Host specificity of insects in a community of three co‐dominant Eucalyptus species

Abstract

In a subalpine association of three Eucalyptus species, phytophagous insects showed strong host preferences even among very closely related Eucalyptus species. Sixty-three per cent of insect species attacked only one eucalypt species, 30% attacked two species and only 8% fed on all three. Ninety-seven per cent of individuals belonged to species using one or two hosts. The results are discussed in relation to the degree of host specificity that might be expected when most potential hosts are members of a single genus, the way in which host specificity is determined, and the potential of insects with host preferences to affect the dynamics of plant communities.

Variation in the Eucalyptus gunnii-archeri Complex. III. Reciprocal Transplant Trials

“…The significance of phytophagous insects as a major selective force in Eucalyptus ecology is well recognized (e.g. Burdon and Chilvers 1974a;Morrow 1977;Springett 1978), and is affirmed in this study where insect-grazing appeared to be a major factor limiting seedling growth at the higher altitude sites (e.g. Fig.…”

“…This contrasts with the observations of Burdon and Chilvers (1974b) on E. paucifora where the amount of leaf-grazing by insects decreased with increasing altitude. There is evidence of host specificity at the subgeneric or specific level in Eucalyptus (see Pryor 1952;Burdon and Chilvers 1974a;Morrow 1977;Springett 1978) and the present study suggests that host preference may extend to the population level and be a significant factor in the competitive interaction between phenotypes within a single species. This is exemplified by differential grazing of seedlings from specific populations at both the Projection Bluff and Liawenee sites (Table 2; Fig.…”

“…Samples were collected from at least 10 trees at each site using an insect net and taking a total of 25 sweeps of the foliage per site. The bias associated with this sampling method is discussed by Morrow (1977). Collections were sorted into species groups and tentatively identified by Dr J. Madden (Faculty of Agricultural Science, University of Tasmania).…”

Taxonomic isolation and the accumulation of herbivorous insects: a comparison of introduced and native trees

“…However, we do know that some herbivorous insects are host-plant specific, others are broadly polyphagous, and that host switches may be very rapid and frequent (Strong, 1979;Futuyma, 1976;Morrow, 1977;Zimmerman, 1960;Opler, 1974;Futuyma & Gould, 1979). Host ranges of phytophagous insects may be restricted by characteristics of the host or the herbivore, involving geography, ecology, and plant chemistry (McClure & Price, 1976;Smiley, 1978).…”

Habitat Complexity, Spatial Interference, and "Minimum Risk Distribution": A Framework for Population Stability

“…Although quantitative effects of habitat heterogeneity on the divergence of actual spatial distributions from the MRD are unknown for other herbivore species, there is substantial evidence that the link between oviposition and subsequent larval performance is weak in many taxa (Wiklund 1975, Chew 1977, Morrow 1977, Jermy and Szentesi 1978, Thompson 1988, Roininen and Tahvanainen 1989, Price 1991, even in some gall-forming and leaf-mining species (Burstein andWool 1993, Marini-Filho et al 1997), which are generally regarded as having a strong preference-performance linkage (Price 1991). Evidence suggests that poor linkage is often due to females ovipositing on ''apparent'' host plants (Cromartie 1975, Feeny 1976, Rausher 1979, Dempster and Hall 1980, Courtney 1982, Fowler 1984, Wiklund 1984, Day 1986, Soberón et al 1988, Firempong and Zalucki 1990 Courtney 1991, Damman 1991), and consequently, the level of habitat interference (which governs variation in resource apparency in the habitat) should have a significant effect on the divergence of actual herbivore distributions from the minimum risk distribution for many herbivore species.…”