Sun and shade coffee (Coffea arabica L.) provide different biotic and abiotic environments which can affect the damage, distribution and reproduction of coffee pests. However, the effect of shade on damage by the coffee berry borer (CBB) Hypothenemus hampei (Ferrari), the most important coffee pest worldwide, is controversial and unclear. We compared infestation, total population per fruit and sex ratio of the CBB between shade and sun coffee, during two coffee-growing seasons in Adjuntas, Puerto Rico. According to generalized linear mixed models, CBB infestation © 2015. This manuscript version is made available under the Elsevier user license http://www.elsevier.com/open-access/userlicense/1.0/ was significantly higher in shade plots, and ranged from 7 -52% compared with 4 -26% in sun. However, the total population per fruit was higher in sun coffee fruits than in shade coffee, and the sex ratio was more biased to females in sun coffee. Sun coffee was characterized by higher temperatures and lower relative humidity. Environmental variables appeared to be important drivers of CBB population densities in field, with positive correlations between temperature and the number of pupae, juveniles, females and males. This tendency of larger populations in sun plots could represent a serious threat for coffee. In addition to fewer CBB in infested fruits in shade plots, we observed that shade coffee also had more natural enemies of CBB such as ants and entomopathogenic fungi.

The coffee berry borer (CBB) (Hypothenemus hampei: Ferrar) was first detected in Puerto Rico in 2007. Its distribution since then has been extensive, but not extensively documented. An island-wide survey was carried out from August to November 2014 (the coffee production season) to assess CBB distribution, infestation, and population per fruit. The CBB was well-established throughout the coffee-growing area of Puerto Rico, but was not evenly distributed. Infestation (or percentages of fruits perforated) in sites sampled ranged from 0 to 95%, and CBB number per infested fruit varied from 1 to 34 individuals. CBB infestation and total population per fruit were positively correlated with altitude. Highest infestation and total population were observed in sites located >400 masl; most of the coffee-producing area in Puerto Rico is above this altitude. Coffea arabica (L.) had higher CBB infestation and population per fruit than Coffea canephora (Pierre ex A. Froehner) (robusta coffee). Based on these results, management tools should be implemented to mitigate the severe damage that CBB is causing in Puerto Rico. These management tools should include the removal of all fruits that remain on the plants after harvest and the use of the entomopathogenic fungus Beauveria bassiana (Balls.) Vuill. for biocontrol, especially on coffee farms at higher elevations.

Wolbachia are widely distributed endosymbiotic bacteria that influence the reproduction and fitness of their hosts. In recent years the manipulation of Wolbachia infection has been considered as a potential tool for biological control. The coffee berry borer (CBB), Hypothenemus hampei, is the most devastating coffee pest worldwide. Wolbachia infection in the CBB has been reported, but until now the role of Wolbachia in CBB reproduction and fitness has not been tested. To address this issue we reared the CBB in artificial diets with and without tetracycline (0.1% w/v) for ten generations. Tetracycline reduced significantly the relative proportion of Wolbachia in the CBB microbiota from 0.49% to 0.04%. This reduction affected CBB reproduction: females fed with tetracycline had significantly fewer progeny, lower fecundity, and fewer eggs per female. Tetracycline also reduced the population growth rate (λ), net reproductive rate (R0), and mean generation time (T) in CBB; the reduction in population growth was mostly due to variation in fertility, according to life time response experiments (LTREs) analysis. Our results suggest that Wolbachia contribute to the reproductive success of the CBB and their manipulation represents a possible approach to CBB biocontrol mediated by microbiome management.

This study demonstrates that stage of development and origin of samples affected the structure and function of the CBB's bacterial communities. This is the first attempt to predict functional significance of the CBB microbiota in nutrition, reproduction and defence.

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