Spatial distribution of homopteran pests and beneficial insects in an orchard and its connection with ecological plant protection

Abstract

It was established that Parthenolecanium corni (Bouchi), Quadraspidiotus perniciosus (Comst.), and Dysaphis plantaginea (Pass.), had stable infestation patterns in the orchard over time. Other species had a stable distribution during part of the year and a random re-distribution at other times [Eriosoma lanigerum (Haus.), Aphidoletes sp.]. Other arthropods (Aphis sp., spiders, Coccznella septempmctata L.) had a random distribution pattern over time. The distribution pattern of insect species was determined variously by surrounding habitat (P. corni; Q . perniciosus; D. luntuginea), or by host plant susceptibility (E. lanigerum; Aphis spp.) which, in part, was a result of different size trees. We were able to detect the arrival of colonizing populations from outside the orchard using analysis of spatial distribution. The distribution pattern of predators was not always determined by the distribution of apple ests, but by alternate prey on weeds or in surrounding vegetation. For a better understandin of spatiardistribution of insects in orchards it was necessary to combine several analysis techniques suck as gra hical methods, analysis of variance, correlation analysis, and chi-square; each method rovidin diierent types of information. The knowledge of aggregated distribution of pests can heyp to refuce the amount of pesticides using local treatments, saving with it natural enemies and increasing the possibilities of ecological plant protection. 1986;STINNER et al. 1983;TAKESHI and TOWNSEND, 1987). We studied two aspects of the colonization pattern of aphid and scale (Homoptera) pests and their natural enemies in an orchard. First was the description of, and methods for analysing, the spatial distribution of insects within an orchard. The second was the study of factors determining spatial patterns. 1986; SAMWAYS

Leucopis annulipes larvae (Diptera: Chamaemyiidae) use a furtive predation strategy within aphid colonies

“…albipuncta eggs are usually laid in group of 2-3 under apple leaves in New Hampshire. As for A. aphidimyza (Kozár et al, 1994;Stewart & Walde, 1997;Brown, 2004;Fréchette et al, 2008), their abundance is highly correlated with aphid density (Tracewski, 1983). In many systems Leucopis spp.…”

Temporal asynchrony, spatial segregation and seasonal abundance of aphids on apple trees

“…D. plantaginea occurred only in May, in an apple orchard in west Virginia, whilst Aphis spp. population densities were higher in June-July (Kozar et al 1994).…”

Apple aphid, Aphis spp. (Hemiptera: Aphididae), and predator populations in an apple orchard at the non-bearing stage: The impact of ground cover and cultivar

“…Aphidoletes aphidimyza has several times been observed as the numerically dominant species of aphid predators in North American apple orchards (Haley & Hogue, 1990;Kozár et al, 1994;Stewart & Walde, 1997;Brown, 2004). According to Bouchard et al (1982), A. aphidimyza may be present in Quebec orchards from late May or early June.…”

“…For example, the larvae of Ctenopseustis obliquana (Walker) (Lepidoptera: Tortricidae) do not develop on Granny Smith, Royal Gala, or Prima leaves, but do so on the scab-resistant Liberty leaves (Wearing & Colhoun, 1999). Apple aphids are among pests whose populations may be influenced by cultivars (Underhill & Cox, 1938;Oatman & Legner, 1961;Kozár et al, 1994;Hogmire & Miller, 2005;Angeli & Simoni, 2006). Therefore, it is important to compare the susceptibility of Liberty and Topaz to Aphis spp.…”