How to control varroa ticks in a Bee

How to control varroa ticks in a Bee. BIT e. Hive PAOLO FONTANA

VARROA: Varroa destructor

LIFE CYCLE OF VARROA DESTRUCTOR ON HONEY BEE PHORETIC PHASE REPRODUCTIVE PHASE The life cycle of Varroa destructor is divided in two phases: 1. PHORETIC PHASE during which tick lives on adult specimens of bees. 2. REPRODUCTIVE PHASE during which tick lives inside the operculate cells. THIS FEATURE IS VERY IMPORTANT TO FORMULATE THE CONTROL STRATEGIES VERSUS VARROA

1 BEFORE THE CELL GETS OPERCULATE, THE FEMALE OF VARROA CRAWLS IN BETWEEN LARVA AND THE CELL’S BOTTOM 2 WHEN THE CELL GETS OPERCULATE AND THE WHOLE LARVA’S FOOD HAS ENDED, VARROA TICK IS FREE TO START FEEDING ON PRE-PUPAL STAGE OF BEE 1 2 3 4 5 6 7 3 VARROA TICK LAYS A FIRST EGG (MALE) 60 HOURS AFTER OPERCULUM APPEARS, THEN FURTHER EGGS (ALL FEMALES) ARE LAYED EVERY 30 HOURS. 4 TICK’S FAECES PILE UP IN THE CELL 5 TICKS CONTINUE DEVELOPING AND FEEDING ON BEE, TRANFERRING VIRUSES 6 TICKS MATING STARTS INSIDE THE CELL 7 THE ADULT FEMALES TICKS EMERGE, WHILE THE MALE AND OTHER IMMATURE SPECIMENS DIE INSIDE THE CELL

VARROA TICK AND BEES MOVING ADULT BEES FEEDING TO SURVIVE FEEDING TO BREED LARVAE PUPAE

LIFE CYCLES OF VARROA AND BEE BROOD DEVELOPMENT Queen bee lays egg DAY TICK DEVELOPMENT EGG STAGE LARVAL STAGE OPEN BROOD Varroa tick lays 4 eggs in brood cell PUPAL STAGE 1 st egg after 2, 5 days 2 nd egg after 1, 25 days 3 rd egg after 1, 25 days 4 th egg after 1, 25 days Development to breeding stage: Females 7 -8 days OPERCULATE BROOD Males 6 -7 days Brood damaged Worker bee is born Ticks emerge with bee or they die

WHEN STARTING WITH TREATMENT? IN THE SECOND YEAR COLONIES, A SUMMER TREATMENT MUST BE CARRIED OUT WITHIN JULY, EVEN IF IT DEPENDS ON THE INFESTATION DEGREE AND THE AVAILABLE TIME FOR THE COLONY TO INCREASE THE NUMBER OF BEES BEFORE WINTERING IN COLONIES BUILT DURING TEH YEARIT’S POSSIBLE TO IDENTIFY TWO SEPARATE OUTLINES: 1) COLONIES BUILT WITHIN MAY: A SUMMER TREATMENT MUST BE CARRIED OUT WITHIN JULY-AUGUST (according to the geographical areas). 2) COLONIES BUILT IN JUNE AND ALREADY TREATED DURING THE BUILDING UP: THE CHANCE TO TREAT ONLY IN AUTUMN-WINTER CAN BE CONSIDERED ANYWAY, IT’S ADVISABLE TO ESTIMATE THE COLONIES INFESTATION DEGREE AND ALSO THE GENERAL FEATURES OF THE APIARY. EACH APIARY, EVEN IF MADE UP BY SEVERAL HIVES WITH DIFFERENT FEATURES, SHOULD BE MANAGED ACCORDING TO A SINGLE STRATEGY IN ORDER TO AVOID REINFESTATION PROBLEMS (VARROA TICKS INTERCHANGES AND SHARINGS BETWEEN COLONIES)

MONITORING VARROA TICK’S INFESTATION ICING SUGAR METHOD Varroa ticks are counted out directly on adult bees using the icing sugar method. This allows every bee-keeper to estimate accurately Varroa ticks infestation during all season, and to be competent for facing the problem. 1) Collect a sample of bees from the edge of the brood nest (about 50 g of bees = 500 specimens) by filling a 120 ml jar and making the jar slippering on the back of bees from the top to the bottom. 2) Drop bees in a 750 ml jar with net bottom (or plug). 3) Add 35 g of icing sugar through the net. 4) Stir bees and sugar for 3 minutes. 5) Shake hardly the sugar over a thin strainer for 1 minute. 6) Place again the bees in the colony dropping them in between two spaced bars. 7) Count Varroa ticks in the strainer (sieve the most of sugar and drop the remained sugar in a tray: ticks will float). 8) Estimate the infestation level

Collect a sample of bees from the edge of the brood nest (about 50 g of bees = 500 specimens) filling a 120 ml jar.

Drop bees in a 750 ml jar with a net on the bottom.

Add 35 g of icing sugar through the net Stir bees and sugar for 3 minutes.

Shake hardly the sugar over a thin strainer for 1 minute.

Place immediately the bees in the colony again In the Top bar it’s not possible to introduce the bees with sugar over the honeycombs. Introduce them directly inside the inhabited space, better if you put them under the partially built honeycombs, near the right diaphragm.

Count Varroa thicks in the strainer

Threshold calculated with 50 g of bees: July August September Non endangered colony (at the moment) <5 < 10 < 15 Needed treatment (soon) 5 -25 10 -25 15 -25 Threshold exceeded, treat immediately > 25 Estimating the infestation level IT’S NOT WELL KNOWN IF THESE INFORMATION ARE IDENTICAL TO THE ONES OF TOP BAR HIVES, WHERE THE RATIO PHORETIC TICKS/TICKS INSIDE BROOD CELLS COULD BE DIFFERENT. THIS DATA MUST BE VERIFIED WITH POSTTREATMENT STAGES.

CONTROL OF VARROA THICKS: USING MITICIDES

PRIMARY MITICIDES TREATMENTS END WINTER TREATMENT: recent surveys show that 75% of Varroa thicks don’t enter brood nests until March. In this phase it could be indicated to treat if the winter treatment might have not been successful. Using dropped oxalic acid (Apibioxal) could be enough. A spring treatment should be carried out within the half of March. SUMMER TREATMENT: summer treatment was considered as a buffer while today it’s considered the primary treatment. Acting successfully and at the proper time in summer allow colonies to produce healthy bees until the winter treatment. The successful of summer treatment may be effective only if coupled with an apicultural technique. Summer treatment must start as soon as possible and not besides the first half of July, concerning the Northern Italy low sites, and the first half of August for the high altitude sites. In Central and Southern Italy it’s possible to have a delay of some weeks. AUTUMN-WINTER TREATMENT: it is the cleanliness treatment and its successfull is higher if it is carried out in case of lacking brood. It’s necessary to wait as much as possible (if the infestation degree is not high).

MITICIDES PRODUCTS ALLOWED BY ITALIAN LAWS: Oxalic acid: Apibioxal® Thymol: Apilife VAR® Thymovar® Apiguard® Formic acid: ADMITTED IN ORGANIC BEEKEEPING MAQS ® Varterminator ® Fluvalinate: Apistan® Amitraz: Apivar® NON ADMITTED IN ORGANIC BEEKEEPING

APICULTURAL METHODS TO CONTROL VARROA • Frame-trap of male brood • Brood stopping • Operculate brood removal • Bee-package technique • Suppression/removal of the queen USEFUL ONLY TO CHECK VARROA TICKS ALSO USEFUL TO PROLIFERATE COLONIES REPLACEMENT OF THE QUEEN BEES OBTAINING ONLY PHORETIC VARROA TICKS ALMOST DURING THE FIRST SEASON, THE MOST SUITABLE TECHNIQUE FOR THE TOP BAR IS THE BROOD STOPPING

APICULTURAL TECHNIQUES PREDISPOSE COLONIES TO THE OXALIC ACID TREATMENT WITH BROOD LACK DROPPED OXALIC ACID TREATMENT (APIBIOXAL) WHICH IS THE RIGHT DOSAGE TO BE USED IN BF TOP BAR HIVES?

THE KNOWN (APPLIED) DOSAGE (5 cc PER INTERFRAME) IS REFERRED TO THE FRAME OF DADANT BLATT HIVES DADANT FRAME 266 mm 433 mm Honeycomb surface: 1151, 78 cm 2

BF TOP BAR DIAPHRAGM

BF TOP BAR HONEYCOMB 380 mm 170 mm 380 mm Honeycomb surface: 467 cm 2 = 0, 4 of the Dadant frame surface OXALIC ACID DOSAGE 5 cc X 0, 4 = 2 cc FOR EACH INHABITED INTER-BAR

OXALIC ACID TREATMENT IN BF TOP BAR OXALIC ACID MAY BE USED ONLY IN CASE OF BROOD LACK, DURING THE END-WINTER TREATMENT. DURING THE WINTER TREATMENT OR IN THE SUMMER IT IS CARRIED OUT ONLY IN CASE OF OPERCULATE BROOD LACK (NATURAL OR INDUCED BY APICULTURIST). One of the most typical advantages (benefits) by using Gareth’s rotating shims is to favour the dropped oxalic acid treatment after they have been removed.

REMOVING GARETH’s ROTATING SHIMS TO REMOVE ALL SHIMS, MOVING ON AS DURING AN ORDINARY CHECK OF THE HIVE 1) Remove a bar placed next to the right of the right diaphragm. 2) Remove slightly the diaphragm with a lever in order to create a small space. 3) Take off the Gareth’s shims using the lever. 4) Remove shims one by one. 5) Check how many and which interbar spaces are inhabited by the bees. 6) Count the oxalic acid dosage (2 cc per each inhabited inter-bar)

DROPPED OXALIC ACID DISPENSATION

REPOSITIONING OF GARETH’S ROTATING SHIMS

VARROA CONTROL IN TOP BAR HIVES Top Bar are considered natural hives, and in colonies inhabiting such hives Varroa control requires the same methods applied for the organic beekeeping. Due to the peculiar structure of Top Bar hives, the usage of substances as the several compounds of Thymol or Formic acid is difficult and they have not yet been tested in Top Bar hives for such reasons. The most tested and very easy applicable techniques are those depending on the life cycle of Varroa ticks and bees, in order to obtain colonies inhabited only by phoretic Varroa ticks and so totally lacking of ticks occurring in breeding cells. This prevents the need of miticides in such kind of cells. In this case when only phoretic Varroa ticks occur, the oxalic acid treatment (APIBIOXAL) is simple, successful and cheap. In order to obtain during summer colonies with only phoretic Varroa, it is advisable to follow these outlines: 1) Exploiting the natural swarming of the colony 2) Suppress or remove the queen bee 3) Carry out the brood-stopping, closing the queen bee in a small cage or neighbouring it in a single honeycomb using a special diaphragm with queen excluder.

NATURAL SWARMING AND STRUGGLING WITH VARROA TICKS The natural swarming may allow a treatment carried out during the springsummer season, in order to arrive to the winter without needing further treatments. The swarming queen bee stops laying eggs some days before the swarming, and then the new queen will start laying eggs 10 -15 days after the swarming stage; there will be a new operculate brood after 8 -9 days. In such way, after 25 days there will be only non operculate brood, and so only phoretic Varroa ticks. If the precise date of the swarming remains unknown, it’s possible to check the partial/total lack of the operculate brood and the eventual occurrence of new eggs and larvae, for being able to carry out the oxalic acid treatment. OXALIC ACID. Day 0 Day -4 BORN OF A NEW QUEEN BEE FECUNDATION FLIGHTS NEW OPERCULATE BROOD START LAYING THE WHOLE LAYING OF THE OLD QUEEN BEE WAS BORN Day 20 SWARMING

Bars with brood comb Bars with honey COLONY DURING SWARM 20 days Bars with a new brood (not operculate) Bars with honey COLONY 20 DAYS AFTER SWARMING

MAKING THE COLONY ORPHAN, STRUGGLING WITH VARROA TICKS Making the colony orphan is intended as suppressing the queen bee in a colony. The queen bee may be suppressed (this might appear cruel, and so anyone has to act accordingly to his own conscientiousness) or removed, even temporarily, by transferring it in another hive with some combs provided with honey and bees. In this way the colony without queen will have to provide itself a new queen and, during the period of its birth, development, fecundation, laying and operculate brood, all the previous brood of the ancient queen will be born and after 24 days there will be only phoretic Varroa, and it will be possible to treat with oxalic acid. CHECKING QUEEN CELLS REGAL CELLS THE WHOLE BROOD IS BORN NEW QUEEN FECUNDATION FLIGHTS IS BORN START LAYING OF THE NEW QUEEN Day 24 Day 0 ORPHAN COLONY ACIDO OSS.

Bars with brood combs Bars with honey COLONY ORPHANHOOD MAKING ORPHANHOOD Bars with new non operculate brood 24 days = QUEEN Bars with honey COLONY 24 DAYS AFTER BECOMING ORPHAN

Bars with brood combs Bars with honey = QUEEN COLONY WHEN QUEEN IS REMOVED QUEEN REMOVAL Queen bee is removed with 3 -4 combs provided only with honey and covered with bees, to which bees brushed from 3 brood honeycombs are added COLONY AFTER REMOVING QUEEN BEE

NEW COLONY WITH QUEEN BEE BUT WITHOUT BROOD NOURISHER HALF TOP BAR = QUEEN The new created colony (MAINTENANCE NUB) with few stock honeycombs, young bees brushed from 3 brood honeycombs, and the queen, must be placed inside a half Top Bar and it must be moved to another apiary almost far 1, 5 km. This nub will have to be treated with oxalic acid within 7 -8 days since its creation. This new nuc should be preferably nourished because bees may build new honeycombs where the queen may lay the brood. The nuc will be able to be repositioned in apiary after the primal colony is treated wit oxalic acid (starting from 24 th day) and the new queen will have been laying. In case of lack of a new fecund queen in the primal colony it may be possible to introduce the one coming from the maintenance nuc, by placing it in a queen cage, and introducing again all combs and bees.

QUEEN REMOVAL Bars with brood combs COLONY WHEN QUEEN IS BEING REMOVED Bars with new non operculate brood 24 days COLONY 24 DAYS AFTER QUEEN REMOVAL

ARTIFICIAL BROOD STOPPING The summer brood stopping obtained by neighbouring the queen bee in a small cage or over a single brood comb by using 2 diaphragms with queen excluder, is a very simple technique and, besides a high efficacy to struggle with Varroa, it often permits bees to increase or restore stocks. Such technique doesn’t determine moving or creating new colonies and it’s highly suggested to small apiculturists of self-consumption (family) level. OXAL. ACID Day 0 THE WHOLE BROOD IS BORN CHECKING QUEEN NEIGHBOURING FREE QUEEN Day 24 ENCAGING / NEIGHBOURING QUEEN BEE QUEEN RESTARTS LAYING

BROOD STOPPING IN TOP BAR HIVES 1) NEIGHBOURING IN CAGE 2) NEIGHBOURING IN COMB WITH QUEEN-EXCLUDER DIAPHRAGMS 1) NEIGHBOURING IN CAGE IS SIMPLE AND EFFECTIVE AND IT PRODUCES A WHOLE BROOD STOPPING WITH PROLONGED LACK OF YOUNG BROOD. 2) NEIGHBOURING IN HONEYCOMB REQUIRES A PERFECT FITTING OF QUEEN EXCLUDER DIAPHRAGMS TO AVOID A QUEEN BEE ESCAPE. MOREOVER, THERE IS NOT A TOTAL LACK OF BROOD AND THE HONEYCOMB WHERE THE QUEEN NEIGHBOURED MUST BE DESTROYED. IT IS ADVISABLE TO ADOPT THE NEIGHBOURING IN CAGE, WHICH ALLOWS BETTER RESULTS

NEIGHBOURING IN CAGE/1 THERE ARE SEVERAL MODELS OF CAGES. CHOOSE A CAGE WHICH PERMITS TO COLLECT THE QUEEN BEE IF POSSIBLE WITHOUT HANDLING IT. ALSO HANGING THE CAGE SHOULD BE TESTED BEFORE, TO ENSURE STEADINESS AND TO ENSURE IT MAY NOT AFFECT THE SPACE IN BETWEEN BARS. FIXING THE CAGE TO THE PLYWOOD STRIP (IF IT OCCURS) OR USING A THIN IRON WIRE ON THE BAR IS RECOMMENDED.

1) OPEN THE HIVE AND IDENTIFY THE QUEEN 2) COLLECT (ENCAGE) THE QUEEN BEE AND PROPERLY FIX THE CAGE TO AN EMPTY BAR. 3) PLACE THE BAR BEARING THE CAGE IN THE MIDDLE OF THE BROOD NEST. 4) REASSEMBLE THE COLONY COMB WITH QUEEN BEE BROOD HONEY EMPTY 1 -2) ENCAGING

3) 4) BROOD HONEY EMPTY

NEIGHBOURING IN CAGE/2 5) AFTER 24 DAYS THERE WILL NOT BE A BROOD IN THE HIVE. ON THE BAR BEARING THE CAGE A HONEYCOMB MIGHT HAVE BEEN BUILT. PRESERVE IT IF WELL MADE. MANY HONEYCOMBS PREVIOUSLY CONTAINING BROOD, WILL NOW CONTAIN ONLY HONEY. MANY COMBS WILL HOST HONEY OR WILL BE MOSTLY EMPTY 6) COLLECT COMBS WITH OPERCULATE HONEY EVEN IF THEY PREVIOUSLY CONTAINED BROOD. 7) GET THE QUEEN BEE FREE BY OPENING THE CAGE. 8) REASSEMBLE THE COLONY REDUCING NUMBER OF BARS. 9) START NOURISHING TO INDUCE THE LAYING START. 10) SOME HOURS LATELY (OR WITHIN 6 -8 DAYS) TREAT THE COLONY WITH OXALIC ACID ONLY BY REMOVING THE ROTATING SHIMS AND DISPOSING 2 cc OF OXALIC ACID (APIBIOXAL) FOR EACH INTER-BAR. 11) CLEAN THE TRAY AND PLACE WHITE SHEETS TREATED WITH VASELINE ON THE BOTTOM. COUNT FALLEN VARROA TICKS AFTER 3 DAYS AND AFTER 1 WEEK.

5 -6) 7) OPEN THE CAGE BROOD HONEY EMPTY

EVENTUAL HONEYCOMBS COLLECTING BEFORE OXALIC ACID TREATMENT THIS WITHDRAWAL MUST OCCUR ONLY IF: 1. COLONIES ARE DEVELOPED IN MORE THAN 15 -16 BARS. 2. IF DURING THE BROOD STOPPING THE COLONY CONTINUED TO IMPORT HONEY ANYWAY. THE AIM OF WITHDRAWAL IS TO REDUCE THE OXALIC ACID TREATMENT VOLUME, BUT ALSO TO START REDUCING COLONIES BEFORE WINTERING

COLLECTING HONEY COLLECTED HONEYCOMBS, IF NONOPERCULATE CELLS OCCUR, MUST BE LEFT IN A ROOM WITH DEHUMIDIFIER FOR A WEEK, AND THEN THEY MAY BE TREAT IN THE PRESSER.

8 -9) OXALIC ACID TREATMENT NOURISHER 10) NOURISHER BROOD HONEY EMPTY

NEIGHBOURING ON A COMB/1 1) IDENTIFICATION OF THE QUEEN BEE 2) ORGANIZE A SPACE FOR THE HONEYCOMB WHICH WILL BEAR QUEEN BEE IN THE MIDDLE OF BROOD NEST 3) PLACING QUEEN EXCLUDER DIAPHRAGMS AND COMB BEARING THE QUEEN (INTRODUCE 2 SHIMS IN BETWEEN TWO DIAPHRAGMS AND THE COMB WITH THE QUEEN) 1) COMBS WITH HONEY COMBS WITH BROOD COMB BEARING QUEEN BEE BROOD HONEY EMPTY

2) COMB WITH QUEEN BEE QUEEN EXCLUDER DIAPHRAGMS 3) BROOD HONEY EMPTY

NEIGHBOURING ON A COMB/2 4) AFTER 24 DAYS THE ONLY OCCURRING BROOD WILL BE THE ONE IN THE COMB BEARING THE QUEEN. MANY COMBS PREVIOUSLY CONTAINING THE BROOD, NOW WILL CONTAIN ONLY HONEY. MANY HONEYCOMBS WILL CONTAIN HONEY OR WILL BE MOSTLY EMPTY 5) COLLECT COMBS WITH OPERCULATE HONEY EVEN IF THEY PREVIOUSLY CONTAINED A BROOD (see previous case). 6) FREE THE QUEEN BY REMOVING EXCLUDE-QUEEN DIAPHRAGMS. INDUCE THE MOVEMENT OF THE QUEEN BEE TO ANOTHER COMB AND CUT OFF THE BROOD HONEYCOMB FROM THE BAR. 7) REASSEMBLE THE COLONY BY REDUCING THE BARS NUMBER. 8) NOURISH THE COLONY TO INDUCE THE START OF LAYING. 9) THE SAME DAY (OR WITHIN 5 -8 DAYS) START THE OXALIC ACID TREATMENT BY REMOVING THE ONLY ROTATING SHIMS AND DISPOSING 2 cc OF OXALIC ACID (APIBIOXAL) PER EACH INTER BAR. 10) CLEAN THE TRAY AND PLACE ON THE BOTTOM SOME WHITE SHEETS PREVIOUSLY TREATED WITH VASELINE. COUNT THE FALLEN VARROA TICKS AFTER 3 DAYS AND AFTER 1 WEEK.

QUEEN EXCLUDER DIAPHRAGM OF BF TOP BAR IN ORDER TO USE THE EXCLUDE-QUEEN DIAPHRAGM, IT MUST BE PERFECTLY FITTED TO THE SIDE WALLS AND TO THE BOTTOM OF THE TOP BAR. IT MAY BE EASILY FITTED BY USING A SHARP KNIFE 1 -2 WIRES OF THE NET MAY BE REMOVED ON THE LOWER SIDE A STRIP OF SOFT NET WITH 2 -3 mm HOLES MAY BE APPLIED TO FIX THE DIAPHRAGM ON THE BOTTOM

4 -5) DESTROYING BROOD COMB 6) BROOD HONEY EMPTY

7 -8) OXALIC ACID TREATMENT NOURISHER REMOVE ALL SHIMS 9) NOURISHER BROOD HONEY EMPTY

POST TREATMENT MANAGEMENT 1 WEEK AFTER THE OXALIC ACID TREATMENT WAS CARRIED OUT CHECK THE QUEEN LAYING AND THE AMOUNT OF OCCURRING BROOD. CHECK THE CONDITIONS OF STOCKS (IF NECESSARY START NOURISHING). CHECK THE EVENTUAL NEED OF SPACE AND PROCEED AS USUAL CREATING SPACE ON THE RIGHT. BROOD NEST BROOD COMBS WITH HONEY EMPTY