The effects of ascorbic acid on development and some biochemical analysis of Pectinophora gossypiella (Saund.) were investigated after feeding newly hatched larvae with different concentrations of three ascorbic acid analogues i.e., L-ascorbic acid, D-isoascorbic and D-glucoascorbic acid. The added analogue and the used concentration significantly affected larval growth. Statistically, L-ascorbic acid seemed to be the best analogue, as the whole mean of survived larvae averaged 63.737% comparing with 54.17 and 32.9% for the D-isoascorbic and D-glucoascorbic acid analogues, respectively. All survived larvae succeeded to develop into pupae after feeding with any of the three concentrations of L-ascorbic acid, while, all larvae died or failed to develop into pupae when fed with 2.32 mg of D-isoascorbic or Dglucoascorbic acid analogue / 100g diet, respectively. The significant low percentages of survived larvae or produced pupae are a reflection to the reduction in the values of total protein, tyrosine and chitin in larval body. Statistical analysis of data yielded a significant correlation between the percentages of larvae which succeeded to develop into pupae and the quantity of their total protein (r = 0.8043**), tyrosine (r = 0.82277**) and chitin (r = 0.69874*) in larvae.
Field studies were conducted at Dakahlia Governorate, Egypt in 2004 and 2005 cotton seasons to evaluate the releases of Trichogramma wasps for pink bollworm, Pectinophora gossypiella (Saund.) and spiny bollworms Earias insulana (Boisd.) management in cotton. In the two seasons, six releases of Trichogramma evanescens Westwood 10-15 days intervals were made into 999 and 600 feddan, respectively. While, the recommended bollworms insecticide control program was applied at the control units. This recommended program suggested to use insecticide applications (insect growth regulators, organophosphoric and pyrethroid compounds) when infestation met or exceed the economic level (3%). The overall reduction of infestation with the two pests in Trichogramma units averaged 23.73 and 40%, since infestation averaged 1.35 & 1.44.0 in these units and 1.77 & 2.4% in control units at the two seasons, respectively. Meanwhile, T. evanescens succeeded to maintain boll infestation below the economic level in 78 and 84% of the dissected boll samples in the two seasons, respectively. The corresponding figures by insecticides were 67 and 56% in the two seasons, respectively.
The newly hatched larvae of pink bollworm (PBW), Pectinophora gossypiella (Saunders) were fed for two days on artificial diet treated with the LC50 concentration of some biocides i.e., Agrin (Bt), Ecotech-pro (Btk x Bta) and Bio-clean (Btk x Beauveria. bassiana). The survived 2 nd and 4 th instar larvae of normal appearance fed on treatments and control diets were used to study the histopathological changes of the aforementioned biocides on the fourth abdomen segment. Examination of the microtomical transverse sections of this segment showed abnormal effects in the histopathology of some organs and tissues (midgut, Malpighian tubules, fat bodies, body muscles & cuticle) of the treated larvae. Generally, the pathological effects of the tested biocides were more serious against the 2 nd instar larvae than against the 4 th one. The type and degree of these effects differed according to the tested biocide, whereas Bio-clean was the most potent one.
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