Defensive Behaviour of Apis Mellifera Against the Invasive Asian Hornet

DefensiveDefensive behaviourbehaviour ofof ApisApis melliferamellifera againstagainst thethe invasiveinvasive AsianAsian HornetHornet ((VespaVespa velutinavelutina)) inin southsouth--westwest ofof FranceFrance

Mariangela ARCA1 Alexandros PAPACHRISTOFOROU1 Nevile MAHER2 Gérard ARNOLD1 Agnès RORTAIS1,3

1 Laboratoire Evolution, Génomes et Spéciation LEGS, CNRS UPR9034, Gif sur-Yvette, France 2 UMR Santé Végétale 1065, INRA, ISVV, IFR 103, Villenave d'Ornon, France 3 Present position: Risk Unit, EFSA, Parma, Italy

Apimondia 2009, Montpellier, France, 15-20 september 1 FourFour teamteam partnerspartners

INRA:UMR Santé végétale MNHN: UMR 5202 Origine, structure et évolution de la biodiversité Development of specific traps Biology of V. velutina, mapping of nests

European Community's Program to help beekeeping EC 797, 2008 - 2010

Génomique, biodiversité, comportements de l’Abeille Diversité, écologie et évolution des insectes tropicaux 2 Impact of V. velutina on honeybees Genetic characterization of V.velutina and invasion dynamics Laboratoire Evolution, Génomes et Spéciation LEGS

Two oral communications in Apimondia Symposium “HORNETS PRESSURE ON HONEYBEES”

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1. Introduction:Introduction: Origin and expansion of the hornet Vespa velutina in France Predatory behaviour of the hornet Vespa velutina Defensive behaviour in honeybees 2. StudyStudy ObjectivesObjectives 3. ObservationsObservations ofof honeybeeshoneybees defensivedefensive behaviourbehaviour Field experiments Observations under natural conditions 4. PreliminaryPreliminary conclusionsconclusions 5. PerspectivesPerspectives

4 IntroductionIntroduction Origin and expansion of the hornet Vespa velutina in France

V. velutina is distributed in regions from northern India to the Indochinese Peninsula, Taiwan and Indonesia, in climates with wide annual temperature range In France: observed for the first time in 2004 in the Department of Lot-et- Garonne Strong pressure on the apiaries and important damages on the local honeybees population Cost on the environment as the pollination of many crops depend on bees

5 IntroductionIntroduction Predatory behaviour of the hornet Vespa velutina at the hive

1-Stationary flight (wasp-hawking) at 30-40 cm 2- the hornet tries to enter into the hive if no from the hive entrance resistance is opposed (due to the weakness of the colony)

Interception of the bees at the hive The hornet carries a captured bee towards a nearby shrub (it clings to a branch) and makes a flesh pellet

the abdomen is thrown to ground Legs are cut one after the other Only the thorax is kept The hornet carries the thorax of the bee to the nest 6 IntroductionIntroduction Defensive behaviour in honeybees

In Japan: Apis cerana japonica vs Vespa mandarinia: «heat-balling»(ball T°, 47°C; lethal T°: A.c., 49.4°C, V.m., 45°C). (Ono et al., 1995)

In Cyprus: Apis mellifera cypria vs Vespa orientalis «asphyxia-balling» (Papachristoforou et al. 2007) high frequency sounds (Papachristoforou et al. 2008)

In China: Apis mellifera present a defensive behaviour not adapted against V. velutina (Ken et al. 2005).

In France: the behaviour of Apis mellifera against the attacks of invasive hornet V. velutina was not studied and, consequently, its defensive capabilities are poorly documented.

7 StudyStudy ObjectivesObjectives StudyStudy ofof honeybeeshoneybees defensivedefensive behaviourbehaviour

ToTo betterbetter understandunderstand howhow ApisApis melliferamellifera defenddefend theirtheir coloniescolonies fromfrom V.V. velutinavelutina

ToTo determinedetermine thethe impactimpact ofof V.V. velutinavelutina predationpredation onon honeybeeshoneybees’’ activityactivity

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9 EvaluationEvaluation ofof honeybeeshoneybees defensivedefensive behaviourbehaviour FieldField experimentsexperiments

End of August till October 2008 (when the hornet pression is the highest) 4 apiaires were studied: l’INRA, Bordeaux, Gironde (n°colonies=6) Artigues, Gironde (n°colonies=10) St Sulpice de Roumagnac, Dordogne (n°colonies=10) Nojals-et-Clotte, Dordogne (n°colonies=5)

Hornet attached to a wire and approached to the hive for monitoring:

Number of guard-bees at the hive entrance Number of outgoing/incoming bees (in/out flows)

Morphometric characterization of observed colonies for identification of subspecies

10 Evaluation of honeybees defensive behaviour Field experiments: results Number of guard bees on the hive entrance

300

Colonies: 250 No Hornet approaching Hornet on the hive hornet I1 the hive entrance entrance I2 200 (30cm) I3

I4 150 I5

I6 100 I7

Number of guard bees on the hive entrance 50 I9

I10 0 00:00 00:15 00:30 00:45 01:00 01:15 01:30 01:45 02:00 02:15 02:30 02:45 03:00 03:15 03:30 03:45 04:00 04:15 04:30 04:45 05:00

Time (minutes) (St. Sulpice Apiary)

Phase I: no hornet. Phase II: hornet approaching the hive. Guard-bees get out progressively from the hive.

Phase III: hornet on the hive entrance. Guard-bees take position on the hive entrance (their number is 11 constant) Evaluation of honeybees defensive behaviour Field experiments: results Monitoring flight activity: Number of outgoing/incoming bees (Mean of 10 observed colonies)

20 18 No Hornet Hornet on the hive hornet approaching entrance Out 16 In the hive 14 entrance 12 (30cm) 10 8 6 Number Number of bees 4 2

Number of outgoing/incoming bees Number 0 0-15 15-30 30-45 45-60 Out Time (seconds) In Phase I: No hornet Phase II: hornet approaching the hive. The flight activity decreases rapidly. Phase III: hornet on the hive entrance. Number of outgoing/incoming bees stabilizes and reaches a plateau after 30-45 seconds of the exposure to the hornet. 12 Evaluation of honeybees defensive behaviour Morphometric characterization of studied colonies

To discriminate the honeybee subspecies, we use a geometric morphometrics method.method The coordinates of 19 landmarks located at vein intersections of the left wings were measured on a sample of 10 workers from each studied colony (n=31) Landmark coordinates are compared to the database Apiclass, based on morphometric and molecular identification of over 5000 workers. The result of the comparison with the database shows that all the studied colonies belong to the subspecies Apis mellifera mellifera .

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14 Evaluation of honeybees defensive behaviour Observations under natural conditions Uninterrupted video recordings of a honeybees colony Inra, Grande Ferrade, Bordeaux: 15th June 2009 and still on.. Observation of the evolution of the colony activity according to the increase in the predation pressure of hornet

Honeybees inflows and outflows are measured by a non-obtrusive video system and allow the honey bees observation in natural environment.

Video sequence is recorded during the daytime, with a black and white digital camera (dragonfly pointgrey), closed in a waterproof case fixed at 2 meters from the hive

The camera is connected to a laptop installed in a weatherproof box near the hive, and uses a digital recording software (Numeriscope, Viewpoint, France).

Recording sequences are analyzed in slow motion (1/5 of normal speed) by an interactive event recording software (LabWatcher, ViewPoint, France) 15 Evaluation of honeybees defensive behaviour Observations under natural conditions: preliminary results

08:00 180 160 10:00 140 120 12:00 100 80 14:00 60 40 16:00

Honeybees20 outflows 18:00 0 20:00

NO HORNETS LOW HORNET Date INTERMEDIATE HIGH HORNET 20 June 2009 24 June 2009 26 June 2009 30 June 2009 05 July 2009 06 July 2009 08 July 2009 11 July 2009 15 July 2009 24 July 2009 07/27/009 30 July 2009 01 August 2009 06 August 2009 10 August 2009 20 August 2009 PRESSURE PRESSURE HORNET PRESSURE PRESSURE

140 140 140 140 Tmin: 17,7 °C Tmin: 17,3 °C Tmin: 17,1 °C Tmin: 19,1 °C 120 120 5 July 2009 120 15 July 2009 27 July 2009 120 20 August 2009 100 Tmax: 25,2°C 100 Tmax: 25°C 100 Tmax: 25,6°C 100 Tmax: 27,6°C 80 80 80 80 60 60 60 60 40 40 40 40 20 20 20 20 Number Number of outgoing bees Number of outgoing bees Number Number of outgoing bees Number Number of outgoing bees 0 0 0 0 08:00 10:00 12:00 14:00 16:00 18:00 20:00 08:00 10:00 12:00 14:00 16:00 18:00 20:00 08:00 10:00 12:00 14:00 16:00 18:00 20:00 08:00 10:00 12:00 14:00 16:00 18:00 20:00 time (hours) time (hours) time (hours) time (hours)

Honeybees activity concentrated Honeybees peak activity Honeybees peak activity Very low honeybees at 8h. between 12h-16h between 8h-12h activity. Guard bees Low activity during the stand on the hive remainder of the day: guard bees entrance all day long take position on the hive entrance

Work in progress…. 16 OUTLINEOUTLINE

1. Introduction: Origin and expansion of the hornet Vespa velutina in France Defensive behaviour in honeybees 2. Study Objectives 3. Observations of hornet behaviour Observations of daily activity at the nest Observations of predatory behaviour at the hive 4. Evaluation of honeybees defensive behaviour Field experiments under controlled conditions Observations under natural conditions 5. Preliminary conclusions 6. Perspectives

17 PreliminaryPreliminary conclusionsconclusions

EuropeanEuropean honeybeeshoneybees ApisApis melliferamellifera maymay notnot bebe ableable toto resistresist toto thethe newnew invaderinvader V.V. velutinavelutina

In France, honeybees (subspecies A. mellifera mellifera) do not develop mechanisms for colony defense as effective as in Asia and in Cyprus No «heat-balling» No «asphyxia-balling» No « shimmering »

When predation pressure is too high, honeybees colony greatly reduces its foraging activity and guard bees stand at the hive entrance

18 PerspectivesPerspectives II

RepeatRepeat observationsobservations ofof thethe defensivedefensive behaviourbehaviour

InIn differentdifferent subsub--speciesspecies ofof honeybeeshoneybees

InIn apiariesapiaries underunder differentdifferent predationpredation pressurepressure levelslevels

RecordingRecording andand analysisanalysis ofof thethe alarmalarm soundssounds emittedemitted byby thethe beebee

19 PerspectivesPerspectives IIII

ToTo developdevelop anan automaticautomatic monitoringmonitoring systemsystem replacingreplacing thethe humanhuman operatoroperator inin thethe videovideo analysisanalysis ((……inin progressprogress ))

View Point, Lyon, France 20 AcknowledgementsAcknowledgements

MrMr CeyralCeyral MrMr MartrencharMartrenchar MrMr BarnierBarnier MrMr andand MrsMrs DufourDufour DrDr Thiery,Thiery, INRA,INRA, Bordeaux,Bordeaux, FranceFrance DrDr BaylacBaylac,, MNHN,MNHN, Paris,Paris, FranceFrance ViewView PointPoint companycompany,, Lyon,Lyon, FranceFrance