict when temperature varies. We tested the hypothesis that resistance of the pea aphid Acyrthosiphon pisum to the parasitoid Aphidius ervi, which is linked to aphid secondary symbionts, may depend on temperature in several resistant and non-resistant aphid clonal lineages of different geographic origin and of known bacterial symbiosis, using experiments in controlled environments. Complete immunity to A. ervi at 20 1C in three different aphid clones whose symbiosis is characterized by the possession of Hamiltonella defensa reversed to high susceptibility at 25 1C and especially 30 1C, suggesting that the aphid's immune responses to the establishment and early development of the parasitoid is strongly reduced at moderately high temperatures. There was no evidence that a pea aphid control genotype that was susceptible to A. ervi at 20 1C could become more resistant as temperature increases, as has been suggested for insect fungal pathogens. By contrast, our results suggest that aphid clonal resistance to A. ervi and related parasitoids is characteristic of cool temperature conditions, similar to various other fitness attributes of aphids. Based on evidence that H. defensa symbionts characterized all three A. ervi resistant pea aphid clones studied, but was absent in control aphids that remained susceptible at all temperatures, we suggest that secondary symbiosis plays a key role in the heat sensitivity of aphid clonal resistance. Our study may also indicate that aphid natural control of variably susceptible host populations by aphid parasitoids is more likely at moderate to high temperatures. r

Biocontrol Science and Technology, 2011

Abstract We evaluated the functional responses of two aphid parasitoids: Aphidius colemani on the green peach aphid Myzus persicae (Hemiptera: Aphididae), and Aphelinus asychis on M. persicae and the potato aphid, Macrosiphum euphorbiae (Hemiptera: Aphididae). Parasitoid oviposition occurred at host densities of 5, 10, 20, 30, 50, 80 or 100 aphids for A. colemani and 5, 10, 20, 30 or 50 aphids for A. asychis. More M. persicae were parasitized by A. colemani than by A. asychis at an aphid density of 50. Among the three types of functional response, type III best described the parasitoid response to the host densities both in A. colemani and A. asychis. The estimated handling time was shorter for A. colemani than for A. asychis (0.017 and 0.043 d, respectively). The proportion of aphids that were parasitized exhibited the same characteristic curve among the three host-parasitoid combinations: a wave form that appeared to be a composite of a decelerating (as in type II) response at low host density and an accelerating-and-decelerating (as in type III) response at medium to high host density. We hypothesize that the novel host species (and its host plant), density-dependent superparasitism, and/or density-dependent host-killing may have induced the modified type III response.

Entomologia Experimentalis et Applicata, 1998

Chromosomal races of the aphid Sitobion miscanthi (Takahashi), and a closely-related species S. near fragariae (Aphididae: Macrosiphini) show seasonal differences in abundance in eastern Australia. We tested whether this was related to differences in temperature response, using controlled laboratory conditions. Intrinsic rate of increase, r m , mean relative growth rate (MRGR), and longevity were compared at different temperatures, and rates of increase were compared outdoors under ambient conditions. Using laboratory data, we simulated population growth, for comparison with outdoor populations. There were significant differences in responses to temperature regimes both in the laboratory and outdoors. Outdoor populations fell well short of predicted sizes. S. miscanthi (2n = 18) showed evidence of adaptation to warmer conditions. In contrast, S. nr fragariae showed consistent evidence for adaptation to cooler conditions, and S. miscanthi 2n = 17 was approximately intermediate. These data indicate that temperature responses are important in the ecology, evolution and pest status of S. miscanthi clones and S. nr fragariae in Australia.

Florida Entomologist, 2009

The impacts of temperature on Harmonia axyridis and its potential as a control agent of Cinara atlantica , the Carolina conifer aphid, were evaluated. The experiments were conducted with eggs from field-collected adults. Each egg batch was kept at 15 °C, 20 °C and 25°C , 70% RH and 12:12 h. L:D. After hatching, the larvae were reared individually until adult emergence and all insects were kept under the same conditions. The mean period of egg incubation, total developmental time and egg viability were longer at 15 °C that than at the other 2 temperatures. Survival was 100% for all the larval, pre-pupal and pupal stages. The longevity was longer at 15 °C and 20 °C than 25 °C. The mean number of eggs produced was significantly higher at 15 °C than at the other 2 temperatures. The post-oviposition period increased with increasing temperature. The highest specific fertility was recorded at 15 °C, followed by 25 °C and 20 °C, respectively. The net reproductive rate was higher at 15 °C than at the 2 higher temperatures. The time interval between each generation (T) decreased with increasing temperature and the population doubling time (DT) was higher at 15 °C than at 20 °C and 25 °C. The intrinsic rates of increase (r m) were very similar at the 3 temperatures, but the finite rate of population increase (λ) was higher at 25 °C than at the 2 lower temperatures. The results indicate that H. axyridis shows great potential as a biological control agent of C. atlantica .

Journal of Pest Science, 2005

The developmental time, survivorship and reproduction of Aphis gossypii Glover was evaluated on detached cucumber leaves at nine constant temperatures ranging from 15±1°C to 35±1°C in 2.5°C increments in the laboratory. Developmental periods of immature stages ranged from 10.8 days at 15°C to 4.1 days at 30°C and 32.5°C. Constant 35°C was lethal to immature stages of A. gossypii. The lower developmental threshold for the cotton aphid was estimated at 6.0°C and it required 92.6 degree–day development for a first instar to become adult. The average reproduction rate was 82.1 nymphs female−1 at 25°C and 2.3 nymphs female−1 at 32.5°C. The mean generation time of the population ranged from 6.8 days at 32.5°C to 22.8 days at 15°C. The highest per capita growth rate (r m=0.526) occurred at 25°C and the lowest at 15°C (r m=0.208) and 32.5°C (r m=0.132). It was evident that temperatures over 30°C prolonged development, increased mortality of immature stages, shortened adult longevity and reduced fecundity. The optimal range of temperature for population growth of A. gossypii on cucumber was very broad and ranged between 22.5°C and 30°C.

Annals of the Entomological Society of America, 2002

Populations of Brachycaudus schwartzi (Bö rner) were found on peach and nectarine (Prunus persica Siebold & Zuccarini) trees in Parlier, CA, in summer 2000. To determine if this aphid could be a pest of P. persica, a nine-variety host range test was conducted using a no-choice arena and temperature-dependent development studies of the aphid at 15, 20, 22.5, 25, 27.5, 30, and 32.5ЊC. Nectarine variety MayÞre (r m ϭ 0.286) and Queencrest peach (r m ϭ 0.283) were found to be the best hosts followed by Mayglo nectarine (r m ϭ 0.253). MayÞre was, therefore, selected as the host plant for the colony and for the temperature development studies. Detached shoot terminals of MayÞre were maintained on HoaglandÕs solution and placed in small cages in growth chambers. One adult aphid was introduced onto each ßush and development of aphid offspring was monitored daily. The shortest developmental time from Þrst instar to adult aphid was 6.9 d at 25ЊC and the longest was 19.9 d at 15ЊC. Adult longevity was 38.5 d at 15ЊC and the highest offspring per female was 46.4 nymphs per female at 20ЊC. The intrinsic rate of increase (r m) rose sharply from 15ЊC (0.109 nymphs/(/d) to a maximum at 25ЊC (r m ϭ 0.286), and then fell sharply at 27.5ЊC with high mortality at 30ЊC and above. The lower threshold for development was 10.04ЊC. Overall, the data indicate that B. schwartzi does better at cooler temperatures and that early season peach or nectarine varieties may be susceptible to damage by this aphid.

Annals of the Entomological Society of America, 2002

Populations of Brachycaudus schwartzi (Bö rner) were found on peach and nectarine (Prunus persica Siebold & Zuccarini) trees in Parlier, CA, in summer 2000. To determine if this aphid could be a pest of P. persica, a nine-variety host range test was conducted using a no-choice arena and temperature-dependent development studies of the aphid at 15, 20, 22.5, 25, 27.5, 30, and 32.5ЊC. Nectarine variety MayÞre (r m ϭ 0.286) and Queencrest peach (r m ϭ 0.283) were found to be the best hosts followed by Mayglo nectarine (r m ϭ 0.253). MayÞre was, therefore, selected as the host plant for the colony and for the temperature development studies. Detached shoot terminals of MayÞre were maintained on HoaglandÕs solution and placed in small cages in growth chambers. One adult aphid was introduced onto each ßush and development of aphid offspring was monitored daily. The shortest developmental time from Þrst instar to adult aphid was 6.9 d at 25ЊC and the longest was 19.9 d at 15ЊC. Adult longevity was 38.5 d at 15ЊC and the highest offspring per female was 46.4 nymphs per female at 20ЊC. The intrinsic rate of increase (r m) rose sharply from 15ЊC (0.109 nymphs/(/d) to a maximum at 25ЊC (r m ϭ 0.286), and then fell sharply at 27.5ЊC with high mortality at 30ЊC and above. The lower threshold for development was 10.04ЊC. Overall, the data indicate that B. schwartzi does better at cooler temperatures and that early season peach or nectarine varieties may be susceptible to damage by this aphid.

PloS one, 2016

During parasitoid development, the immature parasitoid is confined to the host species. As a result, any potential to modify the physiology or behaviour of the host could play an important role in parasitoid fitness. The potential for host manipulation by the aphid parasitoid Aphidius avenae to increase cold thermotolerance was investigated using the aphid host species Metopolophium dirhodum and Sitobion avenae. Aphids were parasitized at L3/L4 instar stage (5 d old) and allowed to develop into pre-reproductive adults (10 d old) containing a 5 d old parasitoid larva. A control group was created of non-parasitized pre-reproductive adults (10 d old). The inherent physiological thermotolerance (LT50) and potential behavioural thermoregulation (behaviour in a declining temperature regime) of parasitized and non-parasitized aphids were investigated. Results revealed no effect of parasitism on the physiological thermotolerance of S. avenae and M. dirhodum. Significant differences in the b...