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Aphid predator (Hemiptera: Miridae)

Atractotomus mali

Apple brown bug

On this page: Identification & Distribution  Biology & Ecology  Biological Control of Aphids 

Identification & Distribution

Atractotomus species are small black or dark red-brown bugs. They are characterised by having the dorsal surface covered in flattened golden or silver hairs, and by having the second antennal segment strongly thickened in one or both sexes. Adults of Atractotomus mali (see first picture below) have the first antennal segment almost triangular (cf Atractotomus magnicornis  which has the first antennal segment approximately cylindrical and lives on Norway spruce) (cf. Atractotomus parvulus which has a slightly shorter second antennal segment, and lives on Scots Pine). Immature Atractotomus mali (see second picture below) are red, with the fore-parts darker.

Both pictures above copyright L. Skipper under a Creative Commons Attribution 4.0 International License. 

Atractomus mali is zoophytophagous, feeding on hawthorn and apple, and preying on aphids and other small insects. It is distributed throughout Europe.

 

Biology & Ecology

Most ecological studies of Atractotomus mali have focused on their predation of psyllids. For example Novak & Achtziger (1995)  studied the relationship between hawthorn psyllids and their main natural enemies in Bavaria, Germany. The most abundant psyllid species were Cacopsylla melanoneura, and Cacopsylla peregrina (see picture below) which pass their larval periods on hawthorn in spring.

Psyllid larvae were observed to be heavily attacked by a multitude of arthropod predators. and psyllid densities on branches where predators had been excluded were significantly higher than on branches with predators present. The mirid Atractotomus mali and the anthocorids. Anthocoris nemorum and Anthocoris nemoralis were considered to be the most important natural enemies of hawthorn psyllids. They regularly reached high densities on hawthorn shrubs and showed a close synchronization with the development of psyllid larvae in each year. All three species exhibited a positive numerical relationship with the abundance of psyllid larvae with Atractotomus mali and Anthocoris nemoralis exploiting this food resource more effectively than Anthocoris nemorum, which is known to be a very polyphagous species. Despite high predation pressure on psyllid larvae, it is concluded that these heteropteran predators are not able to prevent outbreaks of psyllids under favourable climatic conditions as their numerical response to growing psyllid densities occurs with a distinct time delay.

Santas (1987)  found four insect species producing honeydew, exploited by bees, on wild pear trees (Pyrus amygdaliformis). Three of them were psyllids (Cacopsylla species) and one was an aphid Dysaphis pyri.  Although these species produced honeydew from spring to autumn, the bees foraged on it only during September and October, and not every year. A total of 18 predatory species, including Atractotomus mali and Anthocoris nemoralis, were counted. The predators of these Homoptera may be able to cause a decrease of their population levels.

Jerinić-Prodanović & Protić (2013)  review the literature on true bugs as psyllid predators. Atractotomus mali has been recorded as a predator of psyllids in Norway, Greece, Germany and Serbia.

 

Biological Control of Aphids

As a predator

Wheeler (2001)  recorded two instances of aphid predation by Atractotomus mali. Firstly of 'green apple aphid' (probably Aphis pomi ) on apple in Nova Scotia, Canada, and secondly of Hyalopterus pruni  on peach in France (Remaudière & Leclant, 1971 ).

Hradil (2013)  looked at the species diversity of true bugs on apples in unmanaged orchards in the Czech Republic in terms of plant protection. Atractotomus mali was one of the zoophytophagous species found, but it was not very common. It was thought that predatory true bugs may constitute as much as 90% of all predatory insects in apple tree crowns.

But also as a crop pest

Sanford (1964)  notes that the mirid Atractotomus mali is both predacious and phytophagous. At that time the only report of its occurrence in North America was from Nova Scotia, where it had become a pest on apple. The insect has one generation a year and overwinters as an egg which hatches during the apple bloom period. It passes through 5 nymphal instars, becoming an adult 4-5 weeks after hatching. The eggs are laid 1-2 weeks later in spur-type wood, often behind leaf stems and rarely on terminal growth. The feeding punctures of nymphs cause the injury to young fruit. 'Delicious' apples are highly susceptible, while 'McIntosh' are seldom injured. Adults are not phytophagous. Effective control was attained with most insecticides, and in Nova Scotia a low dosage of malathion was recommended. This was selective in that Atractotomus mali was controlled and insufficient residue remained to be toxic to predators that had not emerged.

Saguez et al. (2015)  recorded the first occurence of the zoophytophagous plant bug Atractotomus mali in Quebec orchards. In Canada, it has previously been reported in apple orchards in several provinces, but mainly in Nova Scotia, where it induced more damage on fruit than predatory effects. During the summer of 2014, Saguez collected 33 specimens in an apple orchard in Magog Canada, the first record of the species in Quebec. Possible reasons for this extension in distribution of Atractotomus mali include climate change, changes in pesticide use, and commercial exchanges with areas where Atractotomus mali occurs.

Acknowledgements

For the mirid bugs we have used British Bugs  to aid in identification and for the key characteristics. For aphids we have made provisional identifications from high resolution photos of living specimens, along with host plant identity. In the great majority of cases, identifications have been confirmed by microscopic examination of preserved specimens. We have used the keys and species accounts of Blackman & Eastop (1994)  and Blackman & Eastop (2006)  supplemented with Blackman (1974) , Stroyan (1977) , Stroyan (1984) , Blackman & Eastop (1984) , Heie (1980-1995) , Dixon & Thieme (2007)  and Blackman (2010) . We fully acknowledge these authors as the source for the (summarized) taxonomic information we have presented. Any errors in identification or information are ours alone, and we would be very grateful for any corrections. For assistance on the terms used for aphid morphology we suggest the figure  provided by Blackman & Eastop (2006).

Useful weblinks 

References

  • Hradil, K. et al.. (2013). Species diversity of true bugs on apples in terms of plant protection. Plant Protection Science 49 (2), 73-83. Full text 

  • Jerinić-Prodanović, D. & Protić, L. (2013). True bugs (Hemiptera, Heteroptera) as psyllid predators (Hemiptera, Psylloidea. ZooKeys 319, 169189. Full text 

  • Novak, H. & Achtziger, R. (1995). Influence of heteropteran predators (Het., Anthocoridae, Miridae) on larval populations of hawthorn psyllids (Hom., Psyllidae). Journal of Applied Entomology 119 (1-5), 479-486. Full text 

  • Remaudière, G. & Leclant, F. (1971). Les complexe des ennemis naturels des Aphids du Pêcher dans la moyenne vallée du Rhone. Entomophaga 16(3), 255-267. Abstract 

  • Saguez, J. et al. (2015). First record of the zoophytophagous plant bug Atractotomus mali (Hemiptera: Miridae) in Quebec orchards. La Revue Phytoprotection 95(1), 38-40. Full text 

  • Sanford, K.H. (1964). Life history and control of Atractotomus mali, a new pest of apple in Nova Scotia (Miridae: Hemiptera). Journal of Economic Entomology 57(6), 921-925. Abstract 

  • Santas, L.A. (1987). The predators' complex of pear-feeding psyllids in unsprayed wild pear trees in Greece. Entomophaga 32(3), 291-297. Abstract 

  • Wheeler, A.G.W. (2001). Biology of the Plant Bugs (Hemiptera: Miridae). Cornell University Press. Google