Autonomous Biological Control ofDactylopius opuntiae(Hemiptera: Dactyliiopidae) in a Prickly Pear Plantation With Ecological Management

Abstract

It is broadly known that the conservation of biological diversity in agricultural ecosystems contributes to pest control. This process was studied in a prickly pear plantation (Opuntia megacanthaandOpuntia ficus-indica) located in central Mexico. No insecticides have been used on this plantation since 2000, and local farmers believe that the presence of different species of insects limits the growth of the wild cochineal (Dactylopius opuntiaeCockerell), which is one of the main pests in this crop. From August 2012 to November 2013, we estimated the number of cochineal per stem in the plantation and determined its spatial distribution pattern. In order to identify signs of population regulation, we obtained histograms of the frequency distribution of the size of the clusters and determined if distribution is adjusted to a power function (power law). We identified the cochineal predators and determined the correlation in their abundances. The greater abundance of cochineal occurred between summer and autumn while the minimum value was recorded in spring. The frequency distribution of the cochineal clusters had a high level of adjustment to a power function, suggesting the presence of population regulation processes. Six species that prey on cochineal were identified.Laetilia coccidivoraandHyperaspis trifurcatawere the most active and their abundance was significantly correlated with the abundance of cochineal. We found that the probability of extinction of these insects in a cladode increases with its density, since the density and predator activity also increased. It is likely that, under these conditions, the cochineal have established an autonomous control.

High intermediary mutualist density provides consistent biological control in a tripartite mutualism

“…Our study suggests someone studying the dynamics of the Azteca-Coccus-Coffea interactions in the dry season may come to very different conclusions than someone studying it in the rainy season, and management suggestions that may arise from either year individually could have unseen consequences for producers. We want to point out that research is emerging that suggests preserving interactions in these agroecosystems may offer a viable strategy for reducing the effects of the most impactful issues facing producers (Cruz-Rodríguez et al, 2016, Hajian-Forooshani and Rivera Salinas, 2016, Vandermeer et al, 2010, Koptur et al, 2015. Fig.…”

Biological control of the prickly pear cochineal Dactylopius opuntiae Cockerell (Hemiptera: Dactylopiidae)

“…However, more investigations are needed to review and evaluate the predation potential of other predators on D. opuntiae . In this way multiple predators could lead to an equilibrium (pest/predators) below the economic injury level, as reported recently in Mexico (Cruz‐Rodriguez et al ., ) which is the centre of origin of D. opuntiae . Indeed, further research is planned to investigate the sublethal effects of d ‐limonene on C. montrouzieri and a possible combination of both biological control agents in an integrated pest management programme for the prickly pear cochineal D. opuntiae depending on climate conditions.…”

Dactylopius opuntiae, a new prickly pear cactus pest in the Mediterranean: an overview

“…Dactylopius opuntiae is a sap‐sucking insect that can have a strong negative impact on both the production of prickly pear fruit for fresh consumption and on cladodes as fodder for livestock feed (MacGregor & Sampedro, ). The cochineal species tends to form variably sized colonies on cladodes, which in some cases are totally covered by the insect (Mena & Rosas, ; Cruz‐Rodríguez et al., ). As a consequence, the fruits drop and cladodes dry out and fall off (Mann, ).…”

“…Natural enemies . The carminic acid produced by the cochineal is toxic to other insects (Eisner et al., ) and only some natural enemies are able to overcome this protection system (Gilreath & Smith, ; Eisner et al., ; Cruz‐Rodríguez et al., ). Several species of predators (insects and spiders) have been recorded in association with the cochineal (Torres & Giorgi, ) and some are able to control it.…”