Nesting biology of an Australian resin bee (Megachile sp.; Hymenoptera: Megachilidae):: a study using trap nests

Nesting biology data of an undescribed Megachile sp. (Western Australian Museum number M323/F367) was collected using trap nests placed in the Northern Beekeepers Nature Reserve, Western Australia. Nest construction occurred from October to April with a peak in February, which corresponded to a peak in the number of eggs per nest. Many progeny entered diapause and did not emerge until the beginning of the following season. Four parasitoid species also emerged from nests, three hymenopterans and one dipteran. Nests were clumped at locations within sites and this may have increased progeny survival by the encounter-dilution effect. Female progeny were heavier and more numerous than males with male progeny always emerging first (protandry). This female-biased sex ratio may be an example of local resource enhancement as a consequence of nest clustering.