The surface of the leaf blade as a factor influencing the spider mites development on cucumber
Keywords:
Tetranychus urticae, cotyledons, abaxial sides, adaxial side, mite eggs developmentAbstract
A comparative assessment of spider mite eggs development on the upper and under side of cucumber cotyledons has been made under laboratory experiments on the varieties Ginga F1 and Vyaznikovsky 37. Studies have been conducted on the cotyledons cut off from growing plants and placed on a wet cotton wool in the Petri dish. Mite eggs laid by females for five hours have been used for work. It has been shown that mites develop more slowly on the underside of cotyledons in comparison to the upper side when cotyledons are not exposed to spider mite. This may be due to the peculiarities of gas exchange on the abaxial and adaxial sides of leaves. It has been also found, that the mite embryonic development duration is increased, if occurs on the underside of the cotyledon , damaged by the spider mite within 1 day. Apparently, this is caused by the plant defense reactions to herbivory occurring increasingly on the lower side of cotyledons and associated with volatiles that has adverse effect on the mite eggs development. It is assumed that responses to the spider mites damage in the cucumber cotyledon leaves (in particular, those associated with the releasing of volatile compounds) are more characteristic for the spongy parenchyma cells than for the palisade cells in the leaf mesophyll.