Bioecology of small hive beetles and assessment of their damage in stingless bee colonies
Loading...
Files
Date
2017
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Department of Agricultural Entomology, College of Agriculture, Vellayani
Abstract
The study entitled “Bioecology of small hive beetles and assessment of
their damage in stingless bee colonies” was conducted with the objectives to study
the incidence, bioecology and the extent of damage by small hive beetles in
stingless bee colonies. The study was conducted during the period 2015-2017 at
Department of Agricultural Entomology, College of Agriculture,Vellayani.
A survey was conducted in Southern districts of Kerala viz.,
Thiruvananthapuram, Kollam and Pathanamthitta. Seven beetles (five nitidulids,
one cryptophagid and one tenebrionid) were collected from the hives during the
survey. Among these, the nitidulid beetle which caused the primary infestation is
identified as Epuraea latissima Kirejtshuk and it is the first report from stingless
bee hive. Monthly incidence of the hive beetle revealed that peak period of
infestation was recorded from Thiruvananthapuram in the month of June, whereas
in Kollam district, it was during June and July. However, the incidence was
recorded only during the month of May from Pathanamthitta district. Among the
three districts, highest incidence of small hive E. latissima beetle was recorded
from Kollam (19.00 %), followed by Thiruvananthapuram (16.00 %) and
Pathanamthitta (3.00 %).
The type of hive used for maintaining the stingless bee colony is an
important factor which determines the hive beetle incidence. Majority of bee
keepers maintained stingless bees in wooden box (59.33 %) followed by mud pots
(18.66 %). Among the wooden boxes, the incidence was more prominent in bad
quality wooden boxes (made of locally available soft wood) in
Thiruvananthapuram (60 %), Kollam (50 %) and Pathanamthitta districts (15 %).
Studies on the influence of height of the stingless bee hive from the ground level
with the hive beetle incidence revealed that the hives kept at 3-4 m recorded the
highest incidence (24.79 %) followed by 2-3 m (8.04 %). The colonies maintained
at a height of > 4 m were free from hive beetle incidence.
Regarding the incidence of small hive beetle in different shade conditions, highest hive beetle
incidence (50.70 %) was recorded from apiaries under high shade condition (>80
% canopy coverage) followed by moderate (30-80 % canopy coverage) shade
condition (0.90 %).
The damage symptoms recorded from infested colonies were fermentation
and discolouration of honey due to the feeding and defecation by the beetle larvae
and a light brown coloured undistinguished mass of hive contents. Apart from the
small hive beetles, black soldier fly, Hermetia illucens L., pollen mites and ants
were also documented as pests of stingless bees from the apiaries of Southern
Kerala.
Regarding the studies on biology of the hive beetle, egg period, larval and
pupal period of the beetle was recorded as 2.2 ± 0.537, 14.2 ± 1.686 and 17.77 ±
0.963 days respectively. The length and width of egg, larva, pupa and adult was
recorded as
0.551 ± 0.037× 0.173 ± 0.003 mm, 4.471 ± 0.159 × 1.062 ± 0.025
mm, 2.515 ± 0.123× 1.1124 ± 0.044 mm and 3.0897 ± 0.454 × 1.378 ± 0.0758
mm respectively.
The larvae caused severe damage by tunneling and feeding the pollen pots
while the adults nibbled the hive contents. Studies on the correlation between
larval population and weather parameters showed a significant positive correlation
with rainfall and relative humidity. Highest population of grubs was recorded on
2nd fortnight of May. The time taken by the grubs for complete destruction of
pollen block (4 cm3) was recorded as 16 days, whereas for the destruction of
brood cells and honey block of 4 cm3, it took 13.50 days and 10.83 days respectively.
The small hive beetle which primarily infested the stingless bee colonies is
identified as the nitidulid beetle, E. latissima. The hive beetle incidence can be
reduced by using good quality wooden boxes, where the bad quality wooden
boxes along with high rainfall predisposes hive beetle incidence in the apiaries.
Description
PG
Keywords
null