Effects of Different Temperatures on the Biology of Acyrthosiphon pisum on Different Pea Cultivars

The research studies were carried out at Key Laboratory of Entomology, Northwest A & F University, Yangling, Shaanxi under 60±5% Relative Humidity, light: dark photoperiod at 14 h : 10 h to assess different range temperature effects on the population of Acyrthosiphon pisum on different pea cultivars during, 2018. The results indicated that the shortest pea aphid nymph development period up to (5.75±0.31 days) were lasted on cv. Feizai-3 at 36 o C and longest (9.38±0.34 days) were noted on cv. Nenzao at 30 o C. The shortest A. pisum adult development period (4.16±0.20 days) were recorded on cv. Hanyi-401 at 39 o C and the longest (5.72±0.33 days) on cv. Hanyi-401 at 30 o C. The shortest A. pisum longevity period (5.43±0.72 days) were recorded on cv. Feizai-3 at 39 o C and longest (11.83±0.72 days) on cv. Hanyi-401 at 30 o C. The shortest A. pisum oviposition period (3.61±0.32 days) were recorded on cv. Hanyi-401 at 33 o C and longest (4.41±0.35 days) on Guangzhong-604 at 36 o C. The minimum nymph survival period was counted (0.23±0.07) on Guangzhong-604 at 36 o C and maximum on cv. Hanyi-401 (0.73±0.08) at 30 o C. According to the DMRT-Test, non-significant difference was reported in all the above parameters between the cultivars in all temperature regimes. The present study suggests that temperature fluctuations also affect on the life expectancy of A. pisum . In future endeavors more work should be carried out to restrict the pest population of sap-sucking insects to secure the legumes varieties


Introduction
The Pea aphid, Acyrthosiphon pisum Harris (Homoptera: Aphididae), also known as clover louse, pea louse, and green dolphin (Fakhouri et al., 2021), that sap-sucking insect, fed on the Fabaceae plants, which includes several species of legumes and forages crops such as; broad bean, alfalfa, pea, and clover (Lane and Walters, 1991). There is no system existing for the predict population development of aphids and expensive crop inspections are needed for the management of this pest species (Biddle et al., 1994). The immature stages of the insect pests are massively voracious feeders (Mangrio et al., 2020). The development and effective management of pea aphid focus to understand the biology and effects of prevailing temperatures (Takemoto et al., 2013). The host plant cultivars and temperature particularly affect the development, pre-reproductive behaviors, fecundity, and mortality of the insect population (Markula and Roukka, 1971). In the United Kingdom, there are several reports about the temperature and cultivar's interaction on the lifespan of the pea aphid (Blackman and Eastop, 1984). In every climatic zone of the world, peas crops are grown sufficiently and the fruits of legume plants found in the form of pods called beans (Walters et al., 1994). Peas are commonly consumed in the form of green grains and green peas are generally denoted as nitrogen fixation plants and regarded as friendly food (Biddle, 1985). The peas are winter vegetable crops with excellent dietary quality with a rich source of protein, lysine, and many important minerals (Campbell and Mackauer, 1975). The lower temperature adversely effects the life cycle, survival rate, and reproduction periods of the A. pisum (Siddiqui et al., 1973). Proper insect pest management and appropriate controlling strategies can enhance the quantity and quality of the cultivar's productivity (Mangrio and Sahito, 2022). Keeping in above problematic issue the main motives of present study was to know the co-existence of pest fluctuation on different temperatures to find out the better management strategies.

Materials and Methods
Insect cultures: The population of aphid was obtained from the field of a pea, and the mixed clone culture was initiated using this pest. Insect population was maintained on the plant of V. fabae L. grown in pots (12 cm) plants containing potting media John Innes No.3 in a growth room at 14L: 10D photoperiod and 20±2 o C. The pots were given water daily and in the mesh-breeding cages (45x50 cm) the plants and population of the aphids were kept for further research studies. Experimental design: Within 24 hours in each temperature experiment the newly emerged nymph population was selected and shifted to the other inferior detached leaves end of the pea cultivars, kept in Petri dishes, and given moist filter papers at the bottom of the dishes. In each Petri dish, only one aphid was permitted individually at 27 o C, 30 0 C, 33 o C, 36 o C, 39 o C at a fixed temperatures, and all the aphids were kept in environmental chambers with 60±5% RH and 14 h : 10 h light: dark photoperiod. The thirty Petri dishes were arranged and in every Petri dish single nymph was kept as per temperature requirement. The nymph mortality within 24 hours in each replication was omitted, the filter papers were moistened and kept inside the Petri dishes and after 2 days the aphid was transferred to a new leaf disk of pea cultivars. Each treatment was replicated five times. The nymph population was observed on daily basis, molting, number of nymphs, and till the complete mortality occurred, the data was gathered. For sample collection and application of variable temprature against the population of A. pisum (Stacey and Fellowes, 2002) described methodology was applied. Data analysis: The data was analyzed through the application of student package SWX software 8.1 USA, and the LSD Test was applied among the treatment means to check the significance level at (P<0.05).

Nymph development period (days):
The results in regards to the nymph development period of pea aphids in five different temperatures reared on different pea cultivars. The shortest nymph development period of Acyrthosiphon pisum (5.75±0.31 days) was recorded on cv. Feizai-3 at 39 o C and the longest development period of Acyrthosiphon pisum (9.38±0.34 days) was noted on cv. Nenzao at 30 o C. The overall maximum to minimum mean days of nymph development period at all temperatures was recorded on Nanzao at (7.93±0.39) followed by Guanghzhong-604 at (7.83±0.41), Feizai-3 at (7.71±39), Qizhen-76 at (7.69±0.45) and Hanyyi-401 at (7.33±0.41), respectively. According to the DMRT-Test between all cultivar's temperature regimes in the development period of the nymph found with the significant differences hence shown in (Table-1). According to the DMRT-Test between regimes in the development period of adults found with the nonsignificant difference thus, it was recorded and further justified in (Table-2).  respectively. According to the DMRT-test thus, there was non-significant differences found in longevity period between the cultivars in all temperature regimes as justified in (Table-4).

Discussion
The study of the developmental stages of A. pisum was carried out on different pea plants cultivars at 27°C, 30°C, 33°C, 36°C, and 39°C. The population of the pea aphid successfully developed at all temperatures and as the temperature increased the developmental rate also increased. Our results are more or less comparable with the work of (Stacey and Fellowes, 2002), who documented that greater temperature alters the interaction between entomopathogen and A. pisum but there is little evidence that smaller changes occur between the natural enemy and A. pisum at low temperature (Jeong et al., 2020) at 30°C, the high pre-adult mortality and lower fecundity rate was recorded.
The adult life cycle of the Acyrthosiphon pisum was found by (Melaku et al., 2000), they documented the life cycle of Acyrthosiphon pisum on four different field pea, faba, grass pea, and legumes those found with the non-significant difference in molt stages and nymphal length among the tested crop varieties. The temperature and weather parameters affect the life cycle of the A. pisum as described by (Fakhouri et al., 2021) that environmental fluctuations in different seasons hit the population fluctuation of aphids. The intensity of temperature, wind speed, and RH affect the on A. pisum and pea cultivars (Bieri et al., 1983). In North America and Europe, the high temperature badly affects all life stages of A. pisum (Frazer, 1972). The A. pisum contains several strains and subspecies which may form aphid comparison data from geographically disparate areas (Blackman and Eastop, 1984).
The nymphal development period found as the work agreement of (Lamb (1992), documented that the time of development on pea cultivars at different temperatures was longer than other reported scientific documentation such as at 20°C 6.4, 6.5, 7.6, and 8.4 days, respectively. The adult development period resembles the findings of (Siddiqui et al., 1973) reported the life cycle, survival rate, and reproduction periods were found to generally on lentils longer compared to other crops with three molts and nine to eleven total days but on the development rate adverse effects were observed at lower temperatures. (Bieri et al., 1983) reported the life cycle of pea aphids the temperature influence the higher optimal temperature for the development of pea aphids between 28°C to 30°C compared with the 23.1°C and 26.7°C reported with massive effect and required to prolong time to complete all life cycle stages as reported at 23.1°C (Hutchinson and Hogg, 1984). The oviposition and nymph survival period recorded as used (Lamb, et al., 1987), the variations in the parameters of life history as documented in different studies could be credited for adapting of aphids in climatic conditions but in different rearing methods, they may be influenced.

Conclusions and Recommendations
It is concluded that the maximum nymph period was recorded on Nenzao-3 at 30 o C and minimum The maximum nymph survival period counted on Hanyi-401 at 30 o C and the minimum on Guangzhong-604 at 36 o C, respectively. Whereas, 27 o C temperature is best suited for a high fecundity rate and total preoviposition period in all five pea cultivars, and decreasing trend in fecundity rate and total preoviposition period was observed when the pea aphid was reared beyond 30 to 39 o C. The overall maximum mean developmental days lasted on Hanyi-401, followed by Guangzhong-604, Nenzao, Feizai-3, and Qizhen-76. It is recommended that furthermore study on aphid pest bionomics, and developing forecasting methods should be used to combat this potential insect pest.

Authors Contribution
A.H. Mastoi is the prime author of the manuscript who conceived, experiments performed, data collected, and wrote the paper from the Ph.D research conducted at Key Laboratory of Entomology, Northwest A & F University, Yangling, Shaanxi, China. W.M. Mangrio statistically analyzed the data. H.A. Sahito point by point reviewed the article. F.I. Sahito, F.A. Jatoi and S.P. Solangi arranged tools, materials, and played a collaborated role to finalize the research manuscript.

Impact Statement
The A. pisum widely destructive pest, sap-sucking insect limiting the yield of several varieties of legumes and forage crops in parts of the world, sucking its sap weakens the plants, from infested plants to healthy one's plants, and the control of this potential pest there is no effective tool available. It is necessary to bring awareness and immediately apply certain strategies through IMP to secure the legumes crops from this potential insect pest.

Declaration and Competing Interest
The authors proclaim that there is no personal relationship or financial interest regarding any part of the work which is presented in this research article.