A short test evaluating larval attractiveness of honey bees to Varroa jacobson.
Lilia I De Guzman; Thomas E Rinderer; Vicki A Lancaster;
A controlled experiment which utilized a larval transfer (grafting) technique was used to evaluate attractiveness of larvae from four different stocks of honey bees (Apis mellifera) to Varroa jacobsoni. The stocks of honey bees were: ARS-Y-C-1 (A. m. carnica, from Yugoslavia), Hastings (A. m. carnica, from Canada), an F1hybrid between ARS-Y-C-1 and Hastings, and a Louisiana stock. Newly hatched larvae (target larvae) from each test stock were grafted into an area at the centre of a brood frame occupying 8 rows of 20 cells (160 cells). After larval transfer, each brood frame containing target larvae was introduced into a Varroa-infested colony. Inspection of the frames 2 weeks later showed that ARS-Y-C-1 pupae were less frequently infested than Hastings and Louisiana pupae (20% vs. 36% and 40%), while the infestation rate of the hybrids was intermediate (29%). The stocks did not differ in other parameters of Varroa infestation (mite load per infested pupa, number of females per infested pupa, number of progeny per female, number of progeny per infested pupa, and proportion of infested cells containing infertile females). The results indicate that larvae of the ARS-Y-C-1 stock, which has been selected for resistance to V. jacobsoni, are less attractive to female mites than the larvae of some other honey bee stocks.