Manduca quinquemaculata.

By May 19, 2014 Uncategorized No Comments

The dreaded Tomato Hornworm; loathed by tomato growers everywhere, yet magnificent in its transformation from horned caterpillar, to the lovely sphinx moth.

Bright green in colour, blending like a chameleon into the tomato plant itself, they are often not noticed until the damage is done. These voracious eaters can destroy a tomato plant in a mere day. Tell tale signs of the caterpillars arrival is the disappearance of leaves, stems and even parts of immature fruits. Another dead give away is the frass (caterpillar poop) scattered about the plant. Now the hunt is on!

Start by searching immediately on the underside of the leaves above the frass. These guys are difficult to see when small but they are pretty daunting and hard to miss when fully mature. While ferocious looking, these ‘horned’ caterpillars are harmless. Yes, you could just throw them in the trash or in soapy water for a hellacious death but wouldn’t it be more fun to put them in a bug catcher and watch them mature? Hours of kiddy fun!

They will complete their cycle by descending into the soil to pupate, emerging to the glorious sphinx moth, aka butterfly moth, aka phoenix moth. Remember that these lovely creatures are nighttime pollinators doing a much needed, underrated job.

If you just can’t bare the thought of them descending on your poor tomato plants, throughly till your veggie beds before planting, hopefully burying or destroying the pupae. Of course this won’t stop your fly by night moths from laying single eggs on your plants but an application of BT (Bacillus Thuringiensis) should do the trick. And do keep an eye out for caterpillars covered with white egg sacs. Leave these be as those are the eggs of a parasitic Braconid wasp. Let these hatch and you will have an army of wasps, ready to march upon and destroy a variety of garden pests. But that is another story…