Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) has been the current topic of research for insect taxonomists and applied entomologists in India due to its invasiveness, rapid spread, morphological and biological variations and the need for establishing an effective control strategy. The biology of the mealybug P. solenopsis was studied on cotton under laboratory conditions between August and October of 2009 with mean temperature and relative humidity of 23.3–30.2°C and 40.5–92.5% RH, respectively, in central India. Neonate crawlers that emerged from a field population were collected and constituted the study population. The developmental period from immature crawler to adult stage was greater for males (18.7 ± 0.9 days) compared to females (13.2 ± 1.8 days), probably due to the additional molt to the pupal stage in males. Survival of second instars was lower (45.5%) than first and third instars (71.4%). Females showed dynamic patterns of fecundity with the number of crawlers produced per female ranging between 128 and 812, with a mean of 344 ± 82. The reproductive period lasted 30.2 ± 8.2 days. Parthenogenesis with ovoviviparity (96.5%) was dominant over the oviparous (3.5%) mode of reproduction. Adult females lived 42.4 ± 5.7 days. Males accounted for less than 5% of the population, and lived 1.5 ± 0.1 days. The life history parameters of P. solenopsis adult females are discussed relative to the appearance of symptoms on the cotton crop, and the importance of making management interventions during the effective reproductive period of the insect.

Colon cancer is the third most malignant neoplasm in the world and it remains today an important cause of death, especially in western countries. In this study, we have evaluated the chemopreventive efficacy of morin on tissue lipid peroxidation and antioxidant status, which are used as biomarkers in 1,2-dimethylhydrazine-induced colon carcinogenesis in a rat model. Male Wistar rats were divided into four groups and received high fat diet. Group 1 served as control, groups 2 and 4 were given a daily treatment of morin (50 mg/kg body weight) orally, everyday for a total period of 30 weeks. Groups 3 and 4 were given weekly subcutaneous injections of DMH at a dose of 20 mg/kg body weight in the groin for 15 weeks. Animals were sacrificed at the end of 30 weeks. The liver, intestine, colon and caecum from different groups were subjected to histopathological studies, determination of lipid peroxidation and antioxidant status. Our results showed decreased levels of liver enzymic and non-enzymic antioxidants and increased levels of lipid peroxidation (LPO) products such as tissue thiobarbituricacid substances (TBARS), lipid hydroperoxides (LOOH) and conjugated dienes (CD) in DMH treated rats, which were significantly (P < 0.05) reversed on morin supplementation. Moreover, intestinal, colonic and caecal TBARS, LOOH, CD and also the antioxidants superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), glutathione peroxidase (GPx), glutathione reductase (GR) and reduced glutathione (GSH) were significantly diminished in DMH treated rats, which were significantly (P < 0.05) elevated on simultaneous morin supplementation. Moreover, enhanced activity of intestinal, colonic and caecal ascorbic acid and alpha-tocopherol levels were also observed in DMH alone treated rats, which were significantly (P < 0.05) reduced on morin supplementation. These results indicate that morin could exert a significant chemopreventive effect on colon carcinogenesis induced by DMH.

Field data collected in central India over a two-year period showed that Bt cotton hybrids reduced plant protection costs by Rs1,268/ha (Rs41 = US$1), raised the crop yield by 2.01 q/ha, worth Rs6,394/ha, and reduced the time spent by the crop in the field by 15–20 days. Cultivation of Bt cotton involved an additional cost of Rs3,720/ha, but increased the net returns by Rs2,674/ha over conventional hybrids. The higher price of seed, high risks, poor refuge management, incidence of wilt, high rates of discontinuance and poor monitoring were the major constraints reported by growers. The impact would be greater if the technology were embodied in the commonly grown hybrids. Development of transgenic varieties is one of the prime ways of reducing crop costs for the resource-poor conditions of rainfed central India.

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