Chemical and cultural control of Tropilaelaps mercedesae mites in honeybee (Apis mellifera) colonies in Northern Thailand.

At least two parasitic mites have moved from Asian species of honeybees to infest Apis mellifera. Of these two, Varroa destructor is more widespread globally while Tropilaelaps mercedesae has remained largely in Asia. Tropilaelaps mites are most problematic when A. mellifera is managed outside its native range in contact with Asian species of Apis. In areas where this occurs, beekeepers of A. mellifera treat aggressively for Tropilaelaps and Varroa is either outcompeted or is controlled as a result of the aggressive treatment regime used against Tropilaelaps. Many mite control products used worldwide may in fact control both mites but environmental conditions differ globally and thus a control product that works well in one area may be less or ineffective in other areas. This is especially true of volatile compounds. In the current research we tested several commercial products known to control Varroa and powdered sulfur for efficacy against Tropilaelaps. Additionally, we tested the cultural control method of making a hive division to reduce Tropilaelaps growth in both the parent and offspring colony. Making a split or nucleus colony significantly reduced mite population in both the parent and nucleus colony when compared to un-manipulated control colonies. The formic acid product, Mite-Away Quick Strips®, was the only commercial product that significantly reduced mite population 8 weeks after initiation of treatment without side effects. Sulfur also reduced mite populations but both sulfur and Hopguard® significantly impacted colony growth by reducing adult bee populations. Apivar® (amitraz) strips had no effect on mite or adult bee populations under the conditions tested

Chemical and cultural control of Tropilaelaps mercedesae mites in honeybee (Apis mellifera) colonies in Northern Thailand

At least two parasitic mites have moved from Asian species of honeybees to infest Apis mellifera. Of these two, Varroa destructor is more widespread globally while Tropilaelaps mercedesae has remained largely in Asia. Tropilaelaps mites are most problematic when A. mellifera is managed outside its native range in contact with Asian species of Apis. In areas where this occurs, beekeepers of A. mellifera treat aggressively for Tropilaelaps and Varroa is either outcompeted or is controlled as a result of the aggressive treatment regime used against Tropilaelaps. Many mite control products used worldwide may in fact control both mites but environmental conditions differ globally and thus a control product that works well in one area may be less or ineffective in other areas. This is especially true of volatile compounds. In the current research we tested several commercial products known to control Varroa and powdered sulfur for efficacy against Tropilaelaps. Additionally, we tested the cultural control method of making a hive division to reduce Tropilaelaps growth in both the parent and offspring colony. Making a split or nucleus colony significantly reduced mite population in both the parent and nucleus colony when compared to un-manipulated control colonies. The formic acid product, Mite-Away Quick Strips®, was the only commercial product that significantly reduced mite population 8 weeks after initiation of treatment without side effects. Sulfur also reduced mite populations but both sulfur and Hopguard® significantly impacted colony growth by reducing adult bee populations. Apivar® (amitraz) strips had no effect on mite or adult bee populations under the conditions tested

Chemical and cultural control of <i>Tropilaelaps mercedesae</i> mites in honeybee (<i>Apis mellifera</i>) colonies in Northern Thailand

<div><p>At least two parasitic mites have moved from Asian species of honeybees to infest <i>Apis mellifera</i>. Of these two, <i>Varroa destructor</i> is more widespread globally while <i>Tropilaelaps mercedesae</i> has remained largely in Asia. <i>Tropilaelaps</i> mites are most problematic when <i>A</i>. <i>mellifera</i> is managed outside its native range in contact with Asian species of <i>Apis</i>. In areas where this occurs, beekeepers of <i>A</i>. <i>mellifera</i> treat aggressively for <i>Tropilaelaps</i> and <i>Varroa</i> is either outcompeted or is controlled as a result of the aggressive treatment regime used against <i>Tropilaelaps</i>. Many mite control products used worldwide may in fact control both mites but environmental conditions differ globally and thus a control product that works well in one area may be less or ineffective in other areas. This is especially true of volatile compounds. In the current research we tested several commercial products known to control <i>Varroa</i> and powdered sulfur for efficacy against <i>Tropilaelaps</i>. Additionally, we tested the cultural control method of making a hive division to reduce <i>Tropilaelaps</i> growth in both the parent and offspring colony. Making a split or nucleus colony significantly reduced mite population in both the parent and nucleus colony when compared to un-manipulated control colonies. The formic acid product, Mite-Away Quick Strips®, was the only commercial product that significantly reduced mite population 8 weeks after initiation of treatment without side effects. Sulfur also reduced mite populations but both sulfur and Hopguard® significantly impacted colony growth by reducing adult bee populations. Apivar® (amitraz) strips had no effect on mite or adult bee populations under the conditions tested.</p></div

Colony Failure Linked to Low Sperm Viability in Honey Bee (Apis mellifera) Queens and an Exploration of Potential Causative Factors.

Queen health is closely linked to colony performance in honey bees as a single queen is normally responsible for all egg laying and brood production within the colony. In the U. S. in recent years, queens have been failing at a high rate; with 50% or greater of queens replaced in colonies within 6 months when historically a queen might live one to two years. This high rate of queen failure coincides with the high mortality rates of colonies in the US, some years with >50% of colonies dying. In the current study, surveys of sperm viability in US queens were made to determine if sperm viability plays a role in queen or colony failure. Wide variation was observed in sperm viability from four sets of queens removed from colonies that beekeepers rated as in good health (n = 12; average viability = 92%), were replacing as part of normal management (n = 28; 57%), or where rated as failing (n = 18 and 19; 54% and 55%). Two additional paired set of queens showed a statistically significant difference in viability between colonies rated by the beekeeper as failing or in good health from the same apiaries. Queens removed from colonies rated in good health averaged high viability (ca. 85%) while those rated as failing or in poor health had significantly lower viability (ca. 50%). Thus low sperm viability was indicative of, or linked to, colony performance. To explore the source of low sperm viability, six commercial queen breeders were surveyed and wide variation in viability (range 60-90%) was documented between breeders. This variability could originate from the drones the queens mate with or temperature extremes that queens are exposed to during shipment. The role of shipping temperature as a possible explanation for low sperm viability was explored. We documented that during shipment queens are exposed to temperature spikes ( 40°C) and these spikes can kill 50% or more of the sperm stored in queen spermathecae in live queens. Clearly low sperm viability is linked to colony performance and laboratory and field data provide evidence that temperature extremes are a potential causative factor

Chemical and cultural control of <i>Tropilaelaps mercedesae</i> mites in honeybee (<i>Apis mellifera</i>) colonies in Northern Thailand - Fig 3

<p><b>Average (mean ± SEM) number of frames covered in adult bees (A) and number of <i>Tropilaelaps</i>-infested cells observed by uncapping 100 sealed brood cells (B) from parent honey bee colonies that were used to make a single nucleus colony or unmanipulated control colonies.</b> Letters indicate significant differences between treatment means (ANOVA, P < 0.05).</p

Correction: Colony Failure Linked to Low Sperm Viability in Honey Bee (Apis mellifera) Queens and an Exploration of Potential Causative Factors.

[This corrects the article DOI: 10.1371/journal.pone.0147220.]