ZSI study confirms occurrence of mite species ‘C.summersi’ in India
Kolkata: A recent study by Zoological Survey of India (ZSI) in association with University of Madras has for the first time confirmed the occurrence of the mite species Calvolia summersi (C.summersi) in India and its association with Xylocopa fenestrata (X.fenestrata), a large carpenter bee species.
C. summersi is isolated and studied from different populations of X. fenestrata in Sagar Islands of Bengal, the biggest island of mangrove Sundarban deltaic complex.
The mite species was previously reported from Brazil in association with Zethus, a neotropical potter wasp genus. Mites have long been associated with bees, often showing a close relationship with particular taxa, probably due to a co-evolutionary process.
“Bees are known to be very efficient insect pollinators and though Indian Sunderbans constitute a very critical ecosystem, studies on bee diversity from the region have gained little attention. Hence, we aimed to conduct surveys to understand the current status of bee fauna and their faunal associations from the region,” ZSI scientist Shelley Acharya said.
The following was published in the reputed Sociobiology journal: Islands are very important systems for harboring unique biodiversity around the globe due to the high amount of species endemism, distinctive functional traits, and spectacular evolutionary patterns,
such as adaptive radiations or instances of repeating convergent evolution.
In addition, island species are particularly vulnerable with rapid decline in biodiversity and exhibiting an alarming rate of extinction. The island’s biodiversity has been under significant stress during the past century from invasive alien species, habitat loss and overuse, and, increasingly, from climate change and pollution .
Large carpenter bees are characterised by the large body size with higher flight range and act as a fundamental resource to the mangrove
ecosystem delivering essential pollination services; X. fenestrata is known to be an integral component of pollination biology of subtropical crop and non-crop plants as it has a comparatively longer activity period ranging from early March to November covering a wide seasonal variation and also
because of its higher
foraging rate.
The genus Calvolia Oudemans, 1911 was previously known by a single species from India, i.e., C. bakeri Hughes, 1962 collected from jute leaves. In total, 21 individuals of Xylocopa (Ctenoxylocopa) fenestrata were recorded from the six sites in the current study out of which all 17 specimens were found infested with mites.
“The heavy infestation of C. summersi to different appendages of the whole body of females of X. fenestrata from the study site is the first confirmed occurrence of Xylocopa-Calvolia interaction, but it is subject to future study to verify whether the symbiotic association is of mutualistic or predatory nature,” Dhriti Banerjee, director, ZSI said.
