EDIT

            if (event != null){

                DeleteResult result = eventService.isDeletable(event.getUuid(), null);

                if (result.isOk()){

                    eventService.delete(event);

                }

            }

import eu.etaxonomy.cdm.api.service.pager.Pager;

import eu.etaxonomy.cdm.model.name.NomenclaturalCode;

import eu.etaxonomy.cdm.model.name.Rank;

import eu.etaxonomy.cdm.model.name.SpecimenTypeDesignation;

import eu.etaxonomy.cdm.model.name.TaxonName;

import eu.etaxonomy.cdm.model.name.TypeDesignationBase;

import eu.etaxonomy.cdm.model.occurrence.GatheringEvent;

    private final UUID FIELD_UNIT2_UUID = UUID.fromString("ae798108-6483-4d09-900f-7f849c43bcc9");

    @SpringBeanByType

    private INameService nameService;

        GatheringEvent gatheringEvent = GatheringEvent.NewInstance();

        fieldUnit.setGatheringEvent(gatheringEvent);

        FieldUnit fieldUnit2 = (FieldUnit) occurrenceService.load(FIELD_UNIT2_UUID);

        fieldUnit2.setGatheringEvent(gatheringEvent);

        //check initial state

        assertEquals(assertMessage, 6, occurrenceService.count(SpecimenOrObservationBase.class));

        assertEquals(assertMessage, 4, eventService.count(DerivationEvent.class));

        assertEquals(assertMessage, 2, occurrenceService.count(FieldUnit.class));

        assertEquals(assertMessage, 4, occurrenceService.count(DerivedUnit.class));

        assertEquals(assertMessage, 2, occurrenceService.count(DnaSample.class));

        assertEquals("incorrect number of amplification results", 1, dnaSample.getAmplificationResults().size());

        assertEquals("number of sequences incorrect", 1, dnaSample.getSequences().size());

        assertEquals("incorrect number of single reads", 1, dnaSample.getAmplificationResults().iterator().next().getSingleReads().size());

        assertEquals("incorrect number of gathering events", 1, eventService.count(GatheringEvent.class));

        //delete field unit

        deleteResult = occurrenceService.delete(fieldUnit, config);

        assertTrue(deleteResult.toString(), deleteResult.isOk());

        assertEquals(assertMessage, 2, eventService.count(DerivationEvent.class));

        assertEquals(assertMessage, 3, occurrenceService.count(SpecimenOrObservationBase.class));

        assertEquals(assertMessage, 1, occurrenceService.count(FieldUnit.class));

        assertEquals(assertMessage, 2, occurrenceService.count(DerivedUnit.class));

        assertEquals(assertMessage, 1, occurrenceService.count(DnaSample.class));

        assertEquals("incorrect number of gathering events", 1, eventService.count(GatheringEvent.class));

        deleteResult = occurrenceService.delete(fieldUnit2, config);

        assertEquals(assertMessage, 0, eventService.count(GatheringEvent.class));

    }

    @Test

    @DataSet(loadStrategy=CleanSweepInsertLoadStrategy.class, value="OccurrenceServiceTest.testDeleteDerivateHierarchyStepByStep.xml")

    public void testDeepDelete_FieldUnitWithTypeDesignation(){

        String assertMessage = "Incorrect number of specimens after deletion.";

        DeleteResult deleteResult = null;

        SpecimenDeleteConfigurator config = new SpecimenDeleteConfigurator();

        config.setDeleteMolecularData(true);

        config.setDeleteChildren(true);

        config.setDeleteFromTypeDesignation(true);

        FieldUnit fieldUnit = (FieldUnit) occurrenceService.load(FIELD_UNIT_UUID);

        DnaSample dnaSample = (DnaSample) occurrenceService.load(DNA_SAMPLE_UUID);

        TaxonName name = TaxonName.NewInstance(NomenclaturalCode.ICNAFP, Rank.SPECIES(), "Test", null, "test", null, null, null, null, null);

        SpecimenTypeDesignation specimenTypeDesignation = SpecimenTypeDesignation.NewInstance();

        specimenTypeDesignation.setTypeSpecimen(dnaSample);

        name.addTypeDesignation(specimenTypeDesignation, false);

        nameService.save(name);

        Pager<TypeDesignationBase> typeDesignations = nameService.getTypeDesignations(name, null, 100, 0);

        Long oldCount= typeDesignations.getCount();

        typeDesignations = nameService.getTypeDesignations(name, null, 100, 0);

        Long afterDeleteCount= typeDesignations.getCount();

        assertTrue(oldCount > afterDeleteCount);

<SPECIMENOROBSERVATIONBASE DTYPE="FieldUnit" ID="5003" CREATED="2014-12-12 07:45:32.0" UUID="ae798108-6483-4d09-900f-7f849c43bcc9" UPDATED="[null]" RECORDBASIS="FU" LSID_AUTHORITY="[null]" LSID_LSID="[null]" LSID_NAMESPACE="[null]" LSID_OBJECT="[null]" LSID_REVISION="[null]" PROTECTEDTITLECACHE="false" TITLECACHE="-title cache generation not implemented-" PUBLISH="true" INDIVIDUALCOUNT="[null]" ACCESSIONNUMBER="[null]" BARCODE="[null]" CATALOGNUMBER="[null]" COLLECTORSNUMBER="[null]" EXSICCATUM="[null]" ORIGINALLABELINFO="[null]" FIELDNOTES="[null]" FIELDNUMBER="[null]" CREATEDBY_ID="[null]" UPDATEDBY_ID="[null]" LIFESTAGE_ID="[null]" SEX_ID="[null]" KINDOFUNIT_ID="[null]" COLLECTION_ID="[null]" DERIVEDFROM_ID="[null]" STOREDUNDER_ID="[null]" PRESERVATION_ID="[null]" GATHERINGEVENT_ID="[null]" PRIMARYCOLLECTOR_ID="[null]" MEDIASPECIMEN_ID="[null]" DNAQUALITY_ID="[null]" PROTECTEDIDENTITYCACHE="true" IDENTITYCACHE="ID1"/>

  <SPECIMENOROBSERVATIONBASE DTYPE="DerivedUnit" ID="5004" CREATED="2014-12-12 07:45:32.0" UUID="93fdcf99-af42-41dc-9e8d-ced93ad5188b" UPDATED="2014-12-12 07:45:32.838" RECORDBASIS="FS" LSID_AUTHORITY="[null]" LSID_LSID="[null]" LSID_NAMESPACE="[null]" LSID_OBJECT="[null]" LSID_REVISION="[null]" PROTECTEDTITLECACHE="false" TITLECACHE="class eu.etaxonomy.cdm.model.occurrence.DerivedUnit: 448be6e7-f19c-4a10-9a0a-97aa005f817d" PUBLISH="true" INDIVIDUALCOUNT="[null]" ACCESSIONNUMBER="[null]" BARCODE="[null]" CATALOGNUMBER="[null]" COLLECTORSNUMBER="[null]" EXSICCATUM="[null]" ORIGINALLABELINFO="[null]" FIELDNOTES="[null]" FIELDNUMBER="[null]" CREATEDBY_ID="[null]" UPDATEDBY_ID="[null]" LIFESTAGE_ID="[null]" SEX_ID="[null]" KINDOFUNIT_ID="[null]" COLLECTION_ID="[null]" DERIVEDFROM_ID="5003" STOREDUNDER_ID="[null]" PRESERVATION_ID="[null]" GATHERINGEVENT_ID="[null]" PRIMARYCOLLECTOR_ID="[null]" MEDIASPECIMEN_ID="[null]" DNAQUALITY_ID="[null]" PROTECTEDIDENTITYCACHE="true" IDENTITYCACHE="ID1"/>

  <SPECIMENOROBSERVATIONBASE DTYPE="DnaSample" ID="5005" CREATED="2014-12-12 07:45:32.0" UUID="753a9363-7373-4022-98ab-061a6c8f7f10" UPDATED="2014-12-12 07:45:32.839" RECORDBASIS="DS" LSID_AUTHORITY="[null]" LSID_LSID="[null]" LSID_NAMESPACE="[null]" LSID_OBJECT="[null]" LSID_REVISION="[null]" PROTECTEDTITLECACHE="false" TITLECACHE="-title cache generation not implemented-" PUBLISH="true" INDIVIDUALCOUNT="[null]" ACCESSIONNUMBER="[null]" BARCODE="[null]" CATALOGNUMBER="[null]" COLLECTORSNUMBER="[null]" EXSICCATUM="[null]" ORIGINALLABELINFO="[null]" FIELDNOTES="[null]" FIELDNUMBER="[null]" CREATEDBY_ID="[null]" UPDATEDBY_ID="[null]" LIFESTAGE_ID="[null]" SEX_ID="[null]" KINDOFUNIT_ID="[null]" COLLECTION_ID="[null]" DERIVEDFROM_ID="5004" STOREDUNDER_ID="[null]" PRESERVATION_ID="[null]" GATHERINGEVENT_ID="[null]" PRIMARYCOLLECTOR_ID="[null]" MEDIASPECIMEN_ID="[null]" DNAQUALITY_ID="[null]" PROTECTEDIDENTITYCACHE="true" IDENTITYCACHE="ID1"/>

  <SPECIMENOROBSERVATIONBASE_DERIVATIONEVENT ORIGINALS_ID="5003" DERIVATIONEVENTS_ID="5002"/>

  <SPECIMENOROBSERVATIONBASE_DERIVATIONEVENT ORIGINALS_ID="5004" DERIVATIONEVENTS_ID="5003"/>

  <DERIVATIONEVENT ID="5002" CREATED="2014-12-12 07:45:32.0" UUID="4576df35-d37a-40b3-8d7a-f95319e4c789" UPDATED="2014-12-12 07:45:32.837" DESCRIPTION="[null]" TIMEPERIOD_END="[null]" TIMEPERIOD_FREETEXT="[null]" TIMEPERIOD_START="[null]" CREATEDBY_ID="[null]" UPDATEDBY_ID="[null]" ACTOR_ID="[null]" INSTITUTION_ID="[null]" TYPE_ID="2004"/>

  <DERIVATIONEVENT ID="5003" CREATED="2014-12-12 07:45:32.0" UUID="959b1e61-aee9-42c7-b600-11d6b2fbc065" UPDATED="2014-12-12 07:45:32.838" DESCRIPTION="[null]" TIMEPERIOD_END="[null]" TIMEPERIOD_FREETEXT="[null]" TIMEPERIOD_START="[null]" CREATEDBY_ID="[null]" UPDATEDBY_ID="[null]" ACTOR_ID="[null]" INSTITUTION_ID="[null]" TYPE_ID="2001"/>

  <SEQUENCE ID="5001" CREATED="2014-12-12 07:45:32.0" UUID="112b188d-a27f-4cbf-8dca-06b181c96e85" UPDATED="2014-12-12 07:45:32.841" BARCODESEQUENCEPART_LENGTH="[null]" BARCODESEQUENCEPART_STRING="[null]" BOLDPROCESSID="[null]" CONSENSUSSEQUENCE_LENGTH="5" CONSENSUSSEQUENCE_STRING="ATTCG" GENETICACCESSIONNUMBER="[null]" HAPLOTYPE="[null]" ISBARCODE="[null]" CREATEDBY_ID="[null]" UPDATEDBY_ID="[null]" CONTIGFILE_ID="[null]" DNASAMPLE_ID="5005" DNAMARKER_ID="[null]"/>

  <SINGLEREAD ID="5001" CREATED="2014-12-12 07:45:32.0" UUID="95627568-e707-483d-b8af-201bde71e7ae" UPDATED="2014-12-12 07:45:32.841" DESCRIPTION="[null]" TIMEPERIOD_END="[null]" TIMEPERIOD_FREETEXT="[null]" TIMEPERIOD_START="[null]" DIRECTION="[null]" SEQUENCE_LENGTH="[null]" SEQUENCE_STRING="[null]" CREATEDBY_ID="[null]" UPDATEDBY_ID="[null]" ACTOR_ID="[null]" AMPLIFICATIONRESULT_ID="5001" MATERIALORMETHOD_ID="[null]" PHEROGRAM_ID="[null]" PRIMER_ID="[null]"/>

  <AMPLIFICATIONRESULT ID="5001" CREATED="2014-12-12 07:45:32.0" UUID="b865023f-aa73-4be1-9e16-f2c90b50b052" UPDATED="2014-12-12 07:45:32.84" SUCCESSTEXT="[null]" SUCCESSFUL="[null]" CREATEDBY_ID="[null]" UPDATEDBY_ID="[null]" CLONING_ID="[null]" DNASAMPLE_ID="5005" AMPLIFICATION_ID="[null]" GELPHOTO_ID="[null]"/>