&lt;p&gt;Investigations was carried with a view to find out preferred hosts nature and extent of damage and effectives of dust formulation of insecticides against C. serratus at Department of Agril. Entomology, College of Agriculture, Junagadh during the year 2002-03. Hosts selected for these studies were T. indica, A. hypogaea, C. fistula, A. nilotica, A. senegal, P. cinerarla, B. racemosa. A.chundra, P.juliflora and P. aquanata.&lt;br /&gt;
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The population build up of C. serratus was found maximum 169.82 (60 days), 588.84 (120 days) and 776.25 (180 days) bruchids per 250 gm seeds on T. indica. Whereas, it was minimum at 60 days (117.49), 120 days (354.81) and 180 days (501.18) bruchids per 250 gm seeds on P. juliflora. Maximum per cent kernel damage was found on preferred host T. indica after 60 (29.19), 120 (75.06) and 180 (99.29) days of storage period. Whereas, minimum per cent damage was found on less preferred host P. juliflora AT 60 (18.18), 120 (60.19) and 180 (85.05) days of storage period. Other hosts were found intermediate.&lt;br /&gt;
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The infestation resulted in to maximum per cent weight loss was found on T. indica at 60 (10.06),120 (50.68) and 180 (72.28) days of storage and minimum per cent weight loss at 60 days (5.86), 120 days (39.90)and 180 (55.19)were found on P.juliflora. Similarly, maximum germination loss was found on T. indica and it was ranged from 52.32 to 99.04 per cent at 60 to 180 days. Whereas, minimum germination loss was found on P. juliflora and it was ranged from 39.02 to 70.50 per cent at 60 to 180 days. Other hosts were found intermediate.&lt;br /&gt;
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The hosts differed in preference for oviposition. Maximum (420.00) number of eggs were recorded on T. indica. While minimum (12.27 eggs) on P. juliflora. Maximum (96.42) per cent egg per seed was found on T. indica and minimum (16.94) on P.juliflora.&lt;br /&gt;
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Similarly, T.indica was found more preferred for development of adult and recorded maximum 93.33 per cent adults emergence. Whereas, P.juliflora was found least preferred having minimum 50.00 adults emergence. Other hosts were found intermediate.&lt;br /&gt;
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Adverse effect of different hosts on various biological activities considered as host antibiosis. Maximum (24.50 days) larval period was recorded on P. juliflora and minimum (16.70 days) on T. indica. The maximum (39.20 per cent) larval mortality was recorded on P.juliflora and minimum (4.47 per cent) on T. indica. Maximum pupal period and mortality (19.76 days and 10.80 per cent) and total development period and mortality (45 days and 50 per cent) were recorded on P.juliflora, respectively. Whereas, minimum (14.92 days) pupal period was recorded on T. indica and minimum (2.10 days) pupal mortality was recorded on A. hypgaea. The shortest (35.02 days) total developmental period and minimum mortality (6.67 per cent) were found on T. indica.&lt;br /&gt;
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The minimum (1.11) growth index was recorded on P. juliflora and maximum (2.67) on T. indica. Similarly, minimum (1:0.817) male: female ratio was recorded on P.juliflora and it was maximum (1:1.204) on T. indica.&lt;br /&gt;
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The fecundity behaviour of C.serratus was influenced due to different hosts which was maximum (53.20 eggs/female) on T. indica and minimum (7.00 eggs/female) on P. juliflora.&lt;br /&gt;
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Host T. indica showed maximum (2.10 days) pre-oviposition period. While, minimum (1.20 days) pre-oviposition period was recorded on P.juliflora and A.chundra. similarly, maximum (8.50 days) oviposition period and post oviposition period (15.40 days) were recorded on T. indica. While minimum (4.90 days) oviposition period and post oviposition period (4.20 days) were found on P.juliflora.&lt;br /&gt;
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The longevity of male and female adults of C.serratus was adversely affected due to different hosts. The longevity of male and female were maximum on T. indica (18.90 and 23.40 days), respectively. Whereas, minimum on P.juliflora (7.00 and 9.40 days), respectively.&lt;br /&gt;
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The incubation period of first generation eggs of C.serratus was maximum (4.00 days) on P.juliflora, while minimum (2.67 days) on T.indica. Whereas, maximum (29.81 per cent) eggs mortality was recorded on P.juliflora and minimum (4.45 days) on T.indica. The viability of first generation eggs of C.serratus was found maximum (95.45 per cent) on T.indica and minimum (70.05 per cent) on P.juliflora . Therefore, T.indica was most preferred host. While P.juliflora was least preferred host of C.serratus.&lt;br /&gt;
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Out of the different dust formulation of insecticides tested, chlropyriphos and malathion at the rate 6 gm a.i./kg gave the highest relative protection to groundnut kernels up to 60 days against C.serratus without hampering the gemination.&lt;/p&gt;
