How? Please throw more light

Cameleons feed on flies. Spiders also feed on flies. If there was nothing like spiders, there will be a shorter food chain and web.

E.g;
Mango—>flies—>spiders, lizards—>snake, hawk

This shows that flies feed on mangoes, spiders, lizards (cameleon is a type of lizard) feeds on flies, and hawk and snakes feed on lizards. If there were no spiders, the food chain would have been shortened