I see GG5 has 真田虫 as the headword and uses サナダムシ in examples.

Google N-gram Corpus Counts
╭─ーーーーー─┬────────┬───────╮
│ サナダ虫　 │  5,807 │ 20.8% │ - adding
│ さなだ虫　 │  2,555 │  9.1% │ - adding
│ 真田虫　　 │    535 │  1.9% │ - rK (daijr/s, koj, etc.)
│ 絛虫　　　 │     55 │  0.2% │ - adding (koj, iwakoku, mentioned in shinmeikai)
│ 条虫　　　 │ 16,956 │  N/A  │ - only in daijs. maybe the x-ref is sufficient
│ さなだむし │  5,039 │ 18.0% │
│ サナダムシ │ 13,963 │ 49.9% │
╰─ーーーーー─┴────────┴───────╯

@@ -4,0 +5,6 @@
+<keb>サナダ虫</keb>
+</k_ele>
+<k_ele>
+<keb>さなだ虫</keb>
+</k_ele>
+<k_ele>
@@ -5,0 +12,5 @@
+<ke_inf>&rK;</ke_inf>
+</k_ele>
+<k_ele>
+<keb>絛虫</keb>
+<ke_inf>&rK;</ke_inf>