The approach depends upon what you want to do with the proteins. Do you need them to retain their native structure and function? Do you need them to be purified? How much do you need?

Hi

hope this will be useful:

Bull Entomol Res. 2016 Oct;106(5):633-41. doi: 10.1017/S000748531600033X. Epub 2016 May 24.

The effect of host nutritional quality on multiple components of Trichogramma brassicae fitness.

Kishani Farahani H, Ashouri A1, Zibaee A, Abroon P, Alford L.

Dear colleague,

Several methods of extraction and quantification exist. You can extract several components (carbohydrates, lipids and proteins and nucleic acids) with the same sample using the procedure of Shibko et al. (1966), the most procedure used. In brief, each sample was homogenized in 1 ml of trichloroacetic acid (20%). After homogenization and centrifugation (5000 g/min, 10 min), the first supernatant was used for the carbohydrates using anthrone as reagent and trehalose or glucose as standard, while the pellet added with a mixture of ether and chloroform (1V/1V) was subjected to a second centrifugation (5000 g , 10 min). The resulted supernatant was used to quantify the lipids based on the vanillin method  (Goldsworthy et al., 1972). Finally, protein quantitation was determined in resulting pellet using the Bradford (1976) assay with blue brilliant of coomassie (G 250, Merck) as reagent and bovine serum albumin (Sigma) as standard. The reading of absorbance was performed at a wavelength of 595 nm.

References cited:

Bradford MM. A rapid and sensitive method for quantitation of microgram quantities on protein utilizing the principle of protein-dye binding. Analytical Biochemistry. 1976 ; 72:248-254.

Goldsworthy J, Mordue W, Guthkelch J. Studies on insect  adipokinetic hormones. General and Comparative Endocrinology, 1972; 18:545-551.

Shibko S, Koivistoinen P, Tratnyek CA, Newhall AR, Friedman L. A method for sequential quantitative separation and determination of protein, RNA, DNA, lipid, and glycogen from a single rat liver homogenate or from a subcellular fraction. Analytical Biochemistry. 1966; 19:514-528.

For details, see also attached some publications dealing with the subject made on different compartments (hemolymph, fat body, ovaries, mantle) and organism models (Inseet, Crustacea, Mollusk). 

 Best regards Pr. N. Soltani

Thank you docteur Shailendra Kumarfor the question and thank you professeur SOLTANI Noureddine for your rich answer.

Its a rich answer pr.soltani, is there an effect of treatement  of som diptera by insecticides to change compounds of protein or lipids or others..?

Dear colleague,

Yes several insecticides can affect the biochemical composition. See my profil you can find some papers on the effects of insecticides particularely the insect growth disruptors on Diptera species (Drosophilia, Culex and other mosquitoe spacies).

Best wishes Pr. N. Soltani, 

Thanks pr.soltani, I am your P_G student of Biskra (2007_2008). I want to launch some trials in this contexte. Coordialement