Effects of cold storage on nondiapausing eggs of the western corn rootworm (Coleoptera: Chrysomelidae)

Authors: Geisert, Ryan; LUDWICK, DALTON - UNIVERSITY OF MISSOURI; Hibbard, Bruce

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/6/2018
Publication Date: 3/22/2019
Citation: Geisert, R.W., Ludwick, D.C., Hibbard, B.E. 2019. Effects of cold storage on nondiapausing eggs of the western corn rootworm (Coleoptera: Chrysomelidae). Journal of Economic Entomology. 112(2):708-711. https://doi.org/10.1093/jee/toy405.
DOI: https://doi.org/10.1093/jee/toy405

Interpretive Summary: The western corn rootworm is a highly damaging pest of the corn crop industry across the world. In order to better study this pest, researchers have selected western corn rootworms for a shorter generation time known as a non-diapausing strain. In order to delay there hatch until larvae are needed, researchers sometimes store non-diapausing eggs at cold temperatures. For this experiment we tested how storing at low temperatures could affect the hatch and larval development of non-diapausing western corn rootworms. Eggs were stored in either soil or agar and placed in refrigerators set to 4ºC or 8.5ºC. Non-diapausing eggs were exposed to the cold for one, two, or four weeks at which point they were removed and placed in a chamber set to 25ºC. Eggs were then tested for average hatch percentage in Petri dishes and average larval recovery in containers with seedling corn. Results showed a significant reduction in percentage hatch for eggs stored at 4ºC for four weeks. Larval recovery was significantly reduced in eggs stored for four weeks at both 4ºC and 8.5ºC. Within the treatments tested, egg storage for less than four weeks in soil at 8.5ºC provided the best hatch and larval recovery. Researchers wishing to store eggs may use these results to improve their rearing or testing of western corn rootworm.

Technical Abstract: Non-diapausing eggs of the western corn rootworm, Diabrotica virgifera virgifera LeConte, were stored at low temperatures to test for potential negative effects to hatch and larval development. Eggs were stored in either soil or agar and placed in refrigerators set to 4ºC or 8.5ºC. Non-diapausing eggs were exposed to the cold for one, two, or four weeks at which point they were removed and placed in a chamber set to 25ºC. Eggs were then tested for average hatch percentage in Petri dishes and average larval recovery in containers with seedling corn. Results showed a significant reduction in percentage hatch for eggs stored at 4ºC for four weeks. Larval recovery was significantly reduced in eggs stored for four weeks at both 4ºC and 8.5ºC. Within the treatments tested, egg storage for less than four weeks in soil at 8.5ºC provided the best hatch and larval recovery. Researchers wishing to store eggs may use these results to improve their rearing or testing of western corn rootworm.