Mud Wasp, Sceliphron madraspatanum (Fabricius) (Hymenoptera: Sphecidae): A Threat or Nature's Regulation of Spider Fauna in the Vegetable Agroecosystem?

The biology and behaviour of mud wasp, Sceliphron madraspatanum (Fabricius) and its possible role in insect pest management were studied under vegetable agroecosystem. The gravid female lays a single egg (2.75±0.33 mm in length) in a mud chamber that is provisioned almost exclusively with orb-weaver spiders, wolf spiders and jumping spiders available in the vegetable agroecosystem. Total numbers of spiders provisioned in each cell was negatively correlated with their mean body weight. However, the wasps avoided provisioning of lynx spider, the most predominant spider in this ecosystem, due to its short and reduced abdomen and also the presence of large, strong and erect setae over its body. In the agroecosystem, mud wasp was found to constitute the third trophic level in the food chain comprising of the vegetable crops–insect pests–spiders–S. madraspatanum and thereby their role could be detrimental for the pest management.