Dear Kariyanna B. you're welcome. Please also see this potentially useful article entitled

Rearing the Cotton Bollworm, Helicoverpa armigera, on a Tapioca-Based Artificial Diet

Article Rearing the Cotton Bollworm, Helicoverpa armigera, on a Tapi...

This article is freely available as public full text on RG.

Likely that eggs were not fertilized: Several species of moths lay unfertilized eggs. Some deficiency in the diet (which used, synthetic/semisynthetic?) may also be responsible. References may be many more I have but only two for a good semi-synthetic diet:

Ahmed, K., Khalique, F. and Malik, B. A.1998. Modified artificial diet for mass rearing of chickpea pod borer, Helicoverpa (Heliothis) Armigera (Hubn.). Pakistan Journal of Biological Sciences, 1: 183-187.

Krishnareddy, B. and Vageeshbabu, S. H.anur 2015. Enhanced synthetic diet for rearing H. armigera under laboratory conditions. Journal of Entomology and Zoology Studies 3(1): 165-167

Semi-synthetic diet i used.

Thank you

If the artificial food meets all the needs of the mating and laying stage, then somehow make sure that the eggs are fertilized

Dear Moslem Aletby thanks for your suggestions.

Now I am working on the male and female ratio in the mating box and will cross check it for fertilisation.

Normally unmated females lay unfertilized eggs take care to get them mated.

Shekharappa Katralli Sure, I will definitely work on it.

Thank you

just see there should not be desiccation

Try providing adequate humidity 80 to 90 per cent. Ensure fertility of eggs by proper mating

First, the eggs should be placed in moist support (moist soil, wet filter paper ...), then in the growth chamber it seems that you have used an aerator that dries the eggs and solidifies them (keep a temperature between 20 and 25 ° C without the eggs being attacked by drafts (lime or cold). The third when you transport the eggs from one medium to another may be the eggs were shocked by the outside climate. Besides, the room temperature was low (you need a heating source that does not emit air). So try to put eggs in moist support in room condition away from air and in temperature that oscillates between 20 and 25 °C.

Regards

Dear Amandeep Kaur and J. Ashoka

Thank you so much for the answer and I will definitely focus on it.

Dear Ramzi Amari

Really worth information to adopt and disseminate.

Thanks for your valuable time, in sharing useful information.

From the information you have provided, I guess the environmental conditions are too cold for the eggs and adults. Adult insects and their other stages of development tend to detect cold conditions and then resort to diapause. I suggest you provide an automatic heater in your experimental room set a temperature ranging 23-25 ° C to help you break the diapause.

Henlay Magara, I kept in growth chamber containing 27 +/-1 degree temperature with 60-70 per cent humidity. So I am trying in all the way. Will come back after trying your suggestion.

Thank you.

I suggest to put sterilized sand about 5cm at the bottom of your chamber as a oviposition media for mated female to lay her eggs.

Incubate the eggs using foan rubber pad and wax coated paper. Wax paper should be used as floor and cover for the eggs. Foam rubber pap dipped in water, sequized and kept around the eggs. Set the temperature at 25 to 26 o C till the completion of incubation period. Namaste This we practice for mulberry silkworm eggs for uniform hatching

Good day! this may be due to the food you are humming Imago.

Dear J. Ashoka sir

Thank you, I will try the same for my pest of interest

Susrama i Gede Ketut, how best it will increase the egg hatching ? Because, sand media can’t hold moisture.

Dear Юлия Ляска , I cross checked the ingredients and recipe we are using to prepare a diet for H. armigera with others insect. I feel we are preparing accurately.

Using moist sand as oviposition media rather old way. The way Mr. Ashoka explained better.

Dear Susrama i Gede Ketut

Maintaining sand in moist condition is an another challenge. I am undertaking the suggestions of Dr J. Ashoka .

One of the probable reason for unhatching of eggs is male:female ratio. If possible keep more male adults or keep one male and female in small vial for mating for two to three days with sugar solution and white cloth for egg laying.

Dear Shivam Padaliya

We are maintaining good ratio of male and female. Now we are providing good condition to observe their hatchability.

Thanks

May your research resulted in something novelty. Best wishes.

Dear Susrama i Gede Ketut

Nothing like that, I am just searching other reason behind it.

Okay, hopefully the finding will be an interesting reason . . .

Yes,

After following all the suggestions given by RG members, I found hatching egg of the H. armigera.

Thanka to all

Hello colleagues,

I think first we must make sure that the eggs are fertilized. If that is ok., I think it's both about the relative humidity and the speed of the fan in the growth chamber.

Ebraheem Al-Jouri , I will consider your suggestions.

Dear Kariyanna B. just in case that this is still of interest to you: There is an older, closely related RG thread on the same topic which is entitled

Why did the eggs of Helicoverpa armigera not hatched?

https://www.researchgate.net/post/Why_did_the_eggs_of_Helicoverpa_armigera_not_hatched

Perhaps you'l find some of the answers useful.

Dear Frank T. Edelmann thanks for the useful thread. I will go through it