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  <xs:element id="isba_EquityCollectiveTrustMember" abstract="true" name="EquityCollectiveTrustMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="isba_FinancingReceivableDebtServicingToGrossIncomeRatioMaximum" abstract="false" name="FinancingReceivableDebtServicingToGrossIncomeRatioMaximum" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
  <xs:element id="isba_FederalFundsSoldMaturityTerm" abstract="false" name="FederalFundsSoldMaturityTerm" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="isba_CommercialRealEstateOwnerOccupiedPortfolioSegmentMember" abstract="true" name="CommercialRealEstateOwnerOccupiedPortfolioSegmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="isba_DefinedBenefitPlanPortionAttributabletoEmployeesCoveredbyCorporateOwnedLifeInsurance" abstract="false" name="DefinedBenefitPlanPortionAttributabletoEmployeesCoveredbyCorporateOwnedLifeInsurance" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssetsMinimumCapitalRequiredPlusCapitalConservationBuffer" abstract="false" name="TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssetsMinimumCapitalRequiredPlusCapitalConservationBuffer" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
  <xs:element id="isba_OtherRealEstateForeclosedAssetsandRepossessedAssetsValuationAdjustments" abstract="false" name="OtherRealEstateForeclosedAssetsandRepossessedAssetsValuationAdjustments" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_CompanyOwnedLifeInsurancePolicyTextBlock" abstract="false" name="CompanyOwnedLifeInsurancePolicyTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:textBlockItemType"/>
  <xs:element id="isba_LifeInsuranceCorporateorBankOwnedMaintenanceCost" abstract="false" name="LifeInsuranceCorporateorBankOwnedMaintenanceCost" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_InvestmentOfLowIncomeHousingTaxCreditsNonCashComponent" abstract="false" name="InvestmentOfLowIncomeHousingTaxCreditsNonCashComponent" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_CommercialAgriculturalandResidentialPortfolioSegmentsMember" abstract="true" name="CommercialAgriculturalandResidentialPortfolioSegmentsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="isba_LoansReceivableCollateralizedByAccountsReceivableMember" abstract="true" name="LoansReceivableCollateralizedByAccountsReceivableMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="isba_PledgedFinancialInstrumentsNotSeparatelyReportedSecuritiesAndLoansReceivableForFederalHomeLoanBankDebtAndFederalReserveBankDiscountWindow" abstract="false" name="PledgedFinancialInstrumentsNotSeparatelyReportedSecuritiesAndLoansReceivableForFederalHomeLoanBankDebtAndFederalReserveBankDiscountWindow" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_DeferredCompensationArrangementwithIndividualDeferredFeesContribution" abstract="false" name="DeferredCompensationArrangementwithIndividualDeferredFeesContribution" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_DeferredCompensationArrangementwithIndividualCommonStockIssuedandReservedforFutureIssuanceValue" abstract="false" name="DeferredCompensationArrangementwithIndividualCommonStockIssuedandReservedforFutureIssuanceValue" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_ConsumerUnsecuredPortfolioSegmentMember" abstract="true" name="ConsumerUnsecuredPortfolioSegmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="isba_SafeHarbor401kMember" abstract="true" name="SafeHarbor401kMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="isba_EffectiveIncomeTaxRateReconciliationTaxExemptIncomeMunicipalSecuritiesAmount" abstract="false" name="EffectiveIncomeTaxRateReconciliationTaxExemptIncomeMunicipalSecuritiesAmount" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_LowSatisfactoryRatingMember" abstract="true" name="LowSatisfactoryRatingMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="isba_EffectiveIncomeTaxRateReconciliationTaxExemptIncomeAndTaxCreditsAmount" abstract="false" name="EffectiveIncomeTaxRateReconciliationTaxExemptIncomeAndTaxCreditsAmount" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_DeferredCompensationArrangementwithIndividualCommonStockReservedforFutureIssuanceValue" abstract="false" name="DeferredCompensationArrangementwithIndividualCommonStockReservedforFutureIssuanceValue" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_PledgedFinancialInstrumentsNotSeparatelyReportedSecuritiesAndLoansReceivablePledgedAsCollateral" abstract="false" name="PledgedFinancialInstrumentsNotSeparatelyReportedSecuritiesAndLoansReceivablePledgedAsCollateral" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_CapitalRequiredForCapitalAdequacyToRiskWeightedAssetsMinimumCapitalRequiredPlusCapitalConservationBuffer" abstract="false" name="CapitalRequiredForCapitalAdequacyToRiskWeightedAssetsMinimumCapitalRequiredPlusCapitalConservationBuffer" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
  <xs:element id="isba_AgriculturalRealEstatePortfolioSegmentMember" abstract="true" name="AgriculturalRealEstatePortfolioSegmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="isba_FinancingReceivableNonperformingNonaccrualOfInterestThresholdPeriod" abstract="false" name="FinancingReceivableNonperformingNonaccrualOfInterestThresholdPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="isba_StockRepurchasedDuringPeriodForDeferredCompensationObligationsValue" abstract="false" name="StockRepurchasedDuringPeriodForDeferredCompensationObligationsValue" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_CommercialRealEstateNonOwnerOccupiedMember" abstract="true" name="CommercialRealEstateNonOwnerOccupiedMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="isba_EffectiveIncomeTaxRateReconciliationTaxExemptIncomeCorporateOwnedLifeInsuranceAmount" abstract="false" name="EffectiveIncomeTaxRateReconciliationTaxExemptIncomeCorporateOwnedLifeInsuranceAmount" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_DocumentAndEntityInformationAbstract" abstract="true" name="DocumentAndEntityInformationAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="isba_ScheduleOfFinancialEffectsOfLoansHeldForInvestmentModifiedForBorrowersExperiencingFinancialDifficultyTableTextBlock" abstract="false" name="ScheduleOfFinancialEffectsOfLoansHeldForInvestmentModifiedForBorrowersExperiencingFinancialDifficultyTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="isba_ScheduleOfAmortizedCostBalanceOfFinancialAssetsConsideredCollateralDependentTableTextBlock" abstract="false" name="ScheduleOfAmortizedCostBalanceOfFinancialAssetsConsideredCollateralDependentTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="isba_DepositsWithStatedMaturitiesFairValueDisclosure" abstract="false" name="DepositsWithStatedMaturitiesFairValueDisclosure" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_FinancingReceivableModificationsAmortizedCost" abstract="false" name="FinancingReceivableModificationsAmortizedCost" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_PercentageOfReportableSegmentAssetsAndOperatingResults" abstract="false" name="PercentageOfReportableSegmentAssetsAndOperatingResults" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="isba_DepositsWithoutStatedMaturitiesFairValueDisclosure" abstract="false" name="DepositsWithoutStatedMaturitiesFairValueDisclosure" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_PerformanceBonusExpense" abstract="false" name="PerformanceBonusExpense" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssetsMinimumCapitalRequiredPlusCapitalConservationBuffer" abstract="false" name="TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssetsMinimumCapitalRequiredPlusCapitalConservationBuffer" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
  <xs:element id="isba_FinancialAssets30To89DaysPastDueMember" abstract="true" name="FinancialAssets30To89DaysPastDueMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="isba_FinancingReceivableLoanToValueRatioMaximum" abstract="false" name="FinancingReceivableLoanToValueRatioMaximum" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
  <xs:element id="isba_CommonEquityTierOneRiskBasedCapitalRequiredForCapitalAdequacyMinimumPlusCapitalConservationBuffer" abstract="false" name="CommonEquityTierOneRiskBasedCapitalRequiredForCapitalAdequacyMinimumPlusCapitalConservationBuffer" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_ResidentialRealEstateJuniorLienPortfolioSegmentMember" abstract="true" name="ResidentialRealEstateJuniorLienPortfolioSegmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="isba_EffectiveIncomeTaxRateReconciliationTaxExemptIncomeOtherAmount" abstract="false" name="EffectiveIncomeTaxRateReconciliationTaxExemptIncomeOtherAmount" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_SelfFundedMedicalPlanExpensesDuringPeriod" abstract="false" name="SelfFundedMedicalPlanExpensesDuringPeriod" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_DeferredTaxAssetsCompanyOwnedLifeInsurance" abstract="false" name="DeferredTaxAssetsCompanyOwnedLifeInsurance" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_InterestAndDividendIncomeSecuritiesOperatingAvailableforsaleTaxExempt" abstract="false" name="InterestAndDividendIncomeSecuritiesOperatingAvailableforsaleTaxExempt" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_InterestIncomeFederalFundsSoldAndOther" abstract="false" name="InterestIncomeFederalFundsSoldAndOther" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_IncreaseDecreaseinInterestPayableAndOtherAccruedLiabilities" abstract="false" name="IncreaseDecreaseinInterestPayableAndOtherAccruedLiabilities" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_FinancingReceivableModificationPercentageOfPortfolioSegment" abstract="false" name="FinancingReceivableModificationPercentageOfPortfolioSegment" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
  <xs:element id="isba_AvailableforsaleSecuritiesWithVariableMonthlyPaymentsOrWithoutSingleMaturityDateAmortizedCostBasis" abstract="false" name="AvailableforsaleSecuritiesWithVariableMonthlyPaymentsOrWithoutSingleMaturityDateAmortizedCostBasis" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_OtherLosses" abstract="false" name="OtherLosses" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_SelfFundedMedicalPlanMaximumAmountPaidPerFamily" abstract="false" name="SelfFundedMedicalPlanMaximumAmountPaidPerFamily" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_DeferredCompensationArrangementwithIndividualDeferredCompensationObligations" abstract="false" name="DeferredCompensationArrangementwithIndividualDeferredCompensationObligations" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_CashReserveDepositRequiredAndMadeByCorrespondentBanks" abstract="false" name="CashReserveDepositRequiredAndMadeByCorrespondentBanks" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_EquityMethodAndOtherInvestments" abstract="false" name="EquityMethodAndOtherInvestments" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_ExcellentRatingMember" abstract="true" name="ExcellentRatingMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="isba_CommercialOtherPortfolioSegmentMember" abstract="true" name="CommercialOtherPortfolioSegmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="isba_PreAdoptionAllowanceMember" abstract="true" name="PreAdoptionAllowanceMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="isba_FinancingReceivableContinuingPerformanceAccrualOfInterestThresholdPeriod" abstract="false" name="FinancingReceivableContinuingPerformanceAccrualOfInterestThresholdPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="isba_LoansReceivableAllowanceFairValueDisclosure" abstract="false" name="LoansReceivableAllowanceFairValueDisclosure" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_ImpairedFinancingReceivableFairValueDisclosureAppraisedValueDiscount" abstract="false" name="ImpairedFinancingReceivableFairValueDisclosureAppraisedValueDiscount" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="isba_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueForfeitedInPeriod" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueForfeitedInPeriod" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_ResidentialPrivatelyInsuredFinancingReceivableMember" abstract="true" name="ResidentialPrivatelyInsuredFinancingReceivableMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="isba_CommitmentMaturityPeriod" abstract="false" name="CommitmentMaturityPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="isba_IncomeLossBeforeIncomeTaxesandEquityinUndistributedNetIncomeofSubsidiary" abstract="false" name="IncomeLossBeforeIncomeTaxesandEquityinUndistributedNetIncomeofSubsidiary" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_CommercialAndCommercialRealEstatePortfolioSegmentMember" abstract="true" name="CommercialAndCommercialRealEstatePortfolioSegmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="isba_InterestAndDividendIncomeSecuritiesOperatingAvailableforsaleTaxable" abstract="false" name="InterestAndDividendIncomeSecuritiesOperatingAvailableforsaleTaxable" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_CommonEquityTierOneRiskBasedCapitalToRiskWeightedAssetsMinimumCapitalRequiredPlusCapitalConservationBuffer" abstract="false" name="CommonEquityTierOneRiskBasedCapitalToRiskWeightedAssetsMinimumCapitalRequiredPlusCapitalConservationBuffer" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="isba_CashDonations" abstract="false" name="CashDonations" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_HighQualityRatingMember" abstract="true" name="HighQualityRatingMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="isba_AvailableforsaleSecuritiesExcludingAuctionRateMoneyMarketPreferredandPreferredStocksMember" abstract="true" name="AvailableforsaleSecuritiesExcludingAuctionRateMoneyMarketPreferredandPreferredStocksMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="isba_PaymentsForRepurchaseOfCommonStockForDeferredCompensationObligations" abstract="false" name="PaymentsForRepurchaseOfCommonStockForDeferredCompensationObligations" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_LoansReceivableCollateralizedByLivestockMember" abstract="true" name="LoansReceivableCollateralizedByLivestockMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="isba_DiscountedAppraisalValueValuationTechniqueMember" abstract="true" name="DiscountedAppraisalValueValuationTechniqueMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="isba_EquityMethodAndOtherInvestmentsFairValueDisclosure" abstract="false" name="EquityMethodAndOtherInvestmentsFairValueDisclosure" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_IncomeBeforeEquityInUndistributedNetIncomeOfSubsidiary" abstract="false" name="IncomeBeforeEquityInUndistributedNetIncomeOfSubsidiary" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_ImpairedFinancingReceivableFairValueDisclosure" abstract="false" name="ImpairedFinancingReceivableFairValueDisclosure" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_HighSatisfactoryRatingMember" abstract="true" name="HighSatisfactoryRatingMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="isba_DeferredCompensationArrangementwithIndividualCommonStockIssuedandReservedforFutureIssuanceShares" abstract="false" name="DeferredCompensationArrangementwithIndividualCommonStockIssuedandReservedforFutureIssuanceShares" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="isba_PercentageOfAssetsAndLiabilitiesMeasuredAtFairValue" abstract="false" name="PercentageOfAssetsAndLiabilitiesMeasuredAtFairValue" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="isba_TierOneLeverageCapitalRequiredForCapitalAdequacyMinimumCapitalRequiredPlusCapitalConservationBuffer" abstract="false" name="TierOneLeverageCapitalRequiredForCapitalAdequacyMinimumCapitalRequiredPlusCapitalConservationBuffer" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_MembershipsAndSubscriptionsExpense" abstract="false" name="MembershipsAndSubscriptionsExpense" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_NoninterestIncomeInvestmentandTrustAdvisoryFees" abstract="false" name="NoninterestIncomeInvestmentandTrustAdvisoryFees" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_PerformanceBonusExpenseExecutivePlan" abstract="false" name="PerformanceBonusExpenseExecutivePlan" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_AgriculturalPortfolioSegmentMember" abstract="true" name="AgriculturalPortfolioSegmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="isba_FinancingReceivableTerm" abstract="false" name="FinancingReceivableTerm" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="isba_OtherNoninterestExpenseMiscellaneous" abstract="false" name="OtherNoninterestExpenseMiscellaneous" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_TierOneRiskBasedCapitalRequiredForCapitalAdequacyMinimumCapitalRequiredPlusCapitalConservationBuffer" abstract="false" name="TierOneRiskBasedCapitalRequiredForCapitalAdequacyMinimumCapitalRequiredPlusCapitalConservationBuffer" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="isba_StateandLocalFundsPurchasedMember" abstract="true" name="StateandLocalFundsPurchasedMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="isba_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueVestedInPeriod" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueVestedInPeriod" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
</xs:schema>
