Farmers' knowledge, perceptions and management of the gall-forming wasp,<i>Leptocybe invasa</i>(Hymenoptera: Eulophidae), on<i>Eucalyptus</i>species in Uganda

Leptocybe invasa Fisher & La Salle (Hymenoptera: Eulophidae) first described in 2004, is a new eucalyptus pest of global importance. A thorough understanding of pest biology is essential for development of a reliable pest population prediction system and management strategies, but little is known about this pest. Therefore, we quantified the development, fecundity, fertility, longevity, morphometrics (length, width, and hind tibia length of adults), and other life table parameters of L. invasa in relation to temperature and to provide an experimental basis for developing an overall wasp population model. The results showed that ranging from 20 to 32°C (five constant temperatures were 20, 23, 26, 29 and 32°C, respectively), the developmental period of immatures (egg to adult) was shortest at 29°C but longest at 20°C; the number of eggs per female in the oviduct and survival rate of immatures were greatest at 29°C but smallest at 32°C. The effect of temperature on morphometrics was more pronounced for females than males. When L. invasa was fed with a 40% honey solution, maximum longevity was at 23°C (9.0 days for females and 12.8 days for males). The intrinsic rate of natural increase (rm) was largest (0.0477) at 29°C, and the sex ratio of L. invasa was extremely female-biased. The intrinsic rate of natural increase (rm) indicates that L. invasa population growth is likely to be greatest at 29°C. The developmental zero temperature (t) and the effective cumulative temperature (k) of egg, larva and pupa were 13.0, 19.7 and 17.1°C, and 128.1, 284.2 and 201.2°C, respectively. For L. invasa, 19.1°C (t) and 563.5°C (k) were indispensable for completing development from egg to adult. Therefore, farmers or managers of forests could predict the population dynamics of the wasp and adopt physical or chemical methods to control it according to the temperature.

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“…; Nyeko et al . ). Planting of Eucalyptus camaldulensis Dehnh was curtailed in Israel because of extensive attacks by this wasp (Mendel et al .…”

Section: Introductionmentioning

confidence: 97%

Effect of temperature on life table parameters of Leptocybe invasa (Hymenoptera: Eulophidae)

et al. 2014

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“…The popularity of Eucalyptus species is attributable to them being generally adaptable, fast growing with the potential for producing sawn wood and processed wood products, high calorific value fuelwood and a variety of environmental and ornamental uses (Poore & Fries, 1989). In Uganda, many agencies promote the planting of Eucalyptus , which farmers consider an important source of construction materials, fuelwood and income (Nyeko, Mutitu & Day, 2007).…”

Section: Introductionmentioning

confidence: 99%

“…In Uganda, L. invasa infestation on Eucalyptus species was first reported in December 2002 from Kasese district. Since then, several concerns have been raised about the pest infestation on Eucalyptus in the country (Nyeko et al. , 2007).…”

Section: Introductionmentioning

confidence: 99%

Eucalyptus infestation by Leptocybe invasa in Uganda

Nyeko

Mutitu

Day

2009

African Journal of Ecology

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Very little is known about Leptocybe invasa Fisher & LaSalle, a new fast‐spreading alien pest infesting Eucalyptus in several countries. This study examined L. invasa infestation on Eucalyptus germplasms in different agroecological zones of Uganda. The incidence and severity of the pest infestation were higher in hotter and drier agroecological zones than in cooler and wetter zones. There were direct negative relationships between altitude and L. invasa infestation on Eucalyptus species. No infestation was observed on any Eucalyptus species in stands at altitudes ranging from 1938 to 2452 (the maximum encountered) m above sea level. Leptocybe invasa infestation occurred on all Eucalyptus species encountered (Eucalyptus grandis, Eucalyptus camaldulensis, Eucalyptus saligna, Eucalyptus robusta), except Eucalyptus maidenii that escaped attack because it was located outside the ecological range of the insect. The incidence and severity of L. invasa infestation was generally higher on clonal hybrids E. grandis × E. camaldulensis than on E. grandis × Eucalyptus urophylla. Research on host germplasms, L. invasa biology and ecology, impact of the pest infestation and possible control strategies are suggested to facilitate the development of sustainable management strategies.

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“…The current results demonstrate the potential existence of natural resistance in some eucalyptus species which could be further exploited. Studies in Uganda and Kenya [6,[10][11][12] indicate that L. invasa infestation on eucalyptus is not only influenced by natural resistance, but several other ecological factors such as age of the trees, altitude, etc. Additional studies are therefore necessary to compliment the current studies.…”

Section: Species Namementioning

confidence: 99%

Comparison of the Susceptibility of Six Eucalyptus Tree Species to Leptocybe Invasa-Fisher & La Salle (Hymenoptera: Eulophidae) Attack in a Forest Nursery in Zomba District

Cz.¹

2017

JENR

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This study was conducted in August 2014 to test the relative susceptibility of six eucalyptus tree species Eucalyptus camadulensis, E. grandis, E. microcorys, E. tereticornis, E. maidenii and E. saligna to Leptocybe invasa, a recently introduced pest of blue gum trees In Malawi. Based on calculated Average Damage Indices (ADI), significant differences were observed between species (P=0.001) and Eucalyptus grandis was the most susceptible (ADI= 2.13) followed by E. camadulensis and E. saligna (ADI= 1.46 and 1.55 respectively) in that order. Eucalyptus microcorys, E. teretocornis and E. maidenii were the least susceptible (ADI=0.75, 0.66 and 0.65 respectively). The findings presented an early indication of levels of possible resistance differences among the various eucalyptus species at the early stage of growth.

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Farmers' knowledge, perceptions and management of the gall-forming wasp,Leptocybe invasa(Hymenoptera: Eulophidae), onEucalyptusspecies in Uganda

Cited by 22 publications

References 18 publications

Effect of temperature on life table parameters of Leptocybe invasa (Hymenoptera: Eulophidae)

Effect of temperature on life table parameters of Leptocybe invasa (Hymenoptera: Eulophidae)

Eucalyptus infestation by Leptocybe invasa in Uganda

Comparison of the Susceptibility of Six Eucalyptus Tree Species to Leptocybe Invasa-Fisher & La Salle (Hymenoptera: Eulophidae) Attack in a Forest Nursery in Zomba District

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