Varroa destructor (Mesostigmata: Varroidae) in Costa Rica: population dynamics and its influence on the colony condition of Africanized honey bees (Hymenoptera: Apidae)

The development of Varroa destructor Anderson & Trueman (Mesostigmata: Varroidae) population dynamics in Africanized honey bees, Apis mellifera L. (Hymenoptera: Apidae) colonies was monitored from February to July 2004 in Atenas, Costa Rica. A correlation between the mite infestation level and the colony condition was evaluated. For each colony, infestation of varroa in adult bees was measured twice a month. Sticky boards were placed on the bottom boards of each colony to collect fallen mites. The condition of the colonies was evaluated by measuring the amount of brood and adult bees. Our results consistently showed that mite infestation on adult bees increased significantly in the experimental colonies, rising to 10.0% by the end of the experiment. In addition, the mean mite fall increased significantly over the course of the study in the treated (R= 0.72, P<0.05) and untreated colonies (R= 0.74, P<0.05) to a level of 63.8 and 73.5 mites per day, respectively. The increase in varroa infestation coincided with a decrease in the amount of brood. Furthermore, adult bees with deformed wings or even without wings crawling in front of their hive occurred in highly infested colonies (mite infestation = 10.0% or more). Rev. Biol. Trop. 56 (4): 1741-1747. Epub 2008 December 12.

La dinámica poblacional del ácaro Varroa destructor Anderson & Trueman (Mesostigmata: Varroidae) en abejas africanizadas, Apis mellifera L. (Hymenoptera: Apidae) fue monitoreada de febrero a julio 2004, en Atenas, Costa Rica. Asimismo, se analizó la relación entre el nivel de infestación de varroa y la condición de la colmena. La infestación del ácaro V. destructor fue evaluada en abejas adultas dos veces al mes. Además, se colocaron trampas adhesivas en el fondo de la colmena para recoger los ácaros que caen naturalmente. La condición de la colmena fue determinada midiendo la cantidad de cría y la población de abejas adultas. La infestación del ácaro V. destructor en abejas adultas aumentó significativamente durante el estudio hasta alcanzar un 10.0%. Igualmente, la caída natural de ácaros se incrementó, tanto en colmenas que fueron tratadas previa-mente con un acaricida químico (R= 0.72, P<0.05) como en colmenas sin tratamiento (R= 0.74, P<0.05), hasta llegar a 63.8 y 73.5 ácaros por día, respectivamente. El aumento de la infestación en las colmenas coincidió con una disminución en la cantidad de cría. La presencia de abejas adultas con alas deformes o sin alas, arrastrándose en frente de la colmena, fue observada en colmenas altamente infestadas con el ácaro de la varroa (infestación superior = 10.0%).

A survey of the termite fauna (Isoptera) of an eucalypt plantation in central Brazil

The termite fauna of a plantation of Eucaliptus urophylla S.T. Blake (Myrtales: Mytaceae) in Buritis, Minas Gerais, was manually sampled in 12 transects. The assemblage contained 28 species belonging to Termitidae and Rhinotermitidae. This assemblage corresponds to a subset of the native fauna of the cerrado previously present in this region. Compared to the original native fauna, it has a lower species richness, a much lower proportion of soil-feeders and a higher proportion of litter-feeders. A total of 1600 recently cut trees were examined and only three (0.2 percent) had damage to the heartwood caused by Coptotermes sp. Despite the presence of a diverse termite fauna including several putative pest species, termites are not considered a significant problem to eucalypt plantations in this region.

Os cupins de uma plantação de Eucaliptus urophylla S.T. Blake (Myrtales: Mytaceae) em Buritis, MG, foram amostrados manualmente em 12 transectos. A taxocenose encontrada continha 28 especies pertencentes a Termitidae e Rhinotermitidae. Essa taxocenoce corresponde a um subconjunto da fauna nativa do cerrado anteriormente presente na mesma área. Comparada com a fauna original, ela tem riqueza menor, uma proporção muito menor de humívoros e maior de ceifadores. O exame de 1600 árvores recém-cortadas revelou que apenas três delas (0.2 por cento) apresentavam dano ao cerne causado por Coptotermes sp. Apesar da presença de uma fauna diversa incluindo várias espécies consideradas pragas, os cupins não são considerados um problema significativo nessa região.