Division of Nematology, Indian Agricultural Research Institute New Delhi-12.
Presented at Nematology Symposium held at Coimbatore, India in February, 1981
Absolute measurement of 1020 specimens (460 Topotypes and 560 specimens from other hosts and localitis) of H. indicus Sher, 1963 were used for this study. These specimens were collected from four (sugarcane, sorghum citrus and banana) from each of the five different localities (Karnal, Hissar, Narnaul, Udaipur and Delhi) in order to test the effect of host and/or locality on correlation coefficient between any pair of characters.
Data for 12 different characters of females were computed to obtain correlation matrices giving correlation coefficients between all 78 and 66 combinations of characters for females and males respectively for every host and locality. It was found that:
No constant correlation exists between any two characters other than the body length upto vulva and length upto anus. The correlation between pre-vulval and pre-anal body lengths varied lesser (0.8082–0.9495) than between any of these alone and the body length (0.6496–0.9484 and 0.8036–0.9999 respectively).
The correlation coefficients between any two characters differ with the (1) host (2) locality (3), character under consideration and (4) sex.
Since there is no constant correlation between any of the measurements used to calculate the ratios a, a', b, b', c and c', these ratios have little meaning.
