Here are some references that might be useful to you:

Drosophila egg-laying site selection as a system to study simple decision-making processes.

Yang CH, Belawat P, Hafen E, Jan LY, Jan YN.

Science. 2008 Mar 21;319(5870):1679-83. doi: 10.1126/science.1151842.

https://www.ncbi.nlm.nih.gov/pubmed/18356529

Fruit flies medicate offspring after seeing parasites.

Kacsoh BZ, Lynch ZR, Mortimer NT, Schlenke TA.

Science. 2013 Feb 22;339(6122):947-50. doi: 10.1126/science.1229625.

https://www.ncbi.nlm.nih.gov/pubmed/23430653

Competing dopamine neurons drive oviposition choice for ethanol in Drosophila.

Azanchi R, Kaun KR, Heberlein U.

Proc Natl Acad Sci U S A. 2013 Dec 24;110(52):21153-8. doi: 10.1073/pnas.1320208110.

https://www.ncbi.nlm.nih.gov/pubmed/24324162

Olfactory preference for egg laying on citrus substrates in Drosophila.

Dweck HK, Ebrahim SA, Kromann S, Bown D, Hillbur Y, Sachse S, Hansson BS, Stensmyr MC.

Curr Biol. 2013 Dec 16;23(24):2472-80. doi: 10.1016/j.cub.2013.10.047.

https://www.ncbi.nlm.nih.gov/pubmed/24316206

I am no expert in this area, I found these results just by doing a search on Google Scholar for drosophila + oviposition + preference :

http://scholar.google.com/scholar?q=drosophila+oviposition+preference&btnG=&hl=en&scisbd=1&as_sdt=0%2C5

Most questions like these can be answered by a simple literature search on Pubmed or Google! It is not that difficult, try it yourself !!

Best,

~a.

Thank u so much for the reply. I've going through few literature provided by search engine earlier, but the thing is studies show that flies prefer nutrient media for oviposition. I wanted to know whether people working on fecundity or oviposition behavior of flies have noticed that few flies tend to lay eggs away from nutrient medium unlike other flies. Just curious to know the reason for this unusual behavior.

Thanks for the reply. First of all it's just my observation during fecundity experiments. Population density shouldn't be a problem here because as it was fecundity expt there used to be 1 pair of flies. Also they were not in siesta. Humidity and temperature were maintained in vivarium. Standard wheat cream agar medium was provided. Then experiment was carried out in usual light and dark cycle periods. Moreover, out of many replicates, only few pairs show this type of behavior. I even doubt whether this behavior has something to do with their age and stress (if at all laying more eggs can lead to more stress).