Aphids

Most crops can be infested with aphids. Damage is caused in three ways: sucking plant sap when feeding, excretion of honeydew leading to sooty mould and some species can transmit plant viruses leading to distortion and disfigured plant growth. 

Biological control with parasites, predators and fungal pathogens are available depending on crop and environmental conditions. There are a large number of aphid species and identification can be important when parasitic wasps are to be used. Depending on the species there can be alternate plant hosts. Winged forms develop under conditions of high density to migrate to alternate hosts. Resistance to some insecticides is a serious issue with some species. 


Several species of aphid parasitic wasp are available:
Aphidius colemani is particularly effective against round bodied aphid species such as Myzus persicae (peach-potato aphid) and Aphis gossypii (melon cotton aphid). It is not effective against Macrosiphum species. It can control large populations of aphids, but will take time to achieve this and may leave many parasitised 'mummy' bodies on plants. 

Apidius ervi is specifically for the large elliptical shape species including Macrosiphu euphorbiae (potato aphid and Aulacorthum solani (glasshouse potato aphid).  Several other aphid species such as the pea aphid are also parasitised. 

Aphidius matricariae Has a slightly different host range to A.colemani and includes Ovatus crataegarius (mint aphid). 

Aphelinus abdominalis controls a wide range of aphid species including Macrosiphum euphorbiae (potato aphid) and 
Aulacorthum solani (glasshouse potato aphid). It has a very long life span. 

Praon volucre (mixtures only) controls a wide range of aphid species including a number not controlled by other available aphid parasites. It has a long life cycle. 

Ephedrus cerasicola (mixtures only). Has a long life cycle and high rate of egg laying capacity. Effective on a wide range of aphid species. 

Aphelline ab: Aphelinus abdominalis (single species)  
Aphiline c: Aphidius colemani (single species).
Aphiline e: Aphidius ervi (single species).
Aphiline ACE Mix: Contains Aphelinus abdominalis, Aphidius colemani and Aphidius erv
Aphiline CE Mix: Contains 50:50 mix of Aphidius colemani and Aphidius ervi.
Matriline:  Aphidius matricariae (single species).
Aphilin Berry Mix (MACE PV): (Praon mix) contains a mix of Praon volucre (100), Aphidiu colemani (40), A ervi (40), A. matricariae (40) and Aphelinus abdominalis (20) (count per 240 vial).
Aphiline Strawberry Mix (PACE): Contains equal portions of Aphidius colemani, A.ervi, A.matricariae, Aphelinus abdominalis, Praon volucre and Ephedrus cerasicola.
Aphiline Flower Mix: Contains Aphidiu colemani (30), A ervi (30), A matricariae (30), Aphelinu abdominalis (40), Prao volucre (40) and  Ephedrus cerasicola (70) (count per 240 vial).  
The mixtures reduce the need for accurate pest species identification and are suitable for preventative use against a range of aphid species, particularly in mixed cropping situations. 

How it works: The adult wasp inserts its egg into the aphid, a parasite larva develops killing the aphid, producing a characteristic golden brown papery 'mummy' with Aphidius
and Praon species, and black 'mummy' with Aphelinus species. Aphids parasitised with Ephedrus hide to die. An adult parasitic wasp later emerges through a round hole on the mummified aphid. The adult wasps also feed as a predator on aphids, killing one or more each day.

When to use: All should be used at the first sign of aphids or better, as an early season preventative.

Rate of use: Aphidius colemani: 1 wasp / mummy / 2 m2 per week. Increase to 5 / m2 for 3 weeks if small aphid colonies are present. 
Aphidius ervi: 1 wasp / mummy / 2 m2 per week. Increase as above if necessary. 
ACE Mix or CE Mix:1 wasp / 1 m2.
Berry, Strawberry or Flower Mix: One pack of 240 treats 200 m2

   
Aphidius egg laying into aphid (Photo: Holt Studios)Aphelinus egg laying into aphid 
(Photo: Holt Studios)
Mummified aphid parasitised by Aphidius spp
(Photo: Holt Studios)

Type: A small, orange predatory larva, the adult is a nocturnal midge fly. 

How it works: Introduced as cocoons from which adults emerge. The blister packs enable monitoring and mating of adults on release. Adults lay eggs next to aphid colonies located by the scent of honeydew, larvae develop as tiny orange maggots that feed on aphids. One larva can survive on 5 large aphids but will kill up to 35 or more. 

Species controlled: Larvae feed on over 60 aphid species, including those common in field and protected crops within the UK. 

When to use: Between April and September for re-cycling generations, however they can be used all year round if supplementary lighting is available. 

Rates of use: Normally 1 cocoon per 1 mper week, for local hotspots increase the rate up to 10 per 1 m2

Type: Young larvae of predatory lacewing. 

How it works: An extremely active predator with large pincers used to attack, hold and suck the juices from the pest body. 

Species controlled: Effective at controlling established aphid populations. Also feed on whitefly eggs and scales, thrips larvae, moth eggs, young mealybug nymphs and other small insects. 

When to use: Use on established populations of aphids or other pest colonies, ideal for organic crops. 

Rates of use: 10 larvae per 1 m2 repeat after 2-3 weeks.

Type: A species of ladybird native to the UK. The adult beetle and larvae are both predatory. 

How it works: Adults and larvae feed on most types of aphid. 

Species controlled: Most types of aphid. 

When to use: Apply as a curative.  

Rates of use: Consult Fargro.

   
Aphidoletes larvae feeding in aphid colony
(Photo: Holt Studios)
Chrysoperla larvae feeding on aphid
(Photo: Holt Studios)
Left: Adalia adult. Right: Adalia larva
(Photo: Syngenta Bioline)
   

Contact our Bug Team on 01903 256856 for advise on the best species or mixture to use.