Biology subjects

Khan, M. K.

Publications and source records attributed to Khan, M. K..

8 recordsLinked to original sources

bioRxiv2023

Sex-specific gut bacteria manipulation impacts offspring production in the honeybee parasite small hive beetle, Aethina tumida Murray

Symbiotic bacteria play crucial roles in growth, development, behaviour, immunity, and metabolism of insects. Most of the research until now has explored the role of gut bacteria in insect model systems. The extent to which gut bacteria affect mating behaviour and reproduction of insect pest species still needs, however, to be fully comprehended. In this study, we aimed to investigate the effects of gut bacteria manipulation on mating behaviour and fecundity of a major beehive pest, the small hive beetle Aethina tumida (Murray). We manipulated gut bacteria of both sexes and determined the effects on mating behaviour and reproductive output. Our results provided evidence that manipulation of the gut bacteria influences reproduction in both sexes, negatively affecting mating latency, mating number, mating duration and offspring number (larvae). These results highlight the role of gut bacteria on the reproduction of insect pests, which might help in designing new pest control methods.

microbiology↗

bioRxiv2021

Sexual and developmental variations of ecto-parasitism in damselflies

The prevalence and intensity of parasitism can have different fitness costs between sexes, and across species and developmental stages. This variation could arise because of species specific sexual and developmental differences in body condition, immunity, and resistance. Theory predicts that the prevalence of parasitism will be greater in individuals with poor body condition and the intensity of parasitism will be greater in individuals with larger body size. These predictions have been tested and verified in vertebrates. In insects, however, contradictory evidence has been found in different taxa. Here, we tested these predictions on two species of Agriocnemis (Agriocnemis femina and Agriocnemis pygmaea) damselflies, which are parasitized by Arrenurus water mite ectoparasites. We measured body weight, total body length, abdomen area and thorax area of non-parasitized damselflies and found body condition varied between males and females, between immature females and mature females and between A. femina and A. pygmaea. Then, we calculated the parasite prevalence, i.e., the frequency of parasitism and intensity, i.e., the number of parasites per infected damselfly in eleven natural populations of both species. In line to our predictions, we observed greater prevalence in immature females than mature females but found no difference in parasite prevalence between males and females. Furthermore, we found that parasite load was higher in females than males and in immature females than mature females. Our result also showed that the frequency and intensity of parasitism varied between the two studied species, being higher in A. pygmaea than A. femina. Our study provides evidence that parasitism impacts sexes, developmental stages and species differentially and suggests that variation may occur due to sex, developmental stage, and species-specific resistance and tolerance mechanism.

evolutionary biology↗

bioRxiv2020

Body size and food plants drive local extinction risk in butterflies

Lepidoptera, butterflies and moths, are significant pollinators and ecosystem health indicators. Therefore, monitoring their diversity, distribution, and extinction risks are of critical importance. We aim to understand the drivers of the local extinction risks of the butterflies in Bangladesh. We conducted a systematic review to extract the diversity, distribution and local extinction risks of the butterflies of Bangladesh, and possible drivers of their extinction, e.g., body size, host plants and nectar plants. We updated the current checklist, which now consists of 463 species. We provided distribution and extinctions risk atlas showing both the diversity and extinction risks were highest in the eastern region of Bangladesh. We tested whether body size and host plants contribute to the local extinction risks of butterflies. We predicted butterflies with larger body size and fewer host plants and nectar plants would be in greater extinction risk. Accordingly, we showed that extinction risk was higher in larger butterflies than smaller butterflies, and in butterflies with a fewer number of host plants and nectar plants than the butterflies with higher number host plants. Our study highlights the contribution of body size and host plants as potential drivers of the local extinction risks of butterflies.

ecology↗

bioRxiv2020

Male-male interactions select for conspicuous male colouration in damselflies

Male ornamentation, such as conspicuous male colouration, can evolve through female mate choice. Alternatively, in species without overt female mate preference, conspicuous male colouration can evolve via intrasexual selection to resolve male-male competition or to prevent costly male-male mating attempts. Here, we investigated the drivers of conspicuous male colouration in an ontogenetic colour changing damselfly, Xanthagrion erythroneurum, where the juvenile males are yellow and change colour to red upon sexual maturity. We first showed that red males were chromatically and achromatically more conspicuous than the yellow males. We then quantified the condition of the males and showed that red males were larger and in better condition than yellow males. We tested female preference in a choice experiment where we artificially manipulated male colour, and found that females did not choose mates based on male colouration. We further tested whether the male colouration affected male-male interactions. We presented red and yellow males in the breeding arena, and found that red males received less intra- and interspecific aggression than yellow males. Our study experimentally showed, for the first time, that male conspicuousness is not a target of female mate choice in damselflies. Intra- and interspecific male-male interactions therefore appear to be the driver of conspicuous male colouration in damselflies.View Full Text

animal behavior and cognition↗

bioRxiv2019

Bagworm decorations are an anti-predatory structure

Many animals decorate their exterior with environmental materials and these decorations are predicted to increase their survival. The adaptive significance of these decorations, however, has seldomly been tested experimentally under field conditions. Here, I studied the anti-predatory functions of the decoration (bag) of a bagworm moth, Eumeta crameri against their natural predator, Oecophylla smaragdina, the Asian weaver ant. I experimentally tested if bag removal from caterpillars resulted in more predation than bagged caterpillar under field conditions, which would support the hypothesis that bags are selected to protect the caterpillars against their predators. In support of that, I showed that caterpillars without a bag were attacked, killed and taken to ants nest significantly more than bagged caterpillars. My study provides rare experimental evidence for anti-predatory functions of the decoration. My study suggests that decorating behaviour has evolved in animals as an anti-predatory defence mechanism.

evolutionary biology↗

bioRxiv2019

OdoBD: An online database for the dragonflies and damselflies of Bangladesh

Combining scientific data over a long-time period is necessary to understand the diversity, population trends, and conservation importance of any taxa in a global and regional scale. Bangladesh is located in a biodiversity hotspot region, however, till date, only few animal groups has been extensively investigated at a nation-wide scale. Although being one of the earliest and well-known insect groups, the knowledge on Odonata of this region remains rudimentary and dispersed. To resolve this issue, we have developed an online database for the Odonata of Bangladesh. We have compiled data from our last four years field study, from previously published research articles, field guides, and also collected data from citizen scientists regarding Bangladeshi odonates. Odonata of Bangladesh database (http://www.odobd.org) contains information on morphology, abundance, gene and protein sequences, local and global distribution and conservation status of the Odonata of Bangladesh. The database also demonstrates gender specified photographs with descriptions for better understanding for the novice researchers and naturalists. Odonata of Bangladesh database provides a comprehensive source for meta-analyses in ecology, conservation biology, and genetic research.

ecology↗

bioRxiv2018

Species richness, habitat association and odonata diversity of the south-western region of Bangladesh.

Odonata survey was conducted throughout the south-western region of Bangladesh, concentrated on eight districts and the Sundarban (the largest mangrove forest of the world) from August 2014 to August 2016. A total of 50 species under 30 genera belonging to six families were recorded during the study period. Among the 50 species, 31 species belong to Anisoptera whereas 19 species were recorded from the Zygoptera suborder. Libellulidae and Coenagrionidae were most dominant Anisoptetran and Zygopteran families with 28 and 17 species respectively. One Zygoptera species Mortonagrion varalli was newly added to the Odonata fauna of Bangladesh. Among surveyed habitats, species richness was highest in marshland with 38 species followed by 34 species in the lakeside. On the other hand, odonata diversity was lowest in the mangrove area. Our study shows a positive correlation between environmental variables (such as average rainfall, relative humidity, and average temperature) and species richness in the study area. Species richness is highest during monsoon and lowest in winter.

zoology↗

bioRxiv2017

Odonata diversity of the eastern region of Bangladesh with four new addition to the Bangladeshi dragonfly fauna

A study was conducted in the eastern region to contribute to the Odonata fauna of Bangladesh. A total of 76 species belonging to 9 families have been recorded during the study period of April 2014 to July 2016. Three Zygopteran species e.g, Ceriagrion rubiae, Calicnemia imitans, Prodasineura autumnalis and one Anisopteran species e.g, Megalogomphus smithii have been newly discovered from Bangladesh. Megalogomphus genus have been first time recorded from Bangladesh.

zoology↗