A South American leaf galling psyllid, Calophya schini Tuthill, has recently been discovered attacking the South American tree Schinus molle L. in Kenya and Ethiopia. This represents the first record of the psyllid in each country and the only record of C. schini in Africa outside of South Africa. In Kenya, the psyllid was parasitized by an unidentified tetrastichine (Eulophidae), probably of the genus Tamarixia, while in Ethiopia C. schini nymphs were heavily parasitized by an unidentified hymenopteran.

Psyllids harbor the primary symbiont, Carsonella ruddii (γ-Proteobacteria), within the cytoplasm of specialized cells called bacteriocytes. Carsonella has the smallest known cellular genome (160 kb), lacking numerous genes that appear to be essential for bacterial life. This raises the question regarding the genetic mechanisms of the host which supports the survival of Carsonella. Our preceding analyses have indicated that some of the genes that are encoded in the psyllid genome and which are highly expressed in the bacteriocyte are of bacterial origin. This implies that psyllids acquired genes from bacteria by lateral gene transfer (LGT) and are using these genes to maintain the primary symbiont, Carsonella. To reveal the complete picture of LGT from symbiotic bacteria to the genome of psyllids, whole genome analysis of psyllids is essential. In order to assess the feasibility of whole genome analysis of the host psyllid, the genome size of the hackberry petiole gall psyllid, Pachypsylla venusta, was estimated. Feulgen image analysis densitometry and flow cytometry demonstrated that the haploid genome size of P. venusta is 0.74 pg (724 Mb), verifying the feasibility of whole genome analysis. Feulgen image analysis densitometry further revealed that bacteriocytes of P. venusta are invariably 16-ploid. This higher ploidy may be essential to facilitate the symbiotic relationship with bacteria, as it appears to be a feature common to insect bacteriocytes. These results provide a foundation for genomics-based research into host-symbiont interactions.

It is known that in citrus orchards, the citrus psyllid Trioza erytreae (Homoptera: Triozidae) preferentially chooses certain varieties for egg laying, feeding and larval development. However, the selection mechanism in citrus nurseries is poorly understood. The aim of the present work was to study in the nursery, the behaviour of T. erytreae with respect to choice of egg laying and feeding sites in three species of citrus, namely Villafranca lemon, Mexican lime and Fremont mandarin. One hundred young plants of each were exposed to the citrus psyllid on the fourth month after germination, and psyllids and pit galls counted every month. The impact of the psyllid's damage on citrus was also assessed. Adults of T. erytreae were highly attracted to the young citrus plants three weeks after the germination of seeds. The average number of adults, eggs and larvae of T. erytreae by plant varied with the particular citrus plant: on young plants, adult, larval and egg populations were highest on lime. Four months later, 100 % of lime, 97% of lemon and 76 % of mandarin plants were attacked by T. erytreae. Those plants attacked shortly after germination were stunted and their leaves greatly deformed. In the absence of pest management in the citrus nursery, citrus psylla can cause the loss of up to 91 % of young plants.

The leucaena psyllid, Heteropsylla cubana, was studied under constant temperatures ranging from 21.5 to 35.0°C. Total mean development time was 11.2, 9.6 and 8.1 days at 21.5, 25.0 and 30.0°C respectively. For these temperatures, the mean number of eggs laid was 532.3, 758.3 and 374.7 with hatch rates of over 90%. At 35.0°C, a mean of only 4.5 eggs/female were laid in 24 h, egg hatch (9.0%) was very low and nymphs did not complete their development. Nymphal survival was only 65% at 30.0°C, compared to 84.2 and 87.6% at 21.5 and 25.5°C, respectively. Adult longevity was highest at 25.0°C; females outlived males at all temperatures. Age-specific life table statistics are given for the three temperatures. The calculated intrinsic rates of natural increase (rm) at 21.5, 25.0 and 30.0°C were 0.226, 0.293 and 0.324 respectively. Relative humidities in the range of 25 to 84% did not affect egg hatching, nymphal survival, or adult emergence of H. cubana.