Pests and Diseases

Carnivorous plants are luckily troubled by very few pests and diseases and the grower should be able to control any problems relatively easily.

BOTRYTIS (grey mould)

As with all diseases, prevention is better than cure. Only one disease is likely to cause any real trouble, this being the fungal infection Botrytis. An outbreak is easy to spot, the fungus appearing as a grey fuzz of very slim hairs and, if mature, creating a cloud of grey dust when disturbed. The dust consists of spores, which will spread the infection to other plants, so disturbance must be kept to a minimum and treatment should involve the entire growing area when a major attack occurs. The fungus enjoys cool humid conditions and quickly colonizes dead plant tissue, providing there is sufficient humidity. In winter the risk of an outbreak can be reduced by keeping all soil damp rather than wet. Congested growing plants or plants harbouring dead material, which has fallen between tightly packed leaves or remained attached, are most susceptible and this applies particularly to Sarracenia. To avoid problems, dead or unattractive leaves should be pulled off, making sufficient space for air to circulate. Pitchers or winter leaves of Sarracenia can be pulled carefully and will peel away from the rhizome to leave a leaf scar. Dead flower stems should be removed in the same way.

In the event of an outbreak, benomyl or carbendazim available in retail packs can be used at the recommended strength for other plants. Bad attacks, which usually occur in winter in a poorly ventilated greenhouse, should be followed by removing all the plants and cleaning the greenhouse with a garden disinfectant containing phenols, or dichlorophen.

APHIDS (greenfly)

Even carnivorous plants are subject to these annoying pests and their relatives. Although very few mature plants are attacked, immature growth is vulnerable. In the case of Sarracenia, the trap tops are likely to become deformed, while with Pinguicula, which suffer most of all, the new summer leaves can be badly weakened unless immediate action is taken. Once the summer leaves have unfolded, however, attacks are rare even on successive leaves.

High light intensity changes Sarracenia psittacenia from green to purple, but the unique shape of the pitchers always attracts attention

Pesticides, such as pirimicarb and malathion, can be used, but not too frequently. An alternative is to mop up the offending insects with the sticky leaf of a sundew, especially Drosera capensis. Sundews appear unaffected even by major infestations.

SCALE INSECTS

Although very unusual with carnivorous plants, these pests can occasionally attack Nepenthes, Sarracenia and Darlingtonia. The brown, almost circular, or sometimes elongated scales are rarely seen to move, but they are both unattractive and damaging, weakening the plant by sap-sucking and quickly reproducing themselves.

Most proprietary pesticides intended for scale insects are very strong, because of their resistance to many chemicals. It is therefore recommended that the pests are removed with tweezers - a time-consuming job unless done at the first sign of infestation. Alternatively, they can be pushed off with dampened cotton wool, on the end of an orange stick. Sarracenia and Nepenthes should be able to withstand treatment with malathion, but care should be taken to avoid large amounts of chemical entering the traps.

Very little else should afflict carnivorous plants. Red spider mite sometimes appears and can be treated with malathion. If a plant fails without any obvious sign of damage, inspect the roots and soil for signs of root borers and remove them by hand. Dead or infected tissue should be cut out with a sharp knife.

The intriguing design of Cephalotus makes escape virtually impossible

The intriguing design of Cephalotus makes escape virtually impossible

Was this article helpful?

0 0
How To Reduce Acne Scarring

How To Reduce Acne Scarring

Acne is a name that is famous in its own right, but for all of the wrong reasons. Most teenagers know, and dread, the very word, as it so prevalently wrecks havoc on their faces throughout their adolescent years.

Get My Free Ebook


Post a comment