Introduction
Maize occupies an important place in Indian Agriculture. It is the third most important cereal in India after wheat and rice. The major maize growing states are Uttar Pradesh, Bihar, Rajasthan, Madhya Pradesh, Punjab, Andhra Pradesh, Himachal Pradesh, West Bengal, Karnataka and Jammu & Kashmir, jointly accounting for over 95% of the national maize production. The estimate of maize production in 2007 was 13-14 million tonnes from an area of 7.2 million hectares with an average productivity of 2 tons/hectare As mentioned earlier, maize is traditionally grown during the summer (monsoon) season, which is accompanied by high temperatures (<35 degrees) and rains. Rabi (winter) cultivation of maize is are latively new introduction started in mid sixties in some pockets of Bihar and South India, but now in the country as a whole. Rabi maize has comparative advantage of low incidence of diseases and insect pests, crops do not suffer on account of heavy rainfall, slow growth of weeds, etc. The one reason of low production is the attacks of various insect pests. The damage due to insect pest complex depends upon the population trends in the field which, in turn, rely upon their dynamically of the physical factors of their immediate environment (Isard, 2004). A thorough understanding of the exact relationship between the change in environmental factors and those in the pest population may not only help anticipate the pest losses to the crop, but also help avoid them through some well timed pest control measure (Aasman, 2001). Abiotic factors like temperature and relative humidity play a vital role in the development of insect pests fluctuation of these causes variation in the population present study was designed to investigate the effect of temperature and relative humidity on population of some insect pests of maize in unsprayed condition. Keeping in view the scenario regarding pest attack on maize crop the presented study was planned to investigate the effect of temperature and relative humidity on some insect pest of maize varieties.

1 Result and Dissuction
The present study carried out on the effect of temperature and relative humidity on the infestation of population of some insect pest of maize in Kharif crops. The results indicated that the population of leaf hoper increases with increase in temperature and decrease in relative humidity as the highest population of leaf hopper (mean value = 1.95) at the temperature of 36.2℃ and relative humidity at 75% while, the lowest population of the leaf hopper was found (mean value = 0.65) at the temperature of 30.5℃ and relative humidity 83%. (Table 1). (Zulfikar et al. 2010). found he results show that the population of leaf hoper increases with increase in temperature and decrease in relative humidity as the highest population of leaf hopper (mean value = 1.70) at the temperature of 36.5℃ and relative humidity at 68% while, the lowest population of the leaf hopper was found (mean value = 0.55) at the temperature of 31.5℃ and relative humidity 75% While the infestation of jassid experiment indicted that the population of jassid increases with increase in temperature and vice versa So that temperature and relative humidity highly significant on jassid population the lowest population of jassid was found with mean value of 0.80 at 28.6℃ and relative humidity 73% and the highest population of jassid found (mean value = 1.95) at 36.0℃ and relative humidity 75%. (Table 2) These finding were confirmed (Suggetha, 2001) he found the optimal conditions of temperature and relative humidity for the population build up of jassid at the temperature 30℃ and relative humidity 60.75% (Tamiru et al., 2012). The spotted stemborer, Chilo partellus (Swinhoe) (Lepidoptera: Crambidae), is one of the most important insect pests attacking maize and sorghum in Ethiopia. Recent studies have indicated that the pest is spreading to new locations where it was not reported before. In the current study, laboratory investigations were carried out to determine the combined effect of different levels of relative humidity and temperature regimes on the development and fecundity of C. partellus, as these physical factors are known to play an important role in the life cycle of insects and adaptability to local climate. Developmental time, longevity, potential fecundity and realized fecundity of C. partellus were measured under controlled conditions. Three temperature regimes (22℃, 26℃ and 30℃) and three relative humidity levels (40%, 60% and 80%) were tested. It was found that temperature; relative humidity (RH) and their interaction significantly affected the developmental time, adult longevity, potential fecundity and realized fecundity of the pest. Developmental time was inversely related to temperature. Mean duration of C. partellus life cycle was 70.2 days at 22℃ and 80% RH, whereas it took only 26.5 days to complete its life cycle at 30℃ and 40% RH. Male and female longevity were similar in most cases. The adult life span ranged between 6.9~11.1 days at 22℃ and 3.1~7.2 days at 30℃ for different levels of relative humidity. The most suitable conditions for C. partellus development and fecundity were 26℃~30℃ temperatures regimes and 60%~80% RH levels. The infestation of Chilo partellus in this experiment increased with decrease in temperature and relative humidity. The minimum infestation 20.2% was found at the temperature of 31.2℃ and relative humidity 75%. Maximum infestation 55% was found at temperature of 29.5℃ and relative humidity 85% (Table 3). The population of aphid increase with decrease in temperature and relative humidity, lowest population was fund (mean value 2.32) at temperature 30.4℃ of and relative humidity 83% of and the highest population was found (mean value 3.12) at temperature 30.1℃ and relative humidity 85.5% (Table 4).

Table 1 Infestation level of leaf hopper in relation to temperature and R.H. under unsprayed condition

Table 2 Infestation level of jassid in relation to temperature and R.H. under unsprayed condition

Table 3 Infestation level of stem borer (Chilo particllus) in relation to temperature and R.H. under unsprayed condition

Table 4 Infestation level of aphid in relation to temperature and R.H. under unsprayed condition

2 Material and Method
These studies were carried out in Krishi Vigyan Kendra research area under Rajmata Vijyaraje Scindia Krishi Vigyan Kendra, Zonal Agriculture Research Station, Morena, M.P. During the year 2011~2012.The experiment was laid out in randomized complete block design (RBD) on four verities of maize viz., PEHM-2, Maharaja, NK-6240, NK-30. Having four replications. Plant to plant distance was 25 cm. and row to row distance was 50 cm. Thus the experiment was spread over a plot of about 250 m2 of an area and research area was divided with 16 plots. The plots were surveyed weekly for the presence of the pests from July to September, 2011. However, the data on the pests population after their be coming active on 04-08-11 were collected by selecting plants / plots at random and by taking visual count of the insect pests up to 25-09-11 when they had virtually vanished from the field. The data of infestation of stem borer collected by selecting 10 plants in each plots and count the population of leaf hoper, jassid and aphid by selecting 5 plants/plots. Similarly, the data on different climatic factors like, temperature and relative humidity obtained from the meteorological observatory of Zonal Agriculture Research Station Morena (IASS services Morena M.P.). The data thus obtained subjected to standard statistical analysis, so that to determine the effect of temperature and relative humidity on the population of different insect-pests of maize under unsprayed conditions.

References
Aasman K., 2001, Effect of temperature on development and activity of maize stem borer Chilopartellus, Bull. Environ. Ent. Research, 125-127

Isard S.A., Spencer J.L., Mabry T.R., and Eli Levine, 2004, Influence of atmospheric condition on high elevation flight of Western corn rootworm, Environmental Entomology, 33(3): 650-656
http://dx.doi.org/10.1603/0046-225X-33.3.650

Tamiru A., Getu E., Jembere B., and Bruce T., 2012, Effect of temperature and relative humidity on the development and fecundity of Chilo partellus (Swinhoe) (Lepidoptera: Crambidae), Bull Entomol Res., 102(1): 9-15
http://dx.doi.org/10.1017/S0007485311000307
PMid:21672294

Muhammad A.Z, Muhammad A.S., Muhammad A.R., Amir Hamza, Asim Hayat, and Ahsan Khan, 2010, Effect of Temperature and Relative Humidity on the Population Dynamics of Some Insect Pests of Maize, Pak. J. Life Soc. Sci., 8(1): 16-18

Woodson W.D., and Gustin R.D., 1993, Low temperature effect on hatch of western corn rootworm eggs, J. Kansas Entomol. Soci., 66 (1):104-107