|De Guzman, Lilia|
Submitted to: Bee Culture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/15/2008
Publication Date: 2/1/2009
Citation: De Guzman, L.I., Prudente, J.A., Rinderer, T.E., Frake, A.M., Tubbs, H. Population of small hive beetles (Aethina tumida Murray) in two apiaries having different soil textures in Mississippi. Science of Bee Culture 1(1):4-8; supplement to Bee Culture 137(2). 2009
Interpretive Summary: Small hive beetles (SHB) spend over 75% of their developmental period in the soil. Thus, soil conditions greatly affect their biology. In this study, we examined populations of SHB in the colonies and in the soil using two apiaries. Soil samples collected at 10, 20 and 30 cm deep were also analyzed. Four soil types were identified for apiary 1, and six for apiary 2. This study confirmed previous reports that most SHB normally pupates in the upper 10 cm of soil. Although there were more beetles observed in apiary 1 than in apiary 2, our results indicate that SHB can successfully pupate in various types of soil. The low numbers of beetles in apiary 2 could be attributed to several factors such as soil moisture, drainage slopes and also to the presence of nematodes infecting young SHB in this apiary. This observation on the natural infestation of nematodes in SHB adults is useful in developing an integrated pest management program for this important honey bee pest.
Technical Abstract: Soil samples collected at 0-10, 11-20 and 21-30 cm from two apiaries in Lula, Mississippi were separately analyzed for soil texture. Populations of small hive beetles (SHB) in the soil and inside the hives were also counted. Our results showed that the two apiaries had different soil textures with different levels of infestation both in the soil and inside the hives. We recorded significantly more adult beetles in apiary 1 (May = 109.35 ± 24.42, June = 607.6 ± 136.25 beetles per colony) where the soil was predominantly silty clay and silty clay loam than in apiary 2 (May = 37.08 ± 5.40, June = 260.4 ± 54.97 beetles per colony), which had mostly sandy loam and loam soil. Regardless of soil type, the density of SHB per 1,200 cm3 soil varied with soil depth. The density of SHB was greatest (8.54 ± 1.92 beetles) in the first 10 cm of soil in which most of the larvae and pupae were observed close to the surface of the soil. A few (0.48 ± 0.12 beetles) SHB were also found at 11-20 cm, but no beetle was found at 21-30 cm. This preference for the first 10 cm was not influenced by soil type since no consistent soil type was recorded for a particular soil depth. Our results showed that SHB populations successfully developed in various types of soil and that vertical movement of larvae in the soil was not influenced by soil type. Nevertheless, it is possible that the discrepancy in SHB populations between the two locations may have been due to the amount of available soil moisture. In a field setting, the difference in water retention ability of different soil types and field slope (drainage) potentially affected the amount of moisture in the soil. The presence of nematodes also may have contributed to the death of developing SHB in apiary 2. This is the first report on the natural infestation of nematodes in teneral adults of SHB in the soil.