Study On The Phenotypic Development Of Ladybird (Coccinellidae) Mouthparts Based On The Geometric Morphology

For centuries the core issues in biology is the comparison of anatomical traits,morphological and structural differences between different taxa which are identified through the systematic study,classification and biodiversity of organisms.In modern times,advanced mathematical methods are being used to describe and analyze the morphological characteristics quantitatively.The use of geometric morphology can explain statistically significant differences in the morphological description of insects.It can also reduce the chances of during the description of morphological characteristics,which greatly promotes the development of the basic entomology.In this study morphological differences in mouthparts(labrum,mandible,labia,maxillary palp)of 18 different species of Coccinellidae(165 specimens in total)were analyzed and compared on the basis of geometric morphologics.,based on,morphological differences of mouthparts among three kinds of feeding types were analyzed and compared.The morphological characteristics of 3 different mouthparts were compared between male and female adults.A ONE-WAY ANCOVA of centroid size between male and female adult of Cryptolaemus montrouzieri,Afidentula quinqueddecemguttata and Illeis chinensis,showed no significant differences in morphology of each structure of mouthparts.Our results also showed that sexual dimorphism does not exist between male and female adults.Therefore,structure of male and female specimens can be generally used for geometric analysis.In this study,the differences in labrum,mandible,labia,maxillary palp and 3 different feeding types were analyzed in 18 different species of coccinellidae by using semilandmark method.The results of principal component analysis and canonical variate analysis showed significant differences in labrum,mandible,labia,maxillary palp of different ladybird beetles.The morpohologicaly similar structures appeared like a joint cluster in the Canonical variate analysis(CV1 and CV2 coordinates).Cluster analysis based on morphological data of labrum,mandible,labia,maxillary palp showed that similar structures in the phenotypic development tree clustered in single branch.The results showed that the feeding type of ladybird originated from mycophagy followed by coccidophagy and aphidophagy.The origin of phytophagy is complex one which is related to the survival in unfavorable environment.This work is the first documented effort to explore the evolution of different feeding habits of ladybirds through geometrical morphology.The results showed that the geometric morphology is an effective method to track down the dietary evolution of ladybirds but the credibility of phylogenetic tree based on the morphological characteristics of the Ladybird mouthparts is not too high.Therefore,further research work on feeding habits of ladybird beetles is required by using more larval as well as adult morphological characteristics,the behavior of the ladybug and the internal digestive system of lady birds.