Radiation biology of a serious tropical pigeon pea pest, Maruca vitrata (Fabricius) (Lepidoptera: Crambidae) and potential of radiation mediated ‘inherited (F₁) sterility technique’ for the pest suppression

Abstract

Purpose: The impact of gamma radiation on the reproductive biology of the spotted pod borer, Maruca vitrata (Fabr.) (Lepidoptera: Crambidae) was ascertained to explore the potential of the radio-genetic ‘Inherited (F₁) Sterility’ technique (modified Sterile Insect technique) to control this serious pigeonpea pest in India.

Materials and methods: Radio-biological investigations involved dose–response studies, at a range of 100–250 Gy, with respect to radiation induced adverse effects on reproductive behavior in substerilized parent (P₁) moths, inheritance of sterility and associated metamorphic disruption in F₁ progeny. The reproductive competence of P₁ male moths and their F₁ progeny was evaluated by ascertaining the survival, mating success, sperm transfer and amphimixis of gametes from irradiated male parents and their F₁ progeny. Daily ovipositional and egg fertility profile were evaluated as crucial parameters for simulation modeling for this radio-genetic technique.

Results: Radiation-induced check in insemination rate and sterility in P₁ and F₁ generation had a positive correlation with gamma dose. The metamorphic adverse effects in F₁ progeny of substerilized P₁ males were influenced by P₁ irradiation. A higher dose of 200 Gy that resulted in 21.1% fertility in parent cross (P₁♂x N♀) could form only 14.4% F₁ adults that were all malformed. A gamma dose of 150 Gy (administered to P₁ males) could be considered as a suitable dose for F₁ sterility, that induced 57.4% control of reproduction in parent generation, followed by 72–85% control of reproduction in F₁ progeny involved in three crosses -F₁♂xN♀, N♂xF₁♀, F₁♂xF₁♀. Daily fertility profile of the eggs laid indicated a marked reduction on 4th day onwards during the ovipositional span in P₁ and F₁ generation. High degree of mating competitiveness value (CV) was noticed for 150 Gy irradiated male P₁ moths (0.78–0.93), and their F₁ male progeny (0.70–0.89), released in different sex ratios in the field cages having untreated moths. Reduced relative damage to the pigeon pea plants by the released F₁ progeny in the field cages was observed in comparison to control.

Conclusion: The present study indicated the potential use of a dose of 150 Gy to apply the ‘F₁ sterility’ technique for parabiological suppression of the pigeon pea pod borer. The present findings and reproductive performance of the irradiated moths in F₂ generation along with other compatible biorational pest control tactics (that are in progress), might help in formulating an effective integrated pest management module, including the F₁ sterility technique as an integral component.

Keywords:

• Maruca vitrata
• Sterile Insect Technique
• F1 sterility
• legume pod borer
• parabiological control
• radio-sterilization

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

Additional information

Funding

The authors gratefully acknowledge the financial assistance from National Food Security Mission (NFSM)-Pulses, Ministry of Agriculture, Govt. of India, under Joint project [CPS-5-2/2013-NFSM].

Notes on contributors

Rakesh K. Seth

Rakesh K. Seth, Ph.D., is Professor & In-Charge, Applied Entomology and Radiation Biology Unit, Department of Zoology, University of Delhi, Delhi, India

Basavaraj V. Patil

Basavaraj V. Patil, Ph.D., is an emeritus Professor and former Vice Chancellor and Professor of Entomology, University of Agricultural Sciences, Raichur, Karnataka, India

Zubeda Khan

Zubeda Khan, Ph.D., is post-doctoral fellow in Applied Entomology and Radiation Biology Unit, Department of Zoology, University of Delhi, Delhi, India

Mahtab Zarin

Mahtab Zarin, Ph.D., is post-doctoral fellow in Applied Entomology and Radiation Biology Unit, Department of Zoology, University of Delhi, Delhi, India

Shivanand G. Hanchinal

Shivanand G. Hanchinal, Ph.D., is an Assistant Professor of Entomology Main Agricultural Research Station, University of Agricultural Sciences, Raichur, Karnataka, India

Rachappa V. Haveri

Rachappa V. Haveri, Ph.D., is an Assistant Professor of Entomology, Kalaburagi Agricultural Research Station, University of Agricultural Sciences, Karnataka, India.

Akshatha Gopalkrishna

Akshatha Gopalkrishna, is a Senior Research fellow, Main Agricultural Research Station, University of Agricultural Sciences, Raichur, Karnataka, India.