The present study deals with life tables and intrinsic rates of natural increase of Trichospilus pupivora Ferr. a pupal parasitoid of Opisina arenosella walker. The maximum mean progeny production per day was on Ergolis merione Cr., (86.20). The innate capacity increase ranged from 0.288 to 0.308 per female per day depending on the hosts used. The maximum multiplication of the population also occurred on the same host. The population multiplied 118.31 times in mean generation time of 15.55 days.
The adverse effects of rainwater and artificial urban runoff (an imitation of urban runoff during rainfall event) were investigated using a battery of bioassays employing three test species. Urban dusts were collected at three representative sites; commercial, industrial and highway areas. The water quality parameters of rainwater and artificial runoff revealed low hardness (23.4 approximately 34.2 mg*L(-1) as CaCO(3)) and alkalinity (7.0 approximately 34.2 mg*L(-1) as CaCO(3)). High toxicities were observed in the bioassays for the artificial runoffs. The average toxic units for D. magna, S. capricornutum, and O. latipes were 1.26(+/-0.84), 1.34(+/-1.10) and 2.05(+/-1.08), respectively. Of these species, O. latipes revealed significantly higher toxicity compared to D. magna and S. capricornutum (p < 0.05). Embryo lesions were observed with 6.25% treatments, and these significantly increased at 12.5% treatments (p < 0.05). The EC(50) values for each artificial runoff were 22.5, 22.6 and 25.4% for commercial, industrial and highway areas, respectively. With 12.5% treatment, significant delays in hatching times were observed (p < 0.05); all embryos tested did not hatched at 100% treatment. Similarly, a significant decrease in hatching success was observed at every sampling point from 25% treatment (p < 0.05). The adverse effects of artificial runoff on the three test species suggests that urban surface runoff can cause significant impairment in aquatic ecosystems.
The efficacy of organic amendments (pressmud and zinc enriched pressmud) and zinc fertilisation was studied in paper factory effluent imigated soil. The results showed that available phosphorus content in soil and its uptake in plant were increased due to the application of pressmud. Application of amendments and ZnSO4 significantly increased exchangeable calcium, but decreased the exchangeable sodium. Total day matter production was significantly enhanced by the application of pressmud and soil application of ZnSO4. Enrichment of pressmud with ZnSO4 resulted in increased dry matter production. Foliar spray of zinc at 0.5 per centconcentration given at 90 and 110 days after planting significantly increased the dry matter production over soil application of zinc and control.
Six ecotypes of Trichogramma chilonis collected from Gudimangalam, Palladam, Udumalpet, Pongalur, Chingleput and Mettupalayam, were compared with the laboratory strain of the same species (Coimbatore). All the ecotypes were significantly superior to the laboratory strain in parasitizing the eggs of Corcyra cephalonica, Heliothis armigera and Spodoptera litura and showed a distinct preference for H. armigera eggs. The Palladam ecotype was able to withstand starvation to a maximum extent of 6.86 days.
Two hundred bengal gram accessions (Cicer arietinum L.) were screened for their resistance to Callosobruchus maculatus (F) by Free Choice Test. The number of eggs laid varied from 4 to 60. The adult emergence ranged between one in 11 and 27 in 5 accessions. Hundred per cent survival was observed in four accessions (Shahkot- 2, P-1675, RFG 30 and NEC-1592) as against only five per cent survival in RBH 99 and RC 109. Ovipositional preference was found not related with the suitability of the accession for further development. C. maculatus took 25 to 41 days for development. Based on the suitability index, 22 accessions were categorised as resistant, 40 as moderately resistant, 109 as susceptible and 29 as highly susceptible to C. maculatus.
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