Visitation of Social Wasps in Arabica Coffee Crop ( Coffea arabica L . ) Intercropped with Different Tree Species

Brazil stands currently as the world’s largest coffee producer, having a coffee park of over 2.2 million hectares with a revenue of over 600 million dollars in 2015 (Martins, 2008; CONAB, 2016). The crop yield is closely related to the rainfall in the producing regions and several biotic factors, among which we can mention the insect pests that cause huge yield losses (Reis & Souza, 2002). A lot of phytophagous insects cause damage to coffee plantations. Two stand out as primary pests: the coffee leaf miner Leucoptera coffeella (Guérin-Mèneville, 1842) (Lepidoptera: Lyonetiidae) and the coffee berry borer Hypothenemus hampei (Ferrari, 1867) (Coleoptera: Curculionidae, Scolytinae), which cause large losses because of the injury they inflict (Gallo et al., 2002; Reis & Souza, 2002). The leaf miner is a small whitish moth with nocturnal habits, whose caterpillars cause damage to the leaf parenchyma. The coffee berry borer is a tiny beetle, sleek black, which penetrates the fruit and the larvae destroy partially or totally the seed (Reis et al., 2002). Abstract Brazil stands out for its coffee plantations for which the 2015 harvest yielded a revenue of over 600 million dollars. Its production is closely related to biotic and abiotic factors, and insect pests are noted for reducing this production. However, those insects are highly influenced by biological control agents such as predator wasps. This study aimed to survey the wasps visiting intercropping coffee cultivation with different tree species. Four plots of coffee intercropped with different tree species and coffee in full sun (control) were sampled for comparison. Tree species were: Teak (Tectona grandis L.f), Australian redcedar (Toona ciliata M. Roem.), Mangium (Acacia mangium Willd.) and Avocado (Persea americana Mill.). Six hundred and thirty-nine individuals of social wasps were collected, with 20 species and 7 genera, and an overall diversity index of 1.14. The plot with Avocado had the highest Shannon diversity index (H') 1.23 and the lowest dominance according to the Index Berger-Paker (DPB) 0.54. Sociobiology An international journal on social insects


Introduction
Brazil stands currently as the world's largest coffee producer, having a coffee park of over 2.2 million hectares with a revenue of over 600 million dollars in 2015 (Martins, 2008;CONAB, 2016).The crop yield is closely related to the rainfall in the producing regions and several biotic factors, among which we can mention the insect pests that cause huge yield losses (Reis & Souza, 2002).
A lot of phytophagous insects cause damage to coffee plantations.Two stand out as primary pests: the coffee leaf miner Leucoptera coffeella (Guérin-Mèneville, 1842) (Lepidoptera: Lyonetiidae) and the coffee berry borer Hypothenemus hampei (Ferrari, 1867) (Coleoptera: Curculionidae, Scolytinae), which cause large losses because of the injury they inflict (Gallo et al., 2002;Reis & Souza, 2002).The leaf miner is a small whitish moth with nocturnal habits, whose caterpillars cause damage to the leaf parenchyma.The coffee berry borer is a tiny beetle, sleek black, which penetrates the fruit and the larvae destroy partially or totally the seed (Reis et al., 2002).

Abstract
Brazil stands out for its coffee plantations for which the 2015 harvest yielded a revenue of over 600 million dollars.Its production is closely related to biotic and abiotic factors, and insect pests are noted for reducing this production.However, those insects are highly influenced by biological control agents such as predator wasps.This study aimed to survey the wasps visiting intercropping coffee cultivation with different tree species.Four plots of coffee intercropped with different tree species and coffee in full sun (control) were sampled for comparison.Tree species were: Teak (Tectona grandis L.f), Australian redcedar (Toona ciliata M. Roem.), Mangium (Acacia mangium Willd.) and Avocado (Persea americana Mill.).Six hundred and thirty-nine individuals of social wasps were collected, with 20 species and 7 genera, and an overall diversity index of 1.14.The plot with Avocado had the highest Shannon diversity index (H') 1.23 and the lowest dominance according to the Index Berger-Paker (DPB) 0.54.
The most common form of control of coffee pests is the conventional method, with large and frequent applications of chemicals to control, especially against the miner and the coffee berry borer, the main pests of the crop.The application of such products directly and indirectly affects the natural enemies, causing great loss of their diversity in the fields.In contrast, the diversification of farm agroecosystem contributes to an increase in the diversity of natural enemies (Root, 1973;Altieri & Letourneau, 1982;Altieri et al., 2003) due to several factors, such as alternative food supply for adults (e.g.nectar, pollen and sugary substances), and suitable microclimate, and the presence of preys and alternative hosts (Root, 1973;Andow, 1991).In coffee plantations, several species of predator wasps benefit from this diversification (Fernandes, 2013) and the presence of trees promotes greater predation of leaf miners (Leucoptera coffeella) by these wasps (Hymenoptera: Vespidae) (Amaral et al., 2010).
Wasps of Polistinae subfamily are the only ones that occur in Brazil, belonging to three tribes, Polistini, Mischocyttarini and Epiponini, with 23 genera and 319 species (Carpenter & Marques, 2001).These wasps forages, mainly, in hot periods of the day (Picanço et al., 2010), to find water, nectar, pollen, material for construction of nests and prey for their larvae (Lima & Prezoto, 2003), being the main source of protein of social wasps in their first stages of development (Evans & West-Eberhard, 1970).
Thus, this study aimed to evaluate the influence of different tree species in the diversity of social wasps that visit coffee plantation (Coffea arabica L.).

Material and Methods
This study was conducted at Fazenda da Lagoa, Km 642 on the BR 381, located in Santo Antônio do Amparo municipality, Minas Gerais, Brazil (20 ° 91'S / 44 ° 85'W / 1100m) in Arabica coffee (Coffea arabica L. ) Catuaí 99 variety, in a two-year-old stand with spacing of 3.40m x 0.65m, conducted in the conventional cultivation system with total control of weeds, leaving the culture always in bare ground.Four intercropping coffee plots were used with different tree species and coffee in full sun (control) for comparison (Fig 1).Tree species were: Teak (Tectona grandis L.f), Australian redcedar (Toona ciliata M. Roem.), Mangium (Acacia mangium Willd.) and Avocado (Persea americana Mill.).
Wasp sampling was carried out monthly from November/2014 to October/2015 using two types of traps: oval yellow plastic traps, Moericke type adapted, with 20 cm in greater diameter and 10 cm in the least, suspended 50 cm from the ground, attached to a bamboo stick, and filled in halfway with a saline solution of 10% NaCl and 5 drops of detergent.The second type was an attractive trap, consisting of a PET bottle with a capacity of 2 litres, containing three triangular holes with 2 cm edges, approximately 5 cm from the bottom of the bottle (Souza & Prezoto, 2006).These were hung on a bamboo stake at 1.10 m from the ground, containing 200 ml of passion fruit juice (Passiflora edulis f. flavicarpa Deg.-Passifloraceae) as attractant, made with 1 kg of fruit pulp, 1 L of water and 150 g sugar.Six attractive traps and 18 Moerick adapted yellow trap were used for each treatment.Three Moerick composed a sample and both traps were left in the field for 48 hours.
The insects collected were mounted on entomological pins for later identification with the aid of entomological keys (Richards, 1978).Diversity was calculated using Shannon index (H') and the dominance with the Berger-Parker index (DPB) through Past® program, also the comparative analysis of means (R Development Core Team, 2015).

Results and Discussion
Six hundred and thirty-nine subjects of social wasps were collected, with 20 species and 7 genera, with an overall diversity index of 1.14 (Table 1).This diversity index was low due to the high dominance of Agelaia vicina De Saussure (1854).This dominance is explained because some species of the genus Agelaia (Lepeletier, 1836) can build colonies with population estimated at up to one million adults (Zucchi et al., 1995), what means higher foraging capacity by a greater number of wasps and increase of the chances of capturing individuals of this group (Hunt et al., 2001).The high abundance of this genus was also reported in different ecosystems in Brazil (Gomes & Noll, 2009;Arab et al., 2010;Jacques et al., 2012;Jacques et al., 2015;Gradinete & Noll, 2013;Locher et al., 2014).
There was also the collection of two species of Polistes, a genus that is associated with decreased damage caused by pests in different crops such as cotton (Kirkton, 1970), tobacco (Lawson et al., 1961), cabbage (Gould & Jeanne, 1984) and coffee (Gravena, 1983), showing the importance of this genus for the study of biological control of pests.The introduction of wasps colonies of this genus in tobacco plantation reduced in 68% the damage caused by the caterpillar Protoparce sexta (Johan) (Rabb & Lawson, 1957).A single colony of Polistes can prey on around 2,000 caterpillars of Pieris rapae L., a kale pest, during its development cycle (Morimoto, 1961).For instance, (Prezoto & Machado, 1999b) observed a reduction of 77.16% in the incidence of Spodoptera frugiperda in corn plantations with the utilization of Polistes simillimus Zikan, 1951.
The species richness (S) (Table 2) between the treatments was very similar, what can be explained by the proximity of the treatments, because the shorter the distance between the sampling areas, the greater the probability of finding out a faunistic similarity (Souza et al., 2015).Moreover, there is also the fact that these insects have the habit of nesting in one place and forage in another (Pereira & Santos, 2006).

Fig 1 .
Fig 1. Aerial image of the sample area with separation of plots.Santo Antônio do Amparo, MG.

Table 1 .
Total richness, diversity and dominance of species of social wasps collected in Arabica coffee (Coffea arabica L.).