Is being a specific and damaging insect enough to be considered as a good candidate for the biological control of water hyacinth?

MARINA I OLEIRO; ANA MARINO DE REMES LENICOV; GUILLERMO CABRERA WALSH; ALEJANDRO J SOSA; CELESTE GUERRA ALONSO; CELESTE FRANCESCHINI; PHIL TIPPING; CAROLINA MENGONI GOÑALONS

Engelberg

Simposio; XV International Symposium on Biological Control of Weeds (ISBCW); 2018

Cuernavaca longula is a phloem-feeding insect associated with the aquatic invasive weed Ecichhornia crassipes, and distributed in South America from Peru to Northern Argentina. It was studied and proposed as a potential biocontrol agent demonstrating its host afinity to water hyacinth through host specificity and damage studies. However, the complications to maintain a colony of C. longula under laboratory conditions, due to failure mating in captivity and the lack of information about the effect of this agent on natural populations of E. crassipes make difficult its final consideration as a biological control agent. A population study was carried out throughout a year in two different localities with the aim of studying the reproductive biology of C. longula and its phenological relation with abiotic and biotic parameters, and morphological and physiological aspects of the insects were also considered. Interestingly, this species as many dictyopharids present two pores, one for mating and one for ovipositing. We found that females have the mating pore open and visible only in mated females (mature) with developed ovarioles. The largest proportion of mature females was found in summer. In spite of many females collected in autumn, almost all of them were immature. The largest number of mature females seemed to be associated with low leaf and pseudopetiole toughness, may be associated to the ovisposition. The pattern found through the year could indicate that the species have one, may be two generations a year, even in tropical areas. In addition thermal tolerance studies helped us to understand and modeling its distribution and phenological patterns found in the field. In spite of mating was still not ever observed in nature, these results would allow us to improve and detect rearing features necessarily to have a reproductive laboratory colony.