I've got a Nikon D70, the lense you get when you buy the camera is generally pretty good (for the price), but for macro photography, it's pretty darn awful (not surprised seeing that it's not a macro lense). If you've got some cash, a sigma macro 105mm is probably the best for its price (although it's going to set you back a good 300 pounds, around 450 dollars). Although a sigma macro 50mm (it's either 50 or 60,. i cant remember off the top of my head) will be sufficient for mantids photography, but you've got to get pretty close to the mantids for a good shot.