Occurrence of green lacewings (Neuroptera: Chrysopidae) in two coffee cropping systems
This study aimed to explore the diversity of lacewings in two coffee (Coffea arabica L.) systems. They were observed in unshaded and shaded systems, in which the shaded systems are covered by silky oak trees (Grevillea robusta). This study took place in the SW region of Bahia State, Brazil, and Chrysopidae were characterized by their “faunal indices, frequency, constanty, dominance, richness, and diversity.”
This is applicable in that it shows how agroforestry management can affect predator and prey populations, as well as how photoaxis response may cause species to only visit certain sites. They also mention how having a native forest surrounding these systems likely assists in keeping lacewings nearby, as it allows for a reserve or ecological corridor, depending on how productive the system is at the time.
Different species of lacewings did inhabit the shaded and unshaded plants. Some species did visit both, however there were considerable differences in structures, occurrence, and abundance between the coffee systems. Fifteen lacewing species were identified to have associations with coffee plans, as listed here:
- Ceraeochrysa cubana
- Ceraeochrysa cincta
- Ceraeochrysa dislepis
- Ceraeochrysa everes
- Chrysoperla externa
- Chrysopodes spinella
- Leucochrysa guataparensis
- Leucochrysa cruentata
- Leucochrysa intermedia
- Leucochrysa rodriguezi
- Leucochrysa santani
- Leucochrysa scomparini
- Leucochrysa cidae
- Leucochrysa annae
- Leucochrysa sp.4*
*(this indicates that while it was a distinct species, they couldn’t identify it)
The lacewing species to appear only on shaded coffee plants are as follows:
- C. cincta
- L. guataparensis
- L. cidae
- L. sp.4*
The species only on unshaded plants were:
- L. cruentata
- L. intermedia
- L. scomparini
- L. annae
In both environments, C. externa and L. rodriguezi stood out. C. externa was the most prevalent species in general, and was constant on unshaded coffee plants as well as accessory on shaded ones.
Daytime species include:
- Ceraeochrysa everes
- Chrysoperla externa
- Chrysopodes spinella
While these species were found at night:
- Ceraeochrysa cincta
- Ceraeochrysa dislepis
- Leucochrysa guataparensis
- Leucochrysa cruentata
- Leucochrysa intermedia
- Leucochrysa rodriguezi
- Leucochrysa santani
- Leucochrysa scomparini
- Leucochrysa cidae
- Leucochrysa annae
The only species to be collected during the day and night was Ceraeochrysa cubana.
These findings are interesting because they show not only the species diversity of Chrysopidae, but how important the ecology weighs on them. Different species are active during different times of the day, and prefer shaded or unshaded areas – exhibit clear photoaxis responses. Many species even only appear on one or the other, which goes to show how important the relationship to the greater ecosystem is. It is even beyond just the plant-prey-predator relationship, and is likely reliant on many variables within the ecosystem.
More research upon which Chrysopidae species are present can help in IPM systems, as a wider range of species obviously is able to specialize in different microclimates and ecological niches. A variety of species would likely be best, rather than a larger population of generalists that is encouraged by releases.
Either way, the ecology of an organic system likely has a lot to do with this. The native forest sitting near the TESC organic farm may be helpful with its flow of beneficial insects, allowing them to fall upon natural reserves of pests or migrate onto the farm to find food.