Search

We report the discovery of adult small hive beetles, Aethina tumida, in a honey bee, Apis mellifera, apiary in Piracicaba, São Paulo State, Brazil, in March 2015. This is the first record for South America of this honey bee pest.

In the past two decades, the parasitic mite Varroa destructorhas become harder to control with synthetic acaricide chemicals due to genetic resistance. We determined the efficacy of the natural chemical oxalic acid (OA) in killing phoretic mites on adult worker bees under field conditions in southern England. We compared three OA application methods (trickling, spraying, and sublimation) at three or four (sublimation) doses, using 110 broodless colonies in early January 2013. Treatment efficacy was assessed by extracting mites from samples of c.270 worker bees collected immediately before and 10 days after treatment. All three methods could give high varroa mortality, c.93–95%, using 2.25 g OA per colony. However, sublimation was superior as it gave higher mortality at lower doses (.56 or 1.125 g per colony: trickling 20, 57% mortality; spraying 25, 86%; sublimation 81, 97%.). Sublimation using 2.25 g of OA also resulted in 3 and 12 times less worker bee mortality in the 10 days after application than either trickling or spraying, respectively, and lower colony mortality four months later in mid spring. Colonies treated via sublimation also had greater brood area four months later than colonies treated via trickling, spraying, or control colonies. A second trial in December 2013 treated 89 broodless colonies with 2.25 g OA via sublimation to confirm the previous results. Varroa mortality was 97.6% and 87 (98%) of the colonies survived until spring. This confirms that applying OA via sublimation in broodless honey bee colonies in winter is a highly effective way of controlling V. destructorand causes no harm to the colonies.

SummaryPrevious research has shown that colonies of the stingless bee Tetragonisca angustulahave hovering guards that can detect allospecific intruder bees with volatile odours or different body colour, but conspecific intruders were not detected. Here we show that T. angustulacolony entrances are also defended by guards standing on the entrance tube. These standing guards made very few errors in recognition, accepting 100% of the nestmates and rejecting 92% of the conspecific non-nestmates presented to them at the nest entrance. In addition, 87% of the nestmates contaminated with odours from the stingless bee Scaptotrigona bipunctatawere rejected. Standing guards also reacted to volatile odours from the stingless bees S. bipunctataand Melipona rufiventrisby switching to hovering. The defence reaction, i.e. the increase in the number of hovering guards, was not, however, comparable to the reaction previously reported to citral, the propaganda chemical used by the obligate robber bee Lestrimelitta limaowhen attacking other bee colonies.