Influence of selected biogenic amines on development and demographic parameters of a temperate population of Cinara (Cupressobium) cupressi (Hemiptera, Aphididae)

Cinara (Cupressobium) cupressi, the cypress aphid, is a serious pest of Cupressus spp. and other Cupressaceae, considered to be one of the world’s 100 worst invasive alien species. The potential influence of selected biogenic amines (tryptamine, tyramine, putrescine, and cadaverine) on development and demographic parameters of a temperate population of the cypress aphid was investigated under laboratory conditions. Within parthenogenetic generations, the use of biogenic amines resulted in a significant reduction in the total fecundity and the average daily fecundity both in the fundatrix (F0) and the fundatrigeniae (F1), whereas this influence in the F5 generation was insignificant. In all parthenogenetic generations treated with amines, the dissected female abdomen contained a greater number of mature embryos compared to control samples. Cadaverine caused marked changes in the body length of all viviparous generations studied and a significant reduction in the number of developing embryos, compared to the control sample. The use of biogenic amines did not significantly affect the number of eggs produced by oviparous females but had an impact on their lifespan. Our results indicate that biogenic amines application may disrupt feeding behavior and thus leads to reduced fecundity, consistent with the observation of reduced embryo production. Consequently, bioamines can be used as an alternative agents to control this important pest species.

Tree Diversity and Damage by Cypress Aphid, Cinara cupressi, on Juniperus procera in Gulele Botanical Garden and Entoto

Juniperus procera is an important tree species in Ethiopia. Increasing demand for fuelwood and construction material has also created markets for J. procera products. The impact of cypress aphid, Cinara cupressi, on J. procera is becoming catastrophic in the country. However, the level of cypress aphid damage on J. procera has never been studied in Entoto Mountain forest and Gullele Botanical Garden (GBG) in Ethiopia. The objective of this study was to assess the cypress aphid densities and extent of damage caused by the cypress aphid on solely and mixed planted J. procera in Entoto Mountain forest and GBG in Addis Ababa, Ethiopia, by evaluating aphid adult and nymph densities and damage to J. procera trees. Eight plots of 50 m ∗ 50 m planted with pure J. procera and mixed J. procerawere selected at each site. Five 5 m ∗ 5 m subplots were formed. To assess aphid density hthree tree twigs per whorl were sampled from each tree in the subplots randomly. The collected samples were examined in the laboratory for the presence of nymph and adult cypress aphid. Tree damage was assessed by visually observing the percentage of infestation in the tree crown and was scored on a 1–5 scale. The results showed significant differences in aphid densities between the sites. The highest aphid count was observed at Entoto Mountain. Besides, the solely planted J. procera trees had higher cypress aphid numbers than the mixed plantation. The mean percentage of aphid-infested trees in Entoto and GBG was 53.6 and 46.4, respectively. Tree mortality was extremely low in both sites and planting systems. The level of aphid damage was also significantly different between the planting systems, where mixed plantations had a lower aphid infestation level. Tree damage was directly correlated with the density of aphids collected. In conclusion, cypress aphid was apparent in both sites, and most of the trees were infested by this pest. However, the extent of damage varied with the planting system. Therefore, it is recommended to consider a mixed plantation of trees as one of cypress aphid management tools in J. procera.

Microbial Control of Invasive Forest Pests with Entomopathogenic Fungi: A Review of the Current Situation

The health of the forestlands of the world is impacted by a number of insect pests and some of them cause significant damage with serious economic and environmental implications. Whether it is damage of the North American cypress aphid in South America and Africa, or the destruction of maple trees in North America by the Asian long horned beetle, invasive forest pests are a major problem in many parts of the world. Several studies explored microbial control opportunities of invasive forest pests with entomopathogenic bacteria, fungi, and viruses, and some are successfully utilized as a part of integrated forest pest management programs around the world. This manuscript discusses some invasive pests and the status of their microbial control around the world with entomopathogenic fungi.