First record of invasive Australian psyllid species Glycaspis brimblecombei Moore, 1964 (Hemiptera: Psylloidea: Aphalaridae) in Croatia

The Australian red gum lerp psyllid Glycaspis brimblecombei Moore, 1964 is recorded for the first time in Croatia. In the paper, a brief overview of the new pest with the locality of its first occurrence is provided.

Re-Visiting the Incidence of Environmental Factors on a Pre-Imaginal Population of the Red Gum Lerp Psyllid, Glycaspis brimblecombei Moore

The red gum lerp psyllid, Glycaspis brimblecombei Moore (Hemiptera: Aphalaridae), is an invasive pest of Eucalyptus trees worldwide, responsible for serious damage, including the death of plants. Knowledge about the incidence of climatic factors on the insect development are essential to define useful strategies for controlling this pest. To this aim, G. brimblecombei has been sampled by two different methods from April 2012 to February 2013 in eastern Sicily on Eucalyptus camaldulensis in nine different sites, where the main climatic data (air temperature, relative humidity, and precipitation) have been also registered. The Glycaspis brimblecombei population showed a similar trend in all nine sites, positively correlated only with air temperature, but a negative correlation has emerged with precipitation and relative humidity. The results show the need for a deeper understanding of the role played by other abiotic (such as different concentrations of CO2) and biotic (e.g., the antagonistic action of natural enemies, competition with other pests, etc.) factors. The greater sensitivity, even at low densities of psyllid, of sampling methods based on the random collection of a fixed number of leaves compared to methods based on the collection of infested leaves in a fixed time interval has been also outlined.

Glycaspis brimblecombei (Hemiptera: Psyllidae) attack patterns on different Eucalyptus genotypes

Background The red gum lerp psyllid, Glycaspis brimblecombei Moore (Hemiptera: Psyllidae), an eucalypt insect pest from Australia, was reported in Brazil in 2003. This study evaluated damage patterns of this pest on Eucalyptus camaldulensis Dehn (Myrtaceae) and its hybrids E. urophylla X E. camaldulensis (urocam) and E. urophylla X E. grandis (urograndis). In addition, parasitism rates of Psyllaephagus bliteus Riek (Hymenoptera: Encyrtidae) on G. brimblecombei collected on different eucalypt genotypes are reported. Methods Plantation plots of three eucalypt genotypes were evaluated over one year. The eucalypt leaves were collected and examined for attack by G. brimblecombei. Nymph parasitism of G. brimblecombei by P. bliteus was recorded. Results Damage by G. brimblecombei was lower on the hybrid genotypes and on the adaxial surface of the eucalypt leaves. G. brimblecombei egg and nymph density were negatively correlated with monthly rainfall. Nymph parasitism of G. brimblecombei by P. bliteus was low (2.9%) independent of genotype and did not vary throughout the year. Discussion Our data indicate the use of less susceptible eucalypt genotypes (e.g., hybrids) as an alternative to G. brimblecombei management. Because of the current low mortality rates for G. brimblecombei resulting from P. bliteus parasitism, biological control with this natural enemy is not recommended as a management strategy for G. brimblecombei.

Glycaspis brimblecombei (Hemiptera: Psyllidae) attack patterns on different Eucalyptus genotypes

Background. The red gum lerp psyllid Glycaspis brimblecombei Moore (Hemiptera: Psyllidae), an eucalypt insect pest from Australia, was reported in Brazil in 2003. This study evaluated damage patterns of this pest and the parasitism rates of Psyllaephagus bliteus (Hymenoptera: Encyrtidae) on E. camaldulensis and its hybrids E. urophylla X E. camaldulensis and E. urophylla X E. grandis. Methods. Plantation plots of three eucalypt genotypes were evaluated over one year. The eucalypt leaves were collected and examined. Results. Damage by G. brimblecombei was lower on the hybrid genotypes and on the adaxial surface of the eucalypt leaves. Glycaspis brimblecombei egg and nymph density correlated negatively with monthly rainfall. Nymph parasitism by P. bliteus was low (2.9%) independent of genotype and did not vary throughout the year. Discussion. The use of less susceptible eucalypt genotypes (e.g., hybrids) seems to be an alternative to G. brimblecombei management because mortality rates for this pest resulting from P. bliteus parasitism were low.

Glycaspis brimblecombei (Hemiptera: Psyllidae) attack patterns on different Eucalyptus genotypes

Background. The red gum lerp psyllid Glycaspis brimblecombei Moore (Hemiptera: Psyllidae), an eucalypt insect pest from Australia, was reported in Brazil in 2003. This study evaluated damage patterns of this pest and the parasitism rates of Psyllaephagus bliteus (Hymenoptera: Encyrtidae) on E. camaldulensis and its hybrids E. urophylla X E. camaldulensis and E. urophylla X E. grandis. Methods. Plantation plots of three eucalypt genotypes were evaluated over one year. The eucalypt leaves were collected and examined. Results. Damage by G. brimblecombei was lower on the hybrid genotypes and on the adaxial surface of the eucalypt leaves. Glycaspis brimblecombei egg and nymph density correlated negatively with monthly rainfall. Nymph parasitism by P. bliteus was low (2.9%) independent of genotype and did not vary throughout the year. Discussion. The use of less susceptible eucalypt genotypes (e.g., hybrids) seems to be an alternative to G. brimblecombei management because mortality rates for this pest resulting from P. bliteus parasitism were low.