RELATION OF INFESTATION WITH SUNFLOWER MOTH HOMOEOSOMA ELECTELLUM LARVAE TO THE INCIDENCE OF RHIZOPUS ROT IN SUNFLOWER SEED HEADS
Larvae of the moth Homoeosoma electellum (Hulst.) were found consistently in sunflower (Helianthus annuus L.) seed heads affected with Rhizopus rot in California. Both Rhizopus rot and larvae were found in 88% of the rotted heads examined and only Rhizopus rot was evident in 12% of the heads. Head rot developed in 55–100% of the sunflower heads artificially inoculated in the field with both Rhizopus oryzae Went & Brinsen-Geerlings and H. ellectellum larvae and in 5–20% of the heads inoculated only with Rhizopus. Rot did not occur in heads in which only larvae were present. Larvae enhanced infection of the receptacle by Rhizopus through feeding injury. Ingested spores that are viable after passage through the gut of a larva can be spread by larvae into the inner tissues of the sunflower receptacle.