Aphid is the common name for a large family of insects that have many species within it. Some of these species are better known by their common names such as Blackfly or Greenfly. The damage caused to many different plants can be serious and their ability to reproduce quicky and in large numbers can make control of these insect pests difficult. Some species of aphids reproduce asexually and produce live young aphids rapidily and in big numbers. In warm conditions one female aphid can produce up to 10 aphids per day over several weeks.Other species mate and lay eggs that overwinter. Aphids are wingless most of the time but can develop wings when they want to disperse, this is normally caused by temperature and daylength, lack of food and overcrowding.
Damage and symptoms
Aphids extract sap from plants , which takes nutrients out of the plants and weakens them. This shows on the plants as distorted and crinkled leaves and reduced plant growth. The sap they remove is digested and then moves through the aphid and then is deposited back on the plants as honeydew, which makes plants and fruit sticky. This then often grows black moulds further destroying the appearance of plants. Aphids can also transmit harmful plant viruses, which further weakens and stunts plant growth.
How to control
Biological control of aphids can be a challenge due to their rapid reproductive capacity, so trying to prevent large populations forming is a good starting point, especially if looking after plants in greenhouses or heated areas. For early indoor control and prevention try introducing the parastic wasp products like APHIDIUS or the multi parasite product APHISCOUT. For larger aphid populations, try aphid predators like LACEWING LARVAE or APHIDOLETES, which are capable of consuming large numbers of aphids and can be used in combination witha phid parasite products.
For outdoor control of aphids on vegetables or shrubs like roses, try applying LADYBIRD LARVAE. The larvae can be applied directly to the worse infested areas. They can also be applied by placing inside Dragonfli cotton bags, which are hung on plants, where they will emerge from to consume the aphids. For low growing plants like lettuce or small pot plants, sprinkle LACEWING LARVAE over the infested plants. Predators like these can consume large numbers of aphids quickly. A major benefit of not using chemical insecticides for aphid control is that naturally occuring predators will be attracted to aphid infested plants, so further Ladybird and Lacewing larvae may arrive with other predators like Hoverfly larvae.