Implemented by: Pomme Christiane Gagnaux, UEM (2007-2009)
Thesis superviser: Profa. Dra. Luísa Santos, UEM
Major findings: 41 species of insects were found in Jatropha fields. The flee beetle that is known to harm Jatropha was found at almost all locations. The data showed that planting date has effect on the insect density years after the Jatropha has been established. If planting is done when the pest pressure is high during the first months of the year the pest pressure will be high in the same field years later. Selecting the right planting time can therefore be one of the pest control measures.
Summary
The rapid survey conducted earlier had shown that there are pest
problems in Jatropha. However, there was hardly any records in the literature
about pest in Jatropha. In collaboration with Luísa Santos from UEM it was
decided to undertake a baseline survey of insects in Jatropha as a starting
point. It is important to understand that not all insects found in Jatropha are
pests to Jatropha. This issue was left for later research.
The research was undertaken by Pomme Christiane Gagnaux as thesis work.
Flemming Nielsen with logistic support from Danida and IIAM helped out with the
field sampling.
Due to the great interest in this baseline study an attempt was made to extend
the coverage as much as possible. Jatropha fields located in 11 districts spread
over five provinces namely Maputo, Manica, Sofala, Zambezia and Cabo Delgado
were sampled.
Relationship between Planting Time and Insect Density

The study was conducted in three phases: the first was to survey the
incidence and density of species, as well as collecting information on the
perception of farmers about their occurrence, damage and control strategies
adopted by them.
Additionally, information was
collected about the fields, using a questionnaire, including location, soil
type, irrigation use, fertilizing, spraying, planting date and seed origin. A
GPS was used to register the geographical coordinates of each field.
The second phase consisted of
identifying the samples collected in the field with the help of skilled
personnel in the field of Entomology and the literature review on the species
found.
The third step involved the
analysis of data. 41 species of insects were found.
The most frequent species was
the flee beetle Aphthonia dilutipes
(Jacoby), which is commonly called Yellow Leaf Beetle or Yellow Flee Beetle, and reported for the
first time in Mozambique.
The levels of infestation and
population density of flee beetles in farmers' fields varied, with only seven
sites in Cabo Delgado Province where the species was absent. Elsewhere infestation levels
ranged from 10 to 75% infested plants.
Other important species found was the Caterpillar Green Leaf Mining, Stomphastis thraustica (Meyrick), reported
for the first time in Mozambique, which occurred in 30% of the observed fields.
The district Meluco had the highest infestation levels, reaching 70% of infected plants.
The control strategies for the
Yellow Leaf Beetle include the manipulation of planting date, performance of
deep plowing, and the use of botanical pesticides and pesticide applications.
Further research is needed to verify the efficacy of these methods.