Problem in the Philippines for treating Varroa is the year long presence of brood. There is no broodless period where a single treatment can...
Problem in the Philippines for treating Varroa is the year long presence of brood. There is no broodless period where a single treatment can remove an infestation.
The first treatment must be done at night when all field bees are home to get the mites that are piggybacking. All following treatments can be done during the day as newly emerged mites jump on nurse bees preferentially.
Varroa stays at the adult stage and lives outside the capped brood for 4.5-9 days when brood is present (months if no brood is present). In order to kill mites that emerged just after the last vapping, before they enter brood just being capped, 4 days is as long as they can be left.
Longest the brood is capped is drone at 14 days.
The math...
So you do not want to leave more than 4 days between treatments as some of the adult varroa may have entered capped brood already. The longest varroa will remain sequestered in capped brood is drone brood at 14 days. 4 goes into 14 four times rounding up. Therefore be sure you must followup treat 4 times for a total of 5 times . Day0, Day4, Day8, Day12 and finally Day16.
On day 16 you will get the offspring of the adults that just entered drone brood and were capped before you will did your first treatment on day0 (but before the enter to start the cycle again). If you are using a good amount of Oxalic then all mites, varroa and tracheal, should be dead.
These are some good prime numbers for days to wait between treatments...
7, 11, 13, 17, 19, 23, 29, 31
The first treatment must be done at night when all field bees are home to get the mites that are piggybacking. All following treatments can be done during the day as newly emerged mites jump on nurse bees preferentially.
Varroa stays at the adult stage and lives outside the capped brood for 4.5-9 days when brood is present (months if no brood is present). In order to kill mites that emerged just after the last vapping, before they enter brood just being capped, 4 days is as long as they can be left.
Longest the brood is capped is drone at 14 days.
The math...
So you do not want to leave more than 4 days between treatments as some of the adult varroa may have entered capped brood already. The longest varroa will remain sequestered in capped brood is drone brood at 14 days. 4 goes into 14 four times rounding up. Therefore be sure you must followup treat 4 times for a total of 5 times . Day0, Day4, Day8, Day12 and finally Day16.
On day 16 you will get the offspring of the adults that just entered drone brood and were capped before you will did your first treatment on day0 (but before the enter to start the cycle again). If you are using a good amount of Oxalic then all mites, varroa and tracheal, should be dead.
5 treatments of Oxalic Acid vapor at 4 day intervals will remove most all the Varroa from a hive. Day0 at night, Day4, Day8, Day12 and Day16.
If there is no drone comb present then Day16 can be skipped.
Then you need to think about re-treatment. Mites can not really build up resistance to Organic Acids as it means redesigning the whole body plan and metabolism. Unlike a simple pesticide, resistance should never be a problem on a human time scale. The only way I can think that mites could easily overcome treatment is if the pattern is predictable and they could be sequestered in the capped brood at the time of each treatment.
Fortunately nature shows us a solution. Cicadas stay dormant under the ground for intervals of prime number years. The reason being that no predator can develop a life cycle that is a factor of the cicadas and be there in numbers ready for cicadas to emerge.
If you decide to treat once a week or once a month then the varroa could well adapt the cycle to be in capped brood at that same interval. This is what we have to deal with in the Philippines with year long brood in the hive and high varroa survival rates. The varroa come from here and are perfectly adapted to the conditions in the Philippines.
These are some good prime numbers for days to wait between treatments...
7, 11, 13, 17, 19, 23, 29, 31
So I am going to retreat after 7 days, then after another 11, 13, 17, 19, 23, 29 and then 31. Then settle into a pattern of a 23 day wait and then a 31 day wait between treatments going into the future.
Varroa on workers is not going to have a cycle much faster than 16 days (12 in capped worker brood and 4 on the nurse bees). 29 and 31 days intervals will never allow varroa to get more than one life cycle in front of you.
So varroa can be kept out but this little barbarian will always be at the gate as it is endemic in the Philippines. So first to get the barbarians under control you need to be a Caesar ("Veni, vidi, vici") but once the barbarians are defeated you need to be a Hadrian and build a defensive wall to maintain your empire.
Caste Hatch Cap Emerge Queen 3½ days 8 days +-1 16 days +-2 Laying 28 days +-5 Worker 3½ days 9 days +-1 20 days +-1 Foraging 42 days +-7 Drone 3½ days 10 days +-1 24 days +-1 Flying to DCA 38 days +-5
