Cuticulear hydrocarbons profiles of seven common Egyptian mantis

This is the first chemical taxonomic study of cuticular hydrocarbons of seven common mantis species in Egypt. This study is shedding the light on the role of this chemicals in phylogeny and taxonomy of this charismatic group of Insects.


INTRODUCTION
The cuticular hydrocarbon and lipids of most insect orders have been investigated to some extent and have served as taxonomic characters since the eighties of the last century (Castner & Nation 1984& Carlson 1988).Along with their primary role in controlling dehydration, components of these mixtures have been found to act as pheromones and do many other functions in most insect species (Steinmetz et. al 2003& Rolph et. al 2005).
As a part of an ongoing study of the taxonomy and ecology of mantis in Egypt (Kamal et. al 2010) the cuticular extracts of seven species commonly found in Egypt were investigated.This study forms the first step in studying cuticular hydrocarbons of old world mantis and using the output data for phylogenatic analysis by except the work on most common USA mantis species in the end of last century (Jonesa et al. 1997).

MATERIALS AND METHODS
Seven species belong to the four Egyptian families of order Mantodea and represent most common mantis species in Egypt, were used in this study.The specimens were collected from the field by hand picking and killed using ethyl acetate that consider as a solvent and doesn't affect the result.
Each female specimen was socked in methylene chloride for about two days for extraction of hydrocarbons found in the mantis cuticle.The concentrated extracts were analyzed by gas chromatography technique (GC).The data were obtained using Dani 1000 Italian GC equipped with 105m×0.25mmID×0.5μmdf 100% dimethylpolysiloxane column.The oven was programmed to run from 60 to 100°C at 15°C/min and from 100 to 310°C at the rate of 15°C/min.the injection temperature Salwa K. Mohammad et al. 92 was 250°C using helium (He) as a carrying gas with flow rate 2ml/min splitlen injection.The detection occurred by FID detector at 320°C.
The output chromatograms were analyzed and each peak got a symbol from a -u.The peaks with the same retention time in the different species take the same symbol.The presence/absence data obtained were analyzed using probiosys software to create phelograms of the seven species.

RESULT AND DISCUSSION
The results indicated that the cuticular extractions of the seven species contain twenty one kinds of hydrocarbons.The lighter hydrocarbon emitted at retention time 15.6 minutes and the heavier one emitted at retention time 34.9 minutes; 19.04% of the detected hydrocarbons are specific to single species, 4.76% are found in all species under investigation and 76.19% are shared between them.The cuticular extractions of Sphodromantis viridis Forskal (Hc7) has the large number of hydrocarbons with 12 types while the extractions of Empusa guttula Thunberg (Hc3) has the lowest number with only 9 types (Table 1).2) divided them into two main clusters: the first one containing (Hc1, Hc2, Hc4,Hc5 and Hc7) and the second cluster containing (Hc3 and Hc6).The first cluster shared between three families Eremiaphilidae, Mantidae and Tarachodidae.The second cluster contains species of family Empusidae.; the difference between genera within family Empusidae and Mantidae can't be clear in our qualitative study but the absence and presence of some types of hydrocarbons between these genera may give an idea about such differance which will appear in more deep qualitative study.

93Fig. 1 :
Fig. 1: Showing the phylogram based on presence /absence data of cuticular extractions of the seven mantis species.The main issues to be discussed about the phylogram induced using data of cuticulear hydrocarbons are the clear difference between cuticuler extractions of the family Empusidae and the three other families, which reflect the great difference in their morphology; the position of species of family Mantidae in the first cluster reflect their new taxonomic position according to the classification and phylogenatic analysis of Gavin & Michae 2009 as Mantis religiosa L. (HC4) and Sphodromantis viridis Forskal (Hc7) belongs to subfamily Paramantinae and two differant tribes M.religiosa (Mantini) and S.viridis (Paramantini),while Miomantis paykullii Stål (Hc5) belongs to subfamily Miomantinae; approval of the taxonomic status of Iris oratoria Linne (Hc2) is now at stake as its position is more related to family Mantidae than to family Tarachodidae which genus Iris transfer to it in classification of Ehrmann 2002, Otte & Spearman 2005 and Gavin & Michae 2009; the difference between genera within family Empusidae and Mantidae can't be clear in our qualitative study but the absence and presence of some types of hydrocarbons between these genera may give an idea about such differance which will appear in more deep qualitative study.

Table 1 :
The distribution of hydrocarbons peaks among mantis species

Table 2 :
The resemblances index between the seven species