diff --git a/webservice/src/main/java/life/catalogue/assembly/SectorRunnable.java b/webservice/src/main/java/life/catalogue/assembly/SectorRunnable.java
index 75b4e653f..9fb414597 100644
--- a/webservice/src/main/java/life/catalogue/assembly/SectorRunnable.java
+++ b/webservice/src/main/java/life/catalogue/assembly/SectorRunnable.java
@@ -54,8 +54,6 @@ abstract class SectorRunnable implements Runnable {
   // maps keyed on taxon ids from this sector
   final Map<String, EditorialDecision> decisions = new HashMap<>();
   List<Sector> childSectors;
-  // map with foreign child id to original parent name
-  Map<String, Name> foreignChildrenParents = new HashMap<>();
   private final UsageMatcherGlobal matcher;
   private final boolean clearMatcherCache;
   private final Consumer<SectorRunnable> successCallback;
@@ -283,7 +281,8 @@ private void loadAttachedSectors() {
       SectorMapper sm = session.getMapper(SectorMapper.class);
       childSectors=sm.listChildSectors(sectorKey);
     }
-    LOG.info("Loaded {} sectors targeting taxa from sector {}", childSectors.size(), sectorKey);
+    long mergeCnt = childSectors.stream().filter(s -> s.getMode() == Sector.Mode.MERGE).count();
+    LOG.info("Loaded {} sectors incl {} merge sectors targeting taxa from sector {}", childSectors.size(), mergeCnt, sectorKey);
   }
   
   abstract void doWork() throws Exception;
diff --git a/webservice/src/main/java/life/catalogue/assembly/SectorSync.java b/webservice/src/main/java/life/catalogue/assembly/SectorSync.java
index 912edb52f..534d0b680 100644
--- a/webservice/src/main/java/life/catalogue/assembly/SectorSync.java
+++ b/webservice/src/main/java/life/catalogue/assembly/SectorSync.java
@@ -19,6 +19,7 @@
 import life.catalogue.matching.decision.RematchRequest;
 
 import java.io.IOException;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -57,6 +58,8 @@ public class SectorSync extends SectorRunnable {
   private final int targetDatasetKey; // dataset to sync into
   private @Nullable TreeMergeHandlerConfig mergeCfg;
   private List<SimpleName> foreignChildren;
+  // map with foreign child id to original parent name
+  private final Map<String, Name> foreignChildrenParents = new HashMap<>();
   private final UsageIdGen usageIdGen;
   private final Supplier<String> nameIdGen;
   private final Supplier<String> typeMaterialIdGen;
@@ -145,13 +148,17 @@ void init() throws Exception {
     super.init(true);
     loadForeignChildren();
     if (!disableAutoBlocking) {
-      // also load all sector subjects to auto block them
+      // also load all sector subjects of non merge sources to auto block them
       try (SqlSession session = factory.openSession()) {
         AtomicInteger counter = new AtomicInteger();
         PgUtils.consume(
           () -> session.getMapper(SectorMapper.class).processSectors(sectorKey.getDatasetKey(), subjectDatasetKey),
           s -> {
-            if (!s.getId().equals(sectorKey.getId()) && s.getSubject() != null && s.getSubject().getId() != null) {
+            if (!s.getId().equals(sectorKey.getId())
+                && s.getSubject() != null
+                && s.getSubject().getId() != null
+                && s.getMode() != Sector.Mode.MERGE
+            ) {
               EditorialDecision d = new EditorialDecision();
               d.setSubject(s.getSubject());
               d.setDatasetKey(sectorKey.getDatasetKey());
diff --git a/webservice/src/test/java/life/catalogue/assembly/SectorSyncMergeIT.java b/webservice/src/test/java/life/catalogue/assembly/SectorSyncMergeIT.java
index c6254952e..6c7c316f6 100644
--- a/webservice/src/test/java/life/catalogue/assembly/SectorSyncMergeIT.java
+++ b/webservice/src/test/java/life/catalogue/assembly/SectorSyncMergeIT.java
@@ -83,6 +83,7 @@ public class SectorSyncMergeIT extends SectorSyncTestBase {
   @Parameterized.Parameters
   public static Collection<Object[]> data() {
     return Arrays.asList(new Object[][] {
+      {"myosotis", List.of("taxref", "uksi", "pbdb", "bavaria")},
       {"tetralobus", List.of("wfo", "bouchard", "plazi")},
       {"cactus", List.of("wfo", "wcvp", "grin", "taxref", "tpl", "pbdb")},
       {"aphanizomenon", List.of("worms","ncbi","dyntaxa")}, // https://github.com/CatalogueOfLife/xcol/issues/146