| Abstrakt: |
Heterorhabditis indica from genera Heterorhabditis is an efficient biological control agent, due to their ease of culture, their high fatality against key soil insect pests, and their safety in use. However, their commercial utilization is limited by their limited shelf life in storage. Thus, efficient storage is essential so as to attain successful use of them alone including a part of integrated insect pest management strategies. Heterorhabditis indica isolated from soil in Uttar Pradesh, India (GPS location 28.6691°N, 77.4537°E) was characterized in terms of storage in different media including de-ionized water; at different temperatures and infectivity of their infective juveniles (IJs). After the primary screening of several media alone and in different combinations; a set of six media viz., de-ionized water (S1), cocopeat (S2), vermicompost (S3), earth (S4), potter's clay, talcum powder & earth (S5) and potter's clay, talcum powder, earth & cocopeat (S6) were selected and the survival and infectivity of H. indica IJs were studied at, 15±2 °C, 20±2 °C and 25±2 °C, for a period of 120 days. The effectiveness of H. indica IJs was ascertained on the basis of the establishment of IJs, using Galleria mellonella larval mortality tests in Petridish using baiting method technique at 15 days intervals. The results of this study revealed that storage media markedly affects the survival as well as the establishment of H. indica IJs. At all three test temperatures viz., 15±2 °C, 20±2 °C and 25±2 °C, a comparatively higher survival rate of H. indica IJs was observed in S2 and S6 media for 120 and 90 days, respectively, but the same reduced drastically in other media. Heterorhabditis indica IJs stored in S2 media showed comparatively better establishment following S6 than those stored in others at all temperatures for different storage durations as compared to de-ionized water. Present studies indicate that the storage stability of H. indica IJs enhances up to 120 days in S2 at all ranges of the temperature of 15-25 °C. In conclusion, our study adds further valuable information about the effect of storage media and temperature on the survival and infectivity of H. indica which appears to be promising biocontrol agents of major soil arthropod pests. [ABSTRACT FROM AUTHOR] |
