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Longevity and Parasitism Capacity of Psyttalia concolor (Hymenoptera: Braconidae) Fed on Sugar Solutions and Insect Honeydew
Publication . Pinheiro, Lara A.; Pereira, José Alberto; Medina, Pilar; Santos, Sónia A.P.
Sugars are important food sources required by adult parasitoid species to enhance their
survival, fecundity and fitness. The beneficial capacity of Psyttalia concolor Szépligeti, as a biological
control agent of different fruit fly pest species, is expected to increase when different sugar food
sources are supplied. The objective of this study was to test the effect of seven sugars (glucose,
fructose, sucrose, trehalose, melibiose, melezitose and sorbitol) on the longevity and parasitism
capacity of P. concolor. Moreover, we evaluated the effect of two types of honeydew excreted by
hemipteran pests present in olive trees, Saissetia oleae Olivier (Coccidae) and Euphyllura olivina (Costa)
(Psyllidae) on the longevity of the parasitoid. Our results show a positive effect of carbohydrate
(single sugars and honeydew) consumption on parasitoid survival. Female longevity increased when
fed on sorbitol and melibiose, while males benefited from feeding on glucose and fructose, suggesting
that hexose-nectars would benefit males. Sucrose increased the percentage of non-emerged hosts
and parasitism rate while melezitose significantly decreased these percentages, compared to the
other sugars offered. P. concolor benefited more from feeding on honeydew than on sugars, and this
food item can represent an important source of energy for the parasitoid. This result indicates the
importance of specific nutrients for promoting the action of P. concolor against pests
Response of the Coccinellidae Community within Sustainable Vineyards to the Surrounding Landscape
Publication . Taranto, Luísa; Rodrigues, Isabel; Santos, Sónia A.P.; Villa, Maria; Pereira, José Alberto
The family Coccinellidae (Coleoptera) includes important predatory natural enemies in agricultural
crops. To survive, this group uses different occurring resources across the landscape; therefore,
the landscape can influence the Coccinellidae community in agroecosystems. In this context, this
work aims to evaluate the response of the Coccinellidae community to the landscape context within
a gradient of distances from vineyards managed under sustainable production methods. For that,
Coccinellidae were sampled in thirty-five vineyards distributed by six wine Protected Designation of
Origin (PDO) regions of Portugal, and landscape metrics—composition and configuration—were
calculated in a 2000 m, 1500 m, 1000 m, 750 m, and 500 m buffers around the vineyards. Then,
Coccinellidae species were identified, and the response of the Coccinellidae to the landscape metrics
was analyzed. In total, 326 Coccinellidae from 21 species were collected. The most abundant species
were Scymnus apetzi, Scymnus interruptus, Scymnus subvillosus, Coccinella septempunctata, and Stethorus
pusillus, which together represented 83.4% of the total collected individuals. Most specimens were
concentrated in July and at the vegetation cover. Results from the statistical analysis (Generalized
Linear Mixed Models) indicated that the presence of seminatural habitat surrounding the crop may
favor Coccinellidae, while habitat fragmentation seems detrimental for them. The potential relevance
of the identified Coccinellidae for pest control in vineyards is discussed
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Funding agency
Fundação para a Ciência e a Tecnologia
Funding programme
3599-PPCDT
Funding Award Number
PTDC/ASP-PLA/30003/2017